<?php
/** a single token in the source code of a file */
class Token {
  protected $text;
  protected $token;
  protected $depth;
  function __construct($text, $token, $depth) {
    $this->text = $text;
    $this->token = $token;
    $this->depth = $depth;
  }
  function getText() {
    return $this->text;
  }
  function getToken() {
    return $this->token;
  }
  function getDepth() {
    return $this->depth;
  }
  function isA($type) {
    return $this->getToken() === $type;
  }
  function isCurlyOpen() {
    $token = $this->getToken();
    return $token === T_CURLY_OPEN || $token === T_DOLLAR_OPEN_CURLY_BRACES || $this->getText() === '{';
  }
}
 
/** a collection of tokens */
class TokenStream {
  protected $tokens = array();
  function getHash() {
    return md5(serialize($this->tokens));
  }
  function append(Token $token) {
    $this->tokens[] = $token;
  }
  function iterate(Scanner $scanner) {
    foreach ($this->tokens as $token) {
      $scanner->accept($token);
    }
  }
}
 
/** parses a string -> tokenstream */
class TokenStreamParser {
  function scan($source) {
    //todo: track indentation
    $stream = new TokenStream();
    $depth = 0;
    foreach (token_get_all($source) as $token) {
      if (is_array($token)) {
        list ($token, $text) = $token;
      } elseif (is_string($token)) {
        $text = $token;
        $token = -1;
      }
      if ($token === T_CURLY_OPEN || $token === T_DOLLAR_OPEN_CURLY_BRACES || $text === '{') {
        ++$depth;
      } elseif ($text == '}') {
        --$depth;
      }
      $stream->append(new Token($text, $token, $depth));
    }
    return $stream;
  }
}
 
/** Used by transformers */
class TokenBuffer {
  protected $super;
  protected $tokens = array();
  function __construct(TokenBuffer $super = null) {
    $this->super = $super;
  }
  function prepend(Token $token) {
    array_unshift($this->tokens, $token);
  }
  function append(Token $token) {
    $this->tokens[] = $token;
  }
  function getFirstToken() {
    return isset($this->tokens[0]) ? $this->tokens[0] : null;
  }
  function replaceToken(Token $token, Token $new_token) {
    $tmp = array();
    foreach ($this->tokens as $t) {
      if ($t === $token) {
        $tmp[] = $new_token;
      } else {
        $tmp[] = $t;
      }
    }
    $this->tokens = $tmp;
  }
  function hasSuper() {
    return !! $this->super;
  }
  function raise() {
    return new TokenBuffer($this);
  }
  function flush() {
    if (!$this->super) {
      return $this;
    }
    $tokens = $this->tokens;
    $this->tokens = array();
    foreach ($tokens as $token) {
      $this->super->append($token);
    }
    return $this->super;
  }
  function toText() {
    $out = "";
    foreach ($this->tokens as $token) {
      $out .= $token->getText();
    }
    return $out;
  }
}
 
/** provides access to a file */
interface FileAccess {
  function getContents();
  function getPathname();
}
 
/** default implementation for FileAccess */
class FilePath implements FileAccess {
  protected $pathname;
  function __construct($pathname) {
    $this->pathname = $pathname;
  }
  function getContents() {
    if (!is_file($this->getPathname())) {
      throw new Exception("Not a file or not readable");
    }
    return get_file_contents($this->getPathname());
  }
  function getPathname() {
    return realpath($this->pathname);
  }
}
 
/** entity representing a file with sourcecode */
class SourceFile {
  protected $token_stream;
  protected $hash;
  protected $path;
  function __construct(FileAccess $path, TokenStream $token_stream) {
    $this->path = $path;
    $this->token_stream = $token_stream;
    $this->hash = $token_stream->getHash();
  }
  function getPath() {
    return $this->path;
  }
  function hasChanges() {
    return $this->hash != $this->token_stream->getHash();
  }
  function getTokenStream() {
    return $this->token_stream;
  }
  function setTokenStream(TokenStream $token_stream) {
    $this->token_stream = $token_stream;
  }
}
 
