lib.rs

extern crate lopdf;

use lopdf::content::Content;
use lopdf::*;
use euclid::*;
use std::fmt::{Debug, Formatter};
extern crate encoding;
extern crate euclid;
extern crate adobe_cmap_parser;
extern crate type1_encoding_parser;
extern crate unicode_normalization;
use euclid::vec2;
use encoding::{Encoding, DecoderTrap};
use encoding::all::UTF_16BE;
use std::fmt;
use std::str;
use std::fs::File;
use std::slice::Iter;
use std::collections::HashMap;
use std::collections::hash_map::Entry;
use std::rc::Rc;
use std::marker::PhantomData;
use std::result::Result;
mod core_fonts;
mod glyphnames;
mod zapfglyphnames;
mod encodings;

pub struct Space;
pub type Transform = Transform2D<f64, Space, Space>;

#[derive(Debug)]
pub enum OutputError
{
    FormatError(std::fmt::Error),
    IoError(std::io::Error),
    PdfError(lopdf::Error)
}

impl std::fmt::Display for OutputError
{
    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), std::fmt::Error> {
        match self {
            OutputError::FormatError(e) => write!(f, "Formating error: {}", e),
            OutputError::IoError(e) => write!(f, "IO error: {}", e),
            OutputError::PdfError(e) => write!(f, "PDF error: {}", e)
        }
    }
}

impl std::error::Error for OutputError{}

impl From<std::fmt::Error> for OutputError {
    fn from(e: std::fmt::Error) -> Self {
        OutputError::FormatError(e)
    }
}

impl From<std::io::Error> for OutputError {
    fn from(e: std::io::Error) -> Self {
        OutputError::IoError(e)
    }
}

impl From<lopdf::Error> for OutputError {
    fn from(e: lopdf::Error) -> Self {
        OutputError::PdfError(e)
    }
}

macro_rules! dlog {
    ($($e:expr),*) => { {$(let _ = $e;)*} }
    //($($t:tt)*) => { println!($($t)*) }
}

fn get_info(doc: &Document) -> Option<&Dictionary> {
    match doc.trailer.get(b"Info") {
        Ok(&Object::Reference(ref id)) => {
            match doc.get_object(*id) {
                Ok(&Object::Dictionary(ref info)) => { return Some(info); }
                _ => {}
            }
        }
        _ => {}
    }
    None
}

fn get_catalog(doc: &Document) -> &Dictionary {
    match doc.trailer.get(b"Root").unwrap() {
        &Object::Reference(ref id) => {
            match doc.get_object(*id) {
                Ok(&Object::Dictionary(ref catalog)) => { return catalog; }
                _ => {}
            }
        }
        _ => {}
    }
    panic!();
}

fn get_pages(doc: &Document) -> &Dictionary {
    let catalog = get_catalog(doc);
    match catalog.get(b"Pages").unwrap() {
        &Object::Reference(ref id) => {
            match doc.get_object(*id) {
                Ok(&Object::Dictionary(ref pages)) => { return pages; }
                other => {dlog!("pages: {:?}", other)}
            }
        }
        other => { dlog!("pages: {:?}", other)}
    }
    dlog!("catalog {:?}", catalog);
    panic!();
}

#[allow(non_upper_case_globals)]
const PDFDocEncoding: &'static [u16] = &[
    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008,
    0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f, 0x0010, 0x0011,
    0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x02d8, 0x02c7, 0x02c6,
    0x02d9, 0x02dd, 0x02db, 0x02da, 0x02dc, 0x0020, 0x0021, 0x0022, 0x0023,
    0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c,
    0x002d, 0x002e, 0x002f, 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035,
    0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e,
    0x003f, 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, 0x0050,
    0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059,
    0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f, 0x0060, 0x0061, 0x0062,
    0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b,
    0x006c, 0x006d, 0x006e, 0x006f, 0x0070, 0x0071, 0x0072, 0x0073, 0x0074,
    0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d,
    0x007e, 0x0000, 0x2022, 0x2020, 0x2021, 0x2026, 0x2014, 0x2013, 0x0192,
    0x2044, 0x2039, 0x203a, 0x2212, 0x2030, 0x201e, 0x201c, 0x201d, 0x2018,
    0x2019, 0x201a, 0x2122, 0xfb01, 0xfb02, 0x0141, 0x0152, 0x0160, 0x0178,
    0x017d, 0x0131, 0x0142, 0x0153, 0x0161, 0x017e, 0x0000, 0x20ac, 0x00a1,
    0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7, 0x00a8, 0x00a9, 0x00aa,
    0x00ab, 0x00ac, 0x0000, 0x00ae, 0x00af, 0x00b0, 0x00b1, 0x00b2, 0x00b3,
    0x00b4, 0x00b5, 0x00b6, 0x00b7, 0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc,
    0x00bd, 0x00be, 0x00bf, 0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5,
    0x00c6, 0x00c7, 0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce,
    0x00cf, 0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df, 0x00e0,
    0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7, 0x00e8, 0x00e9,
    0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef, 0x00f0, 0x00f1, 0x00f2,
    0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7, 0x00f8, 0x00f9, 0x00fa, 0x00fb,
    0x00fc, 0x00fd, 0x00fe, 0x00ff];

fn pdf_to_utf8(s: &[u8]) -> String {
    if s.len() > 2 && s[0] == 0xfe && s[1] == 0xff {
        return UTF_16BE.decode(&s[2..], DecoderTrap::Strict).unwrap()
    } else {
        let r : Vec<u8> = s.iter().map(|x| *x).flat_map(|x| {
               let k = PDFDocEncoding[x as usize];
               vec![(k>>8) as u8, k as u8].into_iter()}).collect();
        return UTF_16BE.decode(&r, DecoderTrap::Strict).unwrap()
    }
}

fn to_utf8(encoding: &[u16], s: &[u8]) -> String {
    if s.len() > 2 && s[0] == 0xfe && s[1] == 0xff {
        return UTF_16BE.decode(&s[2..], DecoderTrap::Strict).unwrap()
    } else {
        let r : Vec<u8> = s.iter().map(|x| *x).flat_map(|x| {
            let k = encoding[x as usize];
            vec![(k>>8) as u8, k as u8].into_iter()}).collect();
        return UTF_16BE.decode(&r, DecoderTrap::Strict).unwrap()
    }
}


fn maybe_deref<'a>(doc: &'a Document, o: &'a Object) -> &'a Object {
    match o {
        &Object::Reference(r) => doc.get_object(r).expect("missing object reference"),
        _ => o
    }
}

fn maybe_get_obj<'a>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<&'a Object> {
    dict.get(key).map(|o| maybe_deref(doc, o)).ok()
}

// an intermediate trait that can be used to chain conversions that may have failed
trait FromOptObj<'a> {
    fn from_opt_obj(doc: &'a Document, obj: Option<&'a Object>, key: &[u8]) -> Self;
}

// conditionally convert to Self returns None if the conversion failed
trait FromObj<'a> where Self: std::marker::Sized {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<Self>;
}

impl<'a, T: FromObj<'a>> FromOptObj<'a> for Option<T> {
    fn from_opt_obj(doc: &'a Document, obj: Option<&'a Object>, _key: &[u8]) -> Self {
        obj.and_then(|x| T::from_obj(doc,x))
    }
}

impl<'a, T: FromObj<'a>> FromOptObj<'a> for T {
    fn from_opt_obj(doc: &'a Document, obj: Option<&'a Object>, key: &[u8]) -> Self {
        T::from_obj(doc, obj.expect(&String::from_utf8_lossy(key))).expect("wrong type")
    }
}

// we follow the same conventions as pdfium for when to support indirect objects:
// on arrays, streams and dicts
impl<'a, T: FromObj<'a>> FromObj<'a> for Vec<T> {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<Self> {
        maybe_deref(doc, obj).as_array().map(|x| x.iter()
            .map(|x| T::from_obj(doc, x).expect("wrong type"))
            .collect()).ok()
    }
}

// XXX: These will panic if we don't have the right number of items
// we don't want to do that
impl<'a, T: FromObj<'a>> FromObj<'a> for [T; 4] {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<Self> {
        maybe_deref(doc, obj).as_array().map(|x| {
            let mut all = x.iter()
                .map(|x| T::from_obj(doc, x).expect("wrong type"));
            [all.next().unwrap(), all.next().unwrap(), all.next().unwrap(), all.next().unwrap()]
        }).ok()
    }
}

impl<'a, T: FromObj<'a>> FromObj<'a> for [T; 3] {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<Self> {
        maybe_deref(doc, obj).as_array().map(|x| {
            let mut all = x.iter()
                .map(|x| T::from_obj(doc, x).expect("wrong type"));
            [all.next().unwrap(), all.next().unwrap(), all.next().unwrap()]
        }).ok()
    }
}

impl<'a> FromObj<'a> for f64 {
    fn from_obj(_doc: &Document, obj: &Object) -> Option<Self> {
        match obj {
            &Object::Integer(i) => Some(i as f64),
            &Object::Real(f) => Some(f),
            _ => None
        }
    }
}

impl<'a> FromObj<'a> for i64 {
    fn from_obj(_doc: &Document, obj: &Object) -> Option<Self> {
        match obj {
            &Object::Integer(i) => Some(i),
            _ => None
        }
    }
}

impl<'a> FromObj<'a> for &'a Dictionary {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<&'a Dictionary> {
        maybe_deref(doc, obj).as_dict().ok()
    }
}

impl<'a> FromObj<'a> for &'a Stream {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<&'a Stream> {
        maybe_deref(doc, obj).as_stream().ok()
    }
}

impl<'a> FromObj<'a> for &'a Object {
    fn from_obj(doc: &'a Document, obj: &'a Object) -> Option<&'a Object> {
        Some(maybe_deref(doc, obj))
    }
}

fn get<'a, T: FromOptObj<'a>>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> T {
    T::from_opt_obj(doc, dict.get(key).ok(), key)
}

fn get_name_string<'a>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> String {
    pdf_to_utf8(dict.get(key).map(|o| maybe_deref(doc, o)).unwrap_or_else(|_| panic!("deref")).as_name().expect("name"))
}

