<?php
/**
 * Patch testing component for the Joomla! CMS
 *
 * @copyright  Copyright (C) 2011 - 2012 Ian MacLennan, Copyright (C) 2013 - 2018 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later
 */

namespace PatchTester\Model;

use Joomla\CMS\Component\ComponentHelper;
use Joomla\CMS\Factory;
use Joomla\CMS\Filesystem\Path;
use Joomla\CMS\Language\Text;
use Joomla\CMS\Version;
use Joomla\Filesystem\File;
use PatchTester\GitHub\Exception\UnexpectedResponse;
use PatchTester\Helper;

/**
 * Methods supporting pull requests.
 *
 * @since  2.0
 */
class PullModel extends AbstractModel
{
	/**
	 * Array containing top level non-production folders
	 *
	 * @var    array
	 * @since  2.0
	 */
	protected $nonProductionFolders = array(
		'build',
		'docs',
		'installation',
		'tests',
		'.github',
	);

	/**
	 * Array containing non-production files
	 *
	 * @var    array
	 * @since  2.0
	 */
	protected $nonProductionFiles = array(
		'.drone.yml',
		'.gitignore',
		'.php_cs',
		'.travis.yml',
		'README.md',
		'build.xml',
		'composer.json',
		'composer.lock',
		'phpunit.xml.dist',
		'robots.txt.dist',
		'travisci-phpunit.xml',
		'LICENSE',
		'RoboFile.dist.ini',
		'RoboFile.php',
		'codeception.yml',
		'jorobo.dist.ini',
		'manifest.xml',
		'crowdin.yaml',
	);

	/**
	 * Parse the list of modified files from a pull request
	 *
	 * @param   object  $files  The modified files to parse
	 *
	 * @return  array
	 *
	 * @since   3.0.0
	 */
	protected function parseFileList($files)
	{
		$parsedFiles = array();

		/*
		 * Check if the patch tester is running in a development environment
		 * If we are not in development, we'll need to check the exclusion lists
		 */
		$isDev = file_exists(JPATH_INSTALLATION . '/index.php');

		foreach ($files as $file)
		{
			if (!$isDev)
			{
				$filePath = explode('/', $file->filename);

				if (in_array($filePath[0], $this->nonProductionFiles))
				{
					continue;
				}

				if (in_array($filePath[0], $this->nonProductionFolders))
				{
					continue;
				}
			}

			// Sometimes the repo filename is not the production file name
			$prodFileName        = $file->filename;
			$prodRenamedFileName = isset($file->previous_filename) ? $file->previous_filename : false;
			$filePath            = explode('/', $prodFileName);

			// Remove the `src` here to match the CMS paths if needed
			if ($filePath[0] === 'src')
			{
				$prodFileName = str_replace('src/', '', $prodFileName);
			}

			if ($prodRenamedFileName)
			{
				$filePath = explode('/', $prodRenamedFileName);

				// Remove the `src` here to match the CMS paths if needed
				if ($filePath[0] === 'src')
				{
					$prodRenamedFileName = str_replace('src/', '', $prodRenamedFileName);
				}
			}

			$parsedFiles[] = (object) array(
				'action'       => $file->status,
				'filename'     => $prodFileName,
				'repofilename' => $file->filename,
				'fileurl'      => $file->contents_url,
				'originalFile' => $prodRenamedFileName,
			);
		}

		return $parsedFiles;
	}

	/**
	 * Patches the code with the supplied pull request
	 * However uses different methods for different repositories.
	 *
	 * @param   integer  $id  ID of the pull request to apply
	 *
	 * @return  boolean
	 *
	 * @since   3.0
	 *
	 * @throws  \RuntimeException
	 */
	public function apply($id)
	{
		$params = ComponentHelper::getParams('com_patchtester');

		// Decide based on repository settings whether patch will be applied through Github or CIServer
		if ($params->get('repo', 'joomla-cms') === 'joomla-cms'
			&& $params->get('org', 'joomla') === 'joomla')
		{
			return $this->applyWithCIServer($id);
		}
		else
		{
			return $this->applyWithGitHub($id);
		}
	}

