<?php
/**
 * Shared FAQ renderer used by the shortcode, block and widget.
 *
 * @package AccordionFaq
 */

namespace AccordionFaq\Frontend;

defined( 'ABSPATH' ) || exit;

use AccordionFaq\Setup\Meta;
use AccordionFaq\Setup\Taxonomy;
use AccordionFaq\Schema\Schema;
use AccordionFaq\Support\Options;
use AccordionFaq\Support\Sanitizer;
use AccordionFaq\Support\Template;

/**
 * Class Renderer
 */
class Renderer {

	/**
	 * Schema collector.
	 *
	 * @var Schema
	 */
	private $schema;

	/**
	 * Instance counter for unique IDs within a request.
	 *
	 * @var int
	 */
	private static $counter = 0;

	/**
	 * Constructor.
	 *
	 * @param Schema $schema Schema collector.
	 */
	public function __construct( Schema $schema ) {
		$this->schema = $schema;
	}

	/**
	 * Normalize raw args (from shortcode atts or block attributes) into a
	 * canonical shape, applying settings defaults.
	 *
	 * @param array $raw Raw args.
	 * @return array
	 */
	public function normalize( array $raw ) {
		$defaults = array(
			'id'          => 0,   // Backward-compat: taxonomy term ID.
			'term'        => 0,
			'category'    => '',  // Slug or comma-separated slugs.
			'ids'         => '',  // Explicit FAQ post IDs (comma-separated).
			'style'       => Options::get( 'default_style', 'minimal' ),
			'mode'        => Options::get( 'default_mode', 'accordion' ),
			'engine'      => Options::get( 'engine', 'aria' ),
			'heading'     => Options::get( 'heading_level', 'h3' ),
			'icon'        => Options::get( 'icon_position', 'right' ),
			'icon_style'  => Options::get( 'icon_style', 'chevron' ),
			'voting'      => Options::boolean( 'enable_voting' ),
			'views'       => Options::boolean( 'enable_views' ),
			'open_first'  => Options::boolean( 'default_open_first' ),
			'orderby'     => 'date',
			'order'       => 'ASC',
			'limit'       => -1,
			'search'      => Options::boolean( 'show_search' ),
			'filter'      => Options::boolean( 'show_filter' ),
			'expand_all'  => Options::boolean( 'show_expand_all' ),
			'toc'         => Options::boolean( 'show_toc' ),
			'schema'      => Options::boolean( 'enable_schema' ),
			'per_page'    => (int) Options::get( 'per_page', 0 ),
			'class'       => '',
		);

		$a = wp_parse_args( $raw, $defaults );

		// Backward compatibility: `id`/`ID` meant the taxonomy term ID.
		$term = absint( $a['term'] );
		if ( ! $term && ! empty( $a['id'] ) ) {
			$term = absint( $a['id'] );
		}

		return array(
			'term'       => $term,
			'category'   => Sanitizer::slug_list( $a['category'] ),
			'ids'        => array_filter( array_map( 'absint', Sanitizer::slug_list( is_array( $a['ids'] ) ? $a['ids'] : str_replace( ' ', '', (string) $a['ids'] ) ) ) ),
			'style'      => Sanitizer::enum( $a['style'], array( 'minimal', 'bordered', 'filled', 'separated', 'card', 'modern' ), 'modern' ),
			'mode'       => Sanitizer::enum( $a['mode'], array( 'accordion', 'toggle' ), 'accordion' ),
			'engine'     => Sanitizer::enum( $a['engine'], array( 'aria', 'details' ), 'aria' ),
			'heading'    => Sanitizer::enum( $a['heading'], array( 'h2', 'h3', 'h4', 'h5', 'h6' ), 'h3' ),
			'icon'       => Sanitizer::enum( $a['icon'], array( 'left', 'right' ), 'right' ),
			'icon_style' => Sanitizer::enum( $a['icon_style'], array( 'chevron', 'plus', 'arrow' ), 'chevron' ),
			'voting'     => Sanitizer::boolean( $a['voting'] ),
			'views'      => Sanitizer::boolean( $a['views'] ),
			'open_first' => Sanitizer::boolean( $a['open_first'] ),
			'orderby'    => Sanitizer::enum( $a['orderby'], array( 'date', 'title', 'order' ), 'date' ),
			'order'      => Sanitizer::enum( $a['order'], array( 'ASC', 'DESC' ), 'ASC' ),
			'limit'      => ( '' === $a['limit'] ) ? -1 : (int) $a['limit'],
			'search'     => Sanitizer::boolean( $a['search'] ),
			'filter'     => Sanitizer::boolean( $a['filter'] ),
			'expand_all' => Sanitizer::boolean( $a['expand_all'] ),
			'toc'        => Sanitizer::boolean( $a['toc'] ),
			'schema'     => Sanitizer::boolean( $a['schema'] ),
			'per_page'   => max( 0, (int) $a['per_page'] ),
			'class'      => sanitize_html_class( is_string( $a['class'] ) ? $a['class'] : '' ),
		);
	}

