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

class VC_Importer {
	private $api;
	private $destination_map = array();
	private $tag_map         = array();

	public function __construct( VC_API $api = null ) {
		$this->api = $api ? $api : new VC_API();
	}

	/**
	 * Force-refresh the destination and tag dictionaries and cache them.
	 * Returns a WP_Error if either lookup fails (so a run can abort early).
	 */
	public function prime_dictionaries() {
		$dest = $this->api->get_destination_map();
		if ( is_wp_error( $dest ) ) {
			return $dest;
		}
		$tags = $this->api->get_tag_map();
		if ( is_wp_error( $tags ) ) {
			return $tags;
		}
		set_transient( 'vc_destination_map', $dest, 25 * HOUR_IN_SECONDS );
		set_transient( 'vc_tag_map', $tags, 25 * HOUR_IN_SECONDS );
		$this->destination_map = $dest;
		$this->tag_map         = $tags;
		return true;
	}

	/**
	 * Load dictionaries from cache, fetching them if the cache is cold.
	 */
	public function load_dictionaries() {
		$dest = get_transient( 'vc_destination_map' );
		if ( false === $dest ) {
			$dest = $this->api->get_destination_map();
			$dest = is_wp_error( $dest ) ? array() : $dest;
			set_transient( 'vc_destination_map', $dest, 25 * HOUR_IN_SECONDS );
		}
		$tags = get_transient( 'vc_tag_map' );
		if ( false === $tags ) {
			$tags = $this->api->get_tag_map();
			$tags = is_wp_error( $tags ) ? array() : $tags;
			set_transient( 'vc_tag_map', $tags, 25 * HOUR_IN_SECONDS );
		}
		$this->destination_map = is_array( $dest ) ? $dest : array();
		$this->tag_map         = is_array( $tags ) ? $tags : array();
	}

	/**
	 * Crawl one page of products for a single destination.
	 *
	 * Each product is deduplicated by code within a run (via $run_id) so its
	 * full detail is only fetched once even though it surfaces under several
	 * destinations.
	 *
	 * @return array|WP_Error Per-page summary including totalCount and page size.
	 */
	public function crawl_destination( $destination_id, $start, $count, $run_id ) {
		$currency = vc_get_option( 'currency', 'USD' );
		$response = $this->api->search_products( $destination_id, $start, $count, $currency );
		if ( is_wp_error( $response ) ) {
			return $response;
		}

		$products = vc_array_get( $response, 'products', array() );
		$summary  = array(
			'count'       => 0,
			'imported'    => 0,
			'updated'     => 0,
			'duplicate'   => 0,
			'deactivated' => 0,
			'failed'      => 0,
			'total'       => (int) vc_first_non_empty( array( vc_array_get( $response, 'totalCount' ), vc_array_get( $response, 'total' ) ), 0 ),
		);

		foreach ( (array) $products as $product ) {
			if ( ! is_array( $product ) ) {
				continue;
			}
			$summary['count']++;
			$outcome = $this->process_search_product( $product, $destination_id, $run_id );
			if ( isset( $summary[ $outcome ] ) ) {
				$summary[ $outcome ]++;
			}
		}

		return $summary;
	}

	/**
	 * Process one product returned by search: skip if already handled this
	 * run, otherwise optionally fetch full detail and create/update the post.
	 *
	 * @return string One of imported|updated|duplicate|deactivated|failed.
	 */
	private function process_search_product( array $product, $destination_id, $run_id ) {
		$code = (string) vc_first_non_empty( array( vc_array_get( $product, 'productCode' ), vc_array_get( $product, 'code' ) ) );
		if ( '' === $code ) {
			return 'failed';
		}

		$existing = $this->find_existing_tour( $code );
		if ( $existing && (string) get_post_meta( $existing, '_vc_synced_run', true ) === (string) $run_id ) {
			// Already fully processed under another destination during this run.
			return 'duplicate';
		}

