<?php

/**
 * ---------------------------------------------------------------------
 *
 * GLPI - Gestionnaire Libre de Parc Informatique
 *
 * http://glpi-project.org
 *
 * @copyright 2015-2023 Teclib' and contributors.
 * @copyright 2003-2014 by the INDEPNET Development Team.
 * @licence   https://www.gnu.org/licenses/gpl-3.0.html
 *
 * ---------------------------------------------------------------------
 *
 * LICENSE
 *
 * This file is part of GLPI.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * ---------------------------------------------------------------------
 */

namespace Glpi\Console;

use AppendIterator;
use DirectoryIterator;
use Plugin;
use RecursiveDirectoryIterator;
use RecursiveIteratorIterator;
use ReflectionClass;
use SplFileInfo;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\CommandLoader\CommandLoaderInterface;

/**
 * Core and plugins command loader.
 *
 * @since 9.4.0
 */
class CommandLoader implements CommandLoaderInterface
{
    /**
     * Indicates if plugin commands should be included.
     *
     * @var bool
     */
    private $include_plugins;

    /**
     * Root directory path to search on.
     * @var string
     */
    private $rootdir;

    /**
     * Found commands.
     *
     * @var Command[]|null
     */
    private $commands = null;

    /**
     * Plugins info services
     *
     * @var Plugin|null
     */
    private $plugin = null;

    /**
     * @param bool          $include_plugins
     * @param string        $rootdir         Root directory path of application.
     * @param Plugin|null   $plugin          Needed for units test as we lack DI.
     */
    public function __construct($include_plugins = true, $rootdir = GLPI_ROOT, ?Plugin $plugin = null)
    {
        $this->include_plugins = $include_plugins;
        $this->rootdir         = $rootdir;
        $this->plugin          = $plugin;
    }

    public function get($name)
    {
        $commands = $this->getCommands();

        if (!array_key_exists($name, $commands)) {
            throw new \Symfony\Component\Console\Exception\CommandNotFoundException(sprintf('Command "%s" does not exist.', $name));
        }

        return $commands[$name];
    }

    public function has($name)
    {
        $commands = $this->getCommands();

        return array_key_exists($name, $commands);
    }

    public function getNames()
    {
        $commands = $this->getCommands();

        return array_keys($commands);
    }

    /**
     * Indicates if plugin commands should be included.
     *
     * @param bool $include_plugins
     *
     * @return void
     */
    public function setIncludePlugins(bool $include_plugins)
    {
        $this->include_plugins = $include_plugins;

        $this->commands = null; // Reset registered command list to force (un)registration of plugins commands
    }

    /**
     * Get registered commands.
     *
     * @return Command[]
     */
    private function getCommands()
    {
        if ($this->commands === null) {
            $this->findCoreCommands();
            $this->findToolsCommands();

            if ($this->include_plugins) {
                $this->findPluginCommands();
            }
        }

        return $this->commands;
    }

    /**
     * Find all core commands.
     *
     * return void
     */
    private function findCoreCommands()
    {

        $basedir = $this->rootdir . DIRECTORY_SEPARATOR . 'src';

        $core_files = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($basedir),
            RecursiveIteratorIterator::SELF_FIRST
        );
        /** @var SplFileInfo $file */
        foreach ($core_files as $file) {
            if (!$file->isReadable() || !$file->isFile()) {
                continue;
            }

            $class = $this->getCommandClassnameFromFile(
                $file,
                $basedir,
                ['', NS_GLPI]
            );

            if (null === $class) {
                 continue;
            }

            $this->registerCommand(new $class());
        }
    }

    /**
     * Find all plugins (active or not) commands.
     *
     * @return void
     */
    private function findPluginCommands()
    {

        if ($this->plugin === null) {
            $this->plugin = new Plugin();
        }

        $plugins_directories = new AppendIterator();
        foreach (PLUGINS_DIRECTORIES as $directory) {
            $directory = str_replace(GLPI_ROOT, $this->rootdir, $directory);
            $plugins_directories->append(new DirectoryIterator($directory));
        }

        $already_loaded = [];

        /** @var SplFileInfo $plugin_directory */
        foreach ($plugins_directories as $plugin_directory) {
            if (in_array($plugin_directory->getFilename(), ['.', '..'])) {
                continue;
            }

            $plugin_key = $plugin_directory->getFilename();

            if (in_array($plugin_key, $already_loaded)) {
                continue; // Do not load twice commands of plugin that is installed on multiple locations
            }

            if (!$this->plugin->isActivated($plugin_key)) {
                continue; // Do not load commands of disabled plugins
            }

            foreach (['inc', 'src'] as $source_dir) {
                $plugin_basedir = $plugin_directory->getPathname() . DIRECTORY_SEPARATOR . $source_dir;
                if (!is_readable($plugin_basedir) || !is_dir($plugin_basedir)) {
                    continue;
                }

