<?php
/**
 * List customers for admin.
 *
 * @package Bookline
 */

declare( strict_types=1 );

namespace Bookline\Application\Customer;

use Bookline\Domain\Booking\BookingRepository;
use Bookline\Domain\Customer\Customer;
use Bookline\Domain\Customer\CustomerRepository;
use DateTimeImmutable;

/**
 * Admin customer list handler.
 *
 * @since 0.1.0
 */
final class ListCustomersHandler {

	/**
	 * Constructor.
	 *
	 * @param CustomerRepository $customers Customer port.
	 * @param BookingRepository  $bookings  Booking port.
	 */
	public function __construct(
		private readonly CustomerRepository $customers,
		private readonly BookingRepository $bookings,
	) {}

	/**
	 * Handle a paginated customer list request.
	 *
	 * @param int         $page    Page number (1-based).
	 * @param int         $per_page Items per page.
	 * @param string|null $search  Optional search term.
	 * @return array{items: list<array<string, mixed>>, total: int, page: int, per_page: int}
	 *
	 * @since 0.1.0
	 */
	public function handle( int $page, int $per_page, ?string $search = null ): array {
		$per_page = max( 1, min( 100, $per_page ) );
		$page     = max( 1, $page );
		$offset   = ( $page - 1 ) * $per_page;

		$result = $this->customers->find_all( $per_page, $offset, $search );

		$ids = [];
		foreach ( $result['items'] as $customer ) {
			$id = $customer->id();
			if ( null !== $id ) {
				$ids[] = $id;
			}
		}
		$summaries = $this->bookings->summarise_for_customers( $ids );

		$items = [];
		foreach ( $result['items'] as $customer ) {
			$items[] = $this->to_admin_array( $customer, $summaries );
		}

		return [
			'items'    => $items,
			'total'    => $result['total'],
			'page'     => $page,
			'per_page' => $per_page,
		];
	}

	/**
	 * Map a customer entity to the admin API shape.
	 *
	 * @param Customer                                                      $customer  Customer entity.
	 * @param array<int, array{count: int, first_start: DateTimeImmutable}> $summaries Booking summaries.
	 * @return array<string, mixed>
	 */
	private function to_admin_array( Customer $customer, array $summaries ): array {
		$display = trim(
			$customer->first_name() . ' ' . ( $customer->last_name() ?? '' )
		);
		$id      = $customer->id();
		$summary = null !== $id && isset( $summaries[ $id ] ) ? $summaries[ $id ] : null;

		return [
			'id'               => $id,
			'uuid'             => $customer->uuid()->to_string(),
			'display_name'     => '' !== $display ? $display : $customer->first_name(),
			'email'            => $customer->email()->to_string(),
			'phone'            => $customer->phone()?->to_string(),
			'status'           => $customer->status()->value,
			'created_at'       => $customer->created_at()->format( 'c' ),
			'bookings_count'   => null !== $summary ? $summary['count'] : 0,
			'first_booking_at' => null !== $summary ? $summary['first_start']->format( 'c' ) : null,
		];
	}
}