<?php

namespace OSInet\Class_Grapher;

/**
 * Graph builder.
 */
class Graph {
  /**
   * A PEAR class.
   *
   * @var Image_GraphViz
   */
  public $g;

  /**
   * @var Logger
   */
  public $logger = NULL;

  var $runtimeClasses = array();
  var $runtimeInterfaces = array();
  var $classes = array();
  var $interfaces = array();
  var $registeredClasses = array();
  var $registeredInterfaces = array();

  /**
   * Represent attributes as a string in GraphViz format.
   *
   * @param array $attributes
   */
  public function attributes(array $attributes) {
    $attributes = $this->g->_escapeArray($attributes);
    $ret = array();
    foreach ($attributes as $name => $value) {
      $ret[] = "$name=$value";
    }
    $ret = implode(',', $ret);
    return $ret;
  }

  /**
   * Shortcut to invoke logger->message().
   *
   * @param string $message
   * @param int $level
   */
  public function debug($message = '\n', $level = LOG_DEBUG) {
    $this->logger->debug($message, $level);
  }

  /**
   * Build a list of files to scan below a given base.
   *
   * TODO support base as a file instead of a directory.
   *
   * @param string $base
   *   A starting path or array of paths for file lookup.
   * @param array $blackList
   *   An array of file names to reject, whatever their path.
   * @param string $pattern
   *   A regexp for file paths to match.
   *
   * @return array
   *   An array of compliant file paths.
   */
  public function getFiles($base, $blackList = array(),
    $pattern = '/.*\.(inc|module|php)$/') {
    $files = array();
    foreach ($base as $start) {
      $dir = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($start,
        \FilesystemIterator::KEY_AS_PATHNAME  | \FilesystemIterator::SKIP_DOTS));
      while ($dir->valid()) {
        $name = $dir->key();
        if (preg_match($pattern, $name) && !in_array(basename($name), $blackList)) {
          $files[] = $name;
        }
        elseif ($this->logger->debugLevel >= LOG_INFO) {
          if (in_array(basename($name), $blackList)) {
            $this->debug("$name blacklisted.\n", LOG_INFO);
          }
          else {
            $this->debug("$name does not match source paths.\n", LOG_DEBUG);
          }
        }
        $dir->next();
      }
    }

    $files = array_unique($files);
    sort($files);
    return $files;
  }

  /**
   * Constructor helper: initialize GraphViz settings.
   */
  public function initGraph() {
    $this->g = new \Image_Graphviz();
    $this->g->setDirected(TRUE);
    $this->g->setAttributes(array(
        'rankdir' => 'LR',
        'overlap' => FALSE,
    ));
  }

  public function registerClass(ClassInstance $class) {
    $this->debug('  Registering class '. $class->name . "\n");
    if (!empty($class->parent)) {
      if (!isset($this->registeredClasses[$class->parent])) {
        $this->debug("    Registering parent ". $class->parent . " for " . $class->name . "\n");
        $gpParent = new \PGPClass($class->parent);
        $cpParent = new ClassInstance($gpParent, 1, $this->logger);
        $this->registerClass($cpParent);
      }
    }
    foreach ($class->interfaces as $interface) {
      if (!isset($this->registeredClasses[$interface])) {
        $this->debug("    Registering interface $interface for {$class->name}\n");
        $gpInterface = new \PGPClass($interface);
        $cpInterface = new InterfaceInstance($gpInterface, 1, $this->logger);
        $this->registerInterface($cpInterface);
      }
    }