                $plugin_files = new RecursiveIteratorIterator(
                    new RecursiveDirectoryIterator($plugin_basedir),
                    RecursiveIteratorIterator::SELF_FIRST
                );

                /** @var SplFileInfo $file */
                foreach ($plugin_files as $file) {
                    if (!$file->isReadable() || !$file->isFile()) {
                        continue;
                    }

                     // Prefixes can be:
                     // - GlpiPlugin\Myplugin if class is namespaced
                     // - PluginMyplugin if class is not namespaced nor PSR-4 compliant
                     // - empty if class is not namespaced but PSR-4 compliant
                     $class = $this->getCommandClassnameFromFile(
                         $file,
                         $plugin_basedir,
                         [
                             NS_PLUG . ucfirst($plugin_directory->getFilename()) . '\\',
                             'Plugin' . ucfirst($plugin_directory->getFilename()),
                             '',
                         ]
                     );

                    if (null === $class) {
                          continue;
                    }

                     $this->registerCommand(new $class());
                }
            }

            $already_loaded[] = $plugin_key;
        }
    }

    /**
     * Find all "tools" commands.
     *
     * return void
     */
    private function findToolsCommands()
    {

        $basedir = $this->rootdir . DIRECTORY_SEPARATOR . 'tools';

        if (!is_dir($basedir)) {
            return;
        }

        $tools_files = new DirectoryIterator($basedir);
        /** @var SplFileInfo $file */
        foreach ($tools_files as $file) {
            if (!$file->isReadable() || !$file->isFile()) {
                continue;
            }

            $class = $this->getCommandClassnameFromFile(
                $file,
                $basedir
            );

            if (null === $class) {
                continue;
            }

            $this->registerCommand(new $class());
        }
    }

    /**
     * Register a command on self.
     *
     * @param Command $command
     *
     * @return void
     */
    private function registerCommand(Command $command)
    {

        $this->commands[$command->getName()] = $command;

        $aliases = $command->getAliases();
        foreach ($aliases as $alias) {
            $this->commands[$alias] = $command;
        }
    }

    /**
     * Return classname of command contained in file, if file contains one.
     *
     * @param SplFileInfo $file      File to inspect
     * @param string      $basedir   Directory containing classes (eg GLPI_ROOT . '/inc')
     * @param array       $prefixes  Possible prefixes to add to classname (eg 'PluginExample', 'GlpiPlugin\Example')
     *
     * @return null|string
     */
    private function getCommandClassnameFromFile(SplFileInfo $file, $basedir, array $prefixes = [])
    {

       // Check if file is readable
        if (!$file->isReadable() || !$file->isFile()) {
            return null;
        }

       // Check if is a class file and finishes by "command"
        if (
            !preg_match('/^(.*)command\.class\.php$/', $file->getFilename())
            && !preg_match('/^(.*)Command\.php$/', $file->getFilename())
        ) {
            return null;
        }

       // Classname will be lowercased, but it is ok for PHP.
        $classname = str_replace(
            ['.class.php', '.php', DIRECTORY_SEPARATOR],
            ['', '', '\\'],
            $this->getRelativePath($basedir, $file->getPathname())
        );

        if (empty($prefixes)) {
            $prefixes = [''];
        }
        foreach ($prefixes as $prefix) {
            $classname_to_check = $prefix . $classname;

            include_once($file->getPathname()); // Required as ReflectionClass will not use autoload

            if (!class_exists($classname_to_check, false)) {
               // Try with other prefixes.
               // Needed as a file located in root source dir of Glpi can be either namespaced either not.
                continue;
            }

            $reflectionClass = new ReflectionClass($classname_to_check);
            if ($reflectionClass->isInstantiable() && $reflectionClass->isSubclassOf(Command::class)) {
                return $classname_to_check;
            }
        }

        return null;
    }

    /**
     * Returns path relative to basedir.
     *
     * @param string $basedir
     * @param string $filepath
     * @return string
     */
    private function getRelativePath($basedir, $filepath)
    {

       // Strip (multiple) ending directory separator to normalize input
        while (strrpos($basedir, DIRECTORY_SEPARATOR) == strlen($basedir) - 1) {
            $basedir = substr($basedir, 0, -1);
        }

       // Assume that filepath is prefixed by basedir
       // Cannot use realpath to normalize path as it will not work when using a virtual fs (unit tests)
        return str_replace($basedir . DIRECTORY_SEPARATOR, '', $filepath);
    }
}
