<?php
/**
 * iCal Feed Generator (export)
 *
 * Generates .ics feed per yacht for subscription by Google Calendar or other apps.
 *
 * @package YachtBooking
 */

namespace YachtBooking\Integrations\ICal;

use YachtBooking\Booking;
use YachtBooking\Yacht;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * ICal Feed class
 */
class ICal_Feed {

	/**
	 * Register rewrite rules and query vars
	 */
	public static function register() {
		add_action( 'init', array( __CLASS__, 'add_rewrite_rules' ) );
		add_filter( 'query_vars', array( __CLASS__, 'add_query_vars' ) );
		add_action( 'template_redirect', array( __CLASS__, 'handle_feed_request' ) );
	}

	/**
	 * Add rewrite rule for global ical feed
	 */
	public static function add_rewrite_rules() {
		add_rewrite_rule(
			'^yacht-ical-global/([a-zA-Z0-9]+)\.ics$',
			'index.php?yacht_ical_global=1&yacht_ical_token=$matches[1]',
			'top'
		);

		// Flush rewrite rules if our rule is not registered yet.
		$rules = get_option( 'rewrite_rules' );
		if ( is_array( $rules ) && ! isset( $rules['^yacht-ical-global/([a-zA-Z0-9]+)\.ics$'] ) ) {
			flush_rewrite_rules( false );
		}
	}

	/**
	 * Add query vars
	 *
	 * @param array $vars Query vars.
	 * @return array
	 */
	public static function add_query_vars( $vars ) {
		$vars[] = 'yacht_ical_token';
		$vars[] = 'yacht_ical_global';
		return $vars;
	}

	/**
	 * Handle feed request — globalny feed iCal (jeden plik dla całej floty).
	 */
	public static function handle_feed_request() {
		$is_global = (int) get_query_var( 'yacht_ical_global', 0 );
		$token     = get_query_var( 'yacht_ical_token', '' );

		if ( ! $is_global || ! $token ) {
			return;
		}

		$stored_token = self::get_global_feed_token();
		if ( ! $stored_token || ! hash_equals( $stored_token, $token ) ) {
			status_header( 403 );
			exit;
		}

		self::output_global_ics();
	}

	/**
	 * Get or create global feed token (one shared token for all-yachts feed).
	 *
	 * @return string
	 */
	public static function get_global_feed_token() {
		$token = get_option( 'yacht_booking_global_ical_token', '' );

		if ( empty( $token ) ) {
			$token = wp_generate_password( 24, false );
			update_option( 'yacht_booking_global_ical_token', $token );
		}

		return $token;
	}

	/**
	 * Regenerate global feed token (invalidates the previous URL).
	 *
	 * @return string
	 */
	public static function regenerate_global_token() {
		$token = wp_generate_password( 24, false );
		update_option( 'yacht_booking_global_ical_token', $token );
		return $token;
	}

	/**
	 * Get global feed URL (all yachts in one .ics).
	 *
	 * @return string
	 */
	public static function get_global_feed_url() {
		$token = self::get_global_feed_token();
		return home_url( sprintf( '/yacht-ical-global/%s.ics', $token ) );
	}

	/**
	 * Output global .ics feed — wszystkie jachty w jednym pliku.
	 *
	 * Każdy event ma SUMMARY w formacie "{nazwa_jachtu} - {klient}".
	 * Eventy z _booking_source = 'ical_import_global' są pomijane (anti-loop —
	 * nie wysyłamy z powrotem do Google tego, co stamtąd przyszło).
	 */
	private static function output_global_ics() {
		$bookings = get_posts(
			array(
				'post_type'      => 'yacht_booking',
				'posts_per_page' => -1,
				'post_status'    => 'publish',
				'meta_query'     => array(
					array(
						'key'     => '_booking_status',
						'value'   => 'cancelled',
						'compare' => '!=',
					),
				),
			)
		);

		$site_name = get_bloginfo( 'name' );
		$domain    = wp_parse_url( home_url(), PHP_URL_HOST );

		header( 'Content-Type: text/calendar; charset=utf-8' );
		header( 'Content-Disposition: inline; filename="yachts-all.ics"' );
		header( 'Cache-Control: no-cache, must-revalidate' );

		$lines   = array();
		$lines[] = 'BEGIN:VCALENDAR';
		$lines[] = 'VERSION:2.0';
		$lines[] = 'PRODID:-//YachtBooking//NONSGML v1.0//PL';
		$lines[] = 'CALSCALE:GREGORIAN';
		$lines[] = 'METHOD:PUBLISH';
		$lines[] = 'X-WR-CALNAME:' . self::escape_ical(
			sprintf(
				/* translators: %s: site name */
				__( 'Wszystkie jachty - %s', 'yacht-booking' ),
				$site_name
			)
		);
		$lines[] = 'X-WR-TIMEZONE:Europe/Warsaw';

		foreach ( $bookings as $booking ) {
			// Anti-loop: pomiń eventy które zostały zaimportowane z globalnego GCal.
			$source = get_post_meta( $booking->ID, '_booking_source', true );
			if ( ICal_Import::GLOBAL_IMPORT_SOURCE === $source ) {
				continue;
			}

			$yacht_id = (int) Booking::get_yacht_id( $booking->ID );
			if ( ! $yacht_id ) {
				continue;
			}

			$yacht = get_post( $yacht_id );
			if ( ! $yacht ) {
				continue;
			}

			$start  = Booking::get_start_date( $booking->ID );
			$end    = Booking::get_end_date( $booking->ID );
			$status = Booking::get_status( $booking->ID );
			$name   = Booking::get_customer_name( $booking->ID );

			if ( ! $start || ! $end ) {
				continue;
			}

			// iCal DTEND for all-day events is exclusive.
			$end_exclusive = gmdate( 'Ymd', strtotime( $end . ' +1 day' ) );
			$created       = get_the_date( 'Ymd\THis\Z', $booking );

			// Prefiks nazwy jachtu — kluczowy dla późniejszego importu po prefiksie.
			$summary = sprintf( '%s - %s', $yacht->post_title, $name );
			if ( 'pending' === $status ) {
				$summary = '[' . __( 'Oczekująca', 'yacht-booking' ) . '] ' . $summary;
			}

			$lines[] = 'BEGIN:VEVENT';
			$lines[] = 'UID:booking-' . $booking->ID . '@' . $domain;
			$lines[] = 'DTSTART;VALUE=DATE:' . gmdate( 'Ymd', strtotime( $start ) );
			$lines[] = 'DTEND;VALUE=DATE:' . $end_exclusive;
			$lines[] = 'DTSTAMP:' . gmdate( 'Ymd\THis\Z' );
			$lines[] = 'CREATED:' . $created;
			$lines[] = 'SUMMARY:' . self::escape_ical( $summary );
			$lines[] = 'STATUS:CONFIRMED';
			$lines[] = 'TRANSP:OPAQUE';
			$lines[] = 'END:VEVENT';
		}

		$lines[] = 'END:VCALENDAR';

		echo implode( "\r\n", $lines ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- iCal format
		exit;
	}

	/**
	 * Escape iCal text value
	 *
	 * @param string $text Text.
	 * @return string
	 */
	private static function escape_ical( $text ) {
		$text = str_replace( '\\', '\\\\', $text );
		$text = str_replace( ',', '\\,', $text );
		$text = str_replace( ';', '\\;', $text );
		$text = str_replace( "\n", '\\n', $text );
		return $text;
	}
}