<?php

namespace MediaWiki\Extension\Scribunto;

use MediaWiki\Config\ConfigException;
use MediaWiki\MediaWikiServices;
use MediaWiki\Title\Title;
use Parser;

/**
 * Static function collection for general extension support.
 */
class Scribunto {
	/**
	 * Create a new engine object with specified parameters.
	 *
	 * @param array $options
	 * @return ScribuntoEngineBase
	 */
	public static function newEngine( $options ) {
		if ( isset( $options['factory'] ) ) {
			return call_user_func( $options['factory'], $options );
		} else {
			$class = $options['class'];
			return new $class( $options );
		}
	}

	/**
	 * Create a new engine object with default parameters
	 *
	 * @param array $extraOptions Extra options to pass to the constructor,
	 *  in addition to the configured options
	 * @return ScribuntoEngineBase
	 */
	public static function newDefaultEngine( $extraOptions = [] ) {
		$config = MediaWikiServices::getInstance()->getMainConfig();
		$defaultEngine = $config->get( 'ScribuntoDefaultEngine' );
		if ( !$defaultEngine ) {
			throw new ConfigException(
				'Scribunto extension is enabled but $wgScribuntoDefaultEngine is not set'
			);
		}

		$engineConf = $config->get( 'ScribuntoEngineConf' );
		if ( !isset( $engineConf[$defaultEngine] ) ) {
			throw new ConfigException( 'Invalid scripting engine is specified in $wgScribuntoDefaultEngine' );
		}
		$options = $extraOptions + $engineConf[$defaultEngine];
		// @phan-suppress-next-line PhanTypeMismatchArgument false positive
		return self::newEngine( $options );
	}

	/**
	 * Get an engine instance for the given parser, and cache it in the parser
	 * so that subsequent calls to this function for the same parser will return
	 * the same engine.
	 *
	 * @param Parser $parser
	 * @return ScribuntoEngineBase
	 */
	public static function getParserEngine( Parser $parser ) {
		if ( !isset( $parser->scribunto_engine ) ) {
			$parser->scribunto_engine = self::newDefaultEngine( [ 'parser' => $parser ] );
			$parser->scribunto_engine->setTitle( $parser->getTitle() );
		}
		return $parser->scribunto_engine;
	}

	/**
	 * Check if an engine instance is present in the given parser
	 *
	 * @param Parser $parser
	 * @return bool
	 */
	public static function isParserEnginePresent( Parser $parser ) {
		return isset( $parser->scribunto_engine );
	}

	/**
	 * Remove the current engine instance from the parser
	 * @param Parser $parser
	 */
	public static function resetParserEngine( Parser $parser ) {
		if ( isset( $parser->scribunto_engine ) ) {
			$parser->scribunto_engine->destroy();
			$parser->scribunto_engine = null;
		}
	}

	/**
	 * Test whether the page should be considered a documentation page
	 *
	 * @param Title $title
	 * @param Title|null &$forModule Module for which this is a doc page
	 * @return bool
	 */
	public static function isDocPage( Title $title, Title &$forModule = null ) {
		$docPage = wfMessage( 'scribunto-doc-page-name' )->inContentLanguage();
		if ( $docPage->isDisabled() ) {
			return false;
		}

		// Canonicalize the input pseudo-title. The unreplaced "$1" shouldn't
		// cause a problem.
		$docTitle = Title::newFromText( $docPage->plain() );
		if ( !$docTitle ) {
			return false;
		}
		$docPage = $docTitle->getPrefixedText();

		// Make it into a regex, and match it against the input title
		$docPage = str_replace( '\\$1', '(.+)', preg_quote( $docPage, '/' ) );
		if ( preg_match( "/^$docPage$/", $title->getPrefixedText(), $m ) ) {
			$forModule = Title::makeTitleSafe( NS_MODULE, $m[1] );
			return $forModule !== null;
		} else {
			return false;
		}
	}

	/**
	 * Return the Title for the documentation page
	 *
	 * @param Title $title
	 * @return Title|null
	 */
	public static function getDocPage( Title $title ) {
		$docPage = wfMessage( 'scribunto-doc-page-name', $title->getText() )->inContentLanguage();
		if ( $docPage->isDisabled() ) {
			return null;
		}

		return Title::newFromText( $docPage->plain() );
	}
}