	/**
	 * Patches the code with the supplied pull request
	 *
	 * @param   integer  $id  ID of the pull request to apply
	 *
	 * @return  boolean
	 *
	 * @since   3.0
	 *
	 * @throws  \RuntimeException
	 */
	public function applyWithCIServer($id)
	{
		// Get the CIServer Registry
		$ciSettings = Helper::initializeCISettings();

		// Create tmp folder if it does not exist
		if (!file_exists($ciSettings->get('folder.temp')))
		{
			mkdir($ciSettings->get('folder.temp'));
		}

		$tempPath    = $ciSettings->get('folder.temp') . "/$id";
		$backupsPath = $ciSettings->get('folder.backups') . "/$id";
		$zipPath     = $tempPath . '/' . $ciSettings->get('zip.name');
		$serverPath  = sprintf($ciSettings->get('zip.url'), $id);

		// Patch has already been applied
		if (file_exists($backupsPath))
		{
			return false;
		}

		// Check if zip folder exists on server
		$serverHeaders = @get_headers($serverPath);

		if (!$serverHeaders || $serverHeaders[0] != 'HTTP/1.1 200 OK')
		{
			throw new \RuntimeException(Text::_('File does not exist on Server'));
		}

		mkdir($tempPath);
		file_put_contents($zipPath, fopen($serverPath, "r"));

		// Check if zip folder could have been downloaded
		if (!file_exists($zipPath))
		{
			$this->rmDir($tempPath);
			throw new \RuntimeException(Text::_('Zip has not been created'));
		}

		$zip = new \ZipArchive;
		$zip->open($zipPath);

		// Check if zip contains files
		if ($zip->numFiles === 0)
		{
			$zip->close();
			$this->rmDir($tempPath);
			throw new \RuntimeException(Text::_('Zip is empty'));
		}

		$zip->extractTo($tempPath);
		$zip->close();
		unlink($zipPath);

		// Get a list of files from folder and deleted.log
		$files = $this->getListOfFiles($tempPath);

		// ToDo add deleted files to fileList

		mkdir($backupsPath);

		// Moves existent files to backup and replace them or creates new one if they don't exist
		foreach ($files as $file)
		{
			$filePath = explode("/", $file);
			array_pop($filePath);
			$filePath = implode("/", $filePath);

			if (file_exists(JPATH_ROOT . "/$file"))
			{
				// Create directories if they don't exist until file
				if (!file_exists("$backupsPath/$filePath"))
				{
					mkdir("$backupsPath/$filePath",null, true);
				}

				rename(JPATH_ROOT . "/$file", "$backupsPath/$file");
			}
			// Create directories if they don't exist until file
			if (!file_exists(JPATH_ROOT . "/$filePath"))
			{
				mkdir(JPATH_ROOT . "/$filePath",null, true);
			}

			copy("$tempPath/$file", JPATH_ROOT . "/$file");
		}

		// Clear temp folder and store applied patch in database
		$this->rmDir($tempPath);

		$this->saveAppliedPatch($id, $files);

		// Change the media version
		$version = new Version;
		$version->refreshMediaVersion();

		return true;
	}

	/**
	 * Returns an array containing fileNames as string for a given $dir
	 *
	 * @param   string  $dir     directory to scan
	 * @param   array   $files   array with fileNames
	 * @param   string  $parent  parent directory
	 *
	 * @return  array    fileNames
	 *
	 * @since   3.0
	 */
	private function getListOfFiles($dir, $files = [], $parent = null)
	{
		if (is_dir($dir))
		{
			// Remove dot files/folders
			$temp = preg_grep("/^([^.])/", scandir($dir));

			foreach ($temp as $key => $file)
			{
				if (is_dir($dir . '/' . $file))
				{
					unset($temp[$key]);
					$files = $this->getListOfFiles($dir . '/' . $file, $files,
						(is_null($parent) ? $file : $parent . '/' . $file));
				}

				if (!is_null($parent) && !is_dir($dir . '/' . $file))
				{
					$temp[$key] = $parent . '/' . $file;
				}
			}

