<?php
/**
 * The optimize4 class.
 *
 * @since      	1.9
 * @package  	LiteSpeed
 * @subpackage 	LiteSpeed/inc
 * @author     	LiteSpeed Technologies <info@litespeedtech.com>
 */
namespace LiteSpeed;

defined( 'WPINC' ) || exit;

class Optimizer extends Root {
	private $_conf_css_font_display;

	/**
	 * Init optimizer
	 *
	 * @since  1.9
	 */
	public function __construct() {
		$this->_conf_css_font_display = $this->conf( Base::O_OPTM_CSS_FONT_DISPLAY );
	}

	/**
	 * Run HTML minify process and return final content
	 *
	 * @since  1.9
	 * @access public
	 */
	public function html_min( $content, $force_inline_minify = false ) {
		$options = array();

		if ( $force_inline_minify ) {
			$options[ 'jsMinifier' ] = __CLASS__ . '::minify_js';
		}

		/**
		 * Added exception capture when minify
		 * @since  2.2.3
		 */
		try {
			$obj = new Lib\HTML_MIN( $content, $options );
			$content_final = $obj->process();
			if ( ! defined( 'LSCACHE_ESI_SILENCE' ) ) {
				$content_final .= "\n" . '<!-- Page optimized by LiteSpeed Cache @' . date('Y-m-d H:i:s') . ' -->';
			}
			return $content_final;

		} catch ( \Exception $e ) {
			Debug2::debug( '******[Optmer] html_min failed: ' . $e->getMessage() );
			error_log( '****** LiteSpeed Optimizer html_min failed: ' . $e->getMessage() );
			return $content;
		}
	}

	/**
	 * Run minify process and save content
	 *
	 * @since  1.9
	 * @access public
	 */
	public function serve( $request_url, $file_type, $minify, $src_list ) {
		// Try Unique CSS
		if ( $file_type == 'css' ) {
			$content = false;
			if ( defined( 'LITESPEED_GUEST_OPTM' ) || $this->conf( Base::O_OPTM_UCSS ) ) {
				$filename = $this->cls( 'CSS' )->load_ucss( $request_url );

				if ( $filename ) {
					return array( $filename, 'ucss' );
				}
			}
		}

		// Before generated, don't know the contented hash filename yet, so used url hash as tmp filename
		$file_path_prefix = $this->_build_filepath_prefix( $file_type );

		$static_file = LITESPEED_STATIC_DIR . $file_path_prefix . ( is_404() ? '404' : md5( $request_url ) ) . '.' . $file_type;

		// Create tmp file to avoid conflict
		$tmp_static_file = $static_file . '.tmp';
		if ( file_exists( $tmp_static_file ) && time() - filemtime( $tmp_static_file ) <= 600 ) { // some other request is generating
			return false;
		}
		// File::save( $tmp_static_file, '/* ' . ( is_404() ? '404' : $request_url ) . ' */', true ); // Can't use this bcos this will get filecon md5 changed
		File::save( $tmp_static_file, '', true );

		// Load content
		$real_files = array();
		foreach ( $src_list as $src_info ) {
			$is_min = false;
			if ( ! empty( $src_info[ 'inl' ] ) ) { // Load inline
				$content = $src_info[ 'src' ];
			}
			else { // Load file
				$content = $this->load_file( $src_info[ 'src' ], $file_type );

				if ( ! $content ) {
					continue;
				}

				$is_min = $this->is_min( $src_info[ 'src' ] );
			}
			$content = $this->optm_snippet( $content, $file_type, $minify && ! $is_min, $src_info[ 'src' ], ! empty( $src_info[ 'media' ] ) ? $src_info[ 'media' ] : false );
			// Write to file
			File::save( $tmp_static_file, $content, true, true );
		}

		// validate md5
		$filecon_md5 = md5_file( $tmp_static_file );

		$final_file_path = $file_path_prefix . $filecon_md5 . '.' . $file_type;
		$realfile = LITESPEED_STATIC_DIR . $final_file_path;
		if ( ! file_exists( $realfile ) ) {
			rename( $tmp_static_file, $realfile );
			Debug2::debug2( '[Optmer] Saved static file [path] ' . $realfile );
		}
		else {
			unlink( $tmp_static_file );
		}

		$vary = $this->cls( 'Vary' )->finalize_full_varies();
		Debug2::debug2( "[Optmer] Save URL to file for [file_type] $file_type [file] $filecon_md5 [vary] $vary " );
		$this->cls( 'Data' )->save_url( is_404() ? '404' : $request_url, $vary, $file_type, $filecon_md5, dirname( $realfile ) );

		return array( $filecon_md5 . '.' . $file_type, $file_type );
	}

	/**
	 * Load a single file
	 * @since  4.0
	 */
	public function optm_snippet( $content, $file_type, $minify, $src, $media = false ) {
		// CSS related features
		if ( $file_type == 'css' ) {
			// Font optimize
			if ( $this->_conf_css_font_display ) {
				$content = preg_replace( '#(@font\-face\s*\{)#isU', '${1}font-display:swap;', $content );
			}

