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

final class EB4TEC_Ticket_Manager {

	public function __construct( private readonly EB4TEC_API_Client $api ) {}

	/**
	 * Ensure the hidden "WordPress Purchase" free ticket class exists on Eventbrite.
	 * Creates it if absent; updates capacity if it has changed.
	 * Returns the Eventbrite ticket class ID.
	 */
	public function ensure_wp_ticket_class( string $eb_event_id, int $post_id, int $capacity ): string|WP_Error {
		$existing_class_id = (string) get_post_meta( $post_id, '_eb4tec_wp_ticket_class_id', true );

		if ( $existing_class_id ) {
			// Update capacity in case it changed.
			$result = $this->api->update_ticket_class( $eb_event_id, $existing_class_id, $this->build_ticket_class_body( $capacity, $eb_event_id ) );
			if ( is_wp_error( $result ) ) {
				// Stale ID — try creating a fresh one.
				delete_post_meta( $post_id, '_eb4tec_wp_ticket_class_id' );
				return $this->create_wp_ticket_class( $eb_event_id, $post_id, $capacity );
			}
			return $existing_class_id;
		}

		return $this->create_wp_ticket_class( $eb_event_id, $post_id, $capacity );
	}

	private function create_wp_ticket_class( string $eb_event_id, int $post_id, int $capacity ): string|WP_Error {
		$result = $this->api->create_ticket_class( $eb_event_id, $this->build_ticket_class_body( $capacity, $eb_event_id ) );

		if ( is_wp_error( $result ) ) {
			return $result;
		}

		$class_id = $result['id'] ?? '';
		if ( empty( $class_id ) ) {
			return new WP_Error( 'eb4tec_no_class_id', __( 'Eventbrite did not return a ticket class ID.', 'eb4tec' ) );
		}

		update_post_meta( $post_id, '_eb4tec_wp_ticket_class_id', sanitize_text_field( $class_id ) );
		return $class_id;
	}

	/**
	 * Sync capacity to both the Eventbrite ticket class and the WooCommerce product stock.
	 */
	public function sync_capacity( int $post_id, int $new_capacity ): bool {
		update_post_meta( $post_id, '_eb4tec_capacity', $new_capacity );
		update_post_meta( $post_id, '_EventCapacity', $new_capacity );

		// Update WC product stock.
		$product_id = (int) get_post_meta( $post_id, '_eb4tec_wp_product_id', true );
		if ( $product_id ) {
			$product = wc_get_product( $product_id );
			if ( $product ) {
				$product->set_stock_quantity( $new_capacity );
				$product->save();
			}
		}

		// Update EB ticket class.
		$eb_event_id = (string) get_post_meta( $post_id, '_eb4tec_event_id', true );
		$class_id    = (string) get_post_meta( $post_id, '_eb4tec_wp_ticket_class_id', true );
		if ( $eb_event_id && $class_id ) {
			$result = $this->api->update_ticket_class( $eb_event_id, $class_id, $this->build_ticket_class_body( $new_capacity, $eb_event_id ) );
			return ! is_wp_error( $result );
		}

		return true;
	}

	/**
	 * Remaining available spots based on WooCommerce stock.
	 */
	public function get_available_capacity( int $post_id ): int {
		$product_id = (int) get_post_meta( $post_id, '_eb4tec_wp_product_id', true );
		if ( ! $product_id ) {
			return (int) get_post_meta( $post_id, '_eb4tec_capacity', true );
		}

		$product = wc_get_product( $product_id );
		if ( ! $product || ! $product->managing_stock() ) {
			return (int) get_post_meta( $post_id, '_eb4tec_capacity', true );
		}

		return max( 0, (int) $product->get_stock_quantity() );
	}

	private function build_ticket_class_body( int $capacity, string $eb_event_id ): array {
		$label   = (string) get_option( 'eb4tec_wp_ticket_label', 'WordPress Purchase' );
		$hidden  = get_option( 'eb4tec_wp_ticket_visible', 'hidden' ) === 'hidden';

		$body = [
			'ticket_class' => [
				'name'             => $label,
				'free'             => true,
				'minimum_quantity' => 1,
				'maximum_quantity' => 10,
				'hidden'           => $hidden,
			],
		];

		if ( $capacity > 0 ) {
			$body['ticket_class']['quantity_total'] = $capacity;
		}

		return $body;
	}
}