#[allow(dead_code)]
fn maybe_get_name_string<'a>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<String> {
    maybe_get_obj(doc, dict, key).and_then(|n| n.as_name().ok()).map(|n| pdf_to_utf8(n))
}

fn maybe_get_name<'a>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<&'a [u8]> {
    maybe_get_obj(doc, dict, key).and_then(|n| n.as_name().ok())
}

fn maybe_get_array<'a>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<&'a Vec<Object>> {
    maybe_get_obj(doc, dict, key).and_then(|n| n.as_array().ok())
}

#[derive(Clone)]
struct PdfSimpleFont<'a> {
    font: &'a Dictionary,
    doc: &'a Document,
    encoding: Option<Vec<u16>>,
    unicode_map: Option<HashMap<u32, String>>,
    widths: HashMap<CharCode, f64>, // should probably just use i32 here
    default_width: Option<f64>, // only used for CID fonts and we should probably brake out the different font types
}

#[derive(Clone)]
struct PdfType3Font<'a> {
    font: &'a Dictionary,
    doc: &'a Document,
    encoding: Option<Vec<u16>>,
    unicode_map: Option<HashMap<u32, String>>,
    widths: HashMap<CharCode, f64>, // should probably just use i32 here
}


fn make_font<'a>(doc: &'a Document, font: &'a Dictionary) -> Rc<dyn PdfFont + 'a> {
    let subtype = get_name_string(doc, font, b"Subtype");
    dlog!("MakeFont({})", subtype);
    if subtype == "Type0" {
        Rc::new(PdfCIDFont::new(doc, font))
    } else if subtype == "Type3" {
        Rc::new(PdfType3Font::new(doc, font))
    } else {
        Rc::new(PdfSimpleFont::new(doc, font))
    }
}

fn is_core_font(name: &str) -> bool {
    match name {
        "Courier-Bold" |
        "Courier-BoldOblique" |
        "Courier-Oblique" |
        "Courier" |
        "Helvetica-Bold" |
        "Helvetica-BoldOblique" |
        "Helvetica-Oblique" |
        "Helvetica" |
        "Symbol" |
        "Times-Bold" |
        "Times-BoldItalic" |
        "Times-Italic" |
        "Times-Roman" |
        "ZapfDingbats" => true,
        _ => false,
    }
}

fn encoding_to_unicode_table(name: &[u8]) -> Vec<u16> {
    let encoding = match &name[..] {
        b"MacRomanEncoding" => encodings::MAC_ROMAN_ENCODING,
        b"MacExpertEncoding" => encodings::MAC_EXPERT_ENCODING,
        b"WinAnsiEncoding" => encodings::WIN_ANSI_ENCODING,
        _ => panic!("unexpected encoding {:?}", pdf_to_utf8(name))
    };
    let encoding_table = encoding.iter()
        .map(|x| if let &Some(x) = x { glyphnames::name_to_unicode(x).unwrap() } else { 0 })
        .collect();
    encoding_table
}

/* "Glyphs in the font are selected by single-byte character codes obtained from a string that
    is shown by the text-showing operators. Logically, these codes index into a table of 256
    glyphs; the mapping from codes to glyphs is called the font’s encoding. Each font program
    has a built-in encoding. Under some circumstances, the encoding can be altered by means
    described in Section 5.5.5, “Character Encoding.”
*/
impl<'a> PdfSimpleFont<'a> {
    fn new(doc: &'a Document, font: &'a Dictionary) -> PdfSimpleFont<'a> {
        let base_name = get_name_string(doc, font, b"BaseFont");
        let subtype = get_name_string(doc, font, b"Subtype");

        let encoding: Option<&Object> = get(doc, font, b"Encoding");
        dlog!("base_name {} {} enc:{:?} {:?}", base_name, subtype, encoding, font);
        let descriptor: Option<&Dictionary> = get(doc, font, b"FontDescriptor");
        let mut type1_encoding = None;
        if let Some(descriptor) = descriptor {
            dlog!("descriptor {:?}", descriptor);
            if subtype == "Type1" {
                let file = maybe_get_obj(doc, descriptor, b"FontFile");
                match file {
                    Some(&Object::Stream(ref s)) => {
                        let s = get_contents(s);
                        //dlog!("font contents {:?}", pdf_to_utf8(&s));
                        type1_encoding = Some(type1_encoding_parser::get_encoding_map(&s).expect("encoding"));

                    }
                    _ => { dlog!("font file {:?}", file) }
                }
            } else if subtype == "TrueType" {
                let file = maybe_get_obj(doc, descriptor, b"FontFile2");
                match file {
                    Some(&Object::Stream(ref s)) => {
                        let _s = get_contents(s);
                        //File::create(format!("/tmp/{}", base_name)).unwrap().write_all(&s);
                    }
                    _ => { dlog!("font file {:?}", file) }
                }
            }

            let font_file3 = get::<Option<&Object>>(doc, descriptor, b"FontFile3");
            match font_file3 {
                Some(&Object::Stream(ref s)) => {
                    dlog!("font file {:?}", s);
                }
                None => {}
                _ => { dlog!("unexpected") }
            }

            let charset = maybe_get_obj(doc, descriptor, b"CharSet");
            let _charset = match charset {
                Some(&Object::String(ref s, _)) => { Some(pdf_to_utf8(&s)) }
                _ => { None }
            };
            //dlog!("charset {:?}", charset);
        }

        let mut unicode_map = get_unicode_map(doc, font);

        let mut encoding_table = None;
        match encoding {
            Some(&Object::Name(ref encoding_name)) => {
                dlog!("encoding {:?}", pdf_to_utf8(encoding_name));
                encoding_table = Some(encoding_to_unicode_table(encoding_name));
            }
            Some(&Object::Dictionary(ref encoding)) => {
                //dlog!("Encoding {:?}", encoding);
                let mut table = if let Some(base_encoding) = maybe_get_name(doc, encoding, b"BaseEncoding") {
                    dlog!("BaseEncoding {:?}", base_encoding);
                    encoding_to_unicode_table(base_encoding)
                } else {
                    Vec::from(PDFDocEncoding)
                };
                let differences = maybe_get_array(doc, encoding, b"Differences");
                if let Some(differences) = differences {
                    dlog!("Differences");
                    let mut code = 0;
                    for o in differences {
                        let o = maybe_deref(doc, o);
                        match o {
                            &Object::Integer(i) => { code = i; },
                            &Object::Name(ref n) => {
                                let name = pdf_to_utf8(&n);
                                // XXX: names of Type1 fonts can map to arbitrary strings instead of real
                                // unicode names, so we should probably handle this differently
                                let unicode = glyphnames::name_to_unicode(&name);
                                if let Some(unicode) = unicode{
                                    table[code as usize] = unicode;
                                    if let Some(ref mut unicode_map) = unicode_map {
                                        let be = [unicode];
                                        match unicode_map.entry(code as u32) {
                                            // If there's a unicode table entry missing use one based on the name
                                            Entry::Vacant(v) => { v.insert(String::from_utf16(&be).unwrap()); }
                                            Entry::Occupied(e) => {
                                                if e.get() != &String::from_utf16(&be).unwrap() {
                                                    println!("Unicode mismatch");
                                                }
                                            }
                                        }
                                    }
                                }
                                dlog!("{} = {} ({:?})", code, name, unicode);
                                if let Some(ref mut unicode_map) = unicode_map {
                                    dlog!("{} {}", code, unicode_map[&(code as u32)]);
                                }
                                code += 1;
                            }
                            _ => { panic!("wrong type {:?}", o); }
                        }
                    }
                }
                let name = pdf_to_utf8(encoding.get(b"Type").unwrap().as_name().unwrap());
                dlog!("name: {}", name);

                encoding_table = Some(table);
            }
            None => {
                if let Some(type1_encoding) = type1_encoding {
                    let mut table = Vec::from(PDFDocEncoding);
                    dlog!("type1encoding");
                    for (code, name) in type1_encoding {
                        let unicode = glyphnames::name_to_unicode(&pdf_to_utf8(&name));
                        if let Some(unicode) = unicode {
                            table[code as usize] = unicode;
                        } else {
                            dlog!("unknown character {}", pdf_to_utf8(&name));
                        }
                    }
                    encoding_table = Some(table)
                } else if subtype == "TrueType" {
                    encoding_table = Some(encodings::WIN_ANSI_ENCODING.iter()
                        .map(|x| if let &Some(x) = x { glyphnames::name_to_unicode(x).unwrap() } else { 0 })
                        .collect());
                }
            }
            _ => { panic!() }
        }

        let mut width_map = HashMap::new();
        if is_core_font(&base_name) {
            for font_metrics in core_fonts::metrics().iter() {
                if font_metrics.0 == base_name {
                    if let Some(ref encoding) = encoding_table {
                        dlog!("has encoding");
                        for w in font_metrics.2 {
                            let c = glyphnames::name_to_unicode(w.2).unwrap();
                            for i in 0..encoding.len() {
                                if encoding[i] == c {
                                    width_map.insert(i as CharCode, w.1 as f64);
                                }
                            }
                        }
                    } else {
                        // Instead of using the encoding from the core font we'll just look up all
                        // of the character names. We should probably verify that this produces the
                        // same result.

