<?php

/**
 * The life of a booking, from taken to finished
 *
 * @link       #
 * @since      1.0.0
 *
 * @package    Abfw
 * @subpackage Abfw/Booking
 */

namespace AdvancedBooking\Booking;

use AdvancedBooking\Settings;
use DateTimeImmutable;

/**
 * Moves a booking along as its dates come and go.
 *
 * Each step moves on its own or by hand, and the shop chooses how long the
 * arrival and the departure are worth signalling.
 *
 * @since      1.0.0
 * @package    Abfw
 * @subpackage Abfw/Booking
 */
class Statuses {

	/**
	 * The steps a booking walks through, in order.
	 */
	const LADDER = array( 'pending', 'start', 'processing', 'end', 'completed' );

	/**
	 * What each status is called on screen.
	 *
	 * @since 1.0.0
	 * @return array
	 */
	public static function labels() {
		return array(
			'pending'    => __( 'Booked', 'abogo-booking' ),
			'start'      => __( 'Arriving', 'abogo-booking' ),
			'processing' => __( 'Out now', 'abogo-booking' ),
			'end'        => __( 'Just back', 'abogo-booking' ),
			'completed'  => __( 'Completed', 'abogo-booking' ),
			'cancelled'  => __( 'Cancelled', 'abogo-booking' ),
		);
	}

	/**
	 * Move every booking that the calendar has caught up with.
	 *
	 * @since 1.0.0
	 * @return int How many bookings moved.
	 */
	public static function sweep() {
		$moved = 0;

		foreach ( Repository::open() as $booking ) {
			$next = self::next_for( $booking );

			if ( $next === $booking->status ) {
				continue;
			}

			Repository::update_status( (int) $booking->id, $next );
			++$moved;
		}

		return $moved;
	}

	/**
	 * The furthest step a booking may reach today.
	 *
	 * Walking stops at the first step the shop moves by hand, so nothing ever
	 * jumps over a step the shop wants to control.
	 *
	 * @since 1.0.0
	 * @param object $booking Booking row.
	 * @return string
	 */
	public static function next_for( $booking ) {
		$today   = new DateTimeImmutable( 'today', wp_timezone() );
		$start   = new DateTimeImmutable( $booking->start_date, wp_timezone() );
		$end     = new DateTimeImmutable( $booking->end_date, wp_timezone() );
		$reached = 'pending';

		$steps = array(
			array( 'start', $start->modify( '-' . (int) Settings::get( 'keep_start' ) . ' days' ), Settings::get( 'set_start' ) ),
			array( 'processing', $start, Settings::get( 'set_processing' ) ),
			array( 'end', $end->modify( '+1 day' ), Settings::get( 'set_end' ) ),
			array( 'completed', $end->modify( '+' . ( (int) Settings::get( 'keep_end' ) + 1 ) . ' days' ), Settings::get( 'set_completed' ) ),
		);

		foreach ( $steps as $step ) {
			list( $status, $due, $how ) = $step;

			if ( $today < $due ) {
				break;
			}

			if ( 'automatic' !== $how ) {
				break;
			}

			$reached = $status;
		}

		// A booking already carried further by hand is never pulled back.
		return self::furthest( $reached, $booking->status );
	}

	/**
	 * Whether a status exists.
	 *
	 * @since 1.0.0
	 * @param string $status Status to check.
	 * @return bool
	 */
	public static function exists( $status ) {
		return array_key_exists( $status, self::labels() );
	}

	/**
	 * The later of two steps.
	 *
	 * @since 1.0.0
	 * @param string $one     First status.
	 * @param string $another Second status.
	 * @return string
	 */
	private static function furthest( $one, $another ) {
		$order = array_flip( self::LADDER );

		if ( ! isset( $order[ $one ], $order[ $another ] ) ) {
			return $one;
		}

		return $order[ $another ] > $order[ $one ] ? $another : $one;
	}
}