<?php
/**
 * @package    Joomla.Component.Builder
 *
 * @created    4th September, 2022
 * @author     Llewellyn van der Merwe <https://dev.vdm.io>
 * @git        Joomla Component Builder <https://git.vdm.dev/joomla/Component-Builder>
 * @copyright  Copyright (C) 2015 Vast Development Method. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace VDM\Joomla\Componentbuilder\Power;


use Joomla\CMS\Factory;
use Joomla\CMS\Filesystem\Folder;
use Joomla\CMS\Application\CMSApplication;
use Joomla\CMS\Language\Text;
use VDM\Joomla\Gitea\Repository\Contents;
use VDM\Joomla\Utilities\FileHelper;
use VDM\Joomla\Utilities\JsonHelper;


/**
 * Global Resource Empowerment Platform
 * 
 *    The Grep feature will try to find your power in the repositories listed in the global
 *    Options of JCB in the super powers tab, and if it can't be found there will try the global core
 *    Super powers of JCB. All searches are performed according the the [algorithm:cascading]
 *    See documentation for more details: https://git.vdm.dev/joomla/super-powers/wiki
 * 
 * @since 3.2.0
 */
final class Grep
{
	/**
	 * The local path
	 *
	 * @var    string
	 * @since 3.2.0
	 **/
	public ?string $path;

	/**
	 * All approved paths
	 *
	 * @var    array
	 * @since 3.2.0
	 **/
	public ?array $paths;

	/**
	 * Gitea Repository Contents
	 *
	 * @var    Contents
	 * @since 3.2.0
	 **/
	protected Contents $contents;

	/**
	 * Joomla Application object
	 *
	 * @var    CMSApplication
	 * @since 3.2.0
	 **/
	protected CMSApplication $app;

	/**
	 * Constructor.
	 *
	 * @param string                 $path      The local path
	 * @param array                  $paths     The approved paths
	 * @param Contents               $contents  The Gitea Repository Contents object.
	 * @param CMSApplication|null    $app       The CMS Application object.
	 *
	 * @throws \Exception
	 * @since 3.2.0
	 */
	public function __construct(string $path, array $paths, Contents $contents, ?CMSApplication $app = null)
	{
		$this->path = $path;
		$this->paths = $paths;
		$this->contents = $contents;
		$this->app = $app ?: Factory::getApplication();

		$this->init();
	}

	/**
	 * Get all remote powers GUID's
	 *
	 * @return array|null
	 * @since 3.2.0
	 */
	public function getRemotePowersGuid(): ?array
	{
		if (!is_array($this->paths) || $this->paths === [])
		{
			return null;
		}

		$powers = [];
		foreach ($this->paths as $path)
		{
			// Get local index
			$this->remoteIndex($path);

			if (isset($path->index) && is_object($path->index))
			{
				$powers = array_merge($powers, array_keys((array) $path->index));
			}
		}

		return empty($powers) ? null : array_unique($powers);
	}

	/**
	 * Get a power
	 *
	 * @param string   $guid    The global unique id of the power
	 * @param array    $order   The search order
	 *
	 * @return object|null
	 * @since 3.2.0
	 */
	public function get(string $guid, array $order = ['local', 'remote']): ?object
	{
		// we can only search if we have paths
		if (is_array($this->paths) && $this->paths !== [])
		{
			foreach ($order as $target)
			{
				if (($function_name = $this->getFunctionName($target)) !== null &&
					($power = $this->{$function_name}($guid)) !== null)
				{
					return $power;
				}
			}
		}

		return null;
	}

	/**
	 * Search for a local power
	 *
	 * @param string    $guid    The global unique id of the power
	 *
	 * @return object|null
	 * @since 3.2.0
	 */
	private function searchLocal(string $guid): ?object
	{
		// we can only search if we have paths
		if ($this->path && $this->paths)
		{
			foreach ($this->paths as $path)
			{
				// get local index
				$this->localIndex($path);

				if (!empty($path->local) && isset($path->local->{$guid}))
				{
					return $this->getLocal($path, $guid);
				}
			}
		}

		return null;
	}

	/**
	 * Search for a remote power
	 *
	 * @param string    $guid    The global unique id of the power
	 *
	 * @return object|null
	 * @since 3.2.0
	 */
	private function searchRemote(string $guid): ?object
	{
		// we can only search if we have paths
		if ($this->path && $this->paths)
		{
			foreach ($this->paths as $path)
			{
				// get local index
				$this->remoteIndex($path);

				if (!empty($path->index) && isset($path->index->{$guid}))
				{
					return $this->getRemote($path, $guid);
				}
			}
		}

		return null;
	}

	/**
	 * Get a local power
	 *
	 * @param object    $path    The repository path details
	 * @param string    $guid    The global unique id of the power
	 *
	 * @return object|null
	 * @since 3.2.0
	 */
	private function getLocal(object $path, string $guid): ?object
	{
		if (empty($path->local->{$guid}->settings) || empty($path->local->{$guid}->code))
		{
			return null;
		}