			$files = array_merge($files, $temp);

			return $files;
		}
		else
		{
			return [];
		}
	}

	/**
	 * Removes directory and its content recursively
	 *
	 * @param   string  $dir  directory to delete
	 *
	 * @return  void
	 *
	 * @since   3.0
	 */
	private function rmDir($dir)
	{
		if (is_dir($dir))
		{
			$files = scandir($dir);

			foreach ($files as $file)
			{
				if ($file != "." && $file != "..")
				{
					if (is_dir($dir . "/" . $file))
					{
						$this->rmDir($dir . "/" . $file);
					}
					else
					{
						unlink($dir . "/" . $file);
					}
				}
			}

			rmdir($dir);
		}
	}

	/**
	 * Patches the code with the supplied pull request
	 *
	 * @param   integer  $id  ID of the pull request to apply
	 *
	 * @return  boolean
	 *
	 * @since   2.0
	 *
	 * @throws  \RuntimeException
	 */
	public function applyWithGitHub($id)
	{
		// Get the Github object
		$github = Helper::initializeGithub();

		try
		{
			$rateResponse = $github->getRateLimit();
			$rate         = json_decode($rateResponse->body);
		}
		catch (UnexpectedResponse $e)
		{
			throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_COULD_NOT_CONNECT_TO_GITHUB', $e->getMessage()), $e->getCode(), $e);
		}

		// If over the API limit, we can't build this list
		if ($rate->resources->core->remaining == 0)
		{
			throw new \RuntimeException(
				Text::sprintf('COM_PATCHTESTER_API_LIMIT_LIST', Factory::getDate($rate->resources->core->reset))
			);
		}

		try
		{
			$pullResponse = $github->getPullRequest($this->getState()->get('github_user'), $this->getState()->get('github_repo'), $id);
			$pull         = json_decode($pullResponse->body);
		}
		catch (UnexpectedResponse $e)
		{
			throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_COULD_NOT_CONNECT_TO_GITHUB', $e->getMessage()), $e->getCode(), $e);
		}

		if (is_null($pull->head->repo))
		{
			throw new \RuntimeException(Text::_('COM_PATCHTESTER_REPO_IS_GONE'));
		}

		try
		{
			$filesResponse = $github->getFilesForPullRequest($this->getState()->get('github_user'), $this->getState()->get('github_repo'), $id);
			$files         = json_decode($filesResponse->body);
		}
		catch (UnexpectedResponse $e)
		{
			throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_COULD_NOT_CONNECT_TO_GITHUB', $e->getMessage()), $e->getCode(), $e);
		}

		if (!count($files))
		{
			return false;
		}

		$parsedFiles = $this->parseFileList($files);

		foreach ($parsedFiles as $file)
		{
			switch ($file->action)
			{
				case 'deleted':
					if (!file_exists(JPATH_ROOT . '/' . $file->filename))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_FILE_DELETED_DOES_NOT_EXIST_S', $file->filename));
					}

					break;

				case 'added':
				case 'modified':
				case 'renamed':
					// If the backup file already exists, we can't apply the patch
					if (file_exists(JPATH_COMPONENT . '/backups/' . md5($file->filename) . '.txt'))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_CONFLICT_S', $file->filename));
					}

					if ($file->action == 'modified' && !file_exists(JPATH_ROOT . '/' . $file->filename))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_FILE_MODIFIED_DOES_NOT_EXIST_S', $file->filename));
					}

					try
					{
						$contentsResponse = $github->getFileContents(
							$pull->head->user->login, $this->getState()->get('github_repo'), $file->repofilename, urlencode($pull->head->ref)
						);

						$contents = json_decode($contentsResponse->body);

						// In case encoding type ever changes
						switch ($contents->encoding)
						{
							case 'base64':
								$file->body = base64_decode($contents->content);

								break;

							default:
								throw new \RuntimeException(Text::_('COM_PATCHTESTER_ERROR_UNSUPPORTED_ENCODING'));
						}
					}
					catch (UnexpectedResponse $e)
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_COULD_NOT_CONNECT_TO_GITHUB', $e->getMessage()), $e->getCode(), $e);
					}

					break;
			}
		}

		// At this point, we have ensured that we have all the new files and there are no conflicts
		foreach ($parsedFiles as $file)
		{
			// We only create a backup if the file already exists
			if ($file->action == 'deleted' || (file_exists(JPATH_ROOT . '/' . $file->filename) && $file->action == 'modified')
				|| (file_exists(JPATH_ROOT . '/' . $file->originalFile) && $file->action == 'renamed'))
			{
				$filename = $file->action == 'renamed' ? $file->originalFile : $file->filename;
				$src      = JPATH_ROOT . '/' . $filename;
				$dest     = JPATH_COMPONENT . '/backups/' . md5($filename) . '.txt';

