<?php
/**
 * Availability Checker Class
 *
 * @package YachtBooking
 */

namespace YachtBooking;

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

/**
 * Availability class - handles yacht availability checking and caching
 */
class Availability {

	/**
	 * Check if yacht is available for given date range
	 *
	 * @param int    $yacht_id Yacht post ID.
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @return bool
	 */
	public static function is_available( $yacht_id, $start_date, $end_date ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';

		// Get all dates in range that are not available
		$unavailable = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(*) FROM $table
				WHERE yacht_id = %d
				AND date >= %s
				AND date < %s
				AND status != 'available'",
				$yacht_id,
				$start_date,
				$end_date
			)
		);

		return 0 === (int) $unavailable;
	}

	/**
	 * Mark dates as booked
	 *
	 * @param int    $yacht_id Yacht post ID.
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @param int    $booking_id Booking post ID.
	 * @return bool
	 */
	public static function mark_as_booked( $yacht_id, $start_date, $end_date, $booking_id ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';
		$dates = self::get_date_range( $start_date, $end_date );

		foreach ( $dates as $date ) {
			$wpdb->replace(
				$table,
				array(
					'yacht_id'   => $yacht_id,
					'date'       => $date,
					'status'     => 'booked',
					'booking_id' => $booking_id,
					'created_at' => current_time( 'mysql' ),
					'updated_at' => current_time( 'mysql' ),
				),
				array( '%d', '%s', '%s', '%d', '%s', '%s' )
			);
		}

		return true;
	}

	/**
	 * Mark dates as blocked (from Google Calendar sync)
	 *
	 * @param int    $yacht_id Yacht post ID.
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @return bool
	 */
	public static function mark_as_blocked( $yacht_id, $start_date, $end_date ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';
		$dates = self::get_date_range( $start_date, $end_date );

		foreach ( $dates as $date ) {
			$wpdb->replace(
				$table,
				array(
					'yacht_id'   => $yacht_id,
					'date'       => $date,
					'status'     => 'blocked',
					'booking_id' => null,
					'created_at' => current_time( 'mysql' ),
					'updated_at' => current_time( 'mysql' ),
				),
				array( '%d', '%s', '%s', '%d', '%s', '%s' )
			);
		}

		return true;
	}

	/**
	 * Mark dates as available (when booking is cancelled)
	 *
	 * @param int    $yacht_id Yacht post ID.
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @return bool
	 */
	public static function mark_as_available( $yacht_id, $start_date, $end_date ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';

		$wpdb->delete(
			$table,
			array(
				'yacht_id' => $yacht_id,
			),
			array( '%d' )
		);

		// Alternative: update to available instead of delete
		// $dates = self::get_date_range( $start_date, $end_date );
		// foreach ( $dates as $date ) {
		//     $wpdb->update(
		//         $table,
		//         array( 'status' => 'available', 'booking_id' => null ),
		//         array( 'yacht_id' => $yacht_id, 'date' => $date ),
		//         array( '%s', '%d' ),
		//         array( '%d', '%s' )
		//     );
		// }

		return true;
	}

	/**
	 * Clear availability for booking
	 *
	 * @param int $booking_id Booking post ID.
	 * @return bool
	 */
	public static function clear_booking_availability( $booking_id ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';

		$wpdb->delete(
			$table,
			array( 'booking_id' => $booking_id ),
			array( '%d' )
		);

		return true;
	}

	/**
	 * Get availability calendar for yacht and month
	 *
	 * @param int    $yacht_id Yacht post ID.
	 * @param string $start Start date (Y-m-d).
	 * @param string $end End date (Y-m-d).
	 * @return array
	 */
	public static function get_availability_calendar( $yacht_id, $start, $end ) {
		global $wpdb;

		$table = $wpdb->prefix . 'yacht_availability';

		$results = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT date, status, booking_id FROM $table
				WHERE yacht_id = %d
				AND date >= %s
				AND date <= %s
				ORDER BY date ASC",
				$yacht_id,
				$start,
				$end
			),
			ARRAY_A
		);

		// Create associative array with date as key
		$calendar = array();
		foreach ( $results as $row ) {
			$calendar[ $row['date'] ] = array(
				'status'     => $row['status'],
				'booking_id' => $row['booking_id'],
			);
		}

		// Fill in missing dates as available
		$all_dates = self::get_date_range( $start, $end );
		foreach ( $all_dates as $date ) {
			if ( ! isset( $calendar[ $date ] ) ) {
				$calendar[ $date ] = array(
					'status'     => 'available',
					'booking_id' => null,
				);
			}
		}

		return $calendar;
	}

	/**
	 * Count days between two dates
	 *
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @return int
	 */
	public static function count_days( $start_date, $end_date ) {
		$start = new \DateTime( $start_date );
		$end   = new \DateTime( $end_date );
		$diff  = $start->diff( $end );

		return (int) $diff->days;
	}

	/**
	 * Get array of dates between start and end (exclusive of end date)
	 *
	 * @param string $start_date Start date (Y-m-d).
	 * @param string $end_date End date (Y-m-d).
	 * @return array
	 */
	private static function get_date_range( $start_date, $end_date ) {
		$dates = array();
		$start = new \DateTime( $start_date );
		$end   = new \DateTime( $end_date );

		while ( $start < $end ) {
			$dates[] = $start->format( 'Y-m-d' );
			$start->modify( '+1 day' );
		}

		return $dates;
	}
}