<?php
defined( 'ABSPATH' ) || exit;

class ADCT_LLMS_Scanner {

	/**
	 * @return array<int, array{title:string,url:string,description:string}>
	 */
	public static function collect_section( $section_key, array $section, array $settings, $file ) {
		switch ( $section_key ) {
			case 'pages':
				return self::collect_pages( $section, $settings );
			case 'products':
				return self::collect_products( $section, $settings, $file );
			case 'posts':
				return self::collect_posts( $section, $settings );
			case 'brands':
				return self::collect_brands( $section, $settings );
			default:
				$cpts = $settings[ $file ]['cpts'] ?? $settings['cpts'] ?? array();
				if ( isset( $cpts[ $section_key ] ) ) {
					return self::collect_cpt( $section_key, $cpts[ $section_key ], $settings );
				}
				return array();
		}
	}

	private static function collect_pages( array $section, array $settings ) {
		if ( empty( $section['enabled'] ) || ( $section['mode'] ?? '' ) === 'none' ) {
			return array();
		}

		$mode = $section['mode'] ?? 'pinned';
		$ids  = array();

		if ( in_array( $mode, array( 'pinned', 'selected' ), true ) ) {
			$ids = 'pinned' === $mode ? (array) ( $settings['pinned_page_ids'] ?? array() ) : (array) ( $section['ids'] ?? array() );
			if ( ! empty( $settings['shop_page_id'] ) && 'pinned' === $mode ) {
				$ids[] = absint( $settings['shop_page_id'] );
			}
			$ids = array_values( array_unique( array_filter( array_map( 'absint', $ids ) ) ) );
		}

		$args = array(
			'post_type'              => 'page',
			'post_status'            => 'publish',
			'posts_per_page'         => -1,
			'orderby'                => 'menu_order title',
			'order'                  => 'ASC',
			'no_found_rows'          => true,
			'update_post_meta_cache' => false,
			'update_post_term_cache' => false,
		);

		if ( 'all' === $mode ) {
			$args['posts_per_page'] = -1;
		} elseif ( ! empty( $ids ) ) {
			$args['post__in'] = $ids;
			$args['orderby']  = 'post__in';
		} else {
			return array();
		}

		$exclude_ids = ( 'all' === $mode ) ? self::get_bulk_excluded_ids( $settings, 'page' ) : array();

		return self::query_to_items( new WP_Query( $args ), $settings, $exclude_ids );
	}

	/**
	 * IDs omitted from "All published" scans (structural dedupe + user opt-out).
	 *
	 * @return int[]
	 */
	private static function get_bulk_excluded_ids( array $settings, $post_type ) {
		$exclude = array();

		if ( 'page' === $post_type ) {
			foreach ( array( 'shop_page_id', 'brands_parent_id' ) as $key ) {
				if ( ! empty( $settings[ $key ] ) ) {
					$exclude[] = absint( $settings[ $key ] );
				}
			}

			$exclude = array_merge( $exclude, (array) ( $settings['excluded_page_ids'] ?? array() ) );
		} elseif ( 'post' === $post_type ) {
			$exclude = (array) ( $settings['excluded_post_ids'] ?? array() );
		} elseif ( 'product' === $post_type ) {
			$exclude = (array) ( $settings['excluded_product_ids'] ?? array() );
		}

		return array_values( array_unique( array_filter( array_map( 'absint', $exclude ) ) ) );
	}

	private static function should_skip_post( $post_id, array $settings ) {
		$post_id = absint( $post_id );
		if ( $post_id <= 0 ) {
			return true;
		}

		if ( empty( $settings['skip_yoast_noindex'] ) ) {
			return false;
		}

		return self::is_yoast_noindex( $post_id );
	}

	private static function is_yoast_noindex( $post_id ) {
		$meta = get_post_meta( absint( $post_id ), '_yoast_wpseo_meta-robots-noindex', true );

		return '1' === (string) $meta;
	}

	private static function collect_products( array $section, array $settings, $file ) {
		if ( empty( $section['enabled'] ) || ! post_type_exists( 'product' ) ) {
			return array();
		}

		$include_sold = ADCT_LLMS_Sold_Detector::should_include_sold( $settings, $file );
		$mode         = $section['mode'] ?? 'latest';
		$limit        = absint( $section['limit'] ?? 0 );
		$exclude_ids  = array();