				if (!File::copy(Path::clean($src), $dest))
				{
					throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_COPY_FILE', $src, $dest));
				}
			}

			switch ($file->action)
			{
				case 'modified':
				case 'added':
					if (!File::write(Path::clean(JPATH_ROOT . '/' . $file->filename), $file->body))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_WRITE_FILE', JPATH_ROOT . '/' . $file->filename));
					}

					break;

				case 'deleted':
					if (!File::delete(Path::clean(JPATH_ROOT . '/' . $file->filename)))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', JPATH_ROOT . '/' . $file->filename));
					}

					break;

				case 'renamed':
					if (!File::delete(Path::clean(JPATH_ROOT . '/' . $file->originalFile)))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', JPATH_ROOT . '/' . $file->originalFile));
					}

					if (!File::write(Path::clean(JPATH_ROOT . '/' . $file->filename), $file->body))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_WRITE_FILE', JPATH_ROOT . '/' . $file->filename));
					}

					break;
			}

			// We don't need the file's body any longer (and it causes issues with binary data when json_encode() is run), so remove it
			unset($file->body);
		}

		$this->saveAppliedPatch($pull->number, $parsedFiles, $pull->head->sha);

		// Change the media version
		$version = new Version;
		$version->refreshMediaVersion();

		return true;
	}

	/**
	 * Saves the applied patch into database
	 *
	 * @param   integer  $id        ID of the applied pull request
	 * @param   array    $fileList  List of files
	 * @param   string   $sha       sha-key from pull request
	 *
	 * @return  void
	 *
	 * @since   3.0
	 */
	public function saveAppliedPatch($id, $fileList, $sha = null)
	{
		$record = (object) array(
			'pull_id'         => $id,
			'data'            => json_encode($fileList),
			'patched_by'      => Factory::getUser()->id,
			'applied'         => 1,
			'applied_version' => JVERSION,
		);

		$db = $this->getDb();

		$db->insertObject('#__patchtester_tests', $record);

		if (!is_null($sha))
		{
			// Insert the retrieved commit SHA into the pulls table for this item
			$db->setQuery(
				$db->getQuery(true)
					->update('#__patchtester_pulls')
					->set('sha = ' . $db->quote($sha))
					->where($db->quoteName('pull_id') . ' = ' . (int) $id)
			)->execute();
		}
	}

	/**
	 * Reverts the specified pull request
	 * However uses different methods for different repositories.
	 *
	 * @param   integer  $id  ID of the pull request to revert
	 *
	 * @return  boolean
	 *
	 * @since   3.0
	 * @throws  \RuntimeException
	 */
	public function revert($id)
	{
		$params = ComponentHelper::getParams('com_patchtester');

		// Decide based on repository settings whether patch will be applied through Github or CIServer
		if ($params->get('repo', 'joomla-cms') === 'joomla-cms'
			&& $params->get('org', 'joomla') === 'joomla')
		{
			return $this->revertWithCIServer($id);
		}
		else
		{
			return $this->revertWithGitHub($id);
		}
	}

	/**
	 * Reverts the specified pull request with CIServer options
	 *
	 * @param   integer  $id  ID of the pull request to revert
	 *
	 * @return  boolean
	 *
	 * @since   3.0
	 * @throws  \RuntimeException
	 */
	public function revertWithCIServer($id)
	{
		// Get the CIServer Registry
		$ciSettings = Helper::initializeCISettings();

		$testRecord = $this->getTestRecord($id);

		// We don't want to restore files from an older version
		if ($testRecord->applied_version != JVERSION)
		{
			return $this->removeTest($testRecord);
		}

		$files = json_decode($testRecord->data);

		if (!$files)
		{
			throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_READING_DATABASE_TABLE', __METHOD__, htmlentities($testRecord->data)));
		}

		$backupsPath = $ciSettings->get('folder.backups') . "/$testRecord->pull_id";

		foreach ($files as $file)
		{
			// Delete file from root of it exists
			if (file_Exists(JPATH_ROOT . "/$file"))
			{
				unlink(JPATH_ROOT . "/$file");