			$content = preg_replace( '/@charset[^;]+;\\s*/', '', $content );

			if ( $media ) {
				$content = '@media ' . $media . '{' . $content . "\n}";
			}

			if ( $minify ) {
				$content = self::minify_css( $content );
			}

			$content = $this->cls( 'CDN' )->finalize( $content );

			if ( defined( 'LITESPEED_GUEST_OPTM' ) || $this->conf( Base::O_IMG_OPTM_WEBP_REPLACE ) ) {
				$content = $this->cls( 'Media' )->replace_background_webp( $content );
			}

		}
		else {
			if ( $minify ) {
				$content = self::minify_js( $content );
			}
			else {
				$content = $this->_null_minifier( $content );
			}

			$content .= "\n;";
		}

		// Add filter
		$content = apply_filters( 'litespeed_optm_cssjs', $content, $file_type, $src );

		return $content;
	}

	/**
	 * Load remote/local resource
	 *
	 * @since  3.5
	 */
	public function load_file( $src, $file_type = 'css' ) {
		$real_file = Utility::is_internal_file( $src );
		$postfix = pathinfo( parse_url( $src, PHP_URL_PATH ), PATHINFO_EXTENSION );
		if ( ! $real_file || $postfix != $file_type ) {
			Debug2::debug2( '[CSS] Load Remote [' . $file_type . '] ' . $src );
			$this_url = substr( $src, 0, 2 ) == '//' ? set_url_scheme( $src ) : $src;
			$res = wp_remote_get( $this_url );
			$res_code = wp_remote_retrieve_response_code( $res );
			if ( is_wp_error( $res ) || $res_code == 404 ) {
				Debug2::debug2( '[CSS] ❌ Load Remote error [code] ' . $res_code );
				return false;
			}
			$con = wp_remote_retrieve_body( $res );
			if ( ! $con ) {
				return false;
			}

			if ( $file_type == 'css' ) {
				$dirname = dirname( $this_url ) . '/';

				$con = Lib\CSS_MIN\UriRewriter::prepend( $con, $dirname );
			}
		}
		else {
			Debug2::debug2( '[CSS] Load local [' . $file_type . '] ' . $real_file[ 0 ] );
			$con = File::read( $real_file[ 0 ] );

			if ( $file_type == 'css' ) {
				$dirname = dirname( $real_file[ 0 ] );

				$con = Lib\CSS_MIN\UriRewriter::rewrite( $con, $dirname );
			}
		}

		return $con;
	}

	/**
	 * Minify CSS
	 *
	 * @since  2.2.3
	 * @access private
	 */
	public static function minify_css( $data ) {
		try {
			$obj = new Lib\CSS_MIN\Minifier();
			return $obj->run( $data );

		} catch ( \Exception $e ) {
			Debug2::debug( '******[Optmer] minify_css failed: ' . $e->getMessage() );
			error_log( '****** LiteSpeed Optimizer minify_css failed: ' . $e->getMessage() );
			return $data;
		}
	}

	/**
	 * Minify JS
	 *
	 * Added exception capture when minify
	 *
	 * @since  2.2.3
	 * @access private
	 */
	public static function minify_js( $data, $js_type = '' ) {
		// For inline JS optimize, need to check if it's js type
		if ( $js_type ) {
			preg_match( '#type=([\'"])(.+)\g{1}#isU', $js_type, $matches );
			if ( $matches && $matches[ 2 ] != 'text/javascript' ) {
				Debug2::debug( '******[Optmer] minify_js bypass due to type: ' . $matches[ 2 ] );
				return $data;
			}
		}

		try {
			$data = Lib\JSMin::minify( $data );
			return $data;
		} catch ( \Exception $e ) {
			Debug2::debug( '******[Optmer] minify_js failed: ' . $e->getMessage() );
			// error_log( '****** LiteSpeed Optimizer minify_js failed: ' . $e->getMessage() );
			return $data;
		}
	}

	/**
	 * Basic minifier
	 *
	 * @access private
	 */
	private function _null_minifier( $content ) {
		$content = str_replace( "\r\n", "\n", $content );

		return trim( $content );
	}

	/**
	 * Check if the file is already min file
	 *
	 * @since  1.9
	 */
	public function is_min( $filename ) {
		$basename = basename( $filename );
		if ( preg_match( '/[-\.]min\.(?:[a-zA-Z]+)$/i', $basename ) ) {
			return true;
		}

		return false;
	}

}