<?php
namespace Akram;

defined( 'ABSPATH' ) || exit;

/**
 * Serves pre-rendered documents and loads only the assets a request needs.
 */
final class Frontend {

	const TOKEN = '<!--akram-content-->';

	/** @var array<int,array> outputs that will render on this request, keyed by post id */
	private static $docs = array();
	private static $modules = array();
	private static $printed_css = array();
	private static $enqueued = false;
	private static $stack = array();

	public static function init() {
		add_filter( 'the_content', array( __CLASS__, 'content_early' ), 1 );
		add_filter( 'the_content', array( __CLASS__, 'content_late' ), PHP_INT_MAX );
		add_action( 'wp', array( __CLASS__, 'collect' ), 20 );
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'enqueue' ), 20 );
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'drop_elementor_assets' ), 9999 );
		add_action( 'wp_print_styles', array( __CLASS__, 'drop_elementor_assets' ), 1 );
		add_action( 'wp_print_footer_scripts', array( __CLASS__, 'drop_elementor_assets' ), 1 );
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'head' ), 1 );
		add_action( 'wp_footer', array( __CLASS__, 'footer_modules' ), 5 );
		add_filter( 'body_class', array( __CLASS__, 'body_class' ) );
		add_filter( 'template_include', array( __CLASS__, 'page_templates' ), 99 );
		add_action( 'init', array( __CLASS__, 'register_page_templates' ), 30 );
		add_action( 'template_redirect', array( __CLASS__, 'protect_templates' ) );
		add_action( 'template_redirect', array( __CLASS__, 'unlock' ), 1 );
		add_action( 'template_redirect', array( Conditions::class, 'track' ), 2 );
		add_action( 'admin_bar_menu', array( __CLASS__, 'admin_bar' ), 81 );
		add_filter( 'get_the_excerpt', array( __CLASS__, 'excerpt' ), 5, 2 );
		add_filter( 'script_loader_tag', array( __CLASS__, 'defer_modules' ), 10, 2 );
	}

	// ------------------------------------------------------------------
	// Content
	// ------------------------------------------------------------------
	public static function content_early( $content ) {
		$id = get_the_ID();
		if ( $id && Editor::canvas_id() === $id && ! self::$stack ) {
			return self::TOKEN;
		}
		if ( ! $id || ! Document::is_built( $id ) || post_password_required( $id ) ) {
			return $content;
		}
		if ( in_array( $id, self::$stack, true ) ) {
			return $content; // a template rendering its own post-content
		}
		return self::TOKEN;
	}

	public static function content_late( $content ) {
		if ( false === strpos( $content, self::TOKEN ) ) {
			return $content;
		}
		$id = get_the_ID();
		if ( Editor::canvas_id() === $id ) {
			return str_replace( self::TOKEN, '<div id="nx-canvas-root" class="nx-doc"></div>', $content );
		}
		return str_replace( self::TOKEN, self::render_post( $id ), $content );
	}

	public static function is_preview( $post_id ) {
		return isset( $_GET['nx_preview'], $_GET['_nxp'] ) && wp_verify_nonce( sanitize_text_field( wp_unslash( $_GET['_nxp'] ) ), 'nx_preview_' . $post_id ) && Plugin::can_build( $post_id );
	}

	/** Render a built post/template (runtime placeholders resolved). */
	public static function render_post( $post_id, $wrap_class = '' ) {
		$post_id = (int) $post_id;
		if ( in_array( $post_id, self::$stack, true ) || count( self::$stack ) > 8 ) {
			return '';
		}
		$out = Document::get_out( $post_id, self::is_preview( $post_id ) );
		if ( ! $out ) {
			return '';
		}
		self::$stack[] = $post_id;
		self::ensure_assets( $post_id, $out );
		// Escaped late: the stored layout goes through the same KSES allow-list as on save; the dynamic parts that
		// Runtime inserts (menus, post lists, forms…) are escaped by the functions that build them.
		$html = Runtime::process( Sanitize::html( $out['html'] ), $out, $post_id );
		if ( function_exists( 'wp_filter_content_tags' ) && false !== strpos( $html, 'wp-image-' ) ) {
			// Responsive srcset/sizes, intrinsic size and position-aware lazy/fetchpriority, exactly like core content.
			$html = wp_filter_content_tags( $html, 'the_content' );
		}
		array_pop( self::$stack );
		if ( $wrap_class ) {
			$html = '<div class="' . esc_attr( $wrap_class ) . '">' . $html . '</div>';
		}
		return $html;
	}