				// Move from backup, if it exists there
				if (file_exists("$backupsPath/$file"))
				{
					rename("$backupsPath/$file", JPATH_ROOT . "/$file");
				}
			}
			// Move from backup, if file exists there - got deleted by patch
			elseif (file_exists("$backupsPath/$file"))
			{
				rename("$backupsPath/$file", JPATH_ROOT . "/$file");
			}
		}

		$this->rmDir($backupsPath);

		// Change the media version
		$version = new Version;
		$version->refreshMediaVersion();

		return $this->removeTest($testRecord);
	}

	/**
	 * Reverts the specified pull request with Github Requests
	 *
	 * @param   integer  $id  ID of the pull request to revert
	 *
	 * @return  boolean
	 *
	 * @since   2.0
	 * @throws  \RuntimeException
	 */
	public function revertWithGitHub($id)
	{
		$testRecord = $this->getTestRecord($id);

		// We don't want to restore files from an older version
		if ($testRecord->applied_version != JVERSION)
		{
			return $this->removeTest($testRecord);
		}

		$files = json_decode($testRecord->data);

		if (!$files)
		{
			throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_READING_DATABASE_TABLE', __METHOD__, htmlentities($testRecord->data)));
		}

		foreach ($files as $file)
		{
			switch ($file->action)
			{
				case 'deleted':
				case 'modified':
					$src  = JPATH_COMPONENT . '/backups/' . md5($file->filename) . '.txt';
					$dest = JPATH_ROOT . '/' . $file->filename;

					if (!File::copy($src, $dest))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_COPY_FILE', $src, $dest));
					}

					if (file_exists($src))
					{
						if (!File::delete($src))
						{
							throw new \RuntimeException(
								Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', $src)
							);
						}
					}

					break;

				case 'added':
					$src = JPATH_ROOT . '/' . $file->filename;

					if (file_exists($src))
					{
						if (!File::delete($src))
						{
							throw new \RuntimeException(
								Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', $src)
							);
						}
					}

					break;

				case 'renamed':
					$originalSrc = JPATH_COMPONENT . '/backups/' . md5($file->originalFile) . '.txt';
					$newSrc      = JPATH_ROOT . '/' . $file->filename;
					$dest        = JPATH_ROOT . '/' . $file->originalFile;

					if (!File::copy($originalSrc, $dest))
					{
						throw new \RuntimeException(Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_COPY_FILE', $originalSrc, $dest));
					}

					if (file_exists($originalSrc))
					{
						if (!File::delete($originalSrc))
						{
							throw new \RuntimeException(
								Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', $originalSrc)
							);
						}
					}

					if (file_exists($newSrc))
					{
						if (!File::delete($newSrc))
						{
							throw new \RuntimeException(
								Text::sprintf('COM_PATCHTESTER_ERROR_CANNOT_DELETE_FILE', $newSrc)
							);
						}
					}

					break;
			}
		}

		// Change the media version
		$version = new Version;
		$version->refreshMediaVersion();

		return $this->removeTest($testRecord);
	}

	/**
	 * Remove the database record for a test
	 *
	 * @param   stdClass  $testRecord  The record being deleted
	 *
	 * @return  boolean
	 *
	 * @since   3.0.0
	 */
	private function removeTest($testRecord)
	{
		$db = $this->getDb();

		// Remove the retrieved commit SHA from the pulls table for this item
		$db->setQuery(
			$db->getQuery(true)
				->update('#__patchtester_pulls')
				->set('sha = ' . $db->quote(''))
				->where($db->quoteName('pull_id') . ' = ' . (int) $testRecord->pull_id)
		)->execute();

		// And delete the record from the tests table
		$db->setQuery(
			$db->getQuery(true)
				->delete('#__patchtester_tests')
				->where('id = ' . (int) $testRecord->id)
		)->execute();

		return true;
	}

	/**
	 * Retrieves test data from database by specific id
	 *
	 * @param   integer  $id  ID of the record
	 *
	 * @return  stdClass $testRecord  The record looking for
	 *
	 * @since   3.0.0
	 */
	private function getTestRecord($id)
	{
		$db = $this->getDb();

		return $db->setQuery(
			$db->getQuery(true)
				->select('*')
				->from('#__patchtester_tests')
				->where('id = ' . (int) $id)
		)->loadObject();
	}
}