		// Optionally enrich the summary with full product detail.
		if ( vc_get_option( 'fetch_full_detail', 0 ) ) {
			$detail = $this->api->get_product( $code );
			if ( ! is_wp_error( $detail ) && is_array( $detail ) ) {
				$product = $this->merge_detail( $product, $detail );
			} elseif ( is_wp_error( $detail ) ) {
				VC_Logger::log( 'Detail fetch failed (' . $code . '): ' . $detail->get_error_message() );
			}
		}

		$product  = $this->ensure_destination( $product, $destination_id );
		$inactive = $this->is_product_inactive( $product );

		$result = $this->create_or_update_tour( $product, $inactive );
		if ( is_wp_error( $result ) ) {
			VC_Logger::error( 'Product import failed (' . $code . '): ' . $result->get_error_message() );
			return 'failed';
		}

		update_post_meta( (int) $result, '_vc_synced_run', (string) $run_id );

		if ( $inactive ) {
			return 'deactivated';
		}
		return $existing ? 'updated' : 'imported';
	}

	/**
	 * Overlay full-detail fields onto the search summary while keeping
	 * summary-only fields (pricing/destinations/tags) when detail omits them.
	 */
	private function merge_detail( array $summary, array $detail ) {
		$merged = array_replace( $summary, $detail );
		foreach ( array( 'pricing', 'destinations', 'tags', 'reviews', 'images' ) as $key ) {
			if ( empty( $merged[ $key ] ) && ! empty( $summary[ $key ] ) ) {
				$merged[ $key ] = $summary[ $key ];
			}
		}
		return $merged;
	}

	/**
	 * Make sure the destination we searched is present on the product so its
	 * taxonomy term is assigned even if the payload omits it.
	 */
	private function ensure_destination( array $product, $destination_id ) {
		$destinations = vc_array_get( $product, 'destinations', array() );
		if ( ! is_array( $destinations ) ) {
			$destinations = array();
		}
		foreach ( $destinations as $destination ) {
			$ref = vc_first_non_empty( array( vc_array_get( $destination, 'ref' ), vc_array_get( $destination, 'destinationId' ), is_scalar( $destination ) ? $destination : null ) );
			if ( (string) $ref === (string) $destination_id ) {
				return $product;
			}
		}
		$destinations[]          = array( 'ref' => (string) $destination_id );
		$product['destinations'] = $destinations;
		return $product;
	}

	/**
	 * Fetch full product detail for an already-imported post and merge it into
	 * the stored summary. Used for lazy, on-view enrichment so we only pay the
	 * per-product request for tours that are actually viewed.
	 *
	 * @return bool True on success.
	 */
	public function enrich_from_detail( $post_id, $product_code ) {
		$product_code = sanitize_text_field( (string) $product_code );
		if ( '' === $product_code ) {
			return false;
		}

		$detail = $this->api->get_product( $product_code );
		if ( is_wp_error( $detail ) || ! is_array( $detail ) ) {
			if ( is_wp_error( $detail ) ) {
				VC_Logger::log( 'Detail enrichment failed (' . $product_code . '): ' . $detail->get_error_message() );
			}
			return false;
		}

		$this->load_dictionaries();

		$summary = vc_json_decode_meta( get_post_meta( $post_id, '_vc_raw_response', true ), array() );
		$product = is_array( $summary ) && ! empty( $summary ) ? $this->merge_detail( $summary, $detail ) : $detail;

		$inactive = $this->is_product_inactive( $product );
		$this->save_tour_meta( $post_id, $product, $inactive );
		$this->assign_taxonomies( $post_id, $product );
		$this->save_image_urls( $post_id, $product );
		update_post_meta( $post_id, '_vc_detail_fetched', current_time( 'mysql' ) );

		return true;
	}

	public function import_product_by_code( $product_code ) {
		$product_code = sanitize_text_field( $product_code );
		if ( '' === $product_code ) {
			return new WP_Error( 'vc_missing_product_code', __( 'Product code is required.', 'viator-collector' ) );
		}
		$product = $this->api->get_product( $product_code );
		if ( is_wp_error( $product ) ) {
			return $product;
		}
		$this->load_dictionaries();
		return $this->create_or_update_tour( $product, $this->is_product_inactive( $product ) );
	}

