<?php

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\Autoload;

use Composer\Installer\InstallationManager;
use Composer\Json\JsonFile;
use Composer\Package\Loader\JsonLoader;
use Composer\Package\PackageInterface;
use Composer\Repository\RepositoryInterface;

/**
 * @author Igor Wiedler <igor@wiedler.ch>
 * @author Jordi Boggiano <j.boggiano@seld.be>
 */
class AutoloadGenerator
{
    private $localRepo;
    private $package;
    private $installationManager;

    public function __construct(RepositoryInterface $localRepo, PackageInterface $package, InstallationManager $installationManager)
    {
        $this->localRepo = $localRepo;
        $this->package = $package;
        $this->installationManager = $installationManager;
    }

    public function dump($targetFilename)
    {
        $autoloads = $this->parseAutoloads();

        $file = <<<'EOF'
<?php
// autoload.php generated by composer

namespace Composer\Autoloader;

$loader = new UniversalClassLoader();

EOF;

        if (isset($autoloads['psr0'])) {
            foreach ($autoloads['psr0'] as $def) {
                foreach ($def['mapping'] as $namespace => $path) {
                    $exportedNamespace = var_export($namespace, true);
                    $exportedPath = var_export(($def['path'] ? '/'.$def['path'] : '').'/'.$path, true);
                    $file .= <<<EOF
\$loader->registerNamespace($exportedNamespace, dirname(__DIR__).$exportedPath);

EOF;
                }
            }
        }

        if (isset($autoloads['pear'])) {
            foreach ($autoloads['pear'] as $def) {
                foreach ($def['mapping'] as $prefix => $path) {
                    $exportedPrefix = var_export($prefix, true);
                    $exportedPath = var_export(($def['path'] ? '/'.$def['path'] : '').'/'.$path, true);
                    $file .= <<<EOF
\$loader->registerPrefix($exportedPrefix, dirname(__DIR__).$exportedPath);

EOF;
                }
            }
        }

        $file .= <<<'EOF'
$loader->register();

/*
 * This class was taken from Symfony, the following license applies:
 *
 * Copyright (c) 2004-2011 Fabien Potencier
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is furnished
 * to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * UniversalClassLoader implements a "universal" autoloader for PHP 5.3.
 *
 * It is able to load classes that use either:
 *
 *  * The technical interoperability standards for PHP 5.3 namespaces and
 *    class names (http://groups.google.com/group/php-standards/web/psr-0-final-proposal);
 *
 *  * The PEAR naming convention for classes (http://pear.php.net/).
 *
 * Classes from a sub-namespace or a sub-hierarchy of PEAR classes can be
 * looked for in a list of locations to ease the vendoring of a sub-set of
 * classes for large projects.
 *
 * Example usage:
 *
 *     $loader = new UniversalClassLoader();
 *
 *     // register classes with namespaces
 *     $loader->registerNamespaces(array(
 *         'Symfony\Component' => __DIR__.'/component',
 *         'Symfony'           => __DIR__.'/framework',
 *         'Sensio'            => array(__DIR__.'/src', __DIR__.'/vendor'),
 *     ));
 *
 *     // register a library using the PEAR naming convention
 *     $loader->registerPrefixes(array(
 *         'Swift_' => __DIR__.'/Swift',
 *     ));
 *
 *     // activate the autoloader
 *     $loader->register();
 *
 * In this example, if you try to use a class in the Symfony\Component
 * namespace or one of its children (Symfony\Component\Console for instance),
 * the autoloader will first look for the class under the component/
 * directory, and it will then fallback to the framework/ directory if not
 * found before giving up.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class UniversalClassLoader
{
    private $namespaces = array();
    private $prefixes = array();
    private $namespaceFallbacks = array();
    private $prefixFallbacks = array();

    /**
     * Gets the configured namespaces.
     *
     * @return array A hash with namespaces as keys and directories as values
     */
    public function getNamespaces()
    {
        return $this->namespaces;
    }

    /**
     * Gets the configured class prefixes.
     *
     * @return array A hash with class prefixes as keys and directories as values
     */
    public function getPrefixes()
    {
        return $this->prefixes;
    }

    /**
     * Gets the directory(ies) to use as a fallback for namespaces.
     *
     * @return array An array of directories
     */
    public function getNamespaceFallbacks()
    {
        return $this->namespaceFallbacks;
    }

    /**
     * Gets the directory(ies) to use as a fallback for class prefixes.
     *
     * @return array An array of directories
     */
    public function getPrefixFallbacks()
    {
        return $this->prefixFallbacks;
    }

    /**
     * Registers the directory to use as a fallback for namespaces.
     *
     * @param array $dirs An array of directories
     *
     * @api
     */
    public function registerNamespaceFallbacks(array $dirs)
    {
        $this->namespaceFallbacks = $dirs;
    }