                        let mut table = vec![0; 256];
                        for w in font_metrics.2 {
                            dlog!("{} {}", w.0, w.2);
                            // -1 is "not encoded"
                            if w.0 != -1 {
                                table[w.0 as usize] = if base_name == "ZapfDingbats" {
                                    zapfglyphnames::zapfdigbats_names_to_unicode(w.2).unwrap_or_else(|| panic!("bad name {:?}", w))
                                } else {
                                    glyphnames::name_to_unicode(w.2).unwrap()
                                }
                            }
                        }

                        let encoding = &table[..];
                        for w in font_metrics.2 {
                            width_map.insert(w.0 as CharCode, w.1 as f64);
                            // -1 is "not encoded"
                        }
                        encoding_table = Some(encoding.to_vec());
                    }
                    /* "Ordinarily, a font dictionary that refers to one of the standard fonts
                        should omit the FirstChar, LastChar, Widths, and FontDescriptor entries.
                        However, it is permissible to override a standard font by including these
                        entries and embedding the font program in the PDF file."

                        Note: some PDFs include a descriptor but still don't include these entries */
                    // assert!(maybe_get_obj(doc, font, "FirstChar").is_none());
                    // assert!(maybe_get_obj(doc, font, "LastChar").is_none());
                    // assert!(maybe_get_obj(doc, font, "Widths").is_none());
                }
            }
        } else {
            // Some PDF's don't have these like fips-197.pdf
            let first_char: i64 = get(doc, font, b"FirstChar");
            let last_char: i64 = get(doc, font, b"LastChar");
            let widths: Vec<f64> = get(doc, font, b"Widths");
            let mut i = 0;
            dlog!("first_char {:?}, last_char: {:?}, widths: {} {:?}", first_char, last_char, widths.len(), widths);

            for w in widths {
                width_map.insert((first_char + i) as CharCode, w);
                i += 1;
            }
            assert_eq!(first_char + i - 1, last_char);
        }

        PdfSimpleFont {doc, font, widths: width_map, encoding: encoding_table, default_width: None, unicode_map}
    }

    #[allow(dead_code)]
    fn get_type(&self) -> String {
        get_name_string(self.doc, self.font, b"Type")
    }
    #[allow(dead_code)]
    fn get_basefont(&self) -> String {
        get_name_string(self.doc, self.font, b"BaseFont")
    }
    #[allow(dead_code)]
    fn get_subtype(&self) -> String {
        get_name_string(self.doc, self.font, b"Subtype")
    }
    #[allow(dead_code)]
    fn get_widths(&self) -> Option<&Vec<Object>> {
        maybe_get_obj(self.doc, self.font, b"Widths").map(|widths| widths.as_array().expect("Widths should be an array"))
    }
    /* For type1: This entry is obsolescent and its use is no longer recommended. (See
     * implementation note 42 in Appendix H.) */
    #[allow(dead_code)]
    fn get_name(&self) -> Option<String> {
        maybe_get_name_string(self.doc, self.font, b"Name")
    }

    #[allow(dead_code)]
    fn get_descriptor(&self) -> Option<PdfFontDescriptor> {
        maybe_get_obj(self.doc, self.font, b"FontDescriptor").and_then(|desc| desc.as_dict().ok()).map(|desc| PdfFontDescriptor{desc: desc, doc: self.doc})
    }
}



impl<'a> PdfType3Font<'a> {
    fn new(doc: &'a Document, font: &'a Dictionary) -> PdfType3Font<'a> {

        let unicode_map = get_unicode_map(doc, font);
        let encoding: Option<&Object> = get(doc, font, b"Encoding");

        let encoding_table;
        match encoding {
            Some(&Object::Name(ref encoding_name)) => {
                dlog!("encoding {:?}", pdf_to_utf8(encoding_name));
                encoding_table = Some(encoding_to_unicode_table(encoding_name));
            }
            Some(&Object::Dictionary(ref encoding)) => {
                //dlog!("Encoding {:?}", encoding);
                let mut table = if let Some(base_encoding) = maybe_get_name(doc, encoding, b"BaseEncoding") {
                    dlog!("BaseEncoding {:?}", base_encoding);
                    encoding_to_unicode_table(base_encoding)
                } else {
                    Vec::from(PDFDocEncoding)
                };
                let differences = maybe_get_array(doc, encoding, b"Differences");
                if let Some(differences) = differences {
                    dlog!("Differences");
                    let mut code = 0;
                    for o in differences {
                        match o {
                            &Object::Integer(i) => { code = i; },
                            &Object::Name(ref n) => {
                                let name = pdf_to_utf8(&n);
                                // XXX: names of Type1 fonts can map to arbitrary strings instead of real
                                // unicode names, so we should probably handle this differently
                                let unicode = glyphnames::name_to_unicode(&name);
                                if let Some(unicode) = unicode{
                                    table[code as usize] = unicode;
                                }
                                dlog!("{} = {} ({:?})", code, name, unicode);
                                if let Some(ref unicode_map) = unicode_map {
                                    dlog!("{} {:?}", code, unicode_map.get(&(code as u32)));
                                }
                                code += 1;
                            }
                            _ => { panic!("wrong type"); }
                        }
                    }
                }
                let name_encoded = encoding.get(b"Type");
                if let Ok(Object::Name(name)) = name_encoded {
                    dlog!("name: {}", pdf_to_utf8(name));
                } else {
                    dlog!("name not found");
                }

                encoding_table = Some(table);
            }
            _ => { panic!() }
        }

        let first_char: i64 = get(doc, font, b"FirstChar");
        let last_char: i64 = get(doc, font, b"LastChar");
        let widths: Vec<f64> = get(doc, font, b"Widths");

        let mut width_map = HashMap::new();

        let mut i = 0;
        dlog!("first_char {:?}, last_char: {:?}, widths: {} {:?}", first_char, last_char, widths.len(), widths);

        for w in widths {
            width_map.insert((first_char + i) as CharCode, w);
            i += 1;
        }
        assert_eq!(first_char + i - 1, last_char);
        PdfType3Font {doc, font, widths: width_map, encoding: encoding_table, unicode_map}
    }
}

type CharCode = u32;

struct PdfFontIter<'a>
{
    i: Iter<'a, u8>,
    font: &'a dyn PdfFont,
}

impl<'a> Iterator for PdfFontIter<'a> {
    type Item = (CharCode, u8);
    fn next(&mut self) -> Option<(CharCode, u8)> {
        self.font.next_char(&mut self.i)
    }
}

trait PdfFont : Debug {
    fn get_width(&self, id: CharCode) -> f64;
    fn next_char(&self, iter: &mut Iter<u8>) -> Option<(CharCode, u8)>;
    fn decode_char(&self, char: CharCode) -> String;

        /*fn char_codes<'a>(&'a self, chars: &'a [u8]) -> PdfFontIter {
            let p = self;
            PdfFontIter{i: chars.iter(), font: p as &PdfFont}
        }*/

}

impl<'a> dyn PdfFont + 'a {
    fn char_codes(&'a self, chars: &'a [u8]) -> PdfFontIter {
        PdfFontIter{i: chars.iter(), font: self}
    }
    fn decode(&self, chars: &[u8]) -> String {
        let strings = self.char_codes(chars).map(|x| self.decode_char(x.0)).collect::<Vec<_>>();
        strings.join("")
    }

}


impl<'a> PdfFont for PdfSimpleFont<'a> {
    fn get_width(&self, id: CharCode) -> f64 {
        let width = self.widths.get(&id);
        if let Some(width) = width {
            return *width;
        } else {
            dlog!("missing width for {} falling back to default_width {:?}", id, self.font);
            return self.default_width.unwrap();
        }
    }
    /*fn decode(&self, chars: &[u8]) -> String {
        let encoding = self.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
        to_utf8(encoding, chars)
    }*/

    fn next_char(&self, iter: &mut Iter<u8>) -> Option<(CharCode, u8)> {
        iter.next().map(|x| (*x as CharCode, 1))
    }
    fn decode_char(&self, char: CharCode) -> String {
        let slice = [char as u8];
        if let Some(ref unicode_map) = self.unicode_map {
            let s = unicode_map.get(&char);
            let s = match s {
                None => { panic!("missing char {:?} in map {:?}", char, unicode_map)}
                Some(s) => { s.clone() }
            };
            return s
        }
        let encoding = self.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
        //dlog!("char_code {:?} {:?}", char, self.encoding);
        let s = to_utf8(encoding, &slice);
        s
    }
}



impl<'a> fmt::Debug for PdfSimpleFont<'a> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.font.fmt(f)
    }
}

impl<'a> PdfFont for PdfType3Font<'a> {
    fn get_width(&self, id: CharCode) -> f64 {
        let width = self.widths.get(&id);
        if let Some(width) = width {
            return *width;
        } else {
            panic!("missing width for {} {:?}", id, self.font);
        }
    }
    /*fn decode(&self, chars: &[u8]) -> String {
        let encoding = self.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
        to_utf8(encoding, chars)
    }*/

    fn next_char(&self, iter: &mut Iter<u8>) -> Option<(CharCode, u8)> {
        iter.next().map(|x| (*x as CharCode, 1))
    }
    fn decode_char(&self, char: CharCode) -> String {
        let slice = [char as u8];
        if let Some(ref unicode_map) = self.unicode_map {
            let s = unicode_map.get(&char);
            let s = match s {
                None => { panic!("missing char {:?} in map {:?}", char, unicode_map)}
                Some(s) => { s.clone() }
            };
            return s
        }
        let encoding = self.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
        //dlog!("char_code {:?} {:?}", char, self.encoding);
        let s = to_utf8(encoding, &slice);
        s
    }
}



