<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Offering;

use Unsupervised\Schedular\Auth\RoleManager;

class OfferingEndpoint {

	public function __construct( private OfferingRepository $repository ) {}

	public function registerRoutes( string $route_namespace ): void {
		register_rest_route(
			$route_namespace,
			'/offerings',
			[
				[
					'methods'             => \WP_REST_Server::READABLE,
					'callback'            => [ $this, 'index' ],
					'permission_callback' => [ $this, 'canBook' ],
					'args'                => [
						'instructor_id' => [
							'type'    => 'integer',
							'default' => 0,
						],
						'kind'          => [
							'type'    => 'string',
							'default' => '',
						],
					],
				],
				[
					'methods'             => \WP_REST_Server::CREATABLE,
					'callback'            => [ $this, 'create' ],
					'permission_callback' => [ $this, 'canManage' ],
				],
			]
		);

		register_rest_route(
			$route_namespace,
			'/offerings/(?P<id>\d+)',
			[
				[
					'methods'             => \WP_REST_Server::EDITABLE,
					'callback'            => [ $this, 'update' ],
					'permission_callback' => [ $this, 'canManage' ],
				],
				[
					'methods'             => \WP_REST_Server::DELETABLE,
					'callback'            => [ $this, 'delete' ],
					'permission_callback' => [ $this, 'canManage' ],
				],
			]
		);
	}

	public function index( \WP_REST_Request $request ): \WP_REST_Response {
		$offerings = $this->repository->findAll(
			(int) $request->get_param( 'instructor_id' ),
			(string) $request->get_param( 'kind' ),
			activeOnly: true,
		);

		// Public listing: omit the private e-transfer destination email.
		return new \WP_REST_Response( array_map( fn( Offering $o ) => $o->toArray( includeEtransferEmail: false ), $offerings ), 200 );
	}

	public function create( \WP_REST_Request $request ): \WP_REST_Response|\WP_Error {
		$title = sanitize_text_field( (string) $request->get_param( 'title' ) );
		if ( '' === $title ) {
			return $this->invalid( __( 'A title is required.', 'unsupervised-schedular' ) );
		}

		$kind = (string) $request->get_param( 'kind' );
		if ( ! in_array( $kind, Offering::VALID_KINDS, true ) ) {
			return $this->invalid( __( 'Invalid offering kind.', 'unsupervised-schedular' ) );
		}

		$billingMode = (string) ( $request->get_param( 'billing_mode' ) ?? Offering::BILLING_ONE_TIME );
		if ( ! in_array( $billingMode, Offering::VALID_BILLING_MODES, true ) ) {
			return $this->invalid( __( 'Invalid billing mode.', 'unsupervised-schedular' ) );
		}

		$offering = new Offering(
			instructorId:    get_current_user_id(),
			kind:            $kind,
			title:           $title,
			price:           $this->price( $request->get_param( 'price' ) ),
			currency:        sanitize_text_field( (string) ( $request->get_param( 'currency' ) ?? 'CAD' ) ),
			billingMode:     $billingMode,
			description:     $this->nullableText( $request->get_param( 'description' ) ),
			durationMinutes: $this->nullableInt( $request->get_param( 'duration_minutes' ) ),
			allowWeekly:     (bool) $request->get_param( 'allow_weekly' ),
			capacity:        $this->nullableInt( $request->get_param( 'capacity' ) ),
			termStart:       $this->nullableText( $request->get_param( 'term_start' ) ),
			termEnd:         $this->nullableText( $request->get_param( 'term_end' ) ),
			scheduleNote:    $this->nullableText( $request->get_param( 'schedule_note' ) ),
			etransferEmail:  $this->nullableEmail( $request->get_param( 'etransfer_email' ) ),
			isActive:        null === $request->get_param( 'is_active' ) ? true : (bool) $request->get_param( 'is_active' ),
		);

		$id = $this->repository->insert( $offering );

		return new \WP_REST_Response( [ 'id' => $id ], 201 );
	}

	public function update( \WP_REST_Request $request ): \WP_REST_Response|\WP_Error {
		$id       = absint( $request->get_param( 'id' ) );
		$existing = $this->repository->findById( $id );

		if ( null === $existing ) {
			return new \WP_Error( 'not_found', __( 'Offering not found.', 'unsupervised-schedular' ), [ 'status' => 404 ] );
		}

		if ( ! $this->ownsOrManagesAll( $existing ) ) {
			return new \WP_Error( 'forbidden', __( 'You cannot edit this offering.', 'unsupervised-schedular' ), [ 'status' => 403 ] );
		}

		$kind = $request->has_param( 'kind' ) ? (string) $request->get_param( 'kind' ) : $existing->kind;
		if ( ! in_array( $kind, Offering::VALID_KINDS, true ) ) {
			return $this->invalid( __( 'Invalid offering kind.', 'unsupervised-schedular' ) );
		}

