generate.coffee

fs = require 'fs'
vm = require 'vm'
md = require('markdown').markdown
coffee = require 'coffee-script'
CodeMirror = require 'codemirror/addon/runmode/runmode.node'
PDFDocument = require '../'

process.chdir(__dirname)

# setup code mirror coffeescript mode
filename = require.resolve('codemirror/mode/coffeescript/coffeescript')
coffeeMode = fs.readFileSync filename, 'utf8'
vm.runInNewContext coffeeMode, CodeMirror: CodeMirror

# style definitions for markdown
styles =
  h1:
    font: 'fonts/Alegreya-Bold.ttf'
    fontSize: 25
    padding: 15
  h2:
    font: 'fonts/Alegreya-Bold.ttf'
    fontSize: 18
    padding: 10
  h3:
    font: 'fonts/Alegreya-Bold.ttf'
    fontSize: 18
    padding: 10
  para:
    font: 'fonts/Merriweather-Regular.ttf'
    fontSize: 10
    padding: 10
  code:
    font: 'fonts/SourceCodePro-Regular.ttf'
    fontSize: 9
  code_block:
    padding: 10
    background: '#2c2c2c'
  inlinecode:
    font: 'fonts/SourceCodePro-Bold.ttf'
    fontSize: 10
  listitem:
    font: 'fonts/Merriweather-Regular.ttf'
    fontSize: 10
    padding: 6
  link:
    font: 'fonts/Merriweather-Regular.ttf'
    fontSize: 10
    color: 'blue'
    underline: true
  example:
    font: 'Helvetica'
    fontSize: 9
    color: 'black'
    padding: 10
    
# syntax highlighting colors
# based on Github's theme
colors =
  keyword: '#cb4b16'
  atom: '#d33682'
  number: '#009999'
  def: '#2aa198'
  variable: '#108888'
  'variable-2': '#b58900'
  'variable-3': '#6c71c4'
  property: '#2aa198'
  operator: '#6c71c4'
  comment: '#999988'
  string: '#dd1144'
  'string-2': '#009926'
  meta: '#768E04'
  qualifier: '#b58900'
  builtin: '#d33682'
  bracket: '#cb4b16'
  tag: '#93a1a1'
  attribute: '#2aa198'
  header: '#586e75'
  quote: '#93a1a1'
  link: '#93a1a1'
  special: '#6c71c4'
  default: '#002b36'

# shared lorem ipsum text so we don't need to copy it into every example
lorem = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam in suscipit purus. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Vivamus nec hendrerit felis. Morbi aliquam facilisis risus eu lacinia. Sed eu leo in turpis fringilla hendrerit. Ut nec accumsan nisl. Suspendisse rhoncus nisl posuere tortor tempus et dapibus elit porta. Cras leo neque, elementum a rhoncus ut, vestibulum non nibh. Phasellus pretium justo turpis. Etiam vulputate, odio vitae tincidunt ultricies, eros odio dapibus nisi, ut tincidunt lacus arcu eu elit. Aenean velit erat, vehicula eget lacinia ut, dignissim non tellus. Aliquam nec lacus mi, sed vestibulum nunc. Suspendisse potenti. Curabitur vitae sem turpis. Vestibulum sed neque eget dolor dapibus porttitor at sit amet sem. Fusce a turpis lorem. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae;'

codeBlocks = []
lastType = null

# This class represents a node in the markdown tree, and can render it to pdf
class Node  
  constructor: (tree) ->
    # special case for text nodes
    if typeof tree is 'string'
      @type = 'text'
      @text = tree
      return
    
    @type = tree.shift()
    @attrs = {}
  
    if typeof tree[0] is 'object' and not Array.isArray tree[0]
      @attrs = tree.shift()
    
    # parse sub nodes
    @content = while tree.length
      new Node tree.shift()
      
    switch @type
      when 'header'
        @type = 'h' + @attrs.level
        
      when 'code_block'
        # use code mirror to syntax highlight the code block
        code = @content[0].text
        @content = []
        CodeMirror.runMode code, 'coffeescript', (text, style) =>
          color = colors[style] or colors.default
          opts =
            color: color
            continued: text isnt '\n'
        