	public static function current_stack() {
		return self::$stack;
	}

	// ------------------------------------------------------------------
	// Assets: decide early (on `wp`) what this request renders.
	// ------------------------------------------------------------------
	public static function collect() {
		if ( is_admin() ) {
			return;
		}
		$ids = array();
		if ( is_singular() ) {
			$qid = get_queried_object_id();
			if ( Document::is_built( $qid ) ) {
				$ids[] = $qid;
			}
		}
		foreach ( Theme_Builder::active_templates() as $tid ) {
			$ids[] = $tid;
		}
		foreach ( Popups::active() as $pid ) {
			$ids[] = $pid;
		}
		$canvas = Editor::canvas_id();
		foreach ( array_unique( $ids ) as $id ) {
			if ( $id === $canvas ) {
				continue;
			}
			$out = Document::get_out( $id, self::is_preview( $id ) );
			if ( $out ) {
				self::$docs[ $id ] = $out;
				foreach ( (array) ( $out['tpl'] ?? array() ) as $tpl ) {
					$o = Document::get_out( (int) $tpl );
					if ( $o ) {
						self::$docs[ (int) $tpl ] = $o;
					}
				}
			}
		}
	}

	public static function unlock() {
		if ( self::$docs ) {
			Runtime::maybe_unlock( self::$docs );
		}
	}

	public static function enqueue() {
		self::register_modules();
		$global = Document::global_css_url();
		$any    = self::$docs || Editor::canvas_id();
		if ( ! $any ) {
			return;
		}
		if ( $global ) {
			wp_enqueue_style( 'akram-global', $global, array(), null ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
		} else {
			wp_register_style( 'akram-global', false ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
			wp_enqueue_style( 'akram-global' );
			wp_add_inline_style( 'akram-global', Document::global_css() );
		}
		$fonts = (array) get_option( 'akram_global_fonts', array() );
		if ( ! $fonts && ! get_option( 'akram_global_css' ) ) {
			$fonts = array(
				'Bricolage Grotesque' => array( 400, 600, 700, 800 ),
				'Figtree'             => array( 400, 500, 600, 700 ),
			); // default design system
		}
		foreach ( self::$docs as $id => $out ) {
			self::enqueue_doc_css( $id, $out );
			foreach ( (array) ( $out['fonts'] ?? array() ) as $fam => $w ) {
				$fonts[ $fam ] = array_unique( array_merge( $fonts[ $fam ] ?? array(), (array) $w ) );
			}
			foreach ( (array) ( $out['modules'] ?? array() ) as $m ) {
				self::$modules[ $m ] = true;
			}
		}
		if ( Popups::active() ) {
			self::$modules['popup'] = true;
		}
		Fonts::enqueue( $fonts );
		if ( Editor::canvas_id() ) {
			// The editor injects its own styles; theme + fonts still load normally.
			Fonts::enqueue( $fonts );
		}
		self::$enqueued = true;
		if ( Options::get( 'disable_block_css' ) && self::$docs && is_singular() && Document::is_built( get_queried_object_id() ) && self::block_css_unused() ) {
			wp_dequeue_style( 'wp-block-library' );
			wp_dequeue_style( 'wp-block-library-theme' );
			wp_dequeue_style( 'classic-theme-styles' );
		}
	}

	/**
	 * While Elementor is still active (e.g. mid-migration) it loads its global CSS, kit CSS and Google Fonts
	 * on every page. An Akram-built page uses none of it. Elementor Pro's theme builder (headers/footers) needs
	 * them, so this only runs without Elementor Pro.
	 */
	public static function drop_elementor_assets() {
		if ( ! defined( 'ELEMENTOR_VERSION' ) || defined( 'ELEMENTOR_PRO_VERSION' ) || ! is_singular() || Editor::canvas_id() ) {
			return;
		}
		$id = get_queried_object_id();
		if ( ! Document::is_built( $id ) || 'builder' === get_post_meta( $id, '_elementor_edit_mode', true ) || ! apply_filters( 'akram_drop_elementor_assets', true, $id ) ) {
			return;
		}
		foreach ( array( wp_styles(), wp_scripts() ) as $deps ) {
			foreach ( (array) $deps->queue as $handle ) {
				if ( preg_match( '/^elementor-(frontend|post-\d+|gf-[a-z0-9-]+|icons(-[a-z0-9-]+)?|webpack-runtime|frontend-modules|waypoints|common)$/', $handle ) || 0 === strpos( $handle, 'e-animation' ) || 0 === strpos( $handle, 'widget-' ) ) {
					$deps instanceof \WP_Styles ? wp_dequeue_style( $handle ) : wp_dequeue_script( $handle );
				}
			}
		}
	}

