<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class EB4TEC_Webhook {

	public function __construct(
		private readonly EB4TEC_API_Client  $api,
		private readonly EB4TEC_Event_Sync  $event_sync,
	) {
		add_filter( 'query_vars',      [ $this, 'add_query_var' ] );
		add_action( 'template_redirect', [ $this, 'handle_webhook' ] );
	}

	public function add_query_var( array $vars ): array {
		$vars[] = 'eb4tec_webhook';
		return $vars;
	}

	public function handle_webhook(): void {
		if ( ! get_query_var( 'eb4tec_webhook' ) ) {
			return;
		}

		$payload   = file_get_contents( 'php://input' );
		$signature = $_SERVER['HTTP_X_EVENTBRITE_SIGNATURE'] ?? '';

		if ( ! $this->verify_signature( $payload, $signature ) ) {
			wp_die( 'Forbidden', 'Forbidden', [ 'response' => 403 ] );
		}

		$data = json_decode( $payload, true );
		if ( ! is_array( $data ) ) {
			wp_send_json( [ 'status' => 'error', 'message' => 'Invalid JSON' ], 400 );
		}

		$action   = $data['config']['action'] ?? '';
		$api_url  = $data['api_url'] ?? '';

		// Extract EB event ID from the API URL (e.g. .../events/123456789/).
		$eb_event_id = $this->extract_event_id_from_url( $api_url );

		switch ( $action ) {
			case 'event.published':
			case 'event.updated':
				if ( $eb_event_id ) {
					$this->event_sync->pull_event( $eb_event_id );
				}
				break;

			case 'event.unpublished':
				if ( $eb_event_id ) {
					$this->handle_event_unpublished( $eb_event_id );
				}
				break;

			case 'attendee.updated':
				$this->handle_attendee_updated( $data );
				break;

			default:
				// Unknown action — acknowledge without processing.
				break;
		}

		wp_send_json( [ 'status' => 'ok' ], 200 );
	}

	private function verify_signature( string $payload, string $signature ): bool {
		$secret = (string) get_option( 'eb4tec_webhook_secret', '' );

		// If no secret is configured, skip verification (allows initial setup).
		if ( empty( $secret ) ) {
			return true;
		}

		if ( empty( $signature ) ) {
			return false;
		}

		$expected = hash_hmac( 'sha256', $payload, $secret );
		return hash_equals( $expected, $signature );
	}

	private function handle_event_unpublished( string $eb_event_id ): void {
		$query = new WP_Query( [
			'post_type'      => 'tribe_events',
			'post_status'    => [ 'publish', 'draft' ],
			'posts_per_page' => 1,
			'fields'         => 'ids',
			'meta_query'     => [ [
				'key'   => '_eb4tec_event_id',
				'value' => $eb_event_id,
			] ],
		] );

		if ( ! empty( $query->posts ) ) {
			$post_id = $query->posts[0];
			wp_update_post( [
				'ID'          => $post_id,
				'post_status' => 'draft',
			] );
			update_post_meta( $post_id, '_eb4tec_eb_status', 'unpublished' );
		}
	}

	private function handle_attendee_updated( array $data ): void {
		// Extract attendee ID from the API URL if present.
		$api_url     = $data['api_url'] ?? '';
		$attendee_id = $this->extract_id_from_url( $api_url, 'attendees' );

		if ( ! $attendee_id ) {
			return;
		}

		// Find any WC order that has this attendee and update its note.
		global $wpdb;
		$order_ids = $wpdb->get_col(
			$wpdb->prepare(
				"SELECT post_id FROM {$wpdb->postmeta} WHERE meta_key = '_eb4tec_attendee_ids' AND meta_value LIKE %s",
				'%' . $wpdb->esc_like( $attendee_id ) . '%'
			)
		);

		foreach ( $order_ids as $order_id ) {
			$order = wc_get_order( $order_id );
			if ( $order ) {
				$order->add_order_note(
					sprintf( __( 'EB4TEC: Eventbrite attendee %s was updated.', 'eb4tec' ), esc_html( $attendee_id ) ),
					false,
					false
				);
			}
		}
	}

	private function extract_event_id_from_url( string $url ): string {
		return $this->extract_id_from_url( $url, 'events' );
	}

	private function extract_id_from_url( string $url, string $resource ): string {
		// URLs look like: https://www.eventbriteapi.com/v3/events/123456789/
		if ( preg_match( '#/' . preg_quote( $resource, '#' ) . '/(\d+)/#', $url, $matches ) ) {
			return $matches[1];
		}
		return '';
	}
}