<?php
/**
 * Copyright (C) 2011-2020 Wikimedia Foundation and others.
 *
 * 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.
 */

namespace MWParsoid\Config;

use ContentHandler;
use File;
use Hooks;
use LinkBatch;
use Linker;
use MediaTransformError;
use MediaWiki\MediaWikiServices;
use MediaWiki\Revision\RevisionStore;
use PageProps;
use Parser;
use ParserOptions;
use Title;
use Wikimedia\Parsoid\Config\DataAccess as IDataAccess;
use Wikimedia\Parsoid\Config\PageConfig as IPageConfig;
use Wikimedia\Parsoid\Config\PageContent as IPageContent;

class DataAccess implements IDataAccess {

	/** @var RevisionStore */
	private $revStore;

	/** @var Parser */
	private $parser;

	/** @var ParserOptions */
	private $parserOptions;

	/** @var IPageConfig|null */
	private $previousPageConfig;

	/**
	 * @param RevisionStore $revStore
	 * @param Parser $parser
	 * @param ParserOptions $parserOptions
	 */
	public function __construct(
		RevisionStore $revStore, Parser $parser, ParserOptions $parserOptions
	) {
		$this->revStore = $revStore;
		$this->parser = $parser;
		$this->parserOptions = $parserOptions;

		// Turn off some options since Parsoid/JS currently doesn't
		// do anything with this. As we proceed with closer integration,
		// we can figure out if there is any value to these limit reports.
		$this->parserOptions->setOption( 'enableLimitReport', false );
	}

	/**
	 * @param File $file
	 * @param array $hp
	 * @return array
	 */
	private function makeTransformOptions( $file, array $hp ): array {
		// Validate the input parameters like Parser::makeImage()
		$handler = $file->getHandler();
		if ( !$handler ) {
			return []; // will get iconThumb()
		}
		foreach ( $hp as $name => $value ) {
			if ( !$handler->validateParam( $name, $value ) ) {
				unset( $hp[$name] );
			}
		}

		// This part is similar to Linker::makeImageLink(). If there is no width,
		// set one based on the source file size.
		$page = $hp['page'] ?? 1;
		if ( !isset( $hp['width'] ) ) {
			if ( isset( $hp['height'] ) && $file->isVectorized() ) {
				// If it's a vector image, and user only specifies height
				// we don't want it to be limited by its "normal" width.
				global $wgSVGMaxSize;
				$hp['width'] = $wgSVGMaxSize;
			} else {
				$hp['width'] = $file->getWidth( $page );
			}

			// We don't need to fill in a default thumbnail width here, since
			// that is done by Parsoid. Parsoid always sets the width parameter
			// for thumbnails.
		}

		return $hp;
	}

	/** @inheritDoc */
	public function getPageInfo( IPageConfig $pageConfig, array $titles ): array {
		$titleObjs = [];
		$ret = [];
		foreach ( $titles as $name ) {
			$t = Title::newFromText( $name );
			// Filter out invalid titles. Title::newFromText in core (not our bespoke
			// version in src/Utils/Title.php) can return null for invalid titles.
			if ( !$t ) {
				// FIXME: This is a bandaid to patch up the fact that Env::makeTitle treats
				// this as a valid title, but Title::newFromText treats it as invalid.
				// T237535
				// This matches what ApiQuery::outputGeneralPageInfo() would
				// return for an invalid title.
				$ret[$name] = [
					'pageId' => -1,
					'revId' => -1,
					'invalid' => true,
					'invalidreason' => 'The requested page title is invalid',
				];
			} else {
				$titleObjs[$name] = $t;
			}
		}
		$linkBatch = new LinkBatch( $titleObjs );
		$linkBatch->execute();

		// This depends on the Disambiguator extension :(
		// @todo Either merge that extension into core, or we'll need to make
		// a "ParsoidGetRedlinkData" hook that Disambiguator can implement.
		// T237538
		$pageProps = PageProps::getInstance();
		$properties = $pageProps->getProperties( $titleObjs, [ 'disambiguation' ] );

		foreach ( $titleObjs as $name => $obj ) {
			/** @var Title $obj */
			$ret[$name] = [
				'pageId' => $obj->getArticleID(),
				'revId' => $obj->getLatestRevID(),
				'missing' => !$obj->exists(),
				'known' => $obj->isKnown(),
				'redirect' => $obj->isRedirect(),
				'disambiguation' => isset( $properties[$obj->getArticleID()] ),
			];
		}
		return $ret;
	}