	public function find_existing_tour( $product_code ) {
		$query = new WP_Query(
			array(
				'post_type'              => 'viator_tour',
				'post_status'            => 'any',
				'posts_per_page'         => 1,
				'fields'                 => 'ids',
				'no_found_rows'          => true,
				'update_post_meta_cache' => false,
				'update_post_term_cache' => false,
				'meta_query'             => array(
					array(
						'key'   => '_vc_viator_product_code',
						'value' => sanitize_text_field( (string) $product_code ),
					),
				),
			)
		);

		return ! empty( $query->posts ) ? (int) $query->posts[0] : 0;
	}

	public function create_or_update_tour( array $product, $inactive = false ) {
		$product_code = vc_first_non_empty( array( vc_array_get( $product, 'productCode' ), vc_array_get( $product, 'code' ) ) );
		if ( '' === (string) $product_code ) {
			return new WP_Error( 'vc_missing_product_code', __( 'Product data is missing a Viator product code.', 'viator-collector' ) );
		}

		$title = vc_first_non_empty( array( vc_array_get( $product, 'title' ), vc_array_get( $product, 'name' ), $product_code ) );
		$desc  = vc_first_non_empty( array( vc_array_get( $product, 'description' ), vc_array_get( $product, 'overview' ) ) );
		$short = vc_first_non_empty( array( vc_array_get( $product, 'shortDescription' ), vc_array_get( $product, 'summary' ) ) );

		if ( $inactive ) {
			$status = 'draft';
		} else {
			$status = vc_get_option( 'default_post_status', 'publish' );
			if ( ! in_array( $status, array( 'publish', 'draft', 'pending' ), true ) ) {
				$status = 'publish';
			}
		}

		$postarr = array(
			'post_type'    => 'viator_tour',
			'post_title'   => wp_strip_all_tags( $title ),
			'post_content' => wp_kses_post( $desc ),
			'post_excerpt' => wp_kses_post( $short ),
			'post_status'  => $status,
		);

		$post_id = $this->find_existing_tour( $product_code );
		if ( $post_id ) {
			$postarr['ID'] = $post_id;
			$result        = wp_update_post( wp_slash( $postarr ), true );
		} else {
			$result = wp_insert_post( wp_slash( $postarr ), true );
		}

		if ( is_wp_error( $result ) ) {
			return $result;
		}

		$post_id = (int) $result;
		update_post_meta( $post_id, '_vc_viator_product_code', sanitize_text_field( (string) $product_code ) );
		$this->save_tour_meta( $post_id, $product, $inactive );
		$this->assign_taxonomies( $post_id, $product );
		$this->save_image_urls( $post_id, $product );

		return $post_id;
	}

	public function save_tour_meta( $post_id, array $product, $inactive = false ) {
		$price = vc_first_non_empty(
			array(
				vc_array_get( $product, 'pricing.summary.fromPrice' ),
				vc_array_get( $product, 'price.fromPrice' ),
				vc_array_get( $product, 'fromPrice' ),
			)
		);
		$currency = vc_first_non_empty(
			array(
				vc_array_get( $product, 'pricing.currency' ),
				vc_array_get( $product, 'currency' ),
				vc_get_option( 'currency', 'USD' ),
			)
		);
		$duration_minutes = vc_first_non_empty(
			array(
				vc_array_get( $product, 'duration.fixedDurationInMinutes' ),
				vc_array_get( $product, 'duration.variableDurationFromMinutes' ),
				vc_array_get( $product, 'durationMinutes' ),
			)
		);
		$duration_text = vc_first_non_empty(
			array(
				vc_array_get( $product, 'duration.displayDuration' ),
				vc_array_get( $product, 'durationText' ),
			)
		);
		$booking_url = vc_first_non_empty(
			array(
				vc_array_get( $product, 'productUrl' ),
				vc_array_get( $product, 'bookingUrl' ),
				vc_array_get( $product, 'bookingLink' ),
			)
		);
		$supplier = vc_first_non_empty(
			array(
				vc_array_get( $product, 'supplier.name' ),
				vc_array_get( $product, 'supplierName' ),
			)
		);
		$rating = vc_first_non_empty(
			array(
				vc_array_get( $product, 'reviews.combinedAverageRating' ),
				vc_array_get( $product, 'rating' ),
			)
		);
		$review_count = vc_first_non_empty(
			array(
				vc_array_get( $product, 'reviews.totalReviews' ),
				vc_array_get( $product, 'reviewCount' ),
			)
		);