	/**
	 * Render FAQs to HTML.
	 *
	 * @param array $raw Raw args (shortcode atts / block attributes).
	 * @return string
	 */
	public function render( array $raw ) {
		$args = $this->normalize( $raw );
		$wpq  = ( new Query() )->run( $args );

		if ( ! $wpq->have_posts() ) {
			wp_reset_postdata();
			/**
			 * Filter the empty-state HTML.
			 *
			 * @param string $html Empty-state markup.
			 * @param array  $args Normalized args.
			 */
			return apply_filters( 'accordion_faq_empty_output', '', $args );
		}

		$items = array();
		while ( $wpq->have_posts() ) {
			$wpq->the_post();
			$post_id = get_the_ID();

			// Render the answer through the core content pipeline (shortcodes,
			// embeds, wpautop, …). Using the the_content() template tag applies
			// the same filters and the `]]>` guard that a normal loop would.
			ob_start();
			the_content();
			$answer_html = (string) ob_get_clean();

			$question = get_the_title();
			$categories   = wp_get_post_terms( $post_id, Taxonomy::TAXONOMY, array( 'fields' => 'slugs' ) );

			$items[] = array(
				'id'           => $post_id,
				'question'     => $question,
				'answer_html'  => $answer_html,
				'answer_text'  => wp_strip_all_tags( $answer_html ),
				'icon'         => (string) get_post_meta( $post_id, Meta::META_ICON, true ),
				'default_open' => (bool) get_post_meta( $post_id, Meta::META_OPEN, true ),
				'categories'   => is_wp_error( $categories ) ? array() : $categories,
				'anchor'       => sanitize_title( $question ) . '-' . $post_id,
				'up'           => (int) get_post_meta( $post_id, '_afaq_up', true ),
				'down'         => (int) get_post_meta( $post_id, '_afaq_down', true ),
				'views'        => (int) get_post_meta( $post_id, '_afaq_views', true ),
			);
		}
		wp_reset_postdata();

		/**
		 * Filter the collected FAQ items before rendering.
		 *
		 * @param array $items Item data.
		 * @param array $args  Normalized args.
		 */
		$items = apply_filters( 'accordion_faq_items', $items, $args );

		if ( empty( $items ) ) {
			return apply_filters( 'accordion_faq_empty_output', '', $args );
		}

		// Register schema entities (deduplicated in the Schema service).
		if ( $args['schema'] ) {
			$this->schema->add_items( $items );
		}

		// Ensure assets are present.
		Assets::enqueue();

		self::$counter++;
		$uid = 'afaq-' . self::$counter;

		// Categories available for the filter bar.
		$filter_terms = array();
		if ( $args['filter'] ) {
			$filter_terms = $this->collect_filter_terms( $items );
		}

		$html = Template::render(
			'faq-list.php',
			array(
				'uid'          => $uid,
				'args'         => $args,
				'items'        => $items,
				'filter_terms' => $filter_terms,
			)
		);

		/**
		 * Filter the final rendered FAQ HTML.
		 *
		 * @param string $html  Rendered markup.
		 * @param array  $items Item data.
		 * @param array  $args  Normalized args.
		 */
		return apply_filters( 'accordion_faq_output', $html, $items, $args );
	}

	/**
	 * Build a label map for the categories present in the rendered items.
	 *
	 * @param array $items Items.
	 * @return array[] List of [ 'slug' => ..., 'name' => ... ].
	 */
	private function collect_filter_terms( array $items ) {
		$slugs = array();
		foreach ( $items as $item ) {
			foreach ( $item['categories'] as $slug ) {
				$slugs[ $slug ] = true;
			}
		}
		$out = array();
		foreach ( array_keys( $slugs ) as $slug ) {
			$term = get_term_by( 'slug', $slug, Taxonomy::TAXONOMY );
			if ( $term && ! is_wp_error( $term ) ) {
				$out[] = array(
					'slug' => $slug,
					'name' => $term->name,
				);
			}
		}
		return $out;
	}
}