<?php
/**
 * Landing page sections: loads the stylesheet on pages that use them, prints the site's design values,
 * gives full-width pages a template without the theme's title, and prints FAQ schema.
 */

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

class Gralus_Sections {
	const FAQ_KEY    = '_gralus_faq';
	const DESIGN_KEY = '_gralus_design';
	const LAYOUT_KEY = '_gralus_layout';

	/**
	 * Print the sections stylesheet inline, only on pages that contain our sections.
	 * Inline, not a separate file: ad-blockers and aggressive caches cannot drop it, and it is one request fewer.
	 */
	public static function enqueue() {
		if ( ! is_singular() ) {
			return;
		}
		$post = get_post();
		if ( ! $post || false === strpos( $post->post_content, 'sa-sections' ) ) {
			return;
		}
		$css    = '';
		$design = get_post_meta( $post->ID, self::DESIGN_KEY, true );
		if ( is_array( $design ) ) {
			$css .= "\n" . self::design_css( $design );
		}
		if ( self::is_full( $post->ID ) ) {
			// Block themes print the title as a block; the hero heading is the page's H1.
			// Block themes put their top spacing on these wrappers as inline styles, hence !important.
			$css .= "\nbody.gralus-landing .wp-block-post-title{display:none}"
				. "\nbody.gralus-landing .wp-site-blocks>main,body.gralus-landing main.wp-block-group{margin-top:0!important;padding-top:0!important}"
				. "\nbody.gralus-landing main .wp-block-group:has(>.wp-block-post-content){padding-top:0!important}"
				. "\nbody.gralus-landing .wp-block-post-content{margin-block-start:0!important}";
		}
		wp_enqueue_style( 'gralus-sections', plugins_url( 'assets/sections.css', GRALUS_FILE ), array(), GRALUS_VERSION );
		if ( '' !== $css ) {
			wp_add_inline_style( 'gralus-sections', $css );
		}
	}

	/** Store the page's design values and layout. Values are checked here; anything malformed is dropped. */
	public static function save_look( $post_id, $design, $layout ) {
		$clean = self::clean_design( $design );
		if ( $clean ) {
			update_post_meta( $post_id, self::DESIGN_KEY, $clean );
		} elseif ( null !== $design ) {
			delete_post_meta( $post_id, self::DESIGN_KEY );
		}
		if ( 'full' === $layout ) {
			update_post_meta( $post_id, self::LAYOUT_KEY, 'full' );
		} elseif ( null !== $layout ) {
			delete_post_meta( $post_id, self::LAYOUT_KEY );
		}
	}

	/** Only colours, px numbers and font names get through. */
	public static function clean_design( $d ) {
		if ( ! is_array( $d ) ) {
			return array();
		}
		$out = array();
		foreach ( array( 'accent', 'onAccent', 'ink', 'background' ) as $k ) {
			if ( isset( $d[ $k ] ) && is_string( $d[ $k ] ) && preg_match( '/^#[0-9a-fA-F]{6}$/', $d[ $k ] ) ) {
				$out[ $k ] = strtolower( $d[ $k ] );
			}
		}
		foreach ( array( 'radius' => 32, 'buttonRadius' => 999 ) as $k => $max ) {
			if ( isset( $d[ $k ] ) && is_numeric( $d[ $k ] ) ) {
				$out[ $k ] = max( 0, min( $max, (int) $d[ $k ] ) );
			}
		}
		if ( isset( $d['width'] ) && is_numeric( $d['width'] ) && (int) $d['width'] >= 900 && (int) $d['width'] <= 1600 ) {
			$out['width'] = (int) $d['width'];
		}
		if ( isset( $d['headerVar'] ) && is_string( $d['headerVar'] ) && preg_match( '/^--[a-zA-Z0-9-]{1,40}$/', $d['headerVar'] ) ) {
			$out['headerVar'] = $d['headerVar'];
		}
		foreach ( array( 'headingFont', 'bodyFont' ) as $k ) {
			if ( isset( $d[ $k ] ) && is_string( $d[ $k ] ) ) {
				$f = trim( preg_replace( '/[^\w\s"\',.-]/', '', $d[ $k ] ) );
				if ( '' !== $f ) {
					$out[ $k ] = substr( $f, 0, 200 );
				}
			}
		}
		return isset( $out['accent'] ) ? $out : array();
	}