    /**
     * Registers the directory to use as a fallback for class prefixes.
     *
     * @param array $dirs An array of directories
     *
     * @api
     */
    public function registerPrefixFallbacks(array $dirs)
    {
        $this->prefixFallbacks = $dirs;
    }

    /**
     * Registers an array of namespaces
     *
     * @param array $namespaces An array of namespaces (namespaces as keys and locations as values)
     *
     * @api
     */
    public function registerNamespaces(array $namespaces)
    {
        foreach ($namespaces as $namespace => $locations) {
            $this->namespaces[$namespace] = (array) $locations;
        }
    }

    /**
     * Registers a namespace.
     *
     * @param string       $namespace The namespace
     * @param array|string $paths     The location(s) of the namespace
     *
     * @api
     */
    public function registerNamespace($namespace, $paths)
    {
        $this->namespaces[$namespace] = (array) $paths;
    }

    /**
     * Registers an array of classes using the PEAR naming convention.
     *
     * @param array $classes An array of classes (prefixes as keys and locations as values)
     *
     * @api
     */
    public function registerPrefixes(array $classes)
    {
        foreach ($classes as $prefix => $locations) {
            $this->prefixes[$prefix] = (array) $locations;
        }
    }

    /**
     * Registers a set of classes using the PEAR naming convention.
     *
     * @param string       $prefix  The classes prefix
     * @param array|string $paths   The location(s) of the classes
     *
     * @api
     */
    public function registerPrefix($prefix, $paths)
    {
        $this->prefixes[$prefix] = (array) $paths;
    }

    /**
     * Registers this instance as an autoloader.
     *
     * @param Boolean $prepend Whether to prepend the autoloader or not
     *
     * @api
     */
    public function register($prepend = false)
    {
        spl_autoload_register(array($this, 'loadClass'), true, $prepend);
    }

    /**
     * Loads the given class or interface.
     *
     * @param string $class The name of the class
     */
    public function loadClass($class)
    {
        if ($file = $this->findFile($class)) {
            require $file;
        }
    }

    /**
     * Finds the path to the file where the class is defined.
     *
     * @param string $class The name of the class
     *
     * @return string|null The path, if found
     */
    public function findFile($class)
    {
        if ('\\' == $class[0]) {
            $class = substr($class, 1);
        }

        if (false !== $pos = strrpos($class, '\\')) {
            // namespaced class name
            $namespace = substr($class, 0, $pos);
            foreach ($this->namespaces as $ns => $dirs) {
                foreach ($dirs as $dir) {
                    if (0 === strpos($namespace, $ns)) {
                        $className = substr($class, $pos + 1);
                        $file = $dir.DIRECTORY_SEPARATOR.str_replace('\\', DIRECTORY_SEPARATOR, $namespace).DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $className).'.php';
                        if (file_exists($file)) {
                            return $file;
                        }
                    }
                }
            }

            foreach ($this->namespaceFallbacks as $dir) {
                $file = $dir.DIRECTORY_SEPARATOR.str_replace('\\', DIRECTORY_SEPARATOR, $class).'.php';
                if (file_exists($file)) {
                    return $file;
                }
            }
        } else {
            // PEAR-like class name
            foreach ($this->prefixes as $prefix => $dirs) {
                foreach ($dirs as $dir) {
                    if (0 === strpos($class, $prefix)) {
                        $file = $dir.DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $class).'.php';
                        if (file_exists($file)) {
                            return $file;
                        }
                    }
                }
            }

            foreach ($this->prefixFallbacks as $dir) {
                $file = $dir.DIRECTORY_SEPARATOR.str_replace('_', DIRECTORY_SEPARATOR, $class).'.php';
                if (file_exists($file)) {
                    return $file;
                }
            }
        }
    }
}
EOF;

        file_put_contents($targetFilename, $file);
    }

    private function parseAutoloads()
    {
        $installPaths = array();
        foreach ($this->localRepo->getPackages() as $package) {
            $installPaths[] = array(
                $package,
                $this->installationManager->getInstallPath($package)
            );
        }
        $installPaths[] = array($this->package, '');

        $autoloads = array();
        foreach ($installPaths as $item) {
            list($package, $installPath) = $item;

            if (null !== $package->getTargetDir()) {
                $installPath = substr($installPath, 0, -strlen('/'.$package->getTargetDir()));
            }

            foreach ($package->getAutoload() as $type => $mapping) {
                $autoloads[$type][] = array(
                    'mapping'   => $mapping,
                    'path'      => $installPath,
                );
            }
        }

        return $autoloads;
    }
}