    // At this point, all ascendants are registered.
    if (!isset($this->registeredClasses[$class->name])) {
      $this->registeredClasses[$class->name] = $class;
    }
    // Override implicit status of a previously declared class if needed.
    if (!$class->implicit) {
      $this->registeredClasses[$class->name]->implicit = 0;
    }
  }

  public function registerInterface(InterfaceInstance $interface) {
    $this->debug("Registering interface {$interface->name}\n");
    if (!empty($interface->parent)) {
      if (!isset($this->registeredInterfaces[$interface->parent])) {
        $this->debug("    Registering parent ". $interface->parent . " for " . $interface->name . "\n");
        $gpParent = new \PGPClass($interface->parent);
        $cpParent = new InterfaceInstance($gpParent, 1, $this->logger);
        $this->registerInterface($cpParent);
      }
    }
    // At this point, all ascendants are registered.
    if (!isset($this->registeredInterfaces[$interface->name])) {
      $this->registeredInterfaces[$interface->name] = $interface;
    }
    // Override implicit status of a previously declared interface if needed.
    if (!$interface->implicit) {
      $this->registeredInterfaces[$interface->name]->implicit = 0;
    }
  }

  /**
   * Symbol extractor using grammar_parser.
   *
   * @param string $base
   */
  public function extractGrammar($base) {
    // These files cause a segfault during parse, so we skip them for now.
    // Possible patch at http://drupal.org/node/1485370
    $blackList = array(
      'RouteCollection.php',
      'HeaderBag.php',
      'NativeSessionHandler.php',
      'SimpleXMLElement.php',
      'ContainerBuilderTest.php',
      'YamlFileLoaderTest.php',
      'ResponseTest.php',
      'ConfigDataCollectorTest.php',
      'KernelTest.php',
      'UrlMatcherTest.php',
    );
    $files = $this->getFiles($base, $blackList);

    foreach ($files as $filename) {
      $source = file_get_contents($filename, FALSE);
      $reader = new \PGPReader($source);
      unset($source);
      $this->debug("Parsing $filename\n", LOG_INFO);
      $reader->buildGrammar();

      foreach ($reader->getInterfaces() as $interface) {
        $this->registerInterface(new InterfaceInstance($interface->data, 0, $this->logger));
      }

      foreach ($reader->getClasses() as $class) {
        $this->registerClass(new ClassInstance($class->data, 0, $this->logger));
      }

      $reader->reset();
      unset($reader);
    }
  }

  public function __construct($base, Logger $logger) {
    $this->logger = $logger;
    $this->extractGrammar($base);
    $this->initGraph();
  }

  public function implementsAttributes() {
    $attributes = array(
      'arrowhead' => 'empty',
      'arrowtail' => 'none',
      'style' => 'dotted',
    );
    $attributes = $this->g->_escapeArray($attributes);
    return $attributes;
  }

  public function buildSymbols($collection = array(), $kind = NULL) {
    foreach ($collection as $name => $symbol) {
      $this->debug("Building $kind $name\n");
      $this->g->addNode($name, $symbol->attributes());
      if ($symbol->parent) {
        $this->g->addEdge(array($name => $symbol->parent));
      }

      if (empty($symbol->interfaces)) {
        continue;
      }

      foreach ($symbol->interfaces as $interface_name) {
        $this->g->addEdge(array($name => $interface_name), $this->implementsAttributes());
      }
    }
  }

  /**
   * Build the graph once extraction has been performed.
   */
  public function build($imager = 'dot', $format = 'svg') {
    $this->debug("Starting build for "
      . count($this->registeredInterfaces) . " interfaces and "
      . count($this->registeredClasses) . " classes.\n",
      WATCHDOG_INFO);

    $this->buildSymbols($this->registeredInterfaces, 'interface');
    $this->buildSymbols($this->registeredClasses, 'class');

    if (empty($imager) || $imager == 'dump') {
      // $this->debug(print_r($g->_getGroups(), TRUE));
      $this->debug("Interfaces:\n");
      $this->debug(print_r($this->registeredInterfaces, TRUE));
      $this->debug("Classes\n");
      $this->debug(print_r($this->registeredClasses, TRUE));
      //$this->debug(print_r($this->g));
      $ret = $this->g->parse();
    }
    else {
      ob_start();
      $this->g->image($format, $imager);
      $ret = ob_get_contents();
      ob_end_clean();
    }

    return $ret;
  }
}