	/** @inheritDoc */
	public function getFileInfo( IPageConfig $pageConfig, array $files ): array {
		$page = Title::newFromText( $pageConfig->getTitle() );
		$services = MediaWikiServices::getInstance();
		$fileObjs = $services->getRepoGroup()->findFiles( array_keys( $files ) );
		$badFileLookup = $services->getBadFileLookup();
		$ret = [];
		foreach ( $files as $filename => $dims ) {
			/** @var File $file */
			$file = $fileObjs[$filename] ?? null;
			if ( !$file ) {
				$ret[$filename] = null;
				continue;
			}

			$result = [
				'width' => $file->getWidth(),
				'height' => $file->getHeight(),
				'size' => $file->getSize(),
				'mediatype' => $file->getMediaType(),
				'mime' => $file->getMimeType(),
				'url' => $file->getFullUrl(),
				'mustRender' => $file->mustRender(),
				'badFile' => $badFileLookup->isBadFile( $filename, $page ?: false ),
			];

			$length = $file->getLength();
			if ( $length ) {
				$result['duration'] = (float)$length;
			}

			if ( isset( $dims['seek'] ) ) {
				$dims['thumbtime'] = $dims['seek'];
			}

			$txopts = $this->makeTransformOptions( $file, $dims );
			$mto = $file->transform( $txopts );
			if ( $mto ) {
				if ( $mto->isError() && $mto instanceof MediaTransformError ) {
					$result['thumberror'] = $mto->toText();
				} else {
					if ( $txopts ) {
						// Do srcset scaling
						Linker::processResponsiveImages( $file, $mto, $txopts );
						if ( count( $mto->responsiveUrls ) ) {
							$result['responsiveUrls'] = [];
							foreach ( $mto->responsiveUrls as $density => $url ) {
								$result['responsiveUrls'][$density] = $url;
							}
						}
					}

					// Proposed MediaTransformOutput serialization method for T51896 etc.
					// Note that getAPIData() returns wfExpandUrl(), which
					// doesn't respect the wiki's protocol preferences --
					// instead it uses the protocol used for the API request
					if ( is_callable( [ $mto, 'getAPIData' ] ) ) {
						$result['thumbdata'] = $mto->getAPIData( [ 'withhash' ] );
						// During a transitional period, additionally strip
						// protocol from the result.
						// FIXME: remove once
						// Ib9e30c7734ea266e6be8dd5dd425bf2f7d40100f
						// is merged.
						$stripProto = function ( array &$arr, $key = 'src' ): void {
							foreach ( $arr as &$item ) {
								if ( !empty( $item[$key] ) ) {
									$item[$key] = preg_replace(
										'#^https?://#', '//', $item[$key]
									);
								}
							}
						};
						if ( isset( $result['thumbdata']['derivatives'] ) ) {
							$stripProto( $result['thumbdata']['derivatives'] );
						}
						if ( isset( $result['thumbdata']['timedtext'] ) ) {
							$stripProto( $result['thumbdata']['timedtext'] );
						}
					}

					$result['thumburl'] = $mto->getUrl();
					$result['thumbwidth'] = $mto->getWidth();
					$result['thumbheight'] = $mto->getHeight();
				}
			} else {
				$result['thumberror'] = "Presumably, invalid parameters, despite validation.";
			}

			$ret[$filename] = $result;
		}

		return $ret;
	}

	/**
	 * Prepare MediaWiki's parser for preprocessing or extension tag parsing,
	 * clearing its state if necessary.
	 *
	 * @param IPageConfig $pageConfig
	 * @param int $outputType
	 * @return Parser
	 */
	private function prepareParser( IPageConfig $pageConfig, int $outputType ) {
		// Clear the state only when the PageConfig changes, so that Parser's internal caches can
		// be retained. This should also provide better compatibility with extension tags.
		$clearState = $this->previousPageConfig !== $pageConfig;
		$this->previousPageConfig = $pageConfig;
		$this->parser->startExternalParse(
			Title::newFromText( $pageConfig->getTitle() ), $this->parserOptions,
			$outputType, $clearState, $pageConfig->getRevisionId() );
		$this->parser->resetOutput();
		return $this->parser;
	}

