<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Booking;

use Unsupervised\Schedular\Payment\StudioSettings;

/**
 * Decides whether a student may still cancel a lesson. Cancellation closes once
 * the lesson starts within the effective cutoff window; instructors and studio
 * admins bypass this entirely and cancel through other paths.
 *
 * The window is resolved per lesson: the offering's own cutoff when it sets one,
 * otherwise the studio default. Both are expressed in hours.
 */
class CancellationPolicy {

	public function __construct( private StudioSettings $settings ) {}

	/**
	 * The effective cutoff in hours for a lesson: the offering's override when
	 * set (a non-negative value), otherwise the studio default.
	 */
	public function cutoffHours( ?int $offeringCutoffHours ): int {
		if ( null !== $offeringCutoffHours && $offeringCutoffHours >= 0 ) {
			return $offeringCutoffHours;
		}

		return $this->settings->cancellationCutoffHours();
	}

	/**
	 * Whether a student may still cancel a lesson starting at $slotStartDt
	 * (WordPress-local `Y-m-d H:i:s`), given the offering's optional cutoff
	 * override. A zero cutoff always allows cancellation; unparseable input
	 * fails open so a student is never trapped by bad data. Pass $now to make
	 * the comparison deterministic in tests.
	 */
	public function studentMayCancel( string $slotStartDt, ?int $offeringCutoffHours, ?string $now = null ): bool {
		$hours = $this->cutoffHours( $offeringCutoffHours );
		if ( $hours <= 0 ) {
			return true;
		}

		$start   = strtotime( $slotStartDt );
		$current = strtotime( $now ?? current_time( 'mysql' ) );
		if ( false === $start || false === $current ) {
			return true;
		}

		return ( $start - $current ) >= $hours * 3600;
	}

	/**
	 * A human-readable description of a cutoff for student-facing messages:
	 * whole days as days, anything else as hours.
	 */
	public function describeCutoff( int $hours ): string {
		if ( $hours > 0 && 0 === $hours % 24 ) {
			$days = $hours / 24;

			/* translators: %d: number of days. */
			return sprintf( _n( '%d day', '%d days', $days, 'unsupervised-schedular' ), $days );
		}

		/* translators: %d: number of hours. */
		return sprintf( _n( '%d hour', '%d hours', $hours, 'unsupervised-schedular' ), $hours );
	}
}