<?php
namespace Akram;

defined( 'ABSPATH' ) || exit;

/**
 * Theme builder: chooses header/footer/single/archive/search/404 templates by display rules,
 * and swaps them into classic and block themes.
 *
 * Rule strings: entire | front | blog | singular | singular:{type} | post:{id} | child:{id} | in_term:{id}
 *               archive | pt_archive:{type} | tax:{taxonomy} | term:{id} | author | author:{id} | date | search | 404
 */
final class Theme_Builder {

	public static $body_type = '';
	private static $resolved = null;
	private static $header_done = false;
	private static $footer_done = false;
	/** Block themes: the theme's own header and footer parts, rendered before wp_head() (see header()). */
	private static $parts = array();
	/** The id of the content area (the target of the page's "Skip to content" link), or '' when the theme has it. */
	private static $main_id = 'content';

	public static function init() {
		add_action( 'wp', array( __CLASS__, 'setup' ), 15 );
		add_filter( 'template_include', array( __CLASS__, 'template_include' ), 999 );
		add_filter( 'render_block', array( __CLASS__, 'block_parts' ), 10, 2 );
		// Templates can also be published, drafted, trashed or deleted from the normal WordPress screens.
		add_action( 'transition_post_status', array( __CLASS__, 'status_changed' ), 10, 3 );
		add_action( 'deleted_post', array( __CLASS__, 'post_deleted' ), 10, 2 );
	}

	public static function status_changed( $new, $old, $post ) {
		if ( $post && 'akram_template' === $post->post_type && $new !== $old ) {
			delete_transient( 'akram_tb_index' );
			Frontend::flush_caches();
		}
	}

	public static function post_deleted( $id, $post = null ) {
		if ( $post && 'akram_template' === $post->post_type ) {
			delete_transient( 'akram_tb_index' );
		}
	}

	// ------------------------------------------------------------------
	// Storage
	// ------------------------------------------------------------------
	public static function get_conditions( $id ) {
		$c = get_post_meta( $id, '_akram_conditions', true );
		return is_array( $c ) ? $c : array();
	}

	public static function set_conditions( $id, array $rules ) {
		$clean = array();
		foreach ( $rules as $r ) {
			if ( empty( $r['rule'] ) || ! preg_match( '/^[a-z0-9_]+(:[a-z0-9_\-]+)?$/', (string) $r['rule'] ) ) {
				continue;
			}
			$clean[] = array(
				'mode' => 'exclude' === ( $r['mode'] ?? '' ) ? 'exclude' : 'include',
				'rule' => (string) $r['rule'],
			);
		}
		update_post_meta( $id, '_akram_conditions', $clean );
		delete_transient( 'akram_tb_index' );
		Frontend::flush_caches();
	}

	public static function get_settings( $id ) {
		$s = get_post_meta( $id, '_akram_settings', true );
		return is_array( $s ) ? $s : array();
	}

	public static function set_settings( $id, array $settings ) {
		$clean = array();
		array_walk_recursive( $settings, static function () {} );
		foreach ( $settings as $k => $v ) {
			$k = sanitize_key( $k );
			if ( is_array( $v ) ) {
				$clean[ $k ] = array_map( static function ( $x ) {
					return is_scalar( $x ) ? sanitize_text_field( (string) $x ) : '';
				}, $v );
			} elseif ( is_bool( $v ) || is_numeric( $v ) ) {
				$clean[ $k ] = $v;
			} else {
				$clean[ $k ] = sanitize_text_field( (string) $v );
			}
		}
		update_post_meta( $id, '_akram_settings', $clean );
		if ( isset( $clean['preview'] ) ) {
			update_post_meta( $id, '_akram_preview', (int) $clean['preview'] );
		}
		delete_transient( 'akram_tb_index' );
	}

