<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Loader
 * @subpackage PluginLoader
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */

/** Zend_Loader_PluginLoader_Interface */
require_once 'external/Zend/Loader/PluginLoader/Interface.php';

/** Zend_Loader */
require_once 'external/Zend/Loader.php';

/**
 * Generic plugin class loader
 *
 * @category   Zend
 * @package    Zend_Loader
 * @subpackage PluginLoader
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Loader_PluginLoader implements Zend_Loader_PluginLoader_Interface {
  /**
   * Static registry property
   *
   * @var array
   */
  protected static $_staticPrefixToPaths = array();
  
  /**
   * Instance registry property
   *
   * @var array
   */
  protected $_prefixToPaths = array();
  
  /**
   * Statically loaded plugins
   *
   * @var array
   */
  protected static $_staticLoadedPlugins = array();
  
  /**
   * Instance loaded plugins
   *
   * @var array
   */
  protected $_loadedPlugins = array();
  
  /**
   * Whether to use a statically named registry for loading plugins
   *
   * @var string|null
   */
  protected $_useStaticRegistry = null;

  /**
   * Constructor
   *
   * @param array $prefixToPaths
   * @param string $staticRegistryName OPTIONAL
   */
  public function __construct(Array $prefixToPaths = array(), $staticRegistryName = null) {
    if (is_string($staticRegistryName) && ! empty($staticRegistryName)) {
      $this->_useStaticRegistry = $staticRegistryName;
      self::$_staticPrefixToPaths[$staticRegistryName] = array();
      self::$_staticLoadedPlugins[$staticRegistryName] = array();
    }
    
    foreach ($prefixToPaths as $prefix => $path) {
      $this->addPrefixPath($prefix, $path);
    }
  }

  /**
   * Format prefix for internal use
   *
   * @param  string $prefix
   * @return string
   */
  protected function _formatPrefix($prefix) {
    return rtrim($prefix, '_') . '_';
  }

  /**
   * Add prefixed paths to the registry of paths
   *
   * @param string $prefix
   * @param string $path
   * @return Zend_Loader_PluginLoader
   */
  public function addPrefixPath($prefix, $path) {
    if (! is_string($prefix) || ! is_string($path)) {
      require_once 'external/Zend/Loader/PluginLoader/Exception.php';
      throw new Zend_Loader_PluginLoader_Exception('Zend_Loader_PluginLoader::addPrefixPath() method only takes strings for prefix and path.');
    }
    
    $prefix = $this->_formatPrefix($prefix);
    $path = rtrim($path, '/\\') . '/';
    
    if ($this->_useStaticRegistry) {
      self::$_staticPrefixToPaths[$this->_useStaticRegistry][$prefix][] = $path;
    } else {
      $this->_prefixToPaths[$prefix][] = $path;
    }
    return $this;
  }

  /**
   * Get path stack
   *
   * @param  string $prefix
   * @return false|array False if prefix does not exist, array otherwise
   */
  public function getPaths($prefix = null) {
    if ((null !== $prefix) && is_string($prefix)) {
      $prefix = $this->_formatPrefix($prefix);
      if ($this->_useStaticRegistry) {
        if (isset(self::$_staticPrefixToPaths[$this->_useStaticRegistry][$prefix])) {
          return self::$_staticPrefixToPaths[$this->_useStaticRegistry][$prefix];
        }
        
        return false;
      }
      
      if (isset($this->_prefixToPaths[$prefix])) {
        return $this->_prefixToPaths[$prefix];
      }
      
      return false;
    }
    
    if ($this->_useStaticRegistry) {
      return self::$_staticPrefixToPaths[$this->_useStaticRegistry];
    }
    
    return $this->_prefixToPaths;
  }

  /**
   * Clear path stack
   *
   * @param  string $prefix
   * @return bool False only if $prefix does not exist
   */
  public function clearPaths($prefix = null) {
    if ((null !== $prefix) && is_string($prefix)) {
      $prefix = $this->_formatPrefix($prefix);
      if ($this->_useStaticRegistry) {
        if (isset(self::$_staticPrefixToPaths[$this->_useStaticRegistry][$prefix])) {
          unset(self::$_staticPrefixToPaths[$this->_useStaticRegistry][$prefix]);
          return true;
        }
        
        return false;
      }
      
      if (isset($this->_prefixToPaths[$prefix])) {
        unset($this->_prefixToPaths[$prefix]);
        return true;
      }
      
