<?php
/**
 * Price calculator.
 *
 * Handles price calculations for room bookings.
 *
 * @package Magdev\WpBnb\Pricing
 */

declare( strict_types=1 );

namespace Magdev\WpBnb\Pricing;

use Magdev\WpBnb\PostTypes\Room;

/**
 * Price calculator class.
 */
final class Calculator {

	/**
	 * Meta key prefix for room pricing.
	 *
	 * @var string
	 */
	private const META_PREFIX = '_bnb_room_price_';

	/**
	 * Room post ID.
	 *
	 * @var int
	 */
	private int $room_id;

	/**
	 * Check-in date.
	 *
	 * @var \DateTimeImmutable
	 */
	private \DateTimeImmutable $check_in;

	/**
	 * Check-out date.
	 *
	 * @var \DateTimeImmutable
	 */
	private \DateTimeImmutable $check_out;

	/**
	 * Price breakdown.
	 *
	 * @var array
	 */
	private array $breakdown = array();

	/**
	 * Constructor.
	 *
	 * @param int                                  $room_id   Room post ID.
	 * @param \DateTimeInterface|string            $check_in  Check-in date.
	 * @param \DateTimeInterface|string            $check_out Check-out date.
	 */
	public function __construct( int $room_id, \DateTimeInterface|string $check_in, \DateTimeInterface|string $check_out ) {
		$this->room_id = $room_id;

		if ( is_string( $check_in ) ) {
			$check_in = new \DateTimeImmutable( $check_in );
		} elseif ( $check_in instanceof \DateTime ) {
			$check_in = \DateTimeImmutable::createFromMutable( $check_in );
		}

		if ( is_string( $check_out ) ) {
			$check_out = new \DateTimeImmutable( $check_out );
		} elseif ( $check_out instanceof \DateTime ) {
			$check_out = \DateTimeImmutable::createFromMutable( $check_out );
		}

		$this->check_in  = $check_in;
		$this->check_out = $check_out;
	}

	/**
	 * Get the number of nights.
	 *
	 * @return int
	 */
	public function getNights(): int {
		$interval = $this->check_in->diff( $this->check_out );
		return max( 1, $interval->days );
	}

	/**
	 * Get the pricing tier for this stay.
	 *
	 * @return PricingTier
	 */
	public function getTier(): PricingTier {
		return PricingTier::fromNights( $this->getNights() );
	}

	/**
	 * Get the base price for a room.
	 *
	 * @param PricingTier $tier Pricing tier.
	 * @return float
	 */
	public function getBasePrice( PricingTier $tier ): float {
		$meta_key = self::META_PREFIX . $tier->value;
		$price    = get_post_meta( $this->room_id, $meta_key, true );
		return $price ? (float) $price : 0.0;
	}

	/**
	 * Get the weekend surcharge for a room.
	 *
	 * @return float Surcharge as absolute amount.
	 */
	public function getWeekendSurcharge(): float {
		$surcharge = get_post_meta( $this->room_id, self::META_PREFIX . 'weekend_surcharge', true );
		return $surcharge ? (float) $surcharge : 0.0;
	}

	/**
	 * Check if weekend surcharge is enabled for this room.
	 *
	 * @return bool
	 */
	public function hasWeekendSurcharge(): bool {
		return $this->getWeekendSurcharge() > 0;
	}

	/**
	 * Check if a date is a weekend day.
	 *
	 * @param \DateTimeInterface $date Date to check.
	 * @return bool
	 */
	public static function isWeekend( \DateTimeInterface $date ): bool {
		$day_of_week = (int) $date->format( 'N' ); // 1 = Monday, 7 = Sunday.
		$weekend_days = array_map(
			'intval',
			explode( ',', (string) get_option( 'wp_bnb_weekend_days', '5,6' ) ) // Default: Friday, Saturday.
		);
		return in_array( $day_of_week, $weekend_days, true );
	}

	/**
	 * Calculate the total price.
	 *
	 * @return float
	 */
	public function calculate(): float {
		$this->breakdown = array();

		$nights = $this->getNights();
		$tier   = $this->getTier();

		$base_price        = $this->getBasePrice( $tier );
		$weekend_surcharge = $this->getWeekendSurcharge();

		// If no base price is set, return 0.
		if ( $base_price <= 0 ) {
			return 0.0;
		}

		$total = 0.0;

		// Calculate based on tier.
		switch ( $tier ) {
			case PricingTier::LONG_TERM:
				// Monthly pricing.
				$months = ceil( $nights / 30 );
				$total  = $base_price * $months;
				$this->breakdown['months'] = $months;
				$this->breakdown['monthly_rate'] = $base_price;
				break;

			case PricingTier::MID_TERM:
				// Weekly pricing.
				$weeks = ceil( $nights / 7 );
				$total = $base_price * $weeks;
				$this->breakdown['weeks'] = $weeks;
				$this->breakdown['weekly_rate'] = $base_price;
				break;

			case PricingTier::SHORT_TERM:
			default:
				// Nightly pricing with seasonal adjustments and weekend surcharges.
				$current = $this->check_in;
				$breakdown_nights = array();

				for ( $i = 0; $i < $nights; $i++ ) {
					$night_price = $base_price;
					$modifiers   = array();