impl<'a> fmt::Debug for PdfType3Font<'a> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.font.fmt(f)
    }
}

struct PdfCIDFont<'a> {
    font: &'a Dictionary,
    #[allow(dead_code)]
    doc: &'a Document,
    #[allow(dead_code)]
    encoding: Option<Vec<u16>>,
    to_unicode: Option<HashMap<u32, String>>,
    widths: HashMap<CharCode, f64>, // should probably just use i32 here
    default_width: Option<f64>, // only used for CID fonts and we should probably brake out the different font types
}

fn get_unicode_map<'a>(doc: &'a Document, font: &'a Dictionary) -> Option<HashMap<u32, String>> {
    let to_unicode = maybe_get_obj(doc, font, b"ToUnicode");
    dlog!("ToUnicode: {:?}", to_unicode);
    let mut unicode_map = None;
    match to_unicode {
        Some(&Object::Stream(ref stream)) => {
            let contents = get_contents(stream);
            dlog!("Stream: {}", String::from_utf8(contents.clone()).unwrap());

            let cmap = adobe_cmap_parser::get_unicode_map(&contents).unwrap();
            let mut unicode = HashMap::new();
            // "It must use the beginbfchar, endbfchar, beginbfrange, and endbfrange operators to
            // define the mapping from character codes to Unicode character sequences expressed in
            // UTF-16BE encoding."
            for (&k, v) in cmap.iter() {
                let mut be: Vec<u16> = Vec::new();
                let mut i = 0;
                assert!(v.len() % 2 == 0);
                while i < v.len() {
                    be.push(((v[i] as u16) << 8) | v[i+1] as u16);
                    i += 2;
                }
                match &be[..] {
                    [0xd800 ..= 0xdfff] => {
                        // this range is not specified as not being encoded
                        // we ignore them so we don't an error from from_utt16
                        continue;
                    }
                    _ => {}
                }
                let s = String::from_utf16(&be).unwrap();

                unicode.insert(k, s);
            }
            unicode_map = Some(unicode);

            dlog!("map: {:?}", unicode_map);
        }
        None => { }
        Some(&Object::Name(ref name)) => {
            let name = pdf_to_utf8(name);
            assert!(name == "Identity-H");
        }
        _ => { panic!("unsupported cmap {:?}", to_unicode)}
    }
    unicode_map
}


impl<'a> PdfCIDFont<'a> {
    fn new(doc: &'a Document, font: &'a Dictionary) -> PdfCIDFont<'a> {
        let base_name = get_name_string(doc, font, b"BaseFont");
        let descendants = maybe_get_array(doc, font, b"DescendantFonts").expect("Descendant fonts required");
        let ciddict = maybe_deref(doc, &descendants[0]).as_dict().expect("should be CID dict");
        let encoding = maybe_get_obj(doc, font, b"Encoding").expect("Encoding required in type0 fonts");
        dlog!("base_name {} {:?}", base_name, font);

        match encoding {
            &Object::Name(ref name) => {
                let name = pdf_to_utf8(name);
                dlog!("encoding {:?}", name);
                assert!(name == "Identity-H");
            }
            &Object::Stream(ref stream) => {
                let contents = get_contents(stream);
                dlog!("Stream: {}", String::from_utf8(contents.clone()).unwrap());
            }
            _ => { panic!("unsupported encoding {:?}", encoding)}
        }

        // Sometimes a Type0 font might refer to the same underlying data as regular font. In this case we may be able to extract some encoding
        // data.
        // We should also look inside the truetype data to see if there's a cmap table. It will help us convert as well.
        // This won't work if the cmap has been subsetted. A better approach might be to hash glyph contents and use that against
        // a global library of glyph hashes
        let unicode_map = get_unicode_map(doc, font);

        dlog!("descendents {:?} {:?}", descendants, ciddict);

        let font_dict = maybe_get_obj(doc, ciddict, b"FontDescriptor").expect("required");
        dlog!("{:?}", font_dict);
        let _f = font_dict.as_dict().expect("must be dict");
        let default_width = get::<Option<i64>>(doc, ciddict, b"DW").unwrap_or(1000);
        let w: Option<Vec<&Object>> = get(doc, ciddict, b"W");
        dlog!("widths {:?}", w);
        let mut widths = HashMap::new();
        let mut i = 0;
        if let Some(w) = w {
            while i < w.len() {
                if let &Object::Array(ref wa) = w[i+1] {
                    let cid = w[i].as_i64().expect("id should be num");
                    let mut j = 0;
                    dlog!("wa: {:?} -> {:?}", cid, wa);
                    for w in wa {
                        widths.insert((cid + j) as CharCode, as_num(w) );
                        j += 1;
                    }
                    i += 2;
                } else {
                    let c_first = w[i].as_i64().expect("first should be num");
                    let c_last = w[i].as_i64().expect("last should be num");
                    let c_width = as_num(&w[i]);
                    for id in c_first..c_last {
                        widths.insert(id as CharCode, c_width);
                    }
                    i += 3;
                }
            }
        }
        PdfCIDFont{doc, font, widths, to_unicode: unicode_map, encoding: None, default_width: Some(default_width as f64) }
    }
}

impl<'a> PdfFont for PdfCIDFont<'a> {
    fn get_width(&self, id: CharCode) -> f64 {
        let width = self.widths.get(&id);
        if let Some(width) = width {
            dlog!("GetWidth {} -> {}", id, *width);
            return *width;
        } else {
            dlog!("missing width for {} falling back to default_width", id);
            return self.default_width.unwrap();
        }
    }/*
    fn decode(&self, chars: &[u8]) -> String {
        self.char_codes(chars);

        //let utf16 = Vec::new();

        let encoding = self.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
        to_utf8(encoding, chars)
    }*/

    fn next_char(&self, iter: &mut Iter<u8>) -> Option<(CharCode, u8)> {
        let p = iter.next();
        if let Some(&c) = p {
            let next = *iter.next().unwrap();
            Some((((c as u32) << 8)  | next as u32, 2))
        } else {
            None
        }
    }
    fn decode_char(&self, char: CharCode) -> String {
        let s = self.to_unicode.as_ref().and_then(|x| x.get(&char));
        if let Some(s) = s {
            s.clone()
        } else {
            dlog!("Unknown character {:?} in {:?} {:?}", char, self.font, self.to_unicode);
            "".to_string()
        }
    }
}

impl<'a> fmt::Debug for PdfCIDFont<'a> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.font.fmt(f)
    }
}



#[derive(Copy, Clone)]
struct PdfFontDescriptor<'a> {
    desc: &'a Dictionary,
    doc: &'a Document
}

impl<'a> PdfFontDescriptor<'a> {
    #[allow(dead_code)]
    fn get_file(&self) -> Option<&'a Object> {
        maybe_get_obj(self.doc, self.desc, b"FontFile")
    }
}

impl<'a> fmt::Debug for PdfFontDescriptor<'a> {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        self.desc.fmt(f)
    }
}

#[derive(Clone, Debug)]
struct Type0Func {
    domain: Vec<f64>,
    range: Vec<f64>,
    contents: Vec<u8>,
    size: Vec<i64>,
    bits_per_sample: i64,
    encode: Vec<f64>,
    decode: Vec<f64>,
}

#[allow(dead_code)]
fn interpolate(x: f64, x_min: f64, _x_max: f64, y_min: f64, y_max: f64) -> f64 {
    let divisor = x - x_min;
    if divisor != 0. {
        y_min + (x - x_min) * ((y_max - y_min) / divisor)
    } else {
        // (x - x_min) will be 0 which means we want to discard the interpolation
        // and arbitrarily choose y_min to match pdfium
        y_min
    }
}

impl Type0Func {
    #[allow(dead_code)]
    fn eval(&self, _input: &[f64], _output: &mut [f64]) {
        let _n_inputs = self.domain.len() / 2;
        let _n_ouputs = self.range.len() / 2;

    }
}

#[derive(Clone, Debug)]
struct Type2Func {
    c0: Option<Vec<f64>>,
    c1: Option<Vec<f64>>,
    n: f64,
}

#[derive(Clone, Debug)]
enum Function {
    Type0(Type0Func),
    Type2(Type2Func),
    #[allow(dead_code)]
    Type3,
    #[allow(dead_code)]
    Type4
}

impl Function {
    fn new(doc: &Document, obj: &Object) -> Function {
        let dict = match obj {
            &Object::Dictionary(ref dict) => dict,
            &Object::Stream(ref stream) => &stream.dict,
            _ => panic!()
        };
        let function_type: i64 = get(doc, dict, b"FunctionType");
        let f = match function_type {
            0 => {
                let stream = match obj {
                    &Object::Stream(ref stream) => stream,
                    _ => panic!()
                };
                let range: Vec<f64> = get(doc, dict, b"Range");
                let domain: Vec<f64> = get(doc, dict, b"Domain");
                let contents = get_contents(stream);
                let size: Vec<i64> = get(doc, dict, b"Size");
                let bits_per_sample = get(doc, dict, b"BitsPerSample");
                // We ignore 'Order' like pdfium, poppler and pdf.js

                let encode = get::<Option<Vec<f64>>>(doc, dict, b"Encode");
                // maybe there's some better way to write this.
                let encode = encode.unwrap_or_else(|| {
                    let mut default = Vec::new();
                    for i in &size {
                        default.extend([0., (i - 1) as f64].iter());
                    }
                    default
                });
                let decode = get::<Option<Vec<f64>>>(doc, dict, b"Decode").unwrap_or_else(|| range.clone());