	/** The same CSS Gralus shows in its preview (designCss in packages/core/src/design.ts). */
	public static function design_css( $d ) {
		$vars = array();
		$map  = array( 'accent' => '--sa-accent', 'onAccent' => '--sa-on-accent', 'ink' => '--sa-ink', 'background' => '--sa-bg' );
		foreach ( $map as $k => $var ) {
			if ( isset( $d[ $k ] ) ) {
				$vars[] = $var . ':' . $d[ $k ];
			}
		}
		if ( isset( $d['radius'] ) ) {
			$vars[] = '--sa-radius:' . (int) $d['radius'] . 'px';
		}
		if ( isset( $d['buttonRadius'] ) ) {
			$vars[] = '--sa-btn-radius:' . (int) $d['buttonRadius'] . 'px';
		}
		if ( isset( $d['width'] ) ) {
			$vars[] = '--sa-width:' . (int) $d['width'] . 'px';
		}
		if ( isset( $d['headerVar'] ) ) {
			$vars[] = '--sa-header-offset:var(' . $d['headerVar'] . ')';
		}
		if ( isset( $d['headingFont'] ) ) {
			$vars[] = '--sa-heading-font:' . $d['headingFont'];
		}
		if ( isset( $d['bodyFont'] ) ) {
			$vars[] = '--sa-body-font:' . $d['bodyFont'];
		}
		$out = array( '.sa-sections{' . implode( ';', $vars ) . '}' );
		if ( isset( $d['bodyFont'] ) ) {
			$out[] = '.sa-sections{font-family:' . $d['bodyFont'] . '}';
		}
		if ( isset( $d['headingFont'] ) ) {
			$out[] = '.sa-sections h1,.sa-sections h2,.sa-sections h3{font-family:' . $d['headingFont'] . '}';
		}
		return implode( "\n", $out );
	}

	public static function is_full( $post_id ) {
		return 'full' === get_post_meta( $post_id, self::LAYOUT_KEY, true );
	}

	/**
	 * Full-width landing pages in classic themes: the theme's header and footer around the sections, without the
	 * theme's page title and narrow content column. Block themes keep their own template (the sections are full width there).
	 */
	public static function template( $template ) {
		if ( ! is_singular( 'page' ) || ( function_exists( 'wp_is_block_theme' ) && wp_is_block_theme() ) ) {
			return $template;
		}
		$id = get_queried_object_id();
		if ( ! $id || ! self::is_full( $id ) || false === strpos( (string) get_post_field( 'post_content', $id ), 'sa-sections' ) ) {
			return $template;
		}
		return plugin_dir_path( GRALUS_FILE ) . 'templates/landing.php';
	}

	public static function body_class( $classes ) {
		if ( is_singular( 'page' ) && self::is_full( get_queried_object_id() ) ) {
			$classes[] = 'gralus-landing';
		}
		return $classes;
	}

	/** Store FAQ pairs sent with a post (array of {q,a}); an empty list removes them. */
	public static function save_faq( $post_id, $faq ) {
		$clean = array();
		if ( is_array( $faq ) ) {
			foreach ( array_slice( $faq, 0, 20 ) as $item ) {
				$q = isset( $item['q'] ) ? sanitize_text_field( $item['q'] ) : '';
				$a = isset( $item['a'] ) ? sanitize_textarea_field( $item['a'] ) : '';
				if ( '' !== $q && '' !== $a ) {
					$clean[] = array( 'q' => $q, 'a' => $a );
				}
			}
		}
		if ( $clean ) {
			update_post_meta( $post_id, self::FAQ_KEY, $clean );
		} else {
			delete_post_meta( $post_id, self::FAQ_KEY );
		}
	}

	/** FAQPage schema for AI assistants and search engines. */
	public static function print_schema() {
		if ( ! is_singular() ) {
			return;
		}
		$faq = get_post_meta( get_queried_object_id(), self::FAQ_KEY, true );
		if ( empty( $faq ) || ! is_array( $faq ) ) {
			return;
		}
		$entities = array();
		foreach ( $faq as $item ) {
			$entities[] = array(
				'@type'          => 'Question',
				'name'           => $item['q'],
				'acceptedAnswer' => array( '@type' => 'Answer', 'text' => $item['a'] ),
			);
		}
		$schema = array( '@context' => 'https://schema.org', '@type' => 'FAQPage', 'mainEntity' => $entities );
		// JSON_HEX_TAG: a "</script>" inside an answer can't close the tag.
		wp_print_inline_script_tag( wp_json_encode( $schema, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_HEX_TAG ), array( 'type' => 'application/ld+json' ) );
	}
}