	/** @inheritDoc */
	public function doPst( IPageConfig $pageConfig, string $wikitext ): string {
		// This could use prepareParser(), but it's only called once per page,
		// so it's not essential.
		$titleObj = Title::newFromText( $pageConfig->getTitle() );
		return ContentHandler::makeContent( $wikitext, $titleObj, CONTENT_MODEL_WIKITEXT )
			->preSaveTransform( $titleObj, $this->parserOptions->getUser(), $this->parserOptions )
			->serialize();
	}

	/** @inheritDoc */
	public function parseWikitext( IPageConfig $pageConfig, string $wikitext ): array {
		$parser = $this->prepareParser( $pageConfig, Parser::OT_HTML );
		$html = $parser->parseExtensionTagAsTopLevelDoc( $wikitext );
		$out = $parser->getOutput();
		$out->setText( $html );
		return [
			'html' => $out->getText( [ 'unwrap' => true ] ),
			'modules' => array_values( array_unique( $out->getModules() ) ),
			'modulescripts' => [], // $out->getModuleScripts() is deprecated and always returns []
			'modulestyles' => array_values( array_unique( $out->getModuleStyles() ) ),
			'categories' => $out->getCategories(),
		];
	}

	/** @inheritDoc */
	public function preprocessWikitext( IPageConfig $pageConfig, string $wikitext ): array {
		$parser = $this->prepareParser( $pageConfig, Parser::OT_PREPROCESS );
		$out = $parser->getOutput();
		$wikitext = $parser->replaceVariables( $wikitext );
		$wikitext = $parser->getStripState()->unstripBoth( $wikitext );
		return [
			'wikitext' => $wikitext,
			'modules' => array_values( array_unique( $out->getModules() ) ),
			'modulescripts' => [], // $out->getModuleScripts() is deprecated and always returns []
			'modulestyles' => array_values( array_unique( $out->getModuleStyles() ) ),
			'categories' => $out->getCategories(),
			'properties' => $out->getProperties()
		];
	}

	/** @inheritDoc */
	public function fetchPageContent(
		IPageConfig $pageConfig, string $title, int $oldid = 0
	): ?IPageContent {
		$titleObj = Title::newFromText( $title );

		if ( $oldid ) {
			$revRecord = $this->revStore->getRevisionByTitle( $titleObj, $oldid );
		} else {
			$revRecord = call_user_func(
				$this->parserOptions->getCurrentRevisionRecordCallback(),
				$titleObj,
				$this->parser
			);
		}

		return $revRecord ? new PageContent( $revRecord ) : null;
	}

	/** @inheritDoc */
	public function fetchTemplateData( IPageConfig $pageConfig, string $title ): ?array {
		$ret = [];
		// @todo: Document this hook in MediaWiki
		Hooks::runWithoutAbort( 'ParserFetchTemplateData', [ [ $title ], &$ret ] );

		// Cast value to array since the hook returns this as a stdclass
		$tplData = $ret[$title] ?? null;
		if ( $tplData ) {
			// Deep convert to associative array
			$tplData = json_decode( json_encode( $tplData ), true );
		}
		return $tplData;
	}

	/** @inheritDoc */
	public function logLinterData( IPageConfig $pageConfig, array $lints ): void {
		global $wgReadOnly;
		if ( $wgReadOnly ) {
			return;
		}

		$revId = $pageConfig->getRevisionId();
		$title = $pageConfig->getTitle();
		$pageInfo = $this->getPageInfo( $pageConfig, [ $title ] );
		$latest = $pageInfo[$title]['revId'];

		// Only send the request if it the latest revision
		if ( $revId !== null && $revId === $latest ) {
			// @todo: Document this hook in MediaWiki
			Hooks::runWithoutAbort( 'ParserLogLinterData', [ $title, $revId, $lints ] );
		}
	}

}