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

class VC_API {
	public function get( $endpoint ) {
		return $this->request( 'GET', $endpoint );
	}

	public function post( $endpoint, array $body = array() ) {
		return $this->request( 'POST', $endpoint, $body );
	}

	public function request( $method, $endpoint, array $body = array() ) {
		$api_key = vc_get_api_key();
		if ( '' === $api_key ) {
			return new WP_Error( 'vc_missing_api_key', __( 'Viator API key is missing.', 'viator-collector' ) );
		}

		$this->throttle();

		$base     = untrailingslashit( esc_url_raw( vc_get_option( 'api_base_url', 'https://api.viator.com/partner' ) ) );
		$endpoint = '/' . ltrim( $endpoint, '/' );
		$url      = $base . $endpoint;
		$timeout  = max( 5, absint( vc_get_option( 'timeout', 20 ) ) );

		$args = array(
			'method'  => strtoupper( $method ),
			'timeout' => $timeout,
			'headers' => array(
				'Accept'          => 'application/json;version=2.0',
				'Accept-Language' => sanitize_text_field( vc_get_option( 'language', 'en-US' ) ),
				'Content-Type'    => 'application/json',
				'exp-api-key'     => $api_key,
			),
		);

		if ( ! empty( $body ) && 'GET' !== strtoupper( $method ) ) {
			$args['body'] = wp_json_encode( $body );
		}

		$response = wp_remote_request( $url, $args );
		if ( is_wp_error( $response ) ) {
			VC_Logger::log( 'API request failed: ' . $response->get_error_message(), true );
			return $response;
		}

		$code = (int) wp_remote_retrieve_response_code( $response );
		$raw  = wp_remote_retrieve_body( $response );

		if ( $code < 200 || $code >= 300 ) {
			$message = sprintf( __( 'Viator API request failed with HTTP status %d.', 'viator-collector' ), $code );
			$data    = json_decode( $raw, true );
			if ( is_array( $data ) && ! empty( $data['message'] ) ) {
				$message .= ' ' . sanitize_text_field( $data['message'] );
			}
			VC_Logger::log( $message, true );
			return new WP_Error( 'vc_api_http_error', $message, array( 'status' => $code ) );
		}

		$data = json_decode( $raw, true );
		if ( JSON_ERROR_NONE !== json_last_error() ) {
			return new WP_Error( 'vc_api_json_error', __( 'Viator API returned invalid JSON.', 'viator-collector' ) );
		}

		return is_array( $data ) ? $data : array();
	}

	/**
	 * Block until we are under the configured per-minute request budget.
	 *
	 * Timestamps of recent requests are persisted in an option so the limit
	 * holds across the separate PHP processes that WP-Cron continuation
	 * ticks run in, not just within a single request.
	 */
	private function throttle() {
		$limit = max( 1, (int) vc_get_option( 'rate_limit_per_minute', 25 ) );
		$now   = microtime( true );

		$window = get_option( 'vc_rate_window', array() );
		if ( ! is_array( $window ) ) {
			$window = array();
		}
		$window = array_values(
			array_filter(
				$window,
				static function ( $t ) use ( $now ) {
					return ( $now - (float) $t ) < 60.0;
				}
			)
		);

		if ( count( $window ) >= $limit ) {
			$oldest = min( $window );
			$wait   = 60.0 - ( $now - (float) $oldest ) + 0.05;
			if ( $wait > 0 ) {
				usleep( (int) min( 60.0, $wait ) * 1000000 );
			}
			$now    = microtime( true );
			$window = array_values(
				array_filter(
					$window,
					static function ( $t ) use ( $now ) {
						return ( $now - (float) $t ) < 60.0;
					}
				)
			);
		}

		$window[] = $now;
		update_option( 'vc_rate_window', $window, false );
	}

	/**
	 * Search products within a single destination. This is the only way to
	 * enumerate the catalogue on Basic access: a destination filter is
	 * required and results are returned in pages (max 50 per page).
	 *
	 * @return array|WP_Error Decoded response, typically with `products` and `totalCount`.
	 */
	public function search_products( $destination, $start = 1, $count = 50, $currency = 'USD', array $extra_filters = array() ) {
		$filtering = array_merge( array( 'destination' => (string) $destination ), $extra_filters );
		$body      = array(
			'filtering'  => $filtering,
			'pagination' => array(
				'start' => max( 1, (int) $start ),
				'count' => max( 1, min( 50, (int) $count ) ),
			),
			'currency'   => sanitize_text_field( $currency ),
		);
		return $this->post( '/products/search', $body );
	}

	public function get_product( string $product_code ) {
		return $this->get( '/products/' . rawurlencode( $product_code ) );
	}

	public function get_destinations() {
		$cache_key = 'vc_destinations_' . md5( vc_get_option( 'language', 'en-US' ) );
		$cached    = get_transient( $cache_key );
		if ( false !== $cached ) {
			return $cached;
		}
		$data = $this->get( '/destinations' );
		if ( ! is_wp_error( $data ) ) {
			set_transient( $cache_key, $data, 25 * HOUR_IN_SECONDS );
		}
		return $data;
	}

	public function get_tags() {
		$cache_key = 'vc_tags_' . md5( vc_get_option( 'language', 'en-US' ) );
		$cached    = get_transient( $cache_key );
		if ( false !== $cached ) {
			return $cached;
		}
		$data = $this->get( '/products/tags' );
		if ( ! is_wp_error( $data ) ) {
			set_transient( $cache_key, $data, 25 * HOUR_IN_SECONDS );
		}
		return $data;
	}

	/**
	 * Destination dictionary as a map of destinationId => name.
	 */
	public function get_destination_map() {
		$data = $this->get_destinations();
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		$map = array();
		foreach ( (array) vc_array_get( $data, 'destinations', array() ) as $destination ) {
			$id   = vc_array_get( $destination, 'destinationId' );
			$name = vc_first_non_empty( array( vc_array_get( $destination, 'name' ), vc_array_get( $destination, 'destinationName' ) ) );
			if ( null !== $id && '' !== (string) $name ) {
				$map[ (string) $id ] = $name;
			}
		}
		return $map;
	}

	/**
	 * Tag dictionary as a map of tagId => localized name.
	 */
	public function get_tag_map() {
		$data = $this->get_tags();
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		$lang  = vc_get_option( 'language', 'en-US' );
		$short = strtolower( substr( (string) $lang, 0, 2 ) );
		$map   = array();
		foreach ( (array) vc_array_get( $data, 'tags', array() ) as $tag ) {
			$id    = vc_array_get( $tag, 'tagId' );
			$names = vc_array_get( $tag, 'allNamesByLocale', array() );
			$name  = '';
			if ( is_array( $names ) && ! empty( $names ) ) {
				if ( isset( $names[ $lang ] ) ) {
					$name = $names[ $lang ];
				} elseif ( isset( $names[ $short ] ) ) {
					$name = $names[ $short ];
				} elseif ( isset( $names['en'] ) ) {
					$name = $names['en'];
				} else {
					$name = reset( $names );
				}
			}
			if ( '' === (string) $name ) {
				$name = vc_array_get( $tag, 'name', '' );
			}
			if ( null !== $id && '' !== (string) $name ) {
				$map[ (string) $id ] = $name;
			}
		}
		return $map;
	}
}