	/** Published templates grouped by type (cached). */
	private static function index() {
		$idx = get_transient( 'akram_tb_index' );
		if ( is_array( $idx ) ) {
			return $idx;
		}
		$idx = array();
		$ids = get_posts(
			array(
				'post_type'      => 'akram_template',
				'post_status'    => 'publish',
				'posts_per_page' => 500,
				'fields'         => 'ids',
				'orderby'        => 'modified',
				'order'          => 'DESC',
				'meta_query'     => array( // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query -- bounded query on a builder meta key.
					array(
						'key'     => '_akram_type',
						'value'   => array( 'header', 'footer', 'single', 'archive', 'search', '404', 'popup' ),
						'compare' => 'IN',
					),
				),
			)
		);
		foreach ( $ids as $id ) {
			$idx[ Post_Types::template_type( $id ) ][] = array(
				'id' => $id,
				'c'  => self::get_conditions( $id ),
			);
		}
		set_transient( 'akram_tb_index', $idx, DAY_IN_SECONDS );
		return $idx;
	}

	// ------------------------------------------------------------------
	// Matching
	// ------------------------------------------------------------------
	public static function rule_score( $rule ) {
		list( $name, $arg ) = array_pad( explode( ':', $rule, 2 ), 2, '' );
		switch ( $name ) {
			case 'entire':
				return 10;
			case 'singular':
				return $arg ? 60 : 40;
			case 'archive':
				return 40;
			case 'post':
				return self::is_post( (int) $arg ) ? 100 : 0;
			case 'front':
				return is_front_page() ? 95 : 0;
			case 'blog':
				return is_home() ? 95 : 0;
			default:
				return 70;
		}
	}

	public static function matches( $rule ) {
		list( $name, $arg ) = array_pad( explode( ':', (string) $rule, 2 ), 2, '' );
		$qid = get_queried_object_id();
		switch ( $name ) {
			case 'entire':
				return true;
			case 'front':
				return is_front_page();
			case 'blog':
				return is_home();
			case 'singular':
				return is_singular() && ( ! $arg || is_singular( $arg ) );
			case 'post':
				return self::is_post( (int) $arg );
			case 'child':
				return is_singular() && (int) wp_get_post_parent_id( $qid ) === (int) $arg;
			case 'in_term':
				$t = get_term( (int) $arg );
				return is_singular() && $t && ! is_wp_error( $t ) && has_term( (int) $arg, $t->taxonomy, $qid );
			case 'archive':
				return is_archive() || is_home() && ! is_front_page();
			case 'pt_archive':
				return is_post_type_archive( $arg ) || ( 'post' === $arg && is_home() ) || ( 'product' === $arg && function_exists( 'is_shop' ) && is_shop() );
			case 'tax':
				return 'category' === $arg ? is_category() : ( 'post_tag' === $arg ? is_tag() : is_tax( $arg ) );
			case 'term':
				$t = get_queried_object();
				return ( is_category() || is_tag() || is_tax() ) && $t && (int) $t->term_id === (int) $arg;
			case 'author':
				return is_author( $arg ? (int) $arg : '' );
			case 'date':
				return is_date();
			case 'search':
				return is_search();
			case '404':
				return is_404();
		}
		return (bool) apply_filters( 'akram_condition_rule', false, $name, $arg );
	}

	private static function is_post( $id ) {
		if ( ! $id ) {
			return false;
		}
		if ( is_singular() && get_queried_object_id() === $id ) {
			return true;
		}
		return ( is_home() && (int) get_option( 'page_for_posts' ) === $id );
	}

	/** Best matching template id for a location, 0 if none. */
	public static function resolve( $type ) {
		$idx = self::index();
		$best = 0;
		$score = 0;
		foreach ( (array) ( $idx[ $type ] ?? array() ) as $tpl ) {
			$s = self::score( $tpl['c'] );
			if ( $s > $score ) {
				$score = $s;
				$best  = (int) $tpl['id'];
			}
		}
		return (int) apply_filters( 'akram_template_for_location', $best, $type );
	}