		// Marketing flags (FREE_CANCELLATION, SPECIAL_OFFER, LIKELY_TO_SELL_OUT, …).
		$flags = vc_array_get( $product, 'flags', array() );
		$flags = is_array( $flags ) ? array_values( array_map( 'sanitize_text_field', $flags ) ) : array();

		// Maximum group size (present in full product detail only).
		$max_travelers = vc_first_non_empty(
			array(
				vc_array_get( $product, 'bookingRequirements.maxTravelersPerBooking' ),
				vc_array_get( $product, 'bookingRequirements.maxTravelers' ),
				vc_array_get( $product, 'maxTravelers' ),
			)
		);

		$meta = array(
			'_vc_booking_url'         => esc_url_raw( $booking_url ),
			'_vc_price_from'          => $price,
			'_vc_currency'            => sanitize_text_field( $currency ),
			'_vc_duration_minutes'    => absint( $duration_minutes ),
			'_vc_duration_text'       => sanitize_text_field( $duration_text ),
			'_vc_itinerary'           => wp_json_encode( vc_array_get( $product, 'itinerary', array() ) ),
			'_vc_inclusions'          => wp_json_encode( vc_array_get( $product, 'inclusions', array() ) ),
			'_vc_exclusions'          => wp_json_encode( vc_array_get( $product, 'exclusions', array() ) ),
			'_vc_additional_info'     => wp_json_encode( vc_array_get( $product, 'additionalInfo', array() ) ),
			'_vc_cancellation_policy' => wp_json_encode( vc_first_non_empty( array( vc_array_get( $product, 'cancellationPolicy' ), vc_array_get( $product, 'cancellation' ) ), array() ) ),
			'_vc_supplier'            => sanitize_text_field( $supplier ),
			'_vc_destinations'        => wp_json_encode( vc_array_get( $product, 'destinations', array() ) ),
			'_vc_tags'                => wp_json_encode( vc_array_get( $product, 'tags', array() ) ),
			'_vc_rating'              => sanitize_text_field( (string) $rating ),
			'_vc_review_count'        => absint( $review_count ),
			'_vc_flags'               => wp_json_encode( $flags ),
			'_vc_free_cancellation'   => in_array( 'FREE_CANCELLATION', $flags, true ) ? 1 : 0,
			'_vc_max_travelers'       => absint( $max_travelers ),
			'_vc_is_active'           => $inactive ? 0 : 1,
			'_vc_last_synced_at'      => current_time( 'mysql' ),
		);

		foreach ( $meta as $key => $value ) {
			update_post_meta( $post_id, $key, $value );
		}

		// The full API response is always stored so any field can be surfaced later.
		update_post_meta( $post_id, '_vc_raw_response', wp_json_encode( $product ) );
	}

	public function assign_taxonomies( $post_id, array $product ) {
		$destination_ids = array();
		foreach ( (array) vc_array_get( $product, 'destinations', array() ) as $destination ) {
			$ref = vc_first_non_empty(
				array(
					vc_array_get( $destination, 'ref' ),
					vc_array_get( $destination, 'destinationId' ),
					is_scalar( $destination ) ? $destination : null,
				)
			);
			if ( '' === (string) $ref ) {
				continue;
			}
			$name    = isset( $this->destination_map[ (string) $ref ] ) ? $this->destination_map[ (string) $ref ] : '';
			$term_id = VC_Taxonomies::get_or_create_destination_by_id( $ref, $name );
			if ( $term_id ) {
				$destination_ids[] = (int) $term_id;
			}
		}