          @content.push new Node ['code', opts, text]
    
        @content[@content.length - 1]?.attrs.continued = false
        codeBlocks.push code
      
      when 'img'
        # images are used to generate inline example output
        # compiles the coffeescript to JS so it can be run 
        # in the render method
        @type = 'example'
        code = codeBlocks[@attrs.alt]
        @code = coffee.compile code if code
        @height = +@attrs.title or 0
      
    @style = styles[@type] or styles.para
      
  # sets the styles on the document for this node
  setStyle: (doc) ->
    if @style.font
      doc.font @style.font
  
    if @style.fontSize
      doc.fontSize @style.fontSize
      
    if @style.color or @attrs.color
      doc.fillColor @style.color or @attrs.color
    else
      doc.fillColor 'black'
      
    options = {}
    options.align = @style.align
    options.link  = @attrs.href or false # override continued link
    options.continued = @attrs.continued if @attrs.continued?
    return options
      
  # renders this node and its subnodes to the document
  render: (doc, continued = false) ->
    switch @type
      when 'example'
        @setStyle doc
        
        # translate all points in the example code to 
        # the current point in the document
        doc.moveDown()
        doc.save()
        doc.translate(doc.x, doc.y)
        x = doc.x
        y = doc.y
        doc.x = doc.y = 0
        
        # run the example code with the document
        vm.runInNewContext @code,
          doc: doc
          lorem: lorem
          
        # restore points and styles
        y += doc.y
        doc.restore()
        doc.x = x
        doc.y = y + @height
      when 'hr'
        doc.addPage()
      else
        # loop through subnodes and render them
        for fragment, index in @content
          if fragment.type is 'text'
            # add a new page for each heading, unless it follows another heading
            if @type in ['h1', 'h2'] and lastType? and lastType isnt 'h1'
              doc.addPage()
              
            # set styles and whether this fragment is continued (for rich text wrapping)
            options = @setStyle doc
            options.continued ?= continued or index < @content.length - 1
  
            # remove newlines unless this is code
            unless @type is 'code'
              fragment.text = fragment.text.replace(/[\r\n]\s*/g, ' ')
    
            doc.text fragment.text, options
          else
            fragment.render doc, index < @content.length - 1 and @type isnt 'bulletlist'
          
          lastType = @type
        
    if @style.padding
      doc.y += @style.padding

# reads and renders a markdown/literate coffeescript file to the document
render = (doc, filename) ->
  codeBlocks = []
  tree = md.parse fs.readFileSync(filename, 'utf8')
  tree.shift()
  
  while tree.length
    node = new Node tree.shift()
    node.render(doc)

# renders the title page of the guide    
renderTitlePage = (doc) ->
  title = 'PDFKit Guide'
  author = 'By Devon Govett'
  version = 'Version ' + require('../package.json').version
  
  doc.font 'fonts/AlegreyaSans-Light.ttf', 60
  doc.y = doc.page.height / 2 - doc.currentLineHeight()
  doc.text title, align: 'center'
  w = doc.widthOfString(title)
  
  doc.fontSize 20
  doc.y -= 10
  doc.text author,
    align: 'center'
    indent: w - doc.widthOfString(author)
  
  doc.font styles.para.font, 10
  doc.text version,
    align: 'center'
    indent: w - doc.widthOfString(version)
    
  doc.addPage()

# render all sections of the guide and write the pdf file
do ->
  doc = new PDFDocument
  doc.pipe fs.createWriteStream('guide.pdf')
  renderTitlePage doc
  render doc, 'getting_started.coffee.md'
  render doc, 'vector.coffee.md'
  render doc, 'text.coffee.md'
  render doc, 'images.coffee.md'
  render doc, 'annotations.coffee.md'
  doc.end()