<?php
/**
 * In-progress appointment being built inside a session.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Domain\Steps;

use DateTimeImmutable;

/**
 * Immutable draft booking line for the step engine.
 *
 * @since 0.1.0
 */
final class PreparedBooking {

	/**
	 * Constructor.
	 *
	 * @param int|null                   $service_id       Service id.
	 * @param int|null                   $duration_id      Duration id.
	 * @param int|null                   $location_id      Location id.
	 * @param int|null                   $agent_id         Agent id (null = any).
	 * @param bool                       $any_agent        Customer chose "any".
	 * @param DateTimeImmutable|null     $start_utc        Start UTC.
	 * @param DateTimeImmutable|null     $end_utc          End UTC.
	 * @param DateTimeImmutable|null     $buffer_start_utc Buffer start.
	 * @param DateTimeImmutable|null     $buffer_end_utc   Buffer end.
	 * @param string|null                $timezone         IANA zone.
	 * @param int                        $attendees        Attendees.
	 * @param list<array<string, mixed>> $extras       Selected extras.
	 * @param array<string, mixed>       $custom_fields    Custom fields.
	 * @param int                        $price_minor      Line price minor units.
	 * @param string                     $currency         Currency code.
	 * @param int|null                   $hold_id          Soft-hold booking id.
	 */
	public function __construct(
		private readonly ?int $service_id = null,
		private readonly ?int $duration_id = null,
		private readonly ?int $location_id = null,
		private readonly ?int $agent_id = null,
		private readonly bool $any_agent = false,
		private readonly ?DateTimeImmutable $start_utc = null,
		private readonly ?DateTimeImmutable $end_utc = null,
		private readonly ?DateTimeImmutable $buffer_start_utc = null,
		private readonly ?DateTimeImmutable $buffer_end_utc = null,
		private readonly ?string $timezone = null,
		private readonly int $attendees = 1,
		private readonly array $extras = [],
		private readonly array $custom_fields = [],
		private readonly int $price_minor = 0,
		private readonly string $currency = 'GBP',
		private readonly ?int $hold_id = null,
	) {}

	/**
	 * Empty draft.
	 */
	public static function empty(): self {
		return new self();
	}

	/**
	 * Hydrate from cart-item / draft JSON.
	 *
	 * @param array<string, mixed>|null $data Payload.
	 */
	public static function from_array( ?array $data ): self {
		if ( null === $data ) {
			return self::empty();
		}
		$extras = $data['extras'] ?? [];
		$fields = $data['custom_fields'] ?? [];
		return new self(
			isset( $data['service_id'] ) ? (int) $data['service_id'] : null,
			isset( $data['duration_id'] ) ? (int) $data['duration_id'] : null,
			isset( $data['location_id'] ) ? (int) $data['location_id'] : null,
			isset( $data['agent_id'] ) ? (int) $data['agent_id'] : null,
			isset( $data['any_agent'] ) && true === $data['any_agent'],
			self::parse_instant( $data['start_utc'] ?? null ),
			self::parse_instant( $data['end_utc'] ?? null ),
			self::parse_instant( $data['buffer_start_utc'] ?? null ),
			self::parse_instant( $data['buffer_end_utc'] ?? null ),
			isset( $data['timezone'] ) && is_string( $data['timezone'] ) ? $data['timezone'] : null,
			isset( $data['attendees'] ) ? max( 1, (int) $data['attendees'] ) : 1,
			is_array( $extras ) ? array_values( $extras ) : [],
			is_array( $fields ) ? $fields : [],
			isset( $data['price_minor'] ) ? (int) $data['price_minor'] : 0,
			isset( $data['currency'] ) && is_string( $data['currency'] ) ? $data['currency'] : 'GBP',
			isset( $data['hold_id'] ) ? (int) $data['hold_id'] : null,
		);
	}

	/**
	 * Service id.
	 */
	public function service_id(): ?int {
		return $this->service_id;
	}

	/**
	 * Duration id.
	 */
	public function duration_id(): ?int {
		return $this->duration_id;
	}

	/**
	 * Location id.
	 */
	public function location_id(): ?int {
		return $this->location_id;
	}

	/**
	 * Agent id.
	 */
	public function agent_id(): ?int {
		return $this->agent_id;
	}

	/**
	 * Any-agent preference.
	 */
	public function any_agent(): bool {
		return $this->any_agent;
	}

	/**
	 * Start UTC.
	 */
	public function start_utc(): ?DateTimeImmutable {
		return $this->start_utc;
	}

	/**
	 * End UTC.
	 */
	public function end_utc(): ?DateTimeImmutable {
		return $this->end_utc;
	}

	/**
	 * Buffer start.
	 */
	public function buffer_start_utc(): ?DateTimeImmutable {
		return $this->buffer_start_utc;
	}

	/**
	 * Buffer end.
	 */
	public function buffer_end_utc(): ?DateTimeImmutable {
		return $this->buffer_end_utc;
	}

	/**
	 * Timezone.
	 */
	public function timezone(): ?string {
		return $this->timezone;
	}

	/**
	 * Attendees.
	 */
	public function attendees(): int {
		return $this->attendees;
	}

	/**
	 * Extras.
	 *
	 * @return list<array<string, mixed>>
	 */
	public function extras(): array {
		return $this->extras;
	}

	/**
	 * Custom fields.
	 *
	 * @return array<string, mixed>
	 */
	public function custom_fields(): array {
		return $this->custom_fields;
	}

	/**
	 * Price minor units.
	 */
	public function price_minor(): int {
		return $this->price_minor;
	}