		$args = array(
			'post_type'              => 'product',
			'post_status'            => 'publish',
			'orderby'                => 'date',
			'order'                  => 'DESC',
			'no_found_rows'          => true,
			'update_post_meta_cache' => false,
		);

		if ( 'selected' === $mode ) {
			$ids = array_filter( array_map( 'absint', $section['ids'] ?? array() ) );
			if ( empty( $ids ) ) {
				return array();
			}
			$args['post__in'] = $ids;
			$args['orderby']  = 'post__in';
			$args['posts_per_page'] = count( $ids );
		} elseif ( 'all' === $mode ) {
			$args['posts_per_page'] = -1;
			$exclude_ids            = self::get_bulk_excluded_ids( $settings, 'product' );
		} else {
			$fetch = $limit > 0 ? $limit : 10;
			if ( ! $include_sold ) {
				$fetch = min( 100, max( $fetch * 4, $fetch + 10 ) );
			}
			$args['posts_per_page'] = $fetch;
		}

		$query = new WP_Query( $args );
		$items = array();
		$exclude_lookup = array_fill_keys( array_map( 'absint', $exclude_ids ), true );

		foreach ( $query->posts as $post ) {
			if ( isset( $exclude_lookup[ $post->ID ] ) ) {
				continue;
			}

			if ( self::should_skip_post( $post->ID, $settings ) ) {
				continue;
			}

			if ( ! $include_sold && ADCT_LLMS_Sold_Detector::is_sold( $post->ID, $settings ) ) {
				continue;
			}

			$items[] = self::post_to_item( $post );

			if ( 'latest' === $mode && $limit > 0 && count( $items ) >= $limit ) {
				break;
			}
		}

		return $items;
	}

	private static function collect_posts( array $section, array $settings ) {
		if ( empty( $section['enabled'] ) ) {
			return array();
		}

		$mode  = $section['mode'] ?? 'latest';
		$limit = absint( $section['limit'] ?? 5 );

		$args = array(
			'post_type'      => 'post',
			'post_status'    => 'publish',
			'orderby'        => 'date',
			'order'          => 'DESC',
			'no_found_rows'  => true,
		);

		if ( 'selected' === $mode ) {
			$ids = array_filter( array_map( 'absint', $section['ids'] ?? array() ) );
			if ( empty( $ids ) ) {
				return array();
			}
			$args['post__in']       = $ids;
			$args['orderby']        = 'post__in';
			$args['posts_per_page'] = count( $ids );
		} elseif ( 'all' === $mode ) {
			$args['posts_per_page'] = -1;
		} else {
			$args['posts_per_page'] = $limit > 0 ? $limit : 5;
		}

		$exclude_ids = ( 'all' === $mode ) ? self::get_bulk_excluded_ids( $settings, 'post' ) : array();

		return self::query_to_items( new WP_Query( $args ), $settings, $exclude_ids );
	}

	private static function collect_brands( array $section, array $settings ) {
		if ( empty( $section['enabled'] ) ) {
			return array();
		}

		$mode = $section['mode'] ?? 'taxonomy';

		if ( 'taxonomy' === $mode ) {
			return self::collect_brand_terms( $section, $settings );
		}

		$parent_id = absint( $settings['brands_parent_id'] ?? 0 );

		if ( 'selected' === $mode ) {
			$ids = array_filter( array_map( 'absint', $section['ids'] ?? array() ) );
			if ( empty( $ids ) ) {
				return array();
			}
			$query = new WP_Query(
				array(
					'post_type'      => 'page',
					'post_status'    => 'publish',
					'post__in'       => $ids,
					'orderby'        => 'post__in',
					'posts_per_page' => count( $ids ),
					'no_found_rows'  => true,
				)
			);
			return self::query_to_items( $query, $settings );
		}

		if ( $parent_id <= 0 ) {
			return array();
		}

		$query = new WP_Query(
			array(
				'post_type'              => 'page',
				'post_status'            => 'publish',
				'post_parent'            => $parent_id,
				'posts_per_page'         => -1,
				'orderby'                => 'menu_order title',
				'order'                  => 'ASC',
				'no_found_rows'          => true,
				'update_post_meta_cache' => false,
			)
		);

		return self::query_to_items( $query, $settings );
	}

	private static function collect_brand_terms( array $section, array $settings ) {
		$taxonomy = sanitize_key( $settings['brands_taxonomy'] ?? 'product_brand' );

		if ( '' === $taxonomy || ! taxonomy_exists( $taxonomy ) ) {
			return array();
		}

