<?php
/**
 * DGT Minify – Asset- und HTML-Minifizierung für Gäste.
 *
 * - Tauscht registrierte CSS/JS-Handles gegen .min-Varianten
 * - Entfernt unnötige WordPress-Core-Styles (Block-Library, Global Styles)
 * - Minifiziert HTML, inline <style> und inline <script>
 * - Greift NUR für nicht eingeloggte Besucher
 *
 * @package drogentest-online
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class DGT_Minify {

	public static function init() {
		if ( is_admin() || wp_doing_cron() || wp_doing_ajax() || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
			return;
		}

		add_action( 'template_redirect', array( __CLASS__, 'maybe_start_buffer' ), 0 );
		add_filter( 'style_loader_src', array( __CLASS__, 'swap_asset' ), 999 );
		add_filter( 'script_loader_src', array( __CLASS__, 'swap_asset' ), 999 );

		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'remove_core_bloat' ), 100 );
	}

	public static function is_guest() {
		return ! is_user_logged_in();
	}

	public static function remove_core_bloat() {
		if ( ! self::is_guest() ) {
			return;
		}
		wp_dequeue_style( 'wp-block-library' );
		wp_dequeue_style( 'wp-block-library-theme' );
		wp_dequeue_style( 'classic-theme-styles' );
		wp_dequeue_style( 'global-styles' );
		wp_dequeue_style( 'core-block-supports' );
	}

	public static function swap_asset( $src ) {
		if ( ! self::is_guest() || ! $src ) {
			return $src;
		}

		if ( strpos( $src, '.min.' ) !== false ) {
			return $src;
		}

		$content_url = content_url();
		if ( strpos( $src, $content_url ) === false ) {
			return $src;
		}

		$rel  = str_replace( $content_url, '', strtok( $src, '?' ) );
		$path = WP_CONTENT_DIR . $rel;

		if ( preg_match( '/\.(css|js)$/', $path, $m ) ) {
			$min_path = substr( $path, 0, -strlen( $m[0] ) ) . '.min.' . $m[1];
			if ( file_exists( $min_path ) ) {
				$min_url = $content_url . substr( $rel, 0, -strlen( $m[0] ) ) . '.min.' . $m[1];
				$ver     = filemtime( $min_path );
				return $min_url . '?ver=' . $ver;
			}
		}

		return $src;
	}

	public static function maybe_start_buffer() {
		if ( ! self::is_guest() ) {
			return;
		}
		ob_start( array( __CLASS__, 'minify_html' ) );
	}

	public static function minify_html( $html ) {
		if ( strlen( $html ) < 255 ) {
			return $html;
		}

		$placeholders = array();
		$idx          = 0;

		// <pre>, <textarea>, <!--[if → Platzhalter (unverändert lassen).
		$html = preg_replace_callback(
			'#(<(?:pre|textarea)\b[^>]*>.*?</(?:pre|textarea)>|<!--\[if\b.*?<!\[endif\]-->)#si',
			function ( $m ) use ( &$placeholders, &$idx ) {
				$key                  = "\x1A" . $idx++ . "\x1A";
				$placeholders[ $key ] = $m[0];
				return $key;
			},
			$html
		);

		// Inline <style> → minifizieren, dann Platzhalter.
		$html = preg_replace_callback(
			'#(<style\b[^>]*>)(.*?)(</style>)#si',
			function ( $m ) use ( &$placeholders, &$idx ) {
				$css = $m[2];
				$css = preg_replace( '#/\*.*?\*/#s', '', $css );
				$css = preg_replace( '/\s*([{};:,>~+])\s*/', '$1', $css );
				$css = preg_replace( '/\s{2,}/', ' ', $css );
				$css = trim( $css );
				$key                  = "\x1A" . $idx++ . "\x1A";
				$placeholders[ $key ] = $m[1] . $css . $m[3];
				return $key;
			},
			$html
		);

		// Inline <script> (ohne src) → minifizieren, dann Platzhalter.
		$html = preg_replace_callback(
			'#(<script\b(?![^>]*\bsrc\b)[^>]*>)(.*?)(</script>)#si',
			function ( $m ) use ( &$placeholders, &$idx ) {
				$js = $m[2];
				$js = preg_replace( '#^\s*//[^\n]*$#m', '', $js );
				$js = preg_replace( '#/\*.*?\*/#s', '', $js );
				$js = preg_replace( '/\n{2,}/', "\n", $js );
				$js = preg_replace( '/^\s+/m', '', $js );
				$js = trim( $js );
				$key                  = "\x1A" . $idx++ . "\x1A";
				$placeholders[ $key ] = $m[1] . $js . $m[3];
				return $key;
			},
			$html
		);

		// <script src="..."> → Platzhalter (unverändert).
		$html = preg_replace_callback(
			'#<script\b[^>]*\bsrc\b[^>]*>.*?</script>#si',
			function ( $m ) use ( &$placeholders, &$idx ) {
				$key                  = "\x1A" . $idx++ . "\x1A";
				$placeholders[ $key ] = $m[0];
				return $key;
			},
			$html
		);

		// HTML-Kommentare entfernen.
		$html = preg_replace( '/<!--(?!\s*noindex).*?-->/s', '', $html );

		// Whitespace zwischen Tags.
		$html = preg_replace( '/>\s+</', '> <', $html );

		// Mehrfach-Whitespace.
		$html = preg_replace( '/\s{2,}/', ' ', $html );

		// Führende Leerzeichen pro Zeile.
		$html = preg_replace( '/^ +/m', '', $html );

		// Leere Zeilen.
		$html = preg_replace( '/\n{2,}/', "\n", $html );

		// Platzhalter zurückschreiben.
		$html = str_replace( array_keys( $placeholders ), array_values( $placeholders ), $html );

		// Finale Bereinigung nach Platzhalter-Restore.
		$html = preg_replace( '/>\s+</', '><', $html );
		$html = preg_replace( '/\s{2,}/', ' ', $html );
		$html = trim( $html );

		return $html;
	}
}

DGT_Minify::init();