      return false;
    }
    
    if ($this->_useStaticRegistry) {
      self::$_staticPrefixToPaths[$this->_useStaticRegistry] = array();
    } else {
      $this->_prefixToPaths = array();
    }
    
    return true;
  }

  /**
   * Remove a prefix (or prefixed-path) from the registry
   *
   * @param string $prefix
   * @param string $path OPTIONAL
   * @return Zend_Loader_PluginLoader
   */
  public function removePrefixPath($prefix, $path = null) {
    $prefix = $this->_formatPrefix($prefix);
    if ($this->_useStaticRegistry) {
      $registry = & self::$_staticPrefixToPaths[$this->_useStaticRegistry];
    } else {
      $registry = & $this->_prefixToPaths;
    }
    
    if (! isset($registry[$prefix])) {
      require_once 'external/Zend/Loader/PluginLoader/Exception.php';
      throw new Zend_Loader_PluginLoader_Exception('Prefix ' . $prefix . ' was not found in the PluginLoader.');
    }
    
    if ($path != null) {
      $pos = array_search($path, $registry[$prefix]);
      if ($pos === null) {
        throw new Zend_Loader_PluginLoader_Exception('Prefix ' . $prefix . ' / Path ' . $path . ' was not found in the PluginLoader.');
      }
      unset($registry[$prefix][$pos]);
    } else {
      unset($registry[$prefix]);
    }
    
    return $this;
  }

  /**
   * Normalize plugin name
   *
   * @param  string $name
   * @return string
   */
  protected function _formatName($name) {
    return ucfirst((string)$name);
  }

  /**
   * Whether or not a Plugin by a specific name is loaded
   *
   * @param string $name
   * @return Zend_Loader_PluginLoader
   */
  public function isLoaded($name) {
    $name = $this->_formatName($name);
    if ($this->_useStaticRegistry) {
      return isset(self::$_staticLoadedPlugins[$this->_useStaticRegistry][$name]);
    }
    
    return isset($this->_loadedPlugins[$name]);
  }

  /**
   * Return full class name for a named plugin
   *
   * @param string $name
   * @return string|false False if class not found, class name otherwise
   */
  public function getClassName($name) {
    $name = $this->_formatName($name);
    if ($this->_useStaticRegistry && isset(self::$_staticLoadedPlugins[$this->_useStaticRegistry][$name])) {
      return self::$_staticLoadedPlugins[$this->_useStaticRegistry][$name];
    } elseif (isset($this->_loadedPlugins[$name])) {
      return $this->_loadedPlugins[$name];
    }
    
    return false;
  }

  /**
   * Load a plugin via the name provided
   *
   * @param  string $name
   * @return string
   */
  public function load($name) {
    $name = $this->_formatName($name);
    if ($this->_useStaticRegistry) {
      $registry = self::$_staticPrefixToPaths[$this->_useStaticRegistry];
    } else {
      $registry = $this->_prefixToPaths;
    }
    
    if ($this->isLoaded($name)) {
      return $this->getClassName($name);
    }
    
    $found = false;
    
    $registry = array_reverse($registry, true);
    foreach ($registry as $prefix => $paths) {
      $paths = array_reverse($paths, true);
      foreach ($paths as $path) {
        
        $classFile = str_replace('_', DIRECTORY_SEPARATOR, $name) . '.php';
        $className = $prefix . $name;
        
        if (class_exists($className, false)) {
          $found = true;
          break 2;
        }
        
        if (Zend_Loader::isReadable($path . $classFile)) {
          include_once $path . $classFile;
          
          if (! class_exists($className, false)) {
            throw new Zend_Loader_PluginLoader_Exception('File ' . $classFile . ' was loaded but class named ' . $className . ' was not found within it.');
          }
          
          $found = true;
          break 2;
        }
      }
    }
    
    if ($found) {
      if ($this->_useStaticRegistry) {
        self::$_staticLoadedPlugins[$this->_useStaticRegistry][$name] = $className;
      } else {
        $this->_loadedPlugins[$name] = $className;
      }
      return $className;
    }
    
    require_once 'external/Zend/Loader/PluginLoader/Exception.php';
    throw new Zend_Loader_PluginLoader_Exception('Plugin by name ' . $name . ' was not found in the registry.');
  }
}