	/**
	 * Currency.
	 */
	public function currency(): string {
		return $this->currency;
	}

	/**
	 * Soft-hold id.
	 */
	public function hold_id(): ?int {
		return $this->hold_id;
	}

	/**
	 * With service selection.
	 *
	 * @param int      $service_id  Service.
	 * @param int|null $duration_id Duration.
	 * @param int      $attendees   Attendees.
	 * @param int      $price_minor Price.
	 * @param string   $currency    Currency.
	 */
	public function with_service(
		int $service_id,
		?int $duration_id,
		int $attendees,
		int $price_minor,
		string $currency
	): self {
		return new self(
			$service_id,
			$duration_id,
			$this->location_id,
			$this->agent_id,
			$this->any_agent,
			$this->start_utc,
			$this->end_utc,
			$this->buffer_start_utc,
			$this->buffer_end_utc,
			$this->timezone,
			$attendees,
			$this->extras,
			$this->custom_fields,
			$price_minor,
			$currency,
			$this->hold_id,
		);
	}

	/**
	 * With extras.
	 *
	 * @param list<array<string, mixed>> $extras Extras.
	 * @param int                        $price_minor Updated price.
	 */
	public function with_extras( array $extras, int $price_minor ): self {
		return new self(
			$this->service_id,
			$this->duration_id,
			$this->location_id,
			$this->agent_id,
			$this->any_agent,
			$this->start_utc,
			$this->end_utc,
			$this->buffer_start_utc,
			$this->buffer_end_utc,
			$this->timezone,
			$this->attendees,
			array_values( $extras ),
			$this->custom_fields,
			$price_minor,
			$this->currency,
			$this->hold_id,
		);
	}

	/**
	 * With location.
	 *
	 * @param int|null $location_id Location.
	 */
	public function with_location( ?int $location_id ): self {
		return new self(
			$this->service_id,
			$this->duration_id,
			$location_id,
			$this->agent_id,
			$this->any_agent,
			$this->start_utc,
			$this->end_utc,
			$this->buffer_start_utc,
			$this->buffer_end_utc,
			$this->timezone,
			$this->attendees,
			$this->extras,
			$this->custom_fields,
			$this->price_minor,
			$this->currency,
			$this->hold_id,
		);
	}

	/**
	 * With agent.
	 *
	 * @param int|null $agent_id  Agent id.
	 * @param bool     $any_agent Any preference.
	 */
	public function with_agent( ?int $agent_id, bool $any_agent ): self {
		return new self(
			$this->service_id,
			$this->duration_id,
			$this->location_id,
			$agent_id,
			$any_agent,
			$this->start_utc,
			$this->end_utc,
			$this->buffer_start_utc,
			$this->buffer_end_utc,
			$this->timezone,
			$this->attendees,
			$this->extras,
			$this->custom_fields,
			$this->price_minor,
			$this->currency,
			$this->hold_id,
		);
	}

	/**
	 * With datetime.
	 *
	 * @param DateTimeImmutable $start_utc        Start.
	 * @param DateTimeImmutable $end_utc          End.
	 * @param DateTimeImmutable $buffer_start_utc Buffer start.
	 * @param DateTimeImmutable $buffer_end_utc   Buffer end.
	 * @param string            $timezone         Zone.
	 * @param int|null          $hold_id          Hold.
	 */
	public function with_datetime(
		DateTimeImmutable $start_utc,
		DateTimeImmutable $end_utc,
		DateTimeImmutable $buffer_start_utc,
		DateTimeImmutable $buffer_end_utc,
		string $timezone,
		?int $hold_id = null
	): self {
		return new self(
			$this->service_id,
			$this->duration_id,
			$this->location_id,
			$this->agent_id,
			$this->any_agent,
			$start_utc,
			$end_utc,
			$buffer_start_utc,
			$buffer_end_utc,
			$timezone,
			$this->attendees,
			$this->extras,
			$this->custom_fields,
			$this->price_minor,
			$this->currency,
			$hold_id ?? $this->hold_id,
		);
	}

	/**
	 * Persistable array.
	 *
	 * @return array<string, mixed>
	 */
	public function to_array(): array {
		return [
			'service_id'       => $this->service_id,
			'duration_id'      => $this->duration_id,
			'location_id'      => $this->location_id,
			'agent_id'         => $this->agent_id,
			'any_agent'        => $this->any_agent,
			'start_utc'        => null === $this->start_utc ? null : $this->start_utc->format( 'c' ),
			'end_utc'          => null === $this->end_utc ? null : $this->end_utc->format( 'c' ),
			'buffer_start_utc' => null === $this->buffer_start_utc ? null : $this->buffer_start_utc->format( 'c' ),
			'buffer_end_utc'   => null === $this->buffer_end_utc ? null : $this->buffer_end_utc->format( 'c' ),
			'timezone'         => $this->timezone,
			'attendees'        => $this->attendees,
			'extras'           => $this->extras,
			'custom_fields'    => $this->custom_fields,
			'price_minor'      => $this->price_minor,
			'currency'         => $this->currency,
			'hold_id'          => $this->hold_id,
		];
	}

	/**
	 * Parse an ISO instant.
	 *
	 * @param mixed $value Value.
	 */
	private static function parse_instant( mixed $value ): ?DateTimeImmutable {
		if ( $value instanceof DateTimeImmutable ) {
			return $value;
		}
		if ( ! is_string( $value ) || '' === $value ) {
			return null;
		}
		try {
			return new DateTimeImmutable( $value );
		} catch ( \Exception ) {
			return null;
		}
	}
}