<?php
// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

/**
 * AIO Tools Static CSS & JS Asset Optimizer
 * Safely minifies local non-minified theme & plugin stylesheets/scripts into
 * wp-content/uploads/aio-assets/ with accurate relative CSS url(...) rewriting.
 */
class AIO_Asset_Optimizer {

	private $options;
	private $assets_dir;
	private $assets_url;
	private $site_host;
	private $excludes = array();

	public function __construct() {
		if ( is_admin() || aio_is_speed_safe_mode() ) {
			return;
		}

		$this->options = get_option( 'aio_options', array() );
		$min_css       = ! empty( $this->options['optEnableMinifyCss'] );
		$min_js        = ! empty( $this->options['optEnableMinifyJs'] );

		if ( ! $min_css && ! $min_js ) {
			return;
		}

		if ( ! empty( $this->options['optMinifyExcludes'] ) ) {
			foreach ( preg_split( '/[\r\n]+/', (string) $this->options['optMinifyExcludes'] ) as $ex ) {
				$ex = trim( $ex );
				if ( $ex !== '' ) {
					$this->excludes[] = $ex;
				}
			}
		}

		$uploads          = wp_upload_dir();
		$this->assets_dir = trailingslashit( wp_normalize_path( $uploads['basedir'] ) ) . 'aio-assets/';
		$this->assets_url = trailingslashit( $uploads['baseurl'] ) . 'aio-assets/';
		$this->site_host  = strtolower( (string) wp_parse_url( home_url(), PHP_URL_HOST ) );

		if ( $min_css ) {
			add_filter( 'style_loader_src', array( $this, 'optimize_css_src' ), 999, 2 );
		}
		if ( $min_js ) {
			add_filter( 'script_loader_src', array( $this, 'optimize_js_src' ), 999, 2 );
		}
	}

	private function is_excluded_asset( $src, $handle ) {
		if ( empty( $this->excludes ) ) {
			return false;
		}
		$haystack = (string) $handle . ' ' . (string) $src;
		foreach ( $this->excludes as $ex ) {
			if ( $ex !== '' && stripos( $haystack, $ex ) !== false ) {
				return true;
			}
		}
		return false;
	}

	/**
	 * Map a local WordPress asset URL to its filesystem path safely.
	 */
	private function url_to_local_path( $url ) {
		$clean = strtok( (string) $url, '?#' );
		if ( $clean === '' ) {
			return '';
		}
		if ( strpos( $clean, '//' ) === 0 ) {
			$clean = ( is_ssl() ? 'https:' : 'http:' ) . $clean;
		} elseif ( strpos( $clean, '/' ) === 0 ) {
			$clean = home_url( $clean );
		}

		$host = strtolower( (string) wp_parse_url( $clean, PHP_URL_HOST ) );
		if ( $host === '' || $host !== $this->site_host ) {
			return '';
		}

		$home_path = rtrim( (string) wp_parse_url( home_url( '/' ), PHP_URL_PATH ), '/' );
		$url_path  = rawurldecode( (string) wp_parse_url( $clean, PHP_URL_PATH ) );
		if ( $home_path !== '' && strpos( $url_path, $home_path . '/' ) === 0 ) {
			$url_path = substr( $url_path, strlen( $home_path ) );
		}

		if ( strpos( $url_path, '..' ) !== false || strpos( $url_path, "\0" ) !== false ) {
			return '';
		}

		// Never touch already cached aio-assets or wp-includes core bundles
		if ( strpos( $url_path, '/aio-assets/' ) !== false || strpos( $url_path, '/wp-includes/' ) !== false || strpos( $url_path, '/wp-admin/' ) !== false ) {
			return '';
		}

		$abs_root  = trailingslashit( wp_normalize_path( ABSPATH ) );
		$candidate = wp_normalize_path( $abs_root . ltrim( $url_path, '/' ) );
		if ( strpos( $candidate, $abs_root ) === 0 && is_file( $candidate ) && is_readable( $candidate ) ) {
			return $candidate;
		}

		return '';
	}

	private function ensure_assets_dir() {
		if ( ! file_exists( $this->assets_dir ) ) {
			wp_mkdir_p( $this->assets_dir );
			@file_put_contents( $this->assets_dir . 'index.php', "<?php\n// Silence is golden.\n" ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
		}
		return is_dir( $this->assets_dir ) && is_writable( $this->assets_dir );
	}