                Function::Type0(Type0Func { domain, range, size, contents, bits_per_sample, encode, decode })
            }
            2 => {
                let c0 = get::<Option<Vec<f64>>>(doc, dict, b"C0");
                let c1 = get::<Option<Vec<f64>>>(doc, dict, b"C1");
                let n = get::<f64>(doc, dict, b"N");
                Function::Type2(Type2Func { c0, c1, n})
            }
            _ => { panic!("unhandled function type {}", function_type) }
        };
        f
    }
}

fn as_num(o: &Object) -> f64 {
    match o {
        &Object::Integer(i) => { i as f64 }
        &Object::Real(f) => { f }
        _ => { panic!("not a number") }
    }
}

#[derive(Clone)]
struct TextState<'a>
{
    font: Option<Rc<dyn PdfFont + 'a>>,
    font_size: f64,
    character_spacing: f64,
    word_spacing: f64,
    horizontal_scaling: f64,
    leading: f64,
    rise: f64,
    tm: Transform,
}

// XXX: We'd ideally implement this without having to copy the uncompressed data
fn get_contents(contents: &Stream) -> Vec<u8> {
    if contents.filter().is_ok() {
        contents.decompressed_content().unwrap_or_else(|_|contents.content.clone())
    } else {
        contents.content.clone()
    }
}

#[derive(Clone)]
struct GraphicsState<'a>
{
    ctm: Transform,
    ts: TextState<'a>,
    smask: Option<&'a Dictionary>,
    fill_colorspace: ColorSpace,
    fill_color: Vec<f64>,
    stroke_colorspace: ColorSpace,
    stroke_color: Vec<f64>,
    line_width: f64,
}

fn show_text(gs: &mut GraphicsState, s: &[u8],
             _tlm: &Transform,
             _flip_ctm: &Transform,
             output: &mut dyn OutputDev) -> Result<(), OutputError> {
    let ts = &mut gs.ts;
    let font = ts.font.as_ref().unwrap();
    //let encoding = font.encoding.as_ref().map(|x| &x[..]).unwrap_or(&PDFDocEncoding);
    dlog!("{:?}", font.decode(s));
    dlog!("{:?}", font.decode(s).as_bytes());
    dlog!("{:?}", s);
    output.begin_word()?;

    for (c, length) in font.char_codes(s) {
        let tsm = Transform2D::row_major(ts.horizontal_scaling,
                                                 0.,
                                                 0.,
                                                 1.0,
                                                 0.,
                                                 ts.rise);
        let trm = ts.tm.pre_transform(&gs.ctm);
        let trm = trm.post_transform(&tsm);
        //dlog!("ctm: {:?} tm {:?}", gs.ctm, tm);
        //dlog!("current pos: {:?}", position);
        // 5.9 Extraction of Text Content


        //dlog!("w: {}", font.widths[&(*c as i64)]);
        let w0 = font.get_width(c) / 1000.;

        let mut spacing = ts.character_spacing;
        // "Word spacing is applied to every occurrence of the single-byte character code 32 in a
        //  string when using a simple font or a composite font that defines code 32 as a
        //  single-byte code. It does not apply to occurrences of the byte value 32 in
        //  multiple-byte codes."
        let is_space = c == 32 && length == 1;
        if is_space { spacing += ts.word_spacing }

        output.output_character(&trm, w0, spacing, ts.font_size, &font.decode_char(c))?;
        let tj = 0.;
        let ty = 0.;
        let tx = ts.horizontal_scaling * ((w0 - tj/1000.)* ts.font_size + spacing);
        dlog!("horizontal {} adjust {} {} {} {}", ts.horizontal_scaling, tx, w0, ts.font_size, spacing);
        // dlog!("w0: {}, tx: {}", w0, tx);
        ts.tm = ts.tm.pre_transform(&Transform2D::create_translation(tx, ty));
        let _trm = ts.tm.pre_transform(&gs.ctm);
        //dlog!("post pos: {:?}", trm);

    }
    output.end_word()?;
    Ok(())
}

#[derive(Debug, Clone, Copy)]
pub struct MediaBox {
    pub llx: f64,
    pub lly: f64,
    pub urx: f64,
    pub ury: f64
}

fn apply_state(gs: &mut GraphicsState, state: &Dictionary) {
    for (k, v) in state.iter() {
        let k : &[u8] = k.as_ref();
        match k {
            b"SMask" => { match v {
                &Object::Name(ref name) => {
                    if name == b"None" {
                        gs.smask = None;
                    } else {
                        panic!("unexpected smask name")
                    }
                }
                _ => { panic!("unexpected smask type {:?}", v) }
            }}
            b"Type" => { match v {
                &Object::Name(ref name) => {
                    assert_eq!(name, b"ExtGState")
                }
                _ => { panic!("unexpected type") }
            }}
            _ => {  dlog!("unapplied state: {:?} {:?}", k, v); }
        }
    }

}

#[derive(Debug)]
pub enum PathOp {
    MoveTo(f64, f64),
    LineTo(f64, f64),
    // XXX: is it worth distinguishing the different kinds of curve ops?
    CurveTo(f64, f64, f64, f64, f64, f64),
    Rect(f64, f64, f64, f64),
    Close,
}

#[derive(Debug)]
pub struct Path {
    pub ops: Vec<PathOp>
}

impl Path {
    fn new() -> Path {
        Path { ops: Vec::new() }
    }
    fn current_point(&self) -> (f64, f64) {
        match self.ops.last().unwrap() {
            &PathOp::MoveTo(x, y) => { (x, y) }
            &PathOp::LineTo(x, y) => { (x, y) }
            &PathOp::CurveTo(_, _, _, _, x, y) => { (x, y) }
            _ => { panic!() }
        }
    }
}

#[derive(Clone)]
pub struct CalGray {
    white_point: [f64; 3],
    black_point: Option<[f64; 3]>,
    gamma: Option<f64>,
}

#[derive(Clone)]
pub struct CalRGB {
    white_point: [f64; 3],
    black_point: Option<[f64; 3]>,
    gamma: Option<[f64; 3]>,
    matrix: Option<Vec<f64>>
}

#[derive(Clone)]
pub struct Lab {
    white_point: [f64; 3],
    black_point: Option<[f64; 3]>,
    range: Option<[f64; 4]>,
}

#[derive(Clone)]
pub struct Separation {
    name: String,
    alternate_space: String,
    tint_transform: Box<Function>,
}

#[derive(Clone)]
pub enum ColorSpace {
    DeviceGray,
    DeviceRGB,
    DeviceCMYK,
    Pattern,
    CalRGB(CalRGB),
    CalGray(CalGray),
    Lab(Lab),
    Separation(Separation),
    ICCBased(Vec<u8>)
}

fn make_colorspace<'a>(doc: &'a Document, name: &[u8], resources: &'a Dictionary) -> ColorSpace {
    match name {
        b"DeviceGray" => ColorSpace::DeviceGray,
        b"DeviceRGB" => ColorSpace::DeviceRGB,
        b"DeviceCMYK" => ColorSpace::DeviceCMYK,
        b"Pattern" => ColorSpace::Pattern,
        _ => {
            let colorspaces: &Dictionary = get(&doc, resources, b"ColorSpace");
            let cs = maybe_get_array(doc, colorspaces, &name[..]).unwrap_or_else(|| panic!("missing colorspace {:?}", &name[..]));
            let cs_name = pdf_to_utf8(cs[0].as_name().expect("first arg must be a name"));
            match cs_name.as_ref() {
                "Separation" => {
                    let name = pdf_to_utf8(cs[1].as_name().expect("second arg must be a name"));
                    let alternate_space = pdf_to_utf8(cs[2].as_name().expect("second arg must be a name"));
                    let tint_transform = Box::new(Function::new(doc, maybe_deref(doc, &cs[3])));

                    dlog!("{:?} {:?} {:?}", name, alternate_space, tint_transform);
                    ColorSpace::Separation(Separation{ name, alternate_space, tint_transform})
                }
                "ICCBased" => {
                    let stream = maybe_deref(doc, &cs[1]).as_stream().unwrap();
                    dlog!("ICCBased {:?}", stream);
                    // XXX: we're going to be continually decompressing everytime this object is referenced
                    ColorSpace::ICCBased(get_contents(stream))
                }
                "CalGray" => {
                    let dict = cs[1].as_dict().expect("second arg must be a dict");
                    ColorSpace::CalGray(CalGray {
                        white_point: get(&doc, dict, b"WhitePoint"),
                        black_point: get(&doc, dict, b"BackPoint"),
                        gamma: get(&doc, dict, b"Gamma"),
                    })
                }
                "CalRGB" => {
                    let dict = cs[1].as_dict().expect("second arg must be a dict");
                    ColorSpace::CalRGB(CalRGB {
                        white_point: get(&doc, dict, b"WhitePoint"),
                        black_point: get(&doc, dict, b"BackPoint"),
                        gamma: get(&doc, dict, b"Gamma"),
                        matrix: get(&doc, dict, b"Matrix"),
                    })
                }
                "Lab" => {
                    let dict = cs[1].as_dict().expect("second arg must be a dict");
                    ColorSpace::Lab(Lab {
                        white_point: get(&doc, dict, b"WhitePoint"),
                        black_point: get(&doc, dict, b"BackPoint"),
                        range: get(&doc, dict, b"Range"),
                    })
                }
                "Pattern" => {
                    ColorSpace::Pattern
                }
                _ => {
                    panic!("color_space {:?} {:?} {:?}", name, cs_name, cs)
                }
            }
        }
    }
}

