<?php
/**
 * The signed receipt pixel.
 *
 * DUAL CAPTURE, the same arrangement the CubeCart plugin uses. The server
 * report is the reliable route; the pixel catches the case where the hook ran
 * in a context that had no click, and both carry the same event id so
 * Affiliatant reconciles the pair instead of counting the sale twice.
 *
 * The pixel is the weakest route in the product. It loses the closed tab,
 * anything an ad blocker stops and any confirmation page that never finishes
 * loading, and it puts the payload in a URL that lands in logs and browser
 * history. It is used ALONGSIDE the server report, never instead of it.
 *
 * @package Affiliatant
 */

defined( 'ABSPATH' ) || exit;

/**
 * Builds and prints the pixel.
 */
class Affiliatant_Pixel {

	/**
	 * Hook up.
	 *
	 * @return void
	 */
	public static function boot() {
		// templates/checkout/thankyou.php:
		//   do_action( 'woocommerce_thankyou', $order->get_id() );
		add_action( 'woocommerce_thankyou', array( __CLASS__, 'render' ), 20, 1 );
	}

	/**
	 * The flat query the signed GET route takes.
	 *
	 * PURE. The pixel route takes a flat query with its own parameter names,
	 * not the nested conversion payload. Keeping the mapping in its own
	 * static method is what lets a test sign it and verify the result against
	 * the platform's own verifier rather than against a copy of the
	 * algorithm.
	 *
	 * @param array $payload A conversion payload from Affiliatant_Payload.
	 * @return array
	 */
	public static function params( array $payload ) {
		$params = array(
			'program_id'     => isset( $payload['program_id'] ) ? (int) $payload['program_id'] : 0,
			'order'          => isset( $payload['external_order_id'] ) ? (string) $payload['external_order_id'] : '',
			'event_id'       => isset( $payload['event_id'] ) ? (string) $payload['event_id'] : '',
			'kind'           => isset( $payload['kind'] ) ? (string) $payload['kind'] : 'sale',
			'amount_minor'   => isset( $payload['amount_minor'] ) ? (int) $payload['amount_minor'] : 0,
			'tax_minor'      => isset( $payload['tax_minor'] ) ? (int) $payload['tax_minor'] : 0,
			'shipping_minor' => isset( $payload['shipping_minor'] ) ? (int) $payload['shipping_minor'] : 0,
			'currency'       => isset( $payload['currency'] ) ? (string) $payload['currency'] : '',
			'channel'        => 'woocommerce',
			'occurred_at'    => isset( $payload['occurred_at'] ) ? (string) $payload['occurred_at'] : '',
		);

		if ( isset( $payload['store_id'] ) ) {
			$params['store_id'] = (int) $payload['store_id'];
		}
		if ( ! empty( $payload['click_id'] ) ) {
			$params['aftid'] = (string) $payload['click_id'];
		}
		if ( ! empty( $payload['coupon_code'] ) ) {
			$params['coupon'] = (string) $payload['coupon_code'];
		}
		if ( ! empty( $payload['external_customer_id'] ) ) {
			$params['customer'] = (string) $payload['external_customer_id'];
		}
		if ( ! empty( $payload['is_test'] ) ) {
			$params['test'] = 1;
		}

		return $params;
	}

	/**
	 * Print the pixel on the receipt page.
	 *
	 * Prints nothing when it cannot be signed, which is the correct answer:
	 * an unsigned pixel is refused at the other end, and a broken image on a
	 * receipt page is a support ticket.
	 *
	 * @param int $order_id Order id.
	 * @return void
	 */
	public static function render( $order_id ) {
		try {
			if ( ! Affiliatant_Settings::active() || (int) Affiliatant_Settings::get( 'pixel' ) !== 1 ) {
				return;
			}

			$prefix   = (string) Affiliatant_Settings::get( 'key_prefix' );
			$secret   = (string) Affiliatant_Settings::get( 'signing_secret' );
			$endpoint = (string) Affiliatant_Settings::get( 'pixel_url' );
			if ( '' === $prefix || '' === $secret || '' === $endpoint ) {
				return;
			}

			$order = wc_get_order( $order_id );
			if ( ! is_a( $order, 'WC_Order' ) || 'shop_order' !== $order->get_type() ) {
				return;
			}

			$context = Affiliatant_Order::context( $order );
			$payload = Affiliatant_Payload::conversion(
				Affiliatant_Order::snapshot( $order ),
				array() !== $context ? $context : Affiliatant_Subscriptions::context_for_renewal( $order ),
				array(
					'program_id' => (int) Affiliatant_Settings::get( 'program_id' ),
					'store_ref'  => (string) Affiliatant_Settings::get( 'store_ref' ),
					'kind'       => Affiliatant_Subscriptions::kind_for_order( $order ),
					'is_test'    => Affiliatant_Settings::test_mode(),
				)
			);

			$url = AffiliatantClient::signedUrl( $endpoint, $prefix, $secret, self::params( $payload ) );

			echo '<img src="' . esc_url( $url ) . '" width="1" height="1" alt=""'
				. ' style="position:absolute;left:-9999px;" referrerpolicy="no-referrer">';
		} catch ( \Throwable $e ) {
			// Never out of the receipt page.
			Affiliatant_Sender::log( 'The receipt pixel could not be rendered: ' . $e->getMessage() );
		}
	}
}