	/**
	 * Minify local non-.min.css files and rewrite relative url(...) paths.
	 */
	public function optimize_css_src( $src, $handle ) {
		if ( is_user_logged_in() || empty( $src ) || $this->is_excluded_asset( $src, $handle ) ) {
			return $src;
		}
		$clean = strtok( (string) $src, '?#' );
		if ( substr( strtolower( $clean ), -8 ) === '.min.css' || substr( strtolower( $clean ), -4 ) !== '.css' ) {
			return $src;
		}

		$file = $this->url_to_local_path( $src );
		if ( $file === '' || filesize( $file ) > 600000 ) {
			return $src;
		}

		$mtime    = (int) filemtime( $file );
		$hash     = substr( md5( $file . '|' . $mtime . '|' . AIO_VERSION . '|v2' ), 0, 16 );
		$out_name = sanitize_key( $handle ) . '-' . $hash . '.min.css';
		$out_path = $this->assets_dir . $out_name;

		if ( ! file_exists( $out_path ) ) {
			if ( ! $this->ensure_assets_dir() ) {
				return $src;
			}
			$raw = (string) @file_get_contents( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
			if ( $raw === '' ) {
				return $src;
			}
			$base_dir_url = trailingslashit( dirname( $clean ) );
			$min          = $this->minify_css_content( $raw, $base_dir_url );
			if ( @file_put_contents( $out_path, $min ) === false ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
				return $src;
			}
		}

		return $this->assets_url . $out_name;
	}

	/**
	 * Minify local non-.min.js files using a safe string/regex-preserving comment & whitespace stripper.
	 */
	public function optimize_js_src( $src, $handle ) {
		if ( is_user_logged_in() || empty( $src ) || $this->is_excluded_asset( $src, $handle ) ) {
			return $src;
		}
		$clean = strtok( (string) $src, '?#' );
		if ( substr( strtolower( $clean ), -7 ) === '.min.js' || substr( strtolower( $clean ), -3 ) !== '.js' ) {
			return $src;
		}

		$file = $this->url_to_local_path( $src );
		if ( $file === '' || filesize( $file ) > 500000 ) {
			return $src;
		}

		$mtime        = (int) filemtime( $file );
		$hash         = substr( md5( $file . '|' . $mtime . '|' . AIO_VERSION ), 0, 16 );
		$clean_handle = preg_replace( '/^gt_widget_script_\d+$/', 'gt_widget_script', sanitize_key( $handle ) );
		$out_name     = $clean_handle . '-' . $hash . '.min.js';
		$out_path     = $this->assets_dir . $out_name;

		if ( ! file_exists( $out_path ) ) {
			if ( ! $this->ensure_assets_dir() ) {
				return $src;
			}
			$raw = (string) @file_get_contents( $file ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
			if ( $raw === '' ) {
				return $src;
			}
			$min = $this->minify_js_safe( $raw );
			if ( @file_put_contents( $out_path, $min ) === false ) { // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
				return $src;
			}
		}

		return $this->assets_url . $out_name;
	}

	private function minify_css_content( $css, $base_dir_url ) {
		// Strip CSS block comments first so commented-out @import / url() rules are ignored
		$css = preg_replace( '#/\*(?!\!)[^*]*\*+(?:[^/*][^*]*\*+)*/#', '', $css ) ?? $css;

		// Rewrite relative @import "..." (non-url() form) to original stylesheet directory
		$css = preg_replace_callback(
			'/@import\s+(["\'])([^"\']+)\1/i',
			function ( $m ) use ( $base_dir_url ) {
				$quote = $m[1];
				$u     = trim( $m[2] );
				if ( $u === '' || preg_match( '#^(?:https?:|data:|//|/)#i', $u ) ) {
					return $m[0];
				}
				return '@import ' . $quote . $base_dir_url . $u . $quote;
			},
			$css
		) ?? $css;