struct Processor<'a> {
    _none: PhantomData<&'a ()>
}

impl<'a> Processor<'a> {
    fn new() -> Processor<'a> {
        Processor { _none: PhantomData }
    }

    fn process_stream(&mut self, doc: &'a Document, content: Vec<u8>, resources: &'a Dictionary, media_box: &MediaBox, output: &mut dyn OutputDev, page_num: u32) -> Result<(), OutputError> {
        let content = Content::decode(&content).unwrap();
        let mut font_table = HashMap::new();
        let mut gs: GraphicsState = GraphicsState {
            ts: TextState {
                font: None,
                font_size: std::f64::NAN,
                character_spacing: 0.,
                word_spacing: 0.,
                horizontal_scaling: 100. / 100.,
                leading: 0.,
                rise: 0.,
                tm: Transform2D::identity(),
            },
            fill_color: Vec::new(),
            fill_colorspace: ColorSpace::DeviceGray,
            stroke_color: Vec::new(),
            stroke_colorspace: ColorSpace::DeviceGray,
            line_width: 1.,
            ctm: Transform2D::identity(),
            smask: None
        };
        //let mut ts = &mut gs.ts;
        let mut gs_stack = Vec::new();
        let mut mc_stack = Vec::new();
        // XXX: replace tlm with a point for text start
        let mut tlm = Transform2D::identity();
        let mut path = Path::new();
        let flip_ctm = Transform2D::row_major(1., 0., 0., -1., 0., media_box.ury - media_box.lly);
        dlog!("MediaBox {:?}", media_box);
        for operation in &content.operations {
            //dlog!("op: {:?}", operation);

            match operation.operator.as_ref() {
                "BT" => {
                    tlm = Transform2D::identity();
                    gs.ts.tm = tlm;
                }
                "ET" => {
                    tlm = Transform2D::identity();
                    gs.ts.tm = tlm;
                }
                "cm" => {
                    assert!(operation.operands.len() == 6);
                    let m = Transform2D::row_major(as_num(&operation.operands[0]),
                                                   as_num(&operation.operands[1]),
                                                   as_num(&operation.operands[2]),
                                                   as_num(&operation.operands[3]),
                                                   as_num(&operation.operands[4]),
                                                   as_num(&operation.operands[5]));
                    gs.ctm = gs.ctm.pre_transform(&m);
                    dlog!("matrix {:?}", gs.ctm);
                }
                "CS" => {
                    let name = operation.operands[0].as_name().unwrap();
                    gs.stroke_colorspace = make_colorspace(doc, name, resources);
                }
                "cs" => {
                    let name = operation.operands[0].as_name().unwrap();
                    gs.fill_colorspace = make_colorspace(doc, name, resources);
                }
                "SC" | "SCN" => {
                    gs.stroke_color = match gs.fill_colorspace {
                        ColorSpace::Pattern => { dlog!("unhandled pattern color"); Vec::new() }
                        _ => { operation.operands.iter().map(|x| as_num(x)).collect() }
                    };
                }
                "sc" | "scn" => {
                    gs.fill_color = match gs.fill_colorspace {
                        ColorSpace::Pattern => { dlog!("unhandled pattern color"); Vec::new() }
                        _ => { operation.operands.iter().map(|x| as_num(x)).collect() }
                    };
                }
                "G" | "g" | "RG" | "rg" | "K" | "k" => {
                    dlog!("unhandled color operation {:?}", operation);
                }
                "TJ" => {
                    match operation.operands[0] {
                        Object::Array(ref array) => {
                            for e in array {
                                match e {
                                    &Object::String(ref s, _) => {
                                        show_text(&mut gs, s, &tlm, &flip_ctm, output)?;
                                    }
                                    &Object::Integer(i) => {
                                        let ts = &mut gs.ts;
                                        let w0 = 0.;
                                        let tj = i as f64;
                                        let ty = 0.;
                                        let tx = ts.horizontal_scaling * ((w0 - tj / 1000.) * ts.font_size);
                                        ts.tm = ts.tm.pre_transform(&Transform2D::create_translation(tx, ty));
                                        dlog!("adjust text by: {} {:?}", i, ts.tm);
                                    }
                                    &Object::Real(i) => {
                                        let ts = &mut gs.ts;
                                        let w0 = 0.;
                                        let tj = i as f64;
                                        let ty = 0.;
                                        let tx = ts.horizontal_scaling * ((w0 - tj / 1000.) * ts.font_size);
                                        ts.tm = ts.tm.pre_transform(&Transform2D::create_translation(tx, ty));
                                        dlog!("adjust text by: {} {:?}", i, ts.tm);
                                    }
                                    _ => { dlog!("kind of {:?}", e); }
                                }
                            }
                        }
                        _ => {}
                    }
                }
                "Tj" => {
                    match operation.operands[0] {
                        Object::String(ref s, _) => {
                            show_text(&mut gs, s, &tlm, &flip_ctm, output)?;
                        }
                        _ => { panic!("unexpected Tj operand {:?}", operation) }
                    }
                }
                "Tc" => {
                    gs.ts.character_spacing = as_num(&operation.operands[0]);
                }
                "Tw" => {
                    gs.ts.word_spacing = as_num(&operation.operands[0]);
                }
                "Tz" => {
                    gs.ts.horizontal_scaling = as_num(&operation.operands[0]) / 100.;
                }
                "TL" => {
                    gs.ts.leading = as_num(&operation.operands[0]);
                }
                "Tf" => {
                    let fonts: &Dictionary = get(&doc, resources, b"Font");
                    let name = operation.operands[0].as_name().unwrap();
                    let font = font_table.entry(name.to_owned()).or_insert_with(|| make_font(doc, get::<&Dictionary>(doc, fonts, name))).clone();
                    {
                        /*let file = font.get_descriptor().and_then(|desc| desc.get_file());
                    if let Some(file) = file {
                        let file_contents = filter_data(file.as_stream().unwrap());
                        let mut cursor = Cursor::new(&file_contents[..]);
                        //let f = Font::read(&mut cursor);
                        //dlog!("font file: {:?}", f);
                    }*/
                    }
                    gs.ts.font = Some(font);

                    gs.ts.font_size = as_num(&operation.operands[1]);
                    dlog!("font {} size: {} {:?}", pdf_to_utf8(name), gs.ts.font_size, operation);
                }
                "Ts" => {
                    gs.ts.rise = as_num(&operation.operands[0]);
                }
                "Tm" => {
                    assert!(operation.operands.len() == 6);
                    tlm = Transform2D::row_major(as_num(&operation.operands[0]),
                                                 as_num(&operation.operands[1]),
                                                 as_num(&operation.operands[2]),
                                                 as_num(&operation.operands[3]),
                                                 as_num(&operation.operands[4]),
                                                 as_num(&operation.operands[5]));
                    gs.ts.tm = tlm;
                    dlog!("Tm: matrix {:?}", gs.ts.tm);
                    output.end_line()?;
                }
                "Td" => {
                    /* Move to the start of the next line, offset from the start of the current line by (tx , ty ).
                   tx and ty are numbers expressed in unscaled text space units.
                   More precisely, this operator performs the following assignments:
                 */
                    assert!(operation.operands.len() == 2);
                    let tx = as_num(&operation.operands[0]);
                    let ty = as_num(&operation.operands[1]);
                    dlog!("translation: {} {}", tx, ty);

                    tlm = tlm.pre_transform(&Transform2D::create_translation(tx, ty));
                    gs.ts.tm = tlm;
                    dlog!("Td matrix {:?}", gs.ts.tm);
                    output.end_line()?;
                }

                "TD" => {
                    /* Move to the start of the next line, offset from the start of the current line by (tx , ty ).
                   As a side effect, this operator sets the leading parameter in the text state.
                 */
                    assert!(operation.operands.len() == 2);
                    let tx = as_num(&operation.operands[0]);
                    let ty = as_num(&operation.operands[1]);
                    dlog!("translation: {} {}", tx, ty);
                    gs.ts.leading = -ty;

                    tlm = tlm.pre_transform(&Transform2D::create_translation(tx, ty));
                    gs.ts.tm = tlm;
                    dlog!("TD matrix {:?}", gs.ts.tm);
                    output.end_line()?;
                }