/** a repository + gateway for SourceFile's */
class SourceFileRepository {
  protected $streams = array();
  protected $parser;
  function __construct(TokenStreamParser $parser) {
    $this->parser = $parser;
  }
  function get(FileAccess $path) {
    if (!isset($this->streams[$path->getPathname()])) {
      $this->streams[$path->getPathname()] = $this->load($path);
    }
    // todo: assert not changed on disk
    return $this->streams[$path->getPathname()];
  }
  protected function load(FileAccess $path) {
    return new SourceFile($path, $this->parser->scan($path->getContents(), $path->getPathname()));
  }
}
 
/** a statemachine for scanning a tokenstream  */
interface Scanner {
  function accept(Token $token);
}
 
/** used for sending output to multiple scanners at once */
class ScannerMultiplexer implements Scanner {
  protected $scanners = array();
  function appendScanner(Scanner $scanner) {
    $this->scanners[] = $scanner;
    return $scanner;
  }
  function accept(Token $token) {
    foreach ($this->scanners as $scanner) {
      $scanner->accept($token);
    }
  }
}
 
/** Tracks the current class scope */
class ClassScanner implements Scanner {
  protected $current_class_scope = 0;
  protected $current_class;
  protected $state = 0;
  protected $on_class_begin;
  protected $on_class_end;
  protected $on_classname;
  function notifyOnClassBegin($callback) {
    $this->on_class_begin = $callback;
  }
  function notifyOnClassEnd($callback) {
    $this->on_class_end = $callback;
  }
  function notifyOnClassName($callback) {
    $this->on_classname = $callback;
  }
  function accept(Token $token) {
    if ($token->isA(T_INTERFACE) || $token->isA(T_CLASS)) {
      $this->state = 1;
      if (is_callable($this->on_class_begin)) {
        call_user_func($this->on_class_begin);
      }
    } elseif ($token->isA(T_STRING) && $this->state === 1) {
      $this->current_class = $token->getText();
      $this->current_class_scope = $token->getDepth();
      $this->state = 2;
      if (is_callable($this->on_classname)) {
        call_user_func($this->on_classname);
      }
    } elseif ($this->state === 2 && $token->getDepth() > $this->current_class_scope) {
      $this->state = 3;
    } elseif ($this->state === 3 && $token->getDepth() === $this->current_class_scope) {
      $this->current_class = null;
      $this->state = 0;
      if (is_callable($this->on_class_end)) {
        call_user_func($this->on_class_end);
      }
    }
  }
  function getCurrentClass() {
    return $this->current_class;
  }
}
 
/** Scans for class inheritance */
class ClassExtendsScanner implements Scanner {
  protected $on_extends;
  protected $on_implements;
  protected $state = 0;
  protected $class_scanner;
  function __construct(ClassScanner $class_scanner) {
    $this->class_scanner = $class_scanner;
  }
  function notifyOnExtends($callback) {
    $this->on_extends = $callback;
  }
  function notifyOnImplements($callback) {
    $this->on_implements = $callback;
  }
  function accept(Token $token) {
    if ($token->isA(T_EXTENDS)) {
      $this->state = 1;
    } elseif ($token->isA(T_IMPLEMENTS)) {
      $this->state = 2;
    } elseif ($this->state === 1 && $token->isA(T_STRING)) {
      if (is_callable($this->on_extends)) {
        call_user_func($this->on_extends, $this->class_scanner->getCurrentClass(), $token->getText());
      }
    } elseif ($this->state === 2 && $token->isA(T_STRING)) {
      if (is_callable($this->on_implements)) {
        call_user_func($this->on_implements, $this->class_scanner->getCurrentClass(), $token->getText());
      }
    } elseif ($token->isCurlyOpen()) {
      $this->state = 0;
    }
  }
}
 
/** Tracks possible preludes for functions */
class ModifiersScanner implements Scanner {
  protected $on_modifiers_begin;
  protected $on_modifiers_end;
  protected $was_function = false;
  protected $state = 0;
  function notifyOnModifiersBegin($callback) {
    $this->on_modifiers_begin = $callback;
  }
  function notifyOnModifiersEnd($callback) {
    $this->on_modifiers_end = $callback;
  }
  function accept(Token $token) {
    if ($token->isA(T_PRIVATE) || $token->isA(T_PROTECTED) || $token->isA(T_PUBLIC) || $token->isA(T_FINAL) || $token->isA(T_STATIC) || $token->isA(T_ABSTRACT)) {
      $this->state = 1;
      if (is_callable($this->on_modifiers_begin)) {
        call_user_func($this->on_modifiers_begin);
      }
    } elseif ($token->isA(T_INTERFACE) || $token->isA(T_CLASS) || $token->isA(T_FUNCTION) || $token->isA(T_VARIABLE)) {
      $this->was_function = $token->isA(T_FUNCTION);
      $this->state = 0;
      if (is_callable($this->on_modifiers_end)) {
        call_user_func($this->on_modifiers_end);
      }
    }
  }
  function isActive() {
    return $this->state === 1;
  }
  function wasFunction() {
    return $this->was_function;
  }
}
 