	/**
	 * The ~140 KB block-library stylesheet is dead weight on an Akram page with a classic theme,
	 * unless the theme's sidebars/footer use block widgets. Block themes load per-block CSS on demand,
	 * so they are left alone.
	 */
	private static function block_css_unused() {
		if ( function_exists( 'wp_is_block_theme' ) && wp_is_block_theme() ) {
			return false;
		}
		$blocks = get_option( 'widget_block' );
		if ( is_array( $blocks ) ) {
			foreach ( (array) get_option( 'sidebars_widgets', array() ) as $area => $widgets ) {
				if ( 'wp_inactive_widgets' === $area || ! is_array( $widgets ) ) {
					continue;
				}
				foreach ( $widgets as $w ) {
					if ( 0 === strpos( (string) $w, 'block-' ) ) {
						return false;
					}
				}
			}
		}
		return (bool) apply_filters( 'akram_remove_block_css', true );
	}

	private static function enqueue_doc_css( $id, $out ) {
		if ( isset( self::$printed_css[ $id ] ) ) {
			return;
		}
		self::$printed_css[ $id ] = true;
		if ( ! empty( $out['draft'] ) ) {
			wp_register_style( 'akram-' . $id, false ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
			wp_enqueue_style( 'akram-' . $id );
			wp_add_inline_style( 'akram-' . $id, $out['css'] );
			return;
		}
		$url = Document::css_url( $id );
		if ( $url ) {
			wp_enqueue_style( 'akram-' . $id, $url, array( 'akram-global' ), null ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
		} else {
			wp_register_style( 'akram-' . $id, false, array( 'akram-global' ) ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
			wp_enqueue_style( 'akram-' . $id );
			wp_add_inline_style( 'akram-' . $id, Document::css( $id ) );
		}
	}

	/** Late discovery (shortcodes, loop templates, nested templates): print styles inline once. */
	public static function ensure_assets( $id, $out ) {
		foreach ( (array) ( $out['modules'] ?? array() ) as $m ) {
			self::$modules[ $m ] = true;
		}
		if ( isset( self::$printed_css[ $id ] ) || Editor::canvas_id() === $id ) {
			return;
		}
		if ( ! did_action( 'wp_head' ) || ! self::$enqueued ) {
			self::$docs[ $id ] = $out;
			if ( did_action( 'wp_enqueue_scripts' ) ) {
				self::enqueue_doc_css( $id, $out );
			}
			return;
		}
		self::$printed_css[ $id ] = true;
		$url = empty( $out['draft'] ) ? Document::css_url( $id ) : null;
		self::print_style( 'akram-' . (int) $id, (string) $url, $url ? '' : ( ! empty( $out['draft'] ) ? $out['css'] : Document::css( $id ) ) );
		if ( ! wp_style_is( 'akram-global', 'done' ) && ! wp_style_is( 'akram-global', 'enqueued' ) ) {
			self::print_style( 'akram-global-inline', '', Document::global_css() );
		}
		Fonts::print_late( (array) ( $out['fonts'] ?? array() ) );
	}