                "T*" => {
                    let tx = 0.0;
                    let ty = -gs.ts.leading;

                    tlm = tlm.pre_transform(&Transform2D::create_translation(tx, ty));
                    gs.ts.tm = tlm;
                    dlog!("T* matrix {:?}", gs.ts.tm);
                    output.end_line()?;
                }
                "q" => { gs_stack.push(gs.clone()); }
                "Q" => {
                    let s = gs_stack.pop();
                    if let Some(s) = s {
                        gs = s;
                    } else {
                        println!("No state to pop");
                    }
                }
                "gs" => {
                    let ext_gstate: &Dictionary = get(doc, resources, b"ExtGState");
                    let name = operation.operands[0].as_name().unwrap();
                    let state: &Dictionary = get(doc, ext_gstate, name);
                    apply_state(&mut gs, state);
                }
                "i" => { dlog!("unhandled graphics state flattness operator {:?}", operation); }
                "w" => { gs.line_width = as_num(&operation.operands[0]); }
                "J" | "j" | "M" | "d" | "ri"  => { dlog!("unknown graphics state operator {:?}", operation); }
                "m" => { path.ops.push(PathOp::MoveTo(as_num(&operation.operands[0]), as_num(&operation.operands[1]))) }
                "l" => { path.ops.push(PathOp::LineTo(as_num(&operation.operands[0]), as_num(&operation.operands[1]))) }
                "c" => {
                    path.ops.push(PathOp::CurveTo(
                        as_num(&operation.operands[0]),
                        as_num(&operation.operands[1]),
                        as_num(&operation.operands[2]),
                        as_num(&operation.operands[3]),
                        as_num(&operation.operands[4]),
                        as_num(&operation.operands[5])))
                }
                "v" => {
                    let (x, y) = path.current_point();
                    path.ops.push(PathOp::CurveTo(
                        x,
                        y,
                        as_num(&operation.operands[0]),
                        as_num(&operation.operands[1]),
                        as_num(&operation.operands[2]),
                        as_num(&operation.operands[3])))
                }
                "y" => {
                    path.ops.push(PathOp::CurveTo(
                        as_num(&operation.operands[0]),
                        as_num(&operation.operands[1]),
                        as_num(&operation.operands[2]),
                        as_num(&operation.operands[3]),
                        as_num(&operation.operands[2]),
                        as_num(&operation.operands[3])))
                }
                "h" => { path.ops.push(PathOp::Close) }
                "re" => {
                    path.ops.push(PathOp::Rect(as_num(&operation.operands[0]),
                                               as_num(&operation.operands[1]),
                                               as_num(&operation.operands[2]),
                                               as_num(&operation.operands[3])))
                }
                "s" | "f*" | "B" | "B*" | "b" => {
                    dlog!("unhandled path op {:?}", operation);
                }
                "S" => {
                    output.stroke(&gs.ctm, &gs.stroke_colorspace, &gs.stroke_color, &path)?;
                    path.ops.clear();
                }
                "F" | "f" => {
                    output.fill(&gs.ctm, &gs.fill_colorspace, &gs.fill_color, &path)?;
                    path.ops.clear();
                }
                "W" | "w*" => { dlog!("unhandled clipping operation {:?}", operation); }
                "n" => {
                    dlog!("discard {:?}", path);
                    path.ops.clear();
                }
                "BMC" | "BDC" => {
                    mc_stack.push(operation);
                }
                "EMC" => {
                    mc_stack.pop();
                }
                "Do" => {
                    // `Do` process an entire subdocument, so we do a recursive call to `process_stream`
                    // with the subdocument content and resources
                    let xobject: &Dictionary = get(&doc, resources, b"XObject");
                    let name = operation.operands[0].as_name().unwrap();
                    let xf: &Stream = get(&doc, xobject, name);
                    let resources = maybe_get_obj(&doc, &xf.dict, b"Resources").and_then(|n| n.as_dict().ok()).unwrap_or(resources);
                    let contents = get_contents(xf);
                    self.process_stream(&doc, contents, resources, &media_box, output, page_num)?;
                }
                _ => { dlog!("unknown operation {:?}", operation); }

            }
        }
        Ok(())
    }
}


pub trait OutputDev {
    fn begin_page(&mut self, page_num: u32, media_box: &MediaBox, art_box: Option<(f64, f64, f64, f64)>)-> Result<(), OutputError>;
    fn end_page(&mut self)-> Result<(), OutputError>;
    fn output_character(&mut self, trm: &Transform, width: f64, spacing: f64, font_size: f64, char: &str) -> Result<(), OutputError>;
    fn begin_word(&mut self)-> Result<(), OutputError>;
    fn end_word(&mut self)-> Result<(), OutputError>;
    fn end_line(&mut self)-> Result<(), OutputError>;
    fn stroke(&mut self, _ctm: &Transform, _colorspace: &ColorSpace, _color: &[f64], _path: &Path)-> Result<(), OutputError> {Ok(())}
    fn fill(&mut self, _ctm: &Transform, _colorspace: &ColorSpace, _color: &[f64], _path: &Path)-> Result<(), OutputError> {Ok(())}
}


pub struct HTMLOutput<'a>  {
    file: &'a mut dyn std::io::Write,
    flip_ctm: Transform,
    last_ctm: Transform,
    buf_ctm: Transform,
    buf_font_size: f64,
    buf: String
}

fn insert_nbsp(input: &str) -> String {
    let mut result = String::new();
    let mut word_end = false;
    let mut chars = input.chars().peekable();
    while let Some(c) = chars.next() {
        if c == ' ' {
            if !word_end || chars.peek().filter(|x| **x != ' ').is_none() {
                result += "&nbsp;";
            } else {
                result += " ";
            }
            word_end = false;
        } else {
            word_end = true;
            result.push(c);
        }
    }
    result
}

impl<'a> HTMLOutput<'a> {
    pub fn new(file: &mut dyn std::io::Write) -> HTMLOutput {
        HTMLOutput {
            file,
            flip_ctm: Transform2D::identity(),
            last_ctm: Transform2D::identity(),
            buf_ctm: Transform2D::identity(),
            buf: String::new(),
            buf_font_size: 0.,
        }
    }
    fn flush_string(&mut self) -> Result<(), OutputError>{
        if self.buf.len() != 0 {

            let position = self.buf_ctm.post_transform(&self.flip_ctm);
            let transformed_font_size_vec = self.buf_ctm.transform_vector(vec2(self.buf_font_size, self.buf_font_size));
            // get the length of one sized of the square with the same area with a rectangle of size (x, y)
            let transformed_font_size = (transformed_font_size_vec.x * transformed_font_size_vec.y).sqrt();
            let (x, y) = (position.m31, position.m32);
            println!("flush {} {:?}", self.buf, (x,y));

            write!(self.file, "<div style='position: absolute; left: {}px; top: {}px; font-size: {}px'>{}</div>\n",
                   x, y, transformed_font_size, insert_nbsp(&self.buf))?;
        }
        Ok(())
    }
}

type ArtBox = (f64, f64, f64, f64);

impl<'a> OutputDev for HTMLOutput<'a> {
    fn begin_page(&mut self, page_num: u32, media_box: &MediaBox, _: Option<ArtBox>) -> Result<(), OutputError> {
        write!(self.file, "<meta charset='utf-8' /> ")?;
        write!(self.file, "<!-- page {} -->", page_num)?;
        write!(self.file, "<div id='page{}' style='position: relative; height: {}px; width: {}px; border: 1px black solid'>", page_num, media_box.ury - media_box.lly, media_box.urx - media_box.llx)?;
        self.flip_ctm = Transform::row_major(1., 0., 0., -1., 0., media_box.ury - media_box.lly);
        Ok(())
    }
    fn end_page(&mut self) -> Result<(), OutputError> {
        self.flush_string()?;
        self.buf = String::new();
        self.last_ctm = Transform::identity();
        write!(self.file, "</div>")?;
        Ok(())
    }
    fn output_character(&mut self, trm: &Transform, width: f64, spacing: f64, font_size: f64, char: &str) -> Result<(), OutputError>{
        if trm.approx_eq(&self.last_ctm) {
            let position = trm.post_transform(&self.flip_ctm);
            let (x, y) = (position.m31, position.m32);

            println!("accum {} {:?}", char, (x,y));
            self.buf += char;
        } else {
            println!("flush {} {:?} {:?} {} {} {}", char, trm, self.last_ctm, width, font_size, spacing);
            self.flush_string()?;
            self.buf = char.to_owned();
            self.buf_font_size = font_size;
            self.buf_ctm = *trm;
        }
        let position = trm.post_transform(&self.flip_ctm);
        let transformed_font_size_vec = trm.transform_vector(vec2(font_size, font_size));
        // get the length of one sized of the square with the same area with a rectangle of size (x, y)
        let transformed_font_size = (transformed_font_size_vec.x * transformed_font_size_vec.y).sqrt();
        let (x, y) = (position.m31, position.m32);
        write!(self.file, "<div style='position: absolute; color: red; left: {}px; top: {}px; font-size: {}px'>{}</div>",
               x, y, transformed_font_size, char)?;
        self.last_ctm = trm.pre_transform(&Transform2D::create_translation(width * font_size + spacing, 0.));

        Ok(())
    }
    fn begin_word(&mut self) -> Result<(), OutputError> {Ok(())}
    fn end_word(&mut self) -> Result<(), OutputError> {Ok(())}
    fn end_line(&mut self) -> Result<(), OutputError> {Ok(())}
}

pub struct SVGOutput<'a>  {
    file: &'a mut dyn std::io::Write
}
impl<'a> SVGOutput<'a> {
    pub fn new(file: &mut dyn std::io::Write) -> SVGOutput {
        SVGOutput{file}
    }
}

impl<'a> OutputDev for SVGOutput<'a> {
    fn begin_page(&mut self, _page_num: u32, media_box: &MediaBox, art_box: Option<(f64, f64, f64, f64)>) -> Result<(), OutputError> {
        let ver = 1.1;
        write!(self.file, "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n")?;
        if ver == 1.1 {
            write!(self.file, r#"<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">"#)?;
        } else {
            write!(self.file, r#"<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN" "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">"#)?;
        }
        if let Some(art_box) = art_box {
            let width = art_box.2 - art_box.0;
            let height = art_box.3 - art_box.1;
            let y = media_box.ury - art_box.1 - height;
            write!(self.file, "<svg width=\"{}\" height=\"{}\" xmlns=\"http://www.w3.org/2000/svg\" version=\"{}\" viewBox='{} {} {} {}'>", width, height, ver, art_box.0, y, width, height)?;
        } else {
            let width = media_box.urx - media_box.llx;
            let height = media_box.ury - media_box.lly;
            write!(self.file, "<svg width=\"{}\" height=\"{}\" xmlns=\"http://www.w3.org/2000/svg\" version=\"{}\" viewBox='{} {} {} {}'>", width, height, ver, media_box.llx, media_box.lly, width, height)?;
        }
        write!(self.file, "\n")?;
        type Mat = Transform;

        let ctm = Mat::create_scale(1., -1.).post_translate(vec2(0., media_box.ury));
        write!(self.file, "<g transform='matrix({}, {}, {}, {}, {}, {})'>\n",
               ctm.m11,
               ctm.m12,
               ctm.m21,
               ctm.m22,
               ctm.m31,
               ctm.m32,
        )?;
        Ok(())
    }
    fn end_page(&mut self) -> Result<(), OutputError>{
        write!(self.file, "</g>\n")?;
        write!(self.file, "</svg>")?;
        Ok(())
    }
    fn output_character(&mut self, _trm: &Transform, _width: f64, _spacing: f64, _font_size: f64, _char: &str) -> Result<(), OutputError>{
        Ok(())
    }
    fn begin_word(&mut self) -> Result<(), OutputError> {Ok(())}
    fn end_word(&mut self) -> Result<(), OutputError> {Ok(())}
    fn end_line(&mut self) -> Result<(), OutputError> {Ok(())}
    fn fill(&mut self, ctm: &Transform, _colorspace: &ColorSpace, _color: &[f64], path: &Path) -> Result<(), OutputError>{
        write!(self.file, "<g transform='matrix({}, {}, {}, {}, {}, {})'>",
               ctm.m11,
               ctm.m12,
               ctm.m21,
               ctm.m22,
               ctm.m31,
               ctm.m32,
        )?;

