<?php
/**
 * Pinterest for WooCommerce Tracking. Conversions API.
 *
 * @package     Pinterest_For_WooCommerce/Classes/
 * @version     1.0.0
 */

namespace Automattic\WooCommerce\Pinterest\Tracking;

use Automattic\WooCommerce\Pinterest\API\APIV5;
use Automattic\WooCommerce\Pinterest\Logger;
use Automattic\WooCommerce\Pinterest\Tracking\Data\Category;
use Automattic\WooCommerce\Pinterest\Tracking\Data\Checkout;
use Automattic\WooCommerce\Pinterest\Tracking\Data\None;
use Automattic\WooCommerce\Pinterest\Tracking\Data\Product;
use Automattic\WooCommerce\Pinterest\Tracking\Data\Search;
use Automattic\WooCommerce\Pinterest\Tracking\Data\User;
use Exception;
use Throwable;

/**
 * Pinterest Conversions API support.
 */
class Conversions extends Tracker {

	/** @var User $user User data object. Data for Conversions API. */
	private $user;

	/**
	 * Pinterest Conversions API class constructor.
	 *
	 * @param User $user User data object to hold ip address and agent string.
	 */
	public function __construct( User $user ) {
		$this->user = $user;
	}

	/**
	 * Track event function implementation. Used to send event data to a destination.
	 *
	 * @param string $event_name Tracking event name.
	 * @param Data   $data       Tracking event data class.
	 *
	 * @throws Throwable In case of an API error.
	 *
	 * @return void
	 */
	public function track_event( string $event_name, Data $data ) {
		$data = $this->prepare_request_data( $event_name, $data );

		try {
			$this->send_request( $event_name, $data );

			/* translators: 1: Conversions API event name, 2: JSON encoded event data. */
			$messages = sprintf(
				'Sending Pinterest Conversions API event %1$s with a payload: %2$s',
				$event_name,
				wp_json_encode( $data )
			);
			Logger::log( $messages, 'debug', 'conversions' );
		} catch ( Throwable $e ) {
			/* translators: 1: Conversions API event name, 2: JSON encoded event data, 3: Error code, 4: Error message. */
			$messages = sprintf(
				'Sending Pinterest Conversions API event %1$s with a payload %2$s has failed with the error %3$d code and %4$s message',
				$event_name,
				wp_json_encode( $data ),
				$e->getCode(),
				$e->getMessage()
			);
			Logger::log( $messages, 'error', 'conversions' );

			throw $e;
		}
	}

	/**
	 * Prepares event data for the request.
	 *
	 * @since 1.4.0
	 *
	 * @param string $event_name Tracking event name.
	 * @param Data   $data       Tracking event data.
	 *
	 * @return array Prepared data.
	 */
	public function prepare_request_data( string $event_name, Data $data ) {
		$event_name = static::EVENT_MAP[ $event_name ] ?? '';
		$method     = "get_{$event_name}_data";
		if ( method_exists( $this, $method ) ) {
			$prepared_data = call_user_func( array( $this, $method ), $data );
		} else {
			$prepared_data = array(
				'event_id' => $data->get_event_id(),
			);
		}

		return array_merge( $prepared_data, $this->get_default_data( $event_name ) );
	}

	/**
	 * Prepares default event data.
	 *
	 * @param string $event_name Tracking event name.
	 *
	 * @return array Common data for every event.
	 */
	private function get_default_data( string $event_name ) {
		global $wp;

		$data = array(
			'event_name'       => $event_name,
			'action_source'    => 'web',
			'event_time'       => time(),
			'event_source_url' => home_url( $wp->request ),
			'partner_name'     => 'ss-woocommerce',
			'user_data'        => array(
				'client_ip_address' => $this->user->get_client_ip_address(),
				'client_user_agent' => $this->user->get_client_user_agent(),
			),
			'language'         => 'en',
		);