		$terms = get_terms(
			array(
				'taxonomy'   => $taxonomy,
				'hide_empty' => false,
			)
		);

		if ( is_wp_error( $terms ) || empty( $terms ) ) {
			return array();
		}

		$items = array();

		foreach ( $terms as $term ) {
			$link = get_term_link( $term );
			if ( is_wp_error( $link ) ) {
				continue;
			}

			$items[] = array(
				'title'       => $term->name,
				'url'         => $link,
				'description' => wp_strip_all_tags( $term->description ?? '' ),
			);
		}

		usort(
			$items,
			static function ( $a, $b ) {
				return strcasecmp( $a['title'], $b['title'] );
			}
		);

		$limit = absint( $section['limit'] ?? 0 );
		if ( $limit > 0 ) {
			$items = array_slice( $items, 0, $limit );
		}

		return $items;
	}

	private static function collect_cpt( $post_type, array $section, array $settings = array() ) {
		if ( empty( $section['enabled'] ) ) {
			return array();
		}

		$mode  = $section['mode'] ?? 'latest';
		$limit = absint( $section['limit'] ?? 5 );

		$args = array(
			'post_type'     => sanitize_key( $post_type ),
			'post_status'   => 'publish',
			'orderby'       => 'date',
			'order'         => 'DESC',
			'no_found_rows' => true,
		);

		if ( 'selected' === $mode ) {
			$ids = array_filter( array_map( 'absint', $section['ids'] ?? array() ) );
			if ( empty( $ids ) ) {
				return array();
			}
			$args['post__in']       = $ids;
			$args['orderby']        = 'post__in';
			$args['posts_per_page'] = count( $ids );
		} elseif ( 'all' === $mode ) {
			$args['posts_per_page'] = -1;
		} else {
			$args['posts_per_page'] = $limit > 0 ? $limit : 5;
		}

		return self::query_to_items( new WP_Query( $args ), $settings );
	}

	private static function query_to_items( WP_Query $query, array $settings = array(), array $exclude_ids = array() ) {
		$items          = array();
		$exclude_lookup = array_fill_keys( array_map( 'absint', $exclude_ids ), true );

		foreach ( $query->posts as $post ) {
			if ( isset( $exclude_lookup[ $post->ID ] ) ) {
				continue;
			}

			if ( ! empty( $settings ) && self::should_skip_post( $post->ID, $settings ) ) {
				continue;
			}

			$items[] = self::post_to_item( $post );
		}

		return $items;
	}

	private static function post_to_item( WP_Post $post ) {
		return array(
			'title'       => get_the_title( $post ),
			'url'         => get_permalink( $post ),
			'description' => self::build_description( $post ),
		);
	}

	private static function build_description( WP_Post $post ) {
		if ( 'product' === $post->post_type && function_exists( 'wc_get_product' ) ) {
			$product = wc_get_product( $post->ID );
			if ( $product ) {
				$parts = array_filter(
					array(
						wp_strip_all_tags( $product->get_short_description() ),
						self::product_specs_line( $product ),
					)
				);
				$text = trim( implode( ' | ', $parts ) );
				if ( '' !== $text ) {
					return self::trim_description( $text );
				}
			}
		}

		$excerpt = has_excerpt( $post ) ? $post->post_excerpt : $post->post_content;
		$text    = wp_strip_all_tags( $excerpt );

		return self::trim_description( $text );
	}

	private static function product_specs_line( $product ) {
		$bits = array();

		if ( $product->get_attribute( 'pa_year' ) ) {
			$bits[] = $product->get_attribute( 'pa_year' ) . ' Model';
		}

		if ( $product->get_attribute( 'pa_mileage' ) ) {
			$bits[] = $product->get_attribute( 'pa_mileage' );
		}

		return implode( ' · ', array_filter( $bits ) );
	}

	private static function trim_description( $text ) {
		$text = strip_shortcodes( (string) $text );
		$text = wp_strip_all_tags( $text );
		$text = html_entity_decode( $text, ENT_QUOTES | ENT_HTML5, 'UTF-8' );
		$text = preg_replace( '/\s+/', ' ', trim( $text ) );

		if ( strlen( $text ) > 220 ) {
			$text = substr( $text, 0, 217 ) . '...';
		}

		return $text;
	}
}