/** Scans for function name + body */
class FunctionBodyScanner implements Scanner {
  protected $name;
  protected $state = 0;
  function accept(Token $token) {
    if ($token->isA(T_FUNCTION)) {
      $this->current_class_scope = $token->getDepth();
      $this->state = 1;
    } elseif ($this->state === 1 && $token->isA(T_STRING)) {
      $this->name = $token->getText();
      $this->state = 2;
    } elseif ($this->state === 2 && $token->getDepth() > $this->current_class_scope) {
      $this->state = 3;
    } elseif ($this->state === 3 && $token->getDepth() === $this->current_class_scope) {
      $this->state = 0;
    }
  }
  function isActive() {
    return $this->state > 2;
  }
  function getName() {
    return $this->name;
  }
}
 
/** Scans for, collects and parses function signatures */
class FunctionParametersScanner implements Scanner {
  protected $signature = array();
  protected $paren_count = 0;
  protected $state = 0;
  protected $on_signature_begin;
  protected $on_signature_end;
  function notifyOnSignatureBegin($callback) {
    $this->on_signature_begin = $callback;
  }
  function notifyOnSignatureEnd($callback) {
    $this->on_signature_end = $callback;
  }
  function accept(Token $token) {
    if ($token->isA(T_FUNCTION)) {
      $this->state = 1;
    } elseif ($this->state === 1 && $token->getText() === '(') {
      $this->signature = array();
      $this->signature[] = array($token->getText(), $token->getToken());
      $this->paren_count = 1;
      $this->state = 2;
      if (is_callable($this->on_signature_begin)) {
        call_user_func($this->on_signature_begin);
      }
    } elseif ($this->state === 2) {
      $this->signature[] = array($token->getText(), $token->getToken());
      if ($token->getText() === '(') {
        $this->paren_count++;
      } elseif ($token->getText() === ')') {
        $this->paren_count--;
      }
      if ($this->paren_count === 0) {
        $this->state = 0;
        if (is_callable($this->on_signature_end)) {
          call_user_func($this->on_signature_end);
        }
      }
    }
  }
  function isActive() {
    return $this->state !== 0;
  }
  function getCurrentSignature() {
    return $this->signature;
  }
  function getCurrentSignatureAsString() {
    $txt = "";
    foreach ($this->signature as $struct) {
      $txt .= $struct[0];
    }
    return $txt;
  }
  function getCurrentSignatureAsTypeMap() {
    $current = null;
    $map = array();
    foreach ($this->signature as $tuple) {
      list($text, $token) = $tuple;
      if ($token === T_VARIABLE) {
        $map[$text] = $current ? $current : '???';
      } elseif ($text === ',') {
        $current = null;
      } elseif ($token === T_STRING) {
        $current = $text;
      }
    }
    return $map;
  }
}
 
/** Scans for doc-comments */
class DocBlockScanner implements Scanner {
  protected $last_doc_block;
  protected $state = 0;
  protected $parameters_scanner;
  function __construct(FunctionParametersScanner $parameters_scanner) {
    $this->parameters_scanner = $parameters_scanner;
  }
  function accept(Token $token) {
    if ($token->isA(T_DOC_COMMENT)) {
      $this->last_doc_block = $token->getText();
      $this->state = 1;
    } elseif ($token->isA(T_INTERFACE) || $token->isA(T_CLASS) || $token->isA(T_FUNCTION) || ($token->isA(T_VARIABLE) && !$this->parameters_scanner->isActive())) {
      if ($this->state === 1) {
        $this->state = 2;
      } else {
        $this->last_doc_block = null;
        $this->state = 0;
      }
    }
  }
  function isActive() {
    return $this->state === 1;
  }
  function getCurrentDocBlock() {
    return $this->last_doc_block;
  }
}