	/**
	 * Prints one stylesheet (or an inline style block) through the WordPress styles API, also after wp_head
	 * (late-discovered documents, standalone screens). CSS passed inline was sanitised on save.
	 */
	public static function print_style( $handle, $url = '', $inline = '' ) {
		if ( wp_style_is( $handle, 'done' ) ) {
			return;
		}
		if ( $url ) {
			wp_register_style( $handle, $url, array(), null ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- the URL already carries a content version.
		} else {
			wp_register_style( $handle, false, array(), AKRAM_VERSION );
			wp_add_inline_style( $handle, $inline );
		}
		wp_print_styles( $handle );
	}

	public static function add_module( $name ) {
		self::$modules[ sanitize_key( $name ) ] = true;
	}

	public static function head() {
		if ( ! self::$docs && ! Editor::canvas_id() ) {
			return;
		}
		$needs_js_class = false;
		$dm             = '';
		foreach ( self::$docs as $out ) {
			if ( ! empty( $out['flags']['dm'] ) ) {
				$dm = (string) $out['flags']['dm'];
			}
			if ( ! empty( $out['anim'] ) || array_intersect( (array) ( $out['modules'] ?? array() ), array( 'motion', 'counter' ) ) ) {
				$needs_js_class = true;
			}
		}
		$js = '';
		if ( $dm ) {
			// Apply the saved/system color theme before first paint (no flash of the wrong theme).
			$js .= "(function(){try{var m=localStorage.getItem('nx-theme')||" . wp_json_encode( $dm )
				. ";if(m!=='light'&&m!=='dark')m=matchMedia('(prefers-color-scheme: dark)').matches?'dark':'light';document.documentElement.dataset.nxTheme=m}catch(e){}})();";
		}
		if ( $needs_js_class ) {
			$js .= "document.documentElement.classList.add('nx-js');";
		}
		if ( $js ) {
			// Printed in the head by wp_head(), before first paint.
			wp_register_script( 'akram-head', false, array(), AKRAM_VERSION, false );
			wp_enqueue_script( 'akram-head' );
			wp_add_inline_script( 'akram-head', $js );
		}
	}

	private static function register_modules() {
		$dir = AKRAM_DIR . 'assets/build/m/';
		if ( ! is_dir( $dir ) ) {
			return;
		}
		foreach ( glob( $dir . '*.js' ) as $file ) {
			$name = basename( $file, '.js' );
			if ( '.min' === substr( $name, -4 ) ) {
				continue; // the minified twin of a readable build; Plugin::build_url() picks which one loads
			}
			wp_register_script( 'akram-m-' . $name, Plugin::build_url( 'm/' . $name . '.js' ), array(), AKRAM_VERSION, array(
				'in_footer' => true,
				'strategy'  => 'defer',
			) );
		}
	}

	public static function footer_modules() {
		if ( Editor::canvas_id() ) {
			return; // the editor loads every module into the canvas itself
		}
		if ( ! self::$modules ) {
			return;
		}
		$cfg = array(
			'rest'   => esc_url_raw( rest_url( Rest::NS . '/' ) ),
			'assets' => AKRAM_URL . 'assets/',
			'min'    => Plugin::min_suffix(),
			'home'   => home_url( '/' ),
			'tz'     => (float) get_option( 'gmt_offset' ),
		);
		$cap = Options::get( 'captcha' );
		if ( 'recaptcha' === $cap && Options::get( 'recaptcha_site' ) ) {
			$cfg['captcha'] = array(
				'type' => 'recaptcha',
				'key'  => Options::get( 'recaptcha_site' ),
			);
		} elseif ( 'turnstile' === $cap && Options::get( 'turnstile_site' ) ) {
			$cfg['captcha'] = array(
				'type' => 'turnstile',
				'key'  => Options::get( 'turnstile_site' ),
			);
		}
		$first = true;
		foreach ( array_keys( self::$modules ) as $m ) {
			if ( ! wp_script_is( 'akram-m-' . $m, 'registered' ) ) {
				continue;
			}
			if ( $first ) {
				wp_add_inline_script( 'akram-m-' . $m, 'window.akramCfg=' . wp_json_encode( $cfg ) . ';', 'before' );
				$first = false;
			}
			wp_enqueue_script( 'akram-m-' . $m );
		}
	}

	public static function defer_modules( $tag, $handle ) {
		if ( 0 === strpos( $handle, 'akram-m-' ) && false === strpos( $tag, ' defer' ) && false === strpos( $tag, 'window.akramCfg' ) ) {
			$tag = str_replace( ' src=', ' defer src=', $tag );
		}
		return $tag;
	}

