<?php
/**
 * Copyright © 2015 Geoffrey Mon <geofbot@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
 */

/**
 * API Module to merge page histories
 * @ingroup API
 */
class ApiMergeHistory extends ApiBase {

	public function execute() {
		$this->useTransactionalTimeLimit();

		$params = $this->extractRequestParams();

		$this->requireOnlyOneParameter( $params, 'from', 'fromid' );
		$this->requireOnlyOneParameter( $params, 'to', 'toid' );

		// Get page objects (nonexistant pages get caught in MergeHistory::isValidMerge())
		if ( isset( $params['from'] ) ) {
			$fromTitle = Title::newFromText( $params['from'] );
			if ( !$fromTitle || $fromTitle->isExternal() ) {
				$this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $params['from'] ) ] );
			}
		} elseif ( isset( $params['fromid'] ) ) {
			$fromTitle = Title::newFromID( $params['fromid'] );
			if ( !$fromTitle ) {
				$this->dieWithError( [ 'apierror-nosuchpageid', $params['fromid'] ] );
			}
		}

		if ( isset( $params['to'] ) ) {
			$toTitle = Title::newFromText( $params['to'] );
			if ( !$toTitle || $toTitle->isExternal() ) {
				$this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $params['to'] ) ] );
			}
		} elseif ( isset( $params['toid'] ) ) {
			$toTitle = Title::newFromID( $params['toid'] );
			if ( !$toTitle ) {
				$this->dieWithError( [ 'apierror-nosuchpageid', $params['toid'] ] );
			}
		}

		$reason = $params['reason'];
		$timestamp = $params['timestamp'];

		// Merge!
		$status = $this->merge( $fromTitle, $toTitle, $timestamp, $reason );
		if ( !$status->isOK() ) {
			$this->dieStatus( $status );
		}

		$r = [
			'from' => $fromTitle->getPrefixedText(),
			'to' => $toTitle->getPrefixedText(),
			'timestamp' => wfTimestamp( TS_ISO_8601, $params['timestamp'] ),
			'reason' => $params['reason']
		];
		$result = $this->getResult();

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

	/**
	 * @param Title $from
	 * @param Title $to
	 * @param string $timestamp
	 * @param string $reason
	 * @return Status
	 */
	protected function merge( Title $from, Title $to, $timestamp, $reason ) {
		$mh = new MergeHistory( $from, $to, $timestamp );

		return $mh->merge( $this->getUser(), $reason );
	}

	public function mustBePosted() {
		return true;
	}

	public function isWriteMode() {
		return true;
	}

	public function getAllowedParams() {
		return [
			'from' => null,
			'fromid' => [
				ApiBase::PARAM_TYPE => 'integer'
			],
			'to' => null,
			'toid' => [
				ApiBase::PARAM_TYPE => 'integer'
			],
			'timestamp' => [
				ApiBase::PARAM_TYPE => 'timestamp'
			],
			'reason' => '',
		];
	}

	public function needsToken() {
		return 'csrf';
	}

	protected function getExamplesMessages() {
		return [
			'action=mergehistory&from=Oldpage&to=Newpage&token=123ABC&' .
			'reason=Reason'
			=> 'apihelp-mergehistory-example-merge',
			'action=mergehistory&from=Oldpage&to=Newpage&token=123ABC&' .
			'reason=Reason&timestamp=2015-12-31T04%3A37%3A41Z' // TODO
			=> 'apihelp-mergehistory-example-merge-timestamp',
		];
	}

	public function getHelpUrls() {
		return 'https://www.mediawiki.org/wiki/Special:MyLanguage/API:Mergehistory';
	}
}