	/** Highest matching include score, or 0 if excluded/unmatched. */
	public static function score( array $conds ) {
		$s = 0;
		foreach ( $conds as $c ) {
			if ( 'exclude' === $c['mode'] && self::matches( $c['rule'] ) ) {
				return 0;
			}
		}
		foreach ( $conds as $c ) {
			if ( 'include' === $c['mode'] && self::matches( $c['rule'] ) ) {
				$s = max( $s, self::rule_score( $c['rule'] ) );
			}
		}
		return $s;
	}

	public static function setup() {
		if ( is_admin() || null !== self::$resolved ) {
			return;
		}
		self::$resolved = array();
		$canvas = Editor::canvas_id();
		if ( 'akram-canvas' === get_page_template_slug( get_queried_object_id() ) && is_singular() ) {
			return; // canvas pages never get header/footer
		}
		$canvas_type = $canvas && 'akram_template' === get_post_type( $canvas ) ? Post_Types::template_type( $canvas ) : '';
		foreach ( array( 'header', 'footer' ) as $loc ) {
			if ( $canvas_type === $loc ) {
				continue;
			}
			$id = self::resolve( $loc );
			if ( $id ) {
				self::$resolved[ $loc ] = $id;
			}
		}
		if ( $canvas_type ) {
			return; // body comes from the editor
		}
		$body = '';
		if ( is_404() ) {
			$body = '404';
		} elseif ( is_search() ) {
			$body = self::resolve( 'search' ) ? 'search' : 'archive';
		} elseif ( is_singular() ) {
			$body = 'single';
		} elseif ( is_archive() || is_home() ) {
			$body = 'archive';
		}
		if ( $body ) {
			$id = self::resolve( $body );
			if ( $id && ! ( 'single' === $body && Document::is_built( get_queried_object_id() ) && ! self::explicit_single( $id ) ) ) {
				self::$resolved['body'] = $id;
				self::$body_type        = $body;
			}
		}
		if ( isset( self::$resolved['header'] ) && ! wp_is_block_theme_safe() ) {
			add_action( 'get_header', array( __CLASS__, 'replace_header' ), 999 );
		}
		if ( isset( self::$resolved['footer'] ) && ! wp_is_block_theme_safe() ) {
			add_action( 'get_footer', array( __CLASS__, 'replace_footer' ), 999 );
		}
		if ( ! empty( self::$resolved ) ) {
			add_action( 'wp_enqueue_scripts', array( __CLASS__, 'head_css' ) );
		}
	}

	/** A single template only replaces an Akram-built page when it targets that page explicitly. */
	private static function explicit_single( $tpl ) {
		foreach ( self::get_conditions( $tpl ) as $c ) {
			if ( 'include' === $c['mode'] && 0 === strpos( $c['rule'], 'post:' ) && self::matches( $c['rule'] ) ) {
				return true;
			}
		}
		return false;
	}

	public static function active_templates() {
		self::setup();
		return array_values( array_unique( array_filter( (array) self::$resolved ) ) );
	}

	public static function has( $loc ) {
		self::setup();
		return ! empty( self::$resolved[ $loc ] );
	}

	public static function template_include( $template ) {
		if ( Editor::canvas_id() && 'akram_template' === get_post_type( Editor::canvas_id() ) ) {
			return $template;
		}
		if ( self::has( 'body' ) ) {
			return AKRAM_DIR . 'templates/theme.php';
		}
		return $template;
	}

	public static function head_css() {
		$css = '.nx-site-header,.nx-site-footer{position:relative;z-index:50}.nx-site-header.is-overlay{position:absolute;left:0;right:0;top:0;z-index:60}.admin-bar .nx-site-header.is-overlay{top:var(--wp-admin--admin-bar--height,0)}'
			// The content area fills the theme's wrapper, also when that wrapper is a flex row (Astra, GeneratePress).
			. '.nx-main{display:block;flex:1 1 100%;width:100%;max-width:100%;min-width:0}';
		wp_register_style( 'akram-tb', false, array(), AKRAM_VERSION );
		wp_enqueue_style( 'akram-tb' );
		wp_add_inline_style( 'akram-tb', $css );
	}