		// get the settings
		if (($settings = FileHelper::getContent($path->full_path . '/' . $path->local->{$guid}->settings, null)) !== null &&
			JsonHelper::check($settings))
		{
			$power = json_decode($settings);

			// get the code
			if (($code = FileHelper::getContent($path->full_path . '/' . $path->local->{$guid}->power, null)) !== null)
			{
				$power->main_class_code = $code;
				return $power;
			}
		}

		return null;
	}

	/**
	 * Get a remote power
	 *
	 * @param object    $path    The repository path details
	 * @param string    $guid    The global unique id of the power
	 *
	 * @return object|null
	 * @since 3.2.0
	 */
	private function getRemote(object $path, string $guid): ?object
	{
		if (empty($path->index->{$guid}->settings) || empty($path->index->{$guid}->code))
		{
			return null;
		}

		// get the settings
		if (($power = $this->loadRemoteFile($path->owner, $path->repo, $path->index->{$guid}->settings, $path->branch)) !== null &&
			isset($power->guid))
		{
			// get the code
			if (($code = $this->loadRemoteFile($path->owner, $path->repo, $path->index->{$guid}->power, $path->branch)) !== null)
			{
				$power->main_class_code = $code;
				return $power;
			}
		}

		return null;
	}

	/**
	 * Set path details
	 *
	 * @return void
	 * @since 3.2.0
	 */
	private function init()
	{
		if (is_array($this->paths) && $this->paths !== [])
		{
			foreach ($this->paths as $n => &$path)
			{
				if (isset($path->owner) && strlen($path->owner) > 1 &&
						isset($path->repo) && strlen($path->repo) > 1)
				{
					// build the path
					$path->path = trim($path->owner) . '/' . trim($path->repo);

					// update the branch
					if ($path->branch === 'default' || empty($path->branch))
					{
						$path->branch = null;
					}

					// set local path
					if ($this->path && Folder::exists($this->path . '/' . $path->path))
					{
						$path->full_path = $this->path . '/' . $path->path;
					}
				}
				else
				{
					unset($this->paths[$n]);
				}
			}
		}
	}

	/**
	 * Load the local repository index of powers
	 *
	 * @param object    $path    The repository path details
	 *
	 * @return void
	 * @since 3.2.0
	 */
	private function localIndex(object &$path)
	{
		if (isset($path->local) || !isset($path->full_path))
		{
			return;
		}

		if (($content = FileHelper::getContent($path->full_path . '/super-powers.json', null)) !== null &&
			JsonHelper::check($content))
		{
			$path->local = json_decode($content);

			return;
		}

		$path->local = null;
	}

	/**
	 * Load the remote repository index of powers
	 *
	 * @param object    $path    The repository path details
	 *
	 * @return void
	 * @since 3.2.0
	 */
	private function remoteIndex(object &$path)
	{
		if (isset($path->index))
		{
			return;
		}

		try
		{
			$path->index = $this->contents->get($path->owner, $path->repo, 'super-powers.json', $path->branch);
		}
		catch (\Exception $e)
		{
			$this->app->enqueueMessage(
				Text::sprintf('COM_COMPONENTBUILDER_PSUPER_POWERB_REPOSITORY_AT_BSSB_GAVE_THE_FOLLOWING_ERRORBR_SP', $this->contents->api(), $path->path, $e->getMessage()),
				'Error'
			);

			$path->index = null;
		}
	}

	/**
	 * Load the remote file
	 *
	 * @param string         $owner    The repository owner
	 * @param string         $repo     The repository name
	 * @param string         $path     The repository path to file
	 * @param string|null    $branch   The repository branch name
	 *
	 * @return mixed
	 * @since 3.2.0
	 */
	private function loadRemoteFile(string $owner, string $repo, string $path, ?string $branch)
	{
		try
		{
			$data = $this->contents->get($owner, $repo, $path, $branch);
		}
		catch (\Exception $e)
		{
			$this->app->enqueueMessage(
				Text::sprintf('COM_COMPONENTBUILDER_PFILE_AT_BSSB_GAVE_THE_FOLLOWING_ERRORBR_SP', $this->contents->api(), $path, $e->getMessage()),
				'Error'
			);

			return null;
		}

		return $data;
	}

	/**
	 * Get function name
	 *
	 * @param string     $name The targeted function name
	 *
	 * @return string|null
	 * @since 3.2.0
	 */
	private function getFunctionName(string $name): ?string
	{
		$function_name = 'search' . ucfirst(strtolower($name));

		return method_exists($this, $function_name) ? $function_name : null;
	}
}