		// Rewrite relative url(...) references (including @import url(...)) to original stylesheet directory
		$css = preg_replace_callback(
			'/url\(\s*(["\']?)([^"\')]+)\1\s*\)/i',
			function ( $m ) use ( $base_dir_url ) {
				$quote = $m[1];
				$u     = trim( $m[2] );
				if ( $u === '' || preg_match( '#^(?:https?:|data:|blob:|//|\#|/)#i', $u ) ) {
					return $m[0];
				}
				return 'url(' . $quote . $base_dir_url . $u . $quote . ')';
			},
			$css
		) ?? $css;

		$css = preg_replace( '/\s+/', ' ', $css ) ?? $css;
		$css = preg_replace( '/\s*([{};,>~])\s*/', '$1', $css ) ?? $css;
		$css = preg_replace( '/:\s+/', ':', $css ) ?? $css;
		$css = str_replace( ';}', '}', $css );
		return trim( $css );
	}

	/**
	 * Conservative JS minifier: strips block/line comments outside strings/templates/regexes
	 * and trims blank lines & leading indentation while preserving newlines so ASI never breaks!
	 */
	private function minify_js_safe( $js ) {
		$len     = strlen( $js );
		$out     = '';
		$i       = 0;
		$in_str  = null;

		while ( $i < $len ) {
			$ch   = $js[ $i ];
			$next = ( $i + 1 < $len ) ? $js[ $i + 1 ] : '';

			if ( $in_str !== null ) {
				$out .= $ch;
				if ( $ch === '\\' && $i + 1 < $len ) {
					$out .= $js[ $i + 1 ];
					$i   += 2;
					continue;
				}
				if ( $ch === $in_str ) {
					$in_str = null;
				}
				$i++;
				continue;
			}

			if ( $ch === '"' || $ch === "'" || $ch === '`' ) {
				$in_str = $ch;
				$out   .= $ch;
				$i++;
				continue;
			}

			// Block comment /* ... */
			if ( $ch === '/' && $next === '*' ) {
				$end = strpos( $js, '*/', $i + 2 );
				if ( $end === false ) {
					break;
				}
				$has_nl = strpos( substr( $js, $i, $end - $i + 2 ), "\n" ) !== false;
				$out   .= $has_nl ? "\n" : ' ';
				$i      = $end + 2;
				continue;
			}

			// Single-line comment // ... (only when at start of line or preceded by whitespace/;/{/}/(/)/,)
			if ( $ch === '/' && $next === '/' ) {
				$prev = $out !== '' ? substr( $out, -1 ) : "\n";
				if ( ctype_space( $prev ) || in_array( $prev, array( ';', '{', '}', '(', ')', ',', '[' ), true ) ) {
					$nl = strpos( $js, "\n", $i + 2 );
					if ( $nl === false ) {
						break;
					}
					$out .= "\n";
					$i    = $nl + 1;
					continue;
				}
			}

			$out .= $ch;
			$i++;
		}

		// Trim per-line leading/trailing horizontal spaces & collapse empty lines
		$lines = explode( "\n", str_replace( "\r", '', $out ) );
		$clean = array();
		foreach ( $lines as $line ) {
			$t = trim( $line, " \t" );
			if ( $t !== '' ) {
				$clean[] = $t;
			}
		}

		return implode( "\n", $clean );
	}

	/**
	 * Delete all generated .min.css / .min.js cached files.
	 */
	public static function clear_minified_assets() {
		$uploads = wp_upload_dir();
		$dir     = trailingslashit( wp_normalize_path( $uploads['basedir'] ) ) . 'aio-assets/';
		if ( ! is_dir( $dir ) ) {
			return;
		}
		$files = glob( $dir . '*' );
		if ( is_array( $files ) ) {
			foreach ( $files as $f ) {
				if ( is_file( $f ) && basename( $f ) !== 'index.php' ) {
					@unlink( $f ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
				}
			}
		}
	}
}