	// ------------------------------------------------------------------
	// Output
	// ------------------------------------------------------------------
	public static function header_html() {
		$id = self::$resolved['header'] ?? 0;
		if ( ! $id ) {
			return '';
		}
		$s = self::get_settings( $id );
		return '<header id="masthead" class="nx-site-header'
			. ( ! empty( $s['overlay'] ) ? ' is-overlay' : '' ) . '" role="banner">'
			. Frontend::render_post( $id ) . '</header>';
	}

	public static function footer_html() {
		$id = self::$resolved['footer'] ?? 0;
		return $id ? '<footer id="colophon" class="nx-site-footer" role="contentinfo">' . Frontend::render_post( $id ) . '</footer>' : '';
	}

	/** Classic themes: print our document head + header, then swallow the theme's header.php. */
	public static function replace_header( $name ) {
		if ( self::$header_done ) {
			return;
		}
		self::$header_done = true;
		self::open_document();
		echo self::header_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Frontend::render_post() (KSES allow-list).
		$templates = array();
		if ( $name ) {
			$templates[] = "header-{$name}.php";
		}
		$templates[] = 'header.php';
		remove_all_actions( 'wp_head' );
		remove_all_actions( 'wp_body_open' );
		ob_start();
		locate_template( $templates, true );
		ob_end_clean();
	}

	public static function replace_footer( $name ) {
		if ( self::$footer_done ) {
			return;
		}
		self::$footer_done = true;
		echo self::footer_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Frontend::render_post() (KSES allow-list).
		wp_footer();
		echo "\n</body>\n</html>";
		$templates = array();
		if ( $name ) {
			$templates[] = "footer-{$name}.php";
		}
		$templates[] = 'footer.php';
		remove_all_actions( 'wp_footer' );
		ob_start();
		locate_template( $templates, true );
		ob_end_clean();
	}

	private static function open_document() {
		?><!DOCTYPE html>
<html <?php language_attributes(); ?>>
<head>
<meta charset="<?php bloginfo( 'charset' ); ?>">
<meta name="viewport" content="width=device-width, initial-scale=1">
<?php wp_head(); ?>
</head>
<body <?php body_class(); ?>>
<?php
		wp_body_open();
		echo '<a class="skip-link screen-reader-text" href="#content">' . esc_html__( 'Skip to content', 'akram' ) . '</a>';
	}

	/** Used by Akram page templates: works for classic and block themes. */
	public static function header() {
		self::setup();
		// Akram templates always need the layout rules (wp_head() has not run yet).
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'head_css' ) );
		if ( ! wp_is_block_theme_safe() ) {
			self::classic_full_width();
			ob_start();
			get_header();
			$html = (string) ob_get_clean();
			echo $html; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- the theme's own header.php output, unchanged.
			self::$main_id = self::skip_target( $html );
			return;
		}
		self::$header_done = true;
		// Like core's template canvas, the theme's parts are rendered before wp_head(): blocks such as Navigation
		// enqueue their styles, scripts and script modules while rendering, and a block theme prints them (and the
		// import map) in the head.
		foreach ( array( 'header', 'footer' ) as $part ) {
			if ( ! self::has( $part ) && function_exists( 'block_template_part' ) ) {
				ob_start();
				block_template_part( $part );
				self::$parts[ $part ] = ob_get_clean();
			}
		}
		self::open_document();
		echo '<div class="wp-site-blocks">';
		if ( self::has( 'header' ) ) {
			echo self::header_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Frontend::render_post() (KSES allow-list).
		} elseif ( isset( self::$parts['header'] ) ) {
			echo self::$parts['header']; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- block markup rendered by core's block_template_part().
		}
	}