					// Apply seasonal pricing.
					$season = Season::forDate( $current );
					if ( $season ) {
						$night_price *= $season->modifier;
						$modifiers['season'] = array(
							'name'     => $season->name,
							'modifier' => $season->modifier,
						);
					}

					// Apply weekend surcharge.
					if ( $weekend_surcharge > 0 && self::isWeekend( $current ) ) {
						$night_price += $weekend_surcharge;
						$modifiers['weekend'] = $weekend_surcharge;
					}

					$breakdown_nights[] = array(
						'date'      => $current->format( 'Y-m-d' ),
						'base'      => $base_price,
						'final'     => $night_price,
						'modifiers' => $modifiers,
					);

					$total  += $night_price;
					$current = $current->modify( '+1 day' );
				}

				$this->breakdown['nights']       = $breakdown_nights;
				$this->breakdown['nightly_rate'] = $base_price;
				break;
		}

		$this->breakdown['tier']  = $tier->value;
		$this->breakdown['total'] = $total;

		/**
		 * Filter the calculated price.
		 *
		 * @param float      $total      Calculated total price.
		 * @param int        $room_id    Room post ID.
		 * @param Calculator $calculator Calculator instance.
		 */
		return (float) apply_filters( 'wp_bnb_calculate_price', $total, $this->room_id, $this );
	}

	/**
	 * Get the price breakdown.
	 *
	 * Must be called after calculate().
	 *
	 * @return array
	 */
	public function getBreakdown(): array {
		return $this->breakdown;
	}

	/**
	 * Format a price with currency.
	 *
	 * @param float  $amount   Amount to format.
	 * @param string $currency Currency code. Default from settings.
	 * @return string
	 */
	public static function formatPrice( float $amount, string $currency = '' ): string {
		if ( empty( $currency ) ) {
			$currency = get_option( 'wp_bnb_currency', 'CHF' );
		}

		$symbols = array(
			'CHF' => 'CHF',
			'EUR' => "\u{20AC}",
			'USD' => '$',
			'GBP' => "\u{00A3}",
		);

		$symbol    = $symbols[ $currency ] ?? $currency;
		$formatted = number_format( $amount, 2, '.', "'" );

		// CHF uses suffix, others use prefix.
		if ( 'CHF' === $currency ) {
			return $formatted . ' ' . $symbol;
		}

		return $symbol . ' ' . $formatted;
	}

	/**
	 * Get room pricing summary.
	 *
	 * @param int $room_id Room post ID.
	 * @return array
	 */
	public static function getRoomPricing( int $room_id ): array {
		$pricing = array();

		foreach ( PricingTier::cases() as $tier ) {
			$meta_key = self::META_PREFIX . $tier->value;
			$price    = get_post_meta( $room_id, $meta_key, true );

			$pricing[ $tier->value ] = array(
				'label' => $tier->label(),
				'unit'  => $tier->unit(),
				'price' => $price ? (float) $price : null,
			);
		}

		$pricing['weekend_surcharge'] = array(
			'label' => __( 'Weekend Surcharge', 'wp-bnb' ),
			'price' => (float) get_post_meta( $room_id, self::META_PREFIX . 'weekend_surcharge', true ),
		);

		return $pricing;
	}

	/**
	 * Save room pricing.
	 *
	 * @param int   $room_id Room post ID.
	 * @param array $pricing Pricing data with tier keys.
	 * @return void
	 */
	public static function saveRoomPricing( int $room_id, array $pricing ): void {
		foreach ( PricingTier::cases() as $tier ) {
			if ( isset( $pricing[ $tier->value ] ) ) {
				update_post_meta(
					$room_id,
					self::META_PREFIX . $tier->value,
					floatval( $pricing[ $tier->value ] )
				);
			}
		}

		if ( isset( $pricing['weekend_surcharge'] ) ) {
			update_post_meta(
				$room_id,
				self::META_PREFIX . 'weekend_surcharge',
				floatval( $pricing['weekend_surcharge'] )
			);
		}
	}

	/**
	 * Get the check-in date.
	 *
	 * @return \DateTimeImmutable
	 */
	public function getCheckIn(): \DateTimeImmutable {
		return $this->check_in;
	}

	/**
	 * Get the check-out date.
	 *
	 * @return \DateTimeImmutable
	 */
	public function getCheckOut(): \DateTimeImmutable {
		return $this->check_out;
	}

	/**
	 * Get the room ID.
	 *
	 * @return int
	 */
	public function getRoomId(): int {
		return $this->room_id;
	}
}