	// ------------------------------------------------------------------
	// Page templates
	// ------------------------------------------------------------------
	public static function register_page_templates() {
		foreach ( Options::enabled_post_types() as $pt ) {
			add_filter( "theme_{$pt}_templates", array( __CLASS__, 'add_page_templates' ) );
		}
	}

	public static function add_page_templates( $templates ) {
		$templates['akram-full']   = __( 'Akram Full Width', 'akram' );
		$templates['akram-canvas'] = __( 'Akram Canvas (no header/footer)', 'akram' );
		return $templates;
	}

	public static function page_templates( $template ) {
		if ( is_singular() ) {
			$slug = get_page_template_slug( get_queried_object_id() );
			if ( 'akram-canvas' === $slug ) {
				return AKRAM_DIR . 'templates/canvas.php';
			}
			if ( 'akram-full' === $slug ) {
				return AKRAM_DIR . 'templates/full-width.php';
			}
		}
		return $template;
	}

	public static function body_class( $classes ) {
		if ( is_singular() && Document::is_built( get_queried_object_id() ) ) {
			$classes[] = 'nx-page';
		}
		if ( Editor::canvas_id() ) {
			$classes[] = 'nx-editing';
		}
		return $classes;
	}

	/** Templates are only viewable directly by builders (previewing). */
	public static function protect_templates() {
		if ( is_singular( 'akram_template' ) && ! Plugin::can_build() ) {
			global $wp_query;
			$wp_query->set_404();
			status_header( 404 );
		}
	}

	public static function admin_bar( $bar ) {
		if ( is_admin() || ! is_singular() ) {
			return;
		}
		$id = get_queried_object_id();
		if ( ! $id || ! Plugin::can_build( $id ) || ! in_array( get_post_type( $id ), Options::enabled_post_types(), true ) ) {
			return;
		}
		$bar->add_node(
			array(
				'id'    => 'akram-edit',
				'title' => '<span class="ab-icon" style="width:20px;height:20px;margin-top:6px;color:#5fd0e4">'
					. Brand::svg( '#5fd0e4', 18 ) . '</span>' . esc_html__( 'Edit with Akram', 'akram' ),
				'href'  => Editor::edit_url( $id ),
			)
		);
		foreach ( Theme_Builder::active_templates() as $tid ) {
			$bar->add_node(
				array(
					'parent' => 'akram-edit',
					'id'     => 'akram-edit-' . $tid,
					/* translators: 1: template type, 2: template title */
					'title'  => esc_html( sprintf( __( '%1$s: %2$s', 'akram' ), Post_Types::type_labels()[ Post_Types::template_type( $tid ) ] ?? '', get_the_title( $tid ) ) ),
					'href'   => Editor::edit_url( $tid ),
				)
			);
		}
	}

	/** Builder pages have no meaningful raw excerpt: derive one from the static copy. */
	public static function excerpt( $excerpt, $post = null ) {
		if ( $excerpt || ! $post || ! Document::is_built( $post->ID ) ) {
			return $excerpt;
		}
		// wp_strip_all_tags() also drops the contents of script and style elements (structured data).
		return wp_trim_words( wp_strip_all_tags( $post->post_content ), 40 );
	}

	/** Purge popular page caches when content or design changes. */
	public static function flush_caches( $post_id = 0 ) {
		if ( $post_id ) {
			clean_post_cache( $post_id );
		}
		do_action( 'akram_flush_caches', $post_id );
		if ( function_exists( 'rocket_clean_domain' ) ) {
			$post_id ? rocket_clean_post( $post_id ) : rocket_clean_domain();
		}
		if ( function_exists( 'w3tc_flush_all' ) ) {
			w3tc_flush_all();
		}
		if ( function_exists( 'wp_cache_clear_cache' ) ) {
			wp_cache_clear_cache();
		}
		if ( class_exists( '\LiteSpeed\Purge' ) ) {
			do_action( 'litespeed_purge_all' ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- core or third-party hook.
		}
		if ( function_exists( 'sg_cachepress_purge_cache' ) ) {
			sg_cachepress_purge_cache();
		}
		if ( class_exists( 'autoptimizeCache' ) ) {
			\autoptimizeCache::clearall();
		}
		do_action( 'breeze_clear_all_cache' ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- core or third-party hook.
		do_action( 'cache_enabler_clear_complete_cache' ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedHooknameFound -- core or third-party hook.
	}
}