        /*if path.ops.len() == 1 {
            if let PathOp::Rect(x, y, width, height) = path.ops[0] {
                write!(self.file, "<rect x={} y={} width={} height={} />\n", x, y, width, height);
                write!(self.file, "</g>");
                return;
            }
        }*/
        let mut d = Vec::new();
        for op in &path.ops {
            match op {
                &PathOp::MoveTo(x, y) => { d.push(format!("M{} {}", x, y))}
                &PathOp::LineTo(x, y) => { d.push(format!("L{} {}", x, y))},
                &PathOp::CurveTo(x1, y1, x2, y2, x, y) => { d.push(format!("C{} {} {} {} {} {}", x1, y1, x2, y2, x, y))},
                &PathOp::Close => { d.push(format!("Z"))},
                &PathOp::Rect(x, y, width, height) => {
                    d.push(format!("M{} {}", x, y));
                    d.push(format!("L{} {}", x + width, y));
                    d.push(format!("L{} {}", x + width, y + height));
                    d.push(format!("L{} {}", x, y + height));
                    d.push(format!("Z"));
                }

            }
        }
        write!(self.file, "<path d='{}' />", d.join(" "))?;
        write!(self.file, "</g>")?;
        write!(self.file, "\n")?;
        Ok(())
    }
}

/*
File doesn't implement std::fmt::Write so we have
to do some gymnastics to accept a File or String
See https://github.com/rust-lang/rust/issues/51305
*/

pub trait ConvertToFmt {
    type Writer: std::fmt::Write;
    fn convert(self) -> Self::Writer;
}

impl<'a> ConvertToFmt for &'a mut String {
    type Writer = &'a mut String;
    fn convert(self) -> Self::Writer {
        self
    }
}

pub struct WriteAdapter<W> {
    f: W,
}

impl<W: std::io::Write> std::fmt::Write for WriteAdapter<W> {
    fn write_str(&mut self, s: &str) -> Result<(), std::fmt::Error> {
        self.f.write_all(s.as_bytes()).map_err(|_| fmt::Error)
    }
}

impl<'a> ConvertToFmt for &'a mut dyn std::io::Write {
    type Writer = WriteAdapter<Self>;
    fn convert(self) -> Self::Writer {
        WriteAdapter { f: self }
    }
}

impl<'a> ConvertToFmt for &'a mut File {
    type Writer = WriteAdapter<Self>;
    fn convert(self) -> Self::Writer {
        WriteAdapter { f: self }
    }
}

pub struct PlainTextOutput<W: ConvertToFmt>   {
    writer: W::Writer,
    last_end: f64,
    last_y: f64,
    first_char: bool,
    flip_ctm: Transform,
}

impl<W: ConvertToFmt> PlainTextOutput<W> {
    pub fn new(writer: W) -> PlainTextOutput<W> {
        PlainTextOutput{
            writer: writer.convert(),
            last_end: 100000.,
            first_char: false,
            last_y: 0.,
            flip_ctm: Transform2D::identity(),
        }
    }
}

/* There are some structural hints that PDFs can use to signal word and line endings:
 * however relying on these is not likely to be sufficient. */
impl<W: ConvertToFmt> OutputDev for PlainTextOutput<W> {
    fn begin_page(&mut self, _page_num: u32, media_box: &MediaBox, _: Option<ArtBox>) -> Result<(), OutputError> {
        self.flip_ctm = Transform2D::row_major(1., 0., 0., -1., 0., media_box.ury - media_box.lly);
        Ok(())
    }
    fn end_page(&mut self) -> Result<(), OutputError> {
        Ok(())
    }
    fn output_character(&mut self, trm: &Transform, width: f64, _spacing: f64, font_size: f64, char: &str) -> Result<(), OutputError> {
        let position = trm.post_transform(&self.flip_ctm);
        let transformed_font_size_vec = trm.transform_vector(vec2(font_size, font_size));
        // get the length of one sized of the square with the same area with a rectangle of size (x, y)
        let transformed_font_size = (transformed_font_size_vec.x*transformed_font_size_vec.y).sqrt();
        let (x, y) = (position.m31, position.m32);
        use std::fmt::Write;
        //dlog!("last_end: {} x: {}, width: {}", self.last_end, x, width);
        if self.first_char {
            if (y - self.last_y).abs() > transformed_font_size * 1.5 {
                write!(self.writer, "\n")?;
            }

            // we've moved to the left and down
            if x < self.last_end && (y - self.last_y).abs() > transformed_font_size * 0.5 {
                write!(self.writer, "\n")?;
            }

            if x > self.last_end + transformed_font_size * 0.1 {
                dlog!("width: {}, space: {}, thresh: {}", width, x - self.last_end, transformed_font_size * 0.1);
                write!(self.writer, " ")?;
            }
        }
        //let norm = unicode_normalization::UnicodeNormalization::nfkc(char);
        write!(self.writer, "{}", char)?;
        self.first_char = false;
        self.last_y = y;
        self.last_end = x + width * transformed_font_size;
        Ok(())
    }
    fn begin_word(&mut self) -> Result<(), OutputError> {
        self.first_char = true;
        Ok(())
    }
    fn end_word(&mut self) -> Result<(), OutputError> {Ok(())}
    fn end_line(&mut self) -> Result<(), OutputError>{
        //write!(self.file, "\n");
        Ok(())
    }
}


pub fn print_metadata(doc: &Document) {
    dlog!("Version: {}", doc.version);
    if let Some(ref info) = get_info(&doc) {
        for (k, v) in *info {
            match v {
                &Object::String(ref s, StringFormat::Literal) => { dlog!("{}: {}", pdf_to_utf8(k), pdf_to_utf8(s)); }
                _ => {}
            }
        }
    }
    dlog!("Page count: {}", get::<i64>(&doc, &get_pages(&doc), b"Count"));
    dlog!("Pages: {:?}", get_pages(&doc));
    dlog!("Type: {:?}", get_pages(&doc).get(b"Type").and_then(|x| x.as_name()).unwrap());
}

/// Extract the text from a pdf at `path` and return a `String` with the results
pub fn extract_text<P: std::convert::AsRef<std::path::Path>>(path: P) -> Result<String, OutputError> {
    let mut s = String::new();
    {
        let mut output = PlainTextOutput::new(&mut s);
        let doc = Document::load(path)?;
        output_doc(&doc, &mut output)?;
    }
    return Ok(s);
}

fn get_inherited<'a, T: FromObj<'a>>(doc: &'a Document, dict: &'a Dictionary, key: &[u8]) -> Option<T> {
    let o: Option<T> = get(doc, dict, key);
    if let Some(o) = o {
        Some(o)
    } else {
        let parent = dict.get(b"Parent")
            .and_then(|parent| parent.as_reference())
            .and_then(|id| doc.get_dictionary(id)).ok()?;
        get_inherited(doc, parent, key)
    }
}
/// Parse a given document and output it to `output`
pub fn output_doc(doc: &Document, output: &mut dyn OutputDev) -> Result<(), OutputError> {
    let empty_resources = &Dictionary::new();

    let pages = doc.get_pages();
    let mut p = Processor::new();
    for dict in pages {
        let page_num = dict.0;
        let page_dict = doc.get_object(dict.1).unwrap().as_dict().unwrap();
        dlog!("page {} {:?}", page_num, page_dict);
        // XXX: Some pdfs lack a Resources directory
        let resources = get_inherited(doc, page_dict, b"Resources").unwrap_or(empty_resources);
        dlog!("resources {:?}", resources);

        // pdfium searches up the page tree for MediaBoxes as needed
        let media_box: Vec<f64> = get_inherited(doc, page_dict, b"MediaBox").expect("MediaBox");
        let media_box = MediaBox { llx: media_box[0], lly: media_box[1], urx: media_box[2], ury: media_box[3] };

        let art_box = get::<Option<Vec<f64>>>(&doc, page_dict, b"ArtBox")
            .map(|x| (x[0], x[1], x[2], x[3]));

        output.begin_page(page_num, &media_box, art_box)?;

        p.process_stream(&doc, doc.get_page_content(dict.1).unwrap(), resources,&media_box, output, page_num)?;

        output.end_page()?;
    }
    Ok(())
}