<?php
/**
 * Orders sent to Matomo from the server.
 *
 * @package Rahkar\WP
 */

declare( strict_types = 1 );

namespace Rahkar\WP\Modules\Matomo;

use Rahkar\WP\Queue\Queue;
use Rahkar\WP\Support\Hooks;
use Rahkar\WP\Support\Logger;
use RuntimeException;
use WC_Order;

defined( 'ABSPATH' ) || exit;

/**
 * The second way an order reaches Matomo, for the browsers that never ran the
 * tracker or never saw the thank-you page: a blocker, a closed tab, a payment
 * confirmed days later.
 *
 * When an order first reaches a sale status, a queue job sends it to Matomo's
 * tracking API with the visitor id the browser had at checkout and the time it
 * was placed (`cdt`), so it lands on the visit it belongs to. Matomo keeps an
 * order id once, so whichever way arrives first stays.
 *
 * - Never `new_visit`: with it, an order the browser already recorded would
 *   still open an empty visit (PHASE-5.md, pre-M1 findings).
 * - Without a visitor id the order opens a visit of its own, so it carries
 *   WooCommerce's attribution as campaign and referrer, not "direct".
 * - With a write token the buyer's IP goes too, and `cdt` may be older than a
 *   day. Without one, an order placed more than a day ago goes without `cdt`
 *   and lands on the day it was sent.
 * - `400` is Matomo refusing, which for an order the browser already recorded is
 *   the duplicate: logged, not retried. Network errors and `5xx` throw, so the
 *   queue retries with its own backoff.
 */
final class ServerOrders {

	/**
	 * Seconds to wait before sending, so the thank-you page usually goes first.
	 */
	private const DELAY = 120;

	/**
	 * The most `cdt` may lag without a token, with an hour's margin.
	 */
	private const UNTOKENED_AGE = 23 * HOUR_IN_SECONDS;

	/**
	 * Queue an order that has just reached a sale status, once.
	 *
	 * @param int $orderId Order id.
	 *
	 * @internal Hooked to `woocommerce_order_status_changed`.
	 */
	public static function queue( int $orderId ): void {
		$order = wc_get_order( $orderId );

		if ( ! $order instanceof WC_Order || ! Orders::isSale( $order ) || '' !== (string) $order->get_meta( Orders::META_SENT ) ) {
			return;
		}

		// An order made in the admin never went through a shopper's browser.
		if ( 'admin' === $order->get_created_via() ) {
			return;
		}

		Queue::pushUnique( Hooks::MATOMO_ORDER, [ 'order' => $orderId ], 'matomo:' . $orderId, self::DELAY );
	}

	/**
	 * Send one order.
	 *
	 * @param array<string, mixed> $payload `order`: the order id.
	 *
	 * @throws RuntimeException When Matomo cannot be reached or fails, so the queue retries.
	 *
	 * @internal Queue handler.
	 */
	public function send( array $payload ): void {
		$site  = Config::site();
		$order = wc_get_order( absint( $payload['order'] ?? 0 ) );

		if ( null === $site || ! $order instanceof WC_Order || '' !== (string) $order->get_meta( Orders::META_SENT ) ) {
			return;
		}

		$token    = Config::token();
		$response = wp_remote_post(
			$site['url'] . 'matomo.php',
			[
				'timeout' => 15,
				'body'    => $this->params( $order, $site['site'], $token ),
			]
		);
		$id       = (string) $order->get_id();

		if ( is_wp_error( $response ) ) {
			Config::recordSend( $id, 0, $response->get_error_message() );

			throw new RuntimeException( 'Matomo did not answer: ' . esc_html( $response->get_error_message() ) );
		}