	/**
	 * Opens the content area of an Akram template. The theme's own header.php (a classic theme without an Akram header)
	 * already has its #content element, so the id is only used when Akram prints the document.
	 */
	public static function main_open( $class = '' ) {
		echo '<main' . ( self::$main_id ? ' id="' . esc_attr( self::$main_id ) . '"' : '' ) . ' class="' . esc_attr( trim( 'nx-main ' . $class ) ) . '">';
	}

	/**
	 * Classic themes: the id their "Skip to content" link points to, or '' when the header already has that element
	 * (themes such as Hello and Kadence add it in their own page templates, which an Akram template replaces).
	 */
	private static function skip_target( $html ) {
		$id = 'content';
		if ( preg_match_all( '/<a\b[^>]*>/i', $html, $tags ) ) {
			foreach ( $tags[0] as $tag ) {
				if ( false !== stripos( $tag, 'skip-link' ) && preg_match( '/href=["\']#([\w-]+)["\']/', $tag, $m ) ) {
					$id = $m[1];
					break;
				}
			}
		}
		return preg_match( '/\bid=["\']' . preg_quote( $id, '/' ) . '["\']/', $html ) ? '' : $id;
	}

	/**
	 * Classic themes print their own content wrappers in header.php. Themes that offer a full-width, no-sidebar
	 * layout are asked for it, so Akram pages use the whole width as they do in the editor.
	 */
	private static function classic_full_width() {
		// Astra: "Full Width / Stretched" content layout, no sidebar.
		add_filter( 'astra_page_layout', array( __CLASS__, 'no_sidebar' ) );
		add_filter( 'astra_get_content_layout', array( __CLASS__, 'astra_stretched' ) );
		// GeneratePress: no sidebar and its full-width content container.
		add_filter( 'generate_sidebar_layout', array( __CLASS__, 'no_sidebar' ) );
		if ( 'generatepress' === get_template() ) {
			add_filter( 'body_class', array( __CLASS__, 'generatepress_full_width' ) );
		}
	}

	public static function no_sidebar() {
		return 'no-sidebar';
	}

	public static function astra_stretched() {
		return 'page-builder';
	}

	public static function generatepress_full_width( $classes ) {
		$classes[] = 'full-width-content';
		return $classes;
	}

	public static function footer() {
		if ( ! wp_is_block_theme_safe() ) {
			get_footer();
			return;
		}
		self::$footer_done = true;
		if ( self::has( 'footer' ) ) {
			echo self::footer_html(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Frontend::render_post() (KSES allow-list).
		} elseif ( isset( self::$parts['footer'] ) ) {
			echo self::$parts['footer']; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- block markup rendered by core's block_template_part().
		} elseif ( function_exists( 'block_template_part' ) ) {
			block_template_part( 'footer' );
		}
		echo '</div>';
		wp_footer();
		echo "\n</body>\n</html>";
	}

	/** Block themes: replace header/footer template parts. */
	public static function block_parts( $content, $block ) {
		if ( 'core/template-part' !== ( $block['blockName'] ?? '' ) || is_admin() ) {
			return $content;
		}
		$slug = (string) ( $block['attrs']['slug'] ?? '' );
		$area = (string) ( $block['attrs']['area'] ?? $block['attrs']['tagName'] ?? '' );
		if ( ( 'header' === $area || false !== strpos( $slug, 'header' ) ) && self::has( 'header' ) ) {
			return self::header_html();
		}
		if ( ( 'footer' === $area || false !== strpos( $slug, 'footer' ) ) && self::has( 'footer' ) ) {
			return self::footer_html();
		}
		return $content;
	}

	public static function render_location( $type ) {
		$id = self::$resolved['body'] ?? 0;
		if ( ! $id ) {
			return;
		}
		if ( 'single' === $type && have_posts() ) {
			the_post();
		}
		echo Frontend::render_post( $id ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in Frontend::render_post() (KSES allow-list).
		if ( 'single' === $type ) {
			rewind_posts();
		}
	}
}

/** wp_is_block_theme() exists since 5.9. */
function wp_is_block_theme_safe() {
	return function_exists( 'wp_is_block_theme' ) && wp_is_block_theme();
}