<?php
/**
 *
 *
 * Created on March 5, 2011
 *
 * Copyright © 2011 Bryan Tong Minh <Bryan.TongMinh@Gmail.com>
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * @ingroup API
 */
class ApiFileRevert extends ApiBase {
	/** @var LocalFile */
	protected $file;

	/** @var string */
	protected $archiveName;

	/** @var array */
	protected $params;

	public function execute() {
		$this->params = $this->extractRequestParams();
		// Extract the file and archiveName from the request parameters
		$this->validateParameters();

		// Check whether we're allowed to revert this file
		$this->checkPermissions( $this->getUser() );

		$sourceUrl = $this->file->getArchiveVirtualUrl( $this->archiveName );
		$status = $this->file->upload(
			$sourceUrl,
			$this->params['comment'],
			$this->params['comment'],
			0,
			false,
			false,
			$this->getUser()
		);

		if ( $status->isGood() ) {
			$result = array( 'result' => 'Success' );
		} else {
			$result = array(
				'result' => 'Failure',
				'errors' => $this->getResult()->convertStatusToArray( $status ),
			);
		}

		$this->getResult()->addValue( null, $this->getModuleName(), $result );
	}

	/**
	 * Checks that the user has permissions to perform this revert.
	 * Dies with usage message on inadequate permissions.
	 * @param $user User The user to check.
	 */
	protected function checkPermissions( $user ) {
		$title = $this->file->getTitle();
		$permissionErrors = array_merge(
			$title->getUserPermissionsErrors( 'edit', $user ),
			$title->getUserPermissionsErrors( 'upload', $user )
		);

		if ( $permissionErrors ) {
			$this->dieUsageMsg( $permissionErrors[0] );
		}
	}

	/**
	 * Validate the user parameters and set $this->archiveName and $this->file.
	 * Throws an error if validation fails
	 */
	protected function validateParameters() {
		// Validate the input title
		$title = Title::makeTitleSafe( NS_FILE, $this->params['filename'] );
		if ( is_null( $title ) ) {
			$this->dieUsageMsg( array( 'invalidtitle', $this->params['filename'] ) );
		}
		$localRepo = RepoGroup::singleton()->getLocalRepo();

		// Check if the file really exists
		$this->file = $localRepo->newFile( $title );
		if ( !$this->file->exists() ) {
			$this->dieUsageMsg( 'notanarticle' );
		}

		// Check if the archivename is valid for this file
		$this->archiveName = $this->params['archivename'];
		$oldFile = $localRepo->newFromArchiveName( $title, $this->archiveName );
		if ( !$oldFile->exists() ) {
			$this->dieUsageMsg( 'filerevert-badversion' );
		}
	}

	public function mustBePosted() {
		return true;
	}

	public function isWriteMode() {
		return true;
	}

	public function getAllowedParams() {
		return array(
			'filename' => array(
				ApiBase::PARAM_TYPE => 'string',
				ApiBase::PARAM_REQUIRED => true,
			),
			'comment' => array(
				ApiBase::PARAM_DFLT => '',
			),
			'archivename' => array(
				ApiBase::PARAM_TYPE => 'string',
				ApiBase::PARAM_REQUIRED => true,
			),
			'token' => array(
				ApiBase::PARAM_TYPE => 'string',
				ApiBase::PARAM_REQUIRED => true
			),
		);
	}

	public function getParamDescription() {
		return array(
			'filename' => 'Target filename without the File: prefix',
			'token' => 'Edit token. You can get one of these through prop=info',
			'comment' => 'Upload comment',
			'archivename' => 'Archive name of the revision to revert to',
		);
	}

	public function getResultProperties() {
		return array(
			'' => array(
				'result' => array(
					ApiBase::PROP_TYPE => array(
						'Success',
						'Failure'
					)
				),
				'errors' => array(
					ApiBase::PROP_TYPE => 'string',
					ApiBase::PROP_NULLABLE => true
				)
			)
		);
	}

	public function getDescription() {
		return array(
			'Revert a file to an old version.'
		);
	}

	public function getPossibleErrors() {
		return array_merge( parent::getPossibleErrors(),
			array(
				array( 'mustbeloggedin', 'upload' ),
				array( 'badaccess-groups' ),
				array( 'invalidtitle', 'title' ),
				array( 'notanarticle' ),
				array( 'filerevert-badversion' ),
			)
		);
	}

	public function needsToken() {
		return true;
	}

	public function getTokenSalt() {
		return '';
	}

	public function getExamples() {
		return array(
			'api.php?action=filerevert&filename=Wiki.png&comment=Revert&' .
				'archivename=20110305152740!Wiki.png&token=123ABC'
				=> 'Revert Wiki.png to the version of 20110305152740',
		);
	}
}