		$billingMode = $request->has_param( 'billing_mode' ) ? (string) $request->get_param( 'billing_mode' ) : $existing->billingMode;
		if ( ! in_array( $billingMode, Offering::VALID_BILLING_MODES, true ) ) {
			return $this->invalid( __( 'Invalid billing mode.', 'unsupervised-schedular' ) );
		}

		$offering = new Offering(
			instructorId:    $existing->instructorId,
			kind:            $kind,
			title:           $request->has_param( 'title' ) ? sanitize_text_field( (string) $request->get_param( 'title' ) ) : $existing->title,
			price:           $request->has_param( 'price' ) ? $this->price( $request->get_param( 'price' ) ) : $existing->price,
			currency:        $request->has_param( 'currency' ) ? sanitize_text_field( (string) $request->get_param( 'currency' ) ) : $existing->currency,
			billingMode:     $billingMode,
			description:     $request->has_param( 'description' ) ? $this->nullableText( $request->get_param( 'description' ) ) : $existing->description,
			durationMinutes: $request->has_param( 'duration_minutes' ) ? $this->nullableInt( $request->get_param( 'duration_minutes' ) ) : $existing->durationMinutes,
			allowWeekly:     $request->has_param( 'allow_weekly' ) ? (bool) $request->get_param( 'allow_weekly' ) : $existing->allowWeekly,
			capacity:        $request->has_param( 'capacity' ) ? $this->nullableInt( $request->get_param( 'capacity' ) ) : $existing->capacity,
			termStart:       $request->has_param( 'term_start' ) ? $this->nullableText( $request->get_param( 'term_start' ) ) : $existing->termStart,
			termEnd:         $request->has_param( 'term_end' ) ? $this->nullableText( $request->get_param( 'term_end' ) ) : $existing->termEnd,
			scheduleNote:    $request->has_param( 'schedule_note' ) ? $this->nullableText( $request->get_param( 'schedule_note' ) ) : $existing->scheduleNote,
			etransferEmail:  $request->has_param( 'etransfer_email' ) ? $this->nullableEmail( $request->get_param( 'etransfer_email' ) ) : $existing->etransferEmail,
			isActive:        $request->has_param( 'is_active' ) ? (bool) $request->get_param( 'is_active' ) : $existing->isActive,
			id:              $id,
		);

		$this->repository->update( $id, $offering );

		return new \WP_REST_Response( $offering->toArray(), 200 );
	}

	public function delete( \WP_REST_Request $request ): \WP_REST_Response|\WP_Error {
		$id       = absint( $request->get_param( 'id' ) );
		$existing = $this->repository->findById( $id );

		if ( null === $existing ) {
			return new \WP_Error( 'not_found', __( 'Offering not found.', 'unsupervised-schedular' ), [ 'status' => 404 ] );
		}

		if ( ! $this->ownsOrManagesAll( $existing ) ) {
			return new \WP_Error( 'forbidden', __( 'You cannot delete this offering.', 'unsupervised-schedular' ), [ 'status' => 403 ] );
		}

		$this->repository->delete( $id );

		return new \WP_REST_Response( null, 204 );
	}

	public function canManage(): bool {
		return is_user_logged_in() && current_user_can( RoleManager::CAP_MANAGE_OFFERINGS );
	}

	/**
	 * Reading the offerings catalogue is only needed by the logged-in student
	 * booking flow, so it requires the same capability as booking — there is no
	 * anonymous consumer.
	 */
	public function canBook(): bool {
		return is_user_logged_in() && current_user_can( RoleManager::CAP_BOOK_LESSON );
	}

	/**
	 * An offering may be changed by its owning instructor or by a studio admin
	 * (identified by the studio-only manage_instructors capability).
	 */
	private function ownsOrManagesAll( Offering $offering ): bool {
		return get_current_user_id() === $offering->instructorId
			|| current_user_can( RoleManager::CAP_MANAGE_INSTRUCTORS );
	}

	private function invalid( string $message ): \WP_Error {
		return new \WP_Error( 'invalid_offering', $message, [ 'status' => 400 ] );
	}

	private function price( mixed $value ): float {
		return max( 0.0, (float) $value );
	}

	private function nullableEmail( mixed $value ): ?string {
		$email = sanitize_email( (string) $value );

		return '' !== $email ? $email : null;
	}

	private function nullableInt( mixed $value ): ?int {
		return ( null === $value || '' === $value ) ? null : (int) $value;
	}

	private function nullableText( mixed $value ): ?string {
		if ( null === $value || '' === $value ) {
			return null;
		}

		return sanitize_text_field( (string) $value );
	}
}