		$tag_ids = array();
		foreach ( (array) vc_array_get( $product, 'tags', array() ) as $tag ) {
			$id = is_scalar( $tag ) ? $tag : vc_first_non_empty( array( vc_array_get( $tag, 'tagId' ), vc_array_get( $tag, 'id' ) ) );
			if ( '' === (string) $id ) {
				continue;
			}
			$name    = isset( $this->tag_map[ (string) $id ] ) ? $this->tag_map[ (string) $id ] : '';
			$term_id = VC_Taxonomies::get_or_create_tag_by_id( $id, $name );
			if ( $term_id ) {
				$tag_ids[] = (int) $term_id;
			}
		}

		wp_set_object_terms( $post_id, array_values( array_unique( $destination_ids ) ), 'viator_destination', false );
		wp_set_object_terms( $post_id, array_values( array_unique( $tag_ids ) ), 'viator_tag', false );
	}

	/**
	 * Store image URLs (and a primary URL) without downloading anything.
	 */
	public function save_image_urls( $post_id, array $product ) {
		$images = vc_first_non_empty(
			array(
				vc_array_get( $product, 'images', array() ),
				vc_array_get( $product, 'media.images', array() ),
			),
			array()
		);

		$urls    = array();
		$primary = '';
		foreach ( (array) $images as $image ) {
			$url = $this->best_image_url( $image );
			if ( '' === $url ) {
				continue;
			}
			$urls[] = $url;
			if ( '' === $primary && ( is_scalar( $image ) || vc_array_get( $image, 'isCover' ) ) ) {
				$primary = $url;
			}
		}

		$urls = array_values( array_unique( array_filter( $urls ) ) );
		if ( '' === $primary && ! empty( $urls ) ) {
			$primary = $urls[0];
		}

		update_post_meta( $post_id, '_vc_gallery_image_urls', wp_json_encode( $urls ) );
		update_post_meta( $post_id, '_vc_primary_image_url', esc_url_raw( $primary ) );
	}

	/**
	 * Pick the highest-resolution variant available for an image entry.
	 */
	private function best_image_url( $image ) {
		if ( is_string( $image ) ) {
			return esc_url_raw( $image );
		}
		if ( ! is_array( $image ) ) {
			return '';
		}

		$variants = vc_array_get( $image, 'variants', array() );
		if ( is_array( $variants ) && ! empty( $variants ) ) {
			$best       = '';
			$best_width = -1;
			foreach ( $variants as $variant ) {
				$url = vc_array_get( $variant, 'url' );
				if ( ! $url ) {
					continue;
				}
				$width = (int) vc_array_get( $variant, 'width', 0 );
				if ( $width >= $best_width ) {
					$best_width = $width;
					$best       = $url;
				}
			}
			if ( '' !== $best ) {
				return esc_url_raw( $best );
			}
		}

		$url = vc_first_non_empty(
			array(
				vc_array_get( $image, 'url' ),
				vc_array_get( $image, 'large' ),
				vc_array_get( $image, 'medium' ),
				vc_array_get( $image, 'imageSource' ),
			)
		);
		return $url ? esc_url_raw( $url ) : '';
	}

	/**
	 * Detect whether the feed reports this product as no longer bookable.
	 */
	private function is_product_inactive( array $product ) {
		$status = strtoupper( (string) vc_first_non_empty( array( vc_array_get( $product, 'status' ), vc_array_get( $product, 'productStatus' ) ) ) );
		if ( '' !== $status && in_array( $status, array( 'INACTIVE', 'DEACTIVATED', 'EXPIRED', 'REMOVED', 'DELETED' ), true ) ) {
			return true;
		}
		if ( false === vc_array_get( $product, 'active', null ) ) {
			return true;
		}
		if ( vc_array_get( $product, 'isDeactivated', false ) ) {
			return true;
		}
		return false;
	}
}