		$code = (int) wp_remote_retrieve_response_code( $response );

		if ( $code >= 500 || 0 === $code ) {
			Config::recordSend( $id, $code, 'HTTP ' . $code );

			throw new RuntimeException( 'Matomo answered HTTP ' . (int) $code . '.' );
		}

		if ( $code >= 400 ) {
			// Matomo says nothing in a 400. For an order the browser already sent it
			// is the duplicate; otherwise something about the request is wrong, and
			// sending the same request again would not change the answer.
			$order->update_meta_data( Orders::META_SENT, 'rejected' );
			$order->save_meta_data();
			Config::recordSend( $id, $code, __( 'Matomo سفارش را نپذیرفت؛ معمولاً یعنی صفحه‌ی تشکر آن را پیش‌تر ثبت کرده است.', 'rahkar-toolkit' ) );
			Logger::info( 'matomo', 'Matomo refused a server-side order.', [ 'order' => $id, 'code' => $code ] );

			return;
		}

		$order->update_meta_data( Orders::META_SENT, (string) time() );
		$order->save_meta_data();
		Config::recordSend( $id, $code, '' );
	}

	/**
	 * The tracking request for an order.
	 *
	 * @param WC_Order    $order The order.
	 * @param int         $site  Matomo site id.
	 * @param string|null $token Write token, if set.
	 *
	 * @return array<string, string|int|float>
	 */
	private function params( WC_Order $order, int $site, ?string $token ): array {
		$data    = Orders::ecommerce( $order );
		$created = $order->get_date_created();
		$placed  = null === $created ? time() : $created->getTimestamp();
		$visitor = Orders::visitorId( $order );
		$user    = (int) $order->get_customer_id();

		$params = [
			'idsite'     => $site,
			'rec'        => 1,
			'apiv'       => 1,
			'send_image' => 0,
			'idgoal'     => 0,
			'ec_id'      => $data['id'],
			'revenue'    => $data['total'],
			'ec_st'      => $data['subtotal'],
			'ec_tx'      => $data['tax'],
			'ec_sh'      => $data['shipping'],
			'ec_dt'      => $data['discount'],
			'ec_items'   => (string) wp_json_encode( $data['items'], JSON_UNESCAPED_UNICODE ),
			'url'        => $this->landing( $order, null === $visitor ),
			'rand'       => wp_rand(),
		];

		if ( null !== $visitor ) {
			$params['_id'] = $visitor;
		} else {
			$referrer = (string) $order->get_meta( '_wc_order_attribution_referrer' );

			if ( '' !== $referrer && null !== wp_parse_url( $referrer, PHP_URL_HOST ) ) {
				$params['urlref'] = $referrer;
			}
		}

		if ( $user > 0 ) {
			$params['uid'] = (string) $user;
		}

		$agent = $order->get_customer_user_agent();

		if ( '' !== $agent ) {
			$params['ua'] = $agent;
		}

		if ( null !== $token ) {
			$params['token_auth'] = $token;
			$params['cdt']        = $placed;

			$ip = $order->get_customer_ip_address();

			if ( '' !== $ip ) {
				$params['cip'] = $ip;
			}
		} elseif ( time() - $placed <= self::UNTOKENED_AGE ) {
			$params['cdt'] = $placed;
		}

		return $params;
	}

	/**
	 * The page the request is said to come from.
	 *
	 * With a visitor id it is only the site's home: the visit already has its
	 * pages. Without one it opens a visit, so WooCommerce's UTM tags go on it and
	 * Matomo files the visit under the campaign that brought the order.
	 *
	 * @param WC_Order $order    The order.
	 * @param bool     $campaign Whether to carry the order's UTM tags.
	 */
	private function landing( WC_Order $order, bool $campaign ): string {
		$url = home_url( '/' );

		if ( ! $campaign ) {
			return $url;
		}

		$tags = [];

		foreach ( [ 'utm_source', 'utm_medium', 'utm_campaign', 'utm_content', 'utm_term' ] as $tag ) {
			$value = (string) $order->get_meta( '_wc_order_attribution_' . $tag );

			if ( '' !== $value && '(none)' !== $value ) {
				$tags[ $tag ] = $value;
			}
		}

		return [] === $tags ? $url : add_query_arg( array_map( 'rawurlencode', $tags ), $url );
	}
}