		$email = self::maybe_get_hashed_customer_email();
		if ( false !== $email ) {
			$data['user_data'] = array(
				'em' => array( $email ),
			);
		}

		return $data;
	}

	/**
	 * Prepares data for the checkout event.
	 *
	 * @see Conversions::prepare_request_data()
	 * @since 1.4.0
	 *
	 * @param Checkout $data Checkout data.
	 *
	 * @return array Prepared checkout event specific data.
	 */
	private function get_checkout_data( Checkout $data ) {
		return array(
			'event_id'    => $data->get_event_id(),
			'custom_data' => array(
				'order_id'    => (string) $data->get_order_id(),
				'currency'    => $data->get_currency(),
				'value'       => (string) $data->get_price(),
				'content_ids' => array_map(
					function ( Product $product ) {
						return (string) $product->get_id();
					},
					$data->get_items()
				),
				'contents'    => array_map(
					function ( Product $product ) {
						return array(
							'id'         => (string) $product->get_id(),
							'item_price' => (string) $product->get_price(),
							'quantity'   => (int) $product->get_quantity(),
						);
					},
					$data->get_items()
				),
				'num_items'   => (int) $data->get_quantity(),
			),
		);
	}

	/**
	 * Returns the hashed email of the current user if any.
	 *
	 * @return string|false Hashed email or false if not available.
	 */
	private static function maybe_get_hashed_customer_email() {
		$user_email = '';
		if ( is_user_logged_in() ) {
			$user       = wp_get_current_user();
			$user_email = $user->user_email;
		}
		if ( empty( $user_email ) ) {
			$session_customer = function_exists( 'WC' ) && isset( WC()->session ) ? WC()->session->get( 'customer' ) : false;
			$user_email       = $session_customer ? $session_customer['email'] : '';
		}
		return $user_email ? hash( 'sha256', $user_email ) : false;
	}

	/**
	 * Prepares data for add to cart event.
	 *
	 * @see Conversions::prepare_request_data()
	 * @since 1.4.0
	 *
	 * @param Product $data Product data.
	 *
	 * @return array Prepared add to cart event specific data.
	 */
	private function get_add_to_cart_data( Product $data ) {
		return array(
			'event_id'    => $data->get_event_id(),
			'custom_data' => array(
				'currency'    => $data->get_currency(),
				'value'       => (string) ( $data->get_price() * $data->get_quantity() ),
				'content_ids' => array( (string) $data->get_id() ),
				'contents'    => array(
					array(
						'id'         => (string) $data->get_id(),
						'item_price' => (string) $data->get_price(),
						'quantity'   => (int) $data->get_quantity(),
					),
				),
				'num_items'   => (int) $data->get_quantity(),
			),
		);
	}

	/**
	 * Prepares data for view category event.
	 *
	 * @see Conversions::prepare_request_data()
	 * @since 1.4.0
	 *
	 * @param Category $data Category data.
	 *
	 * @return array Prepared view category event specific data.
	 */
	private function get_view_category_data( Category $data ) {
		return array(
			'event_id' => $data->get_event_id(),
		);
	}

	/**
	 * Prepares data for page visit event.
	 *
	 * @see Conversions::prepare_request_data()
	 * @since 1.4.0
	 *
	 * @param Product|None $data Product or None data.
	 *
	 * @return array Prepared page visit event specific data.
	 */
	private function get_page_visit_data( Data $data ) {
		if ( $data instanceof None ) {
			return array(
				'event_id' => $data->get_event_id(),
			);
		}

		return array(
			'event_id'    => $data->get_event_id(),
			'custom_data' => array(
				'currency'    => $data->get_currency(),
				'value'       => (string) ( $data->get_price() * $data->get_quantity() ),
				'content_ids' => array( (string) $data->get_id() ),
				'contents'    => array(
					array(
						'id'         => (string) $data->get_id(),
						'item_price' => (string) $data->get_price(),
						'quantity'   => (int) $data->get_quantity(),
					),
				),
				'num_items'   => (int) $data->get_quantity(),
			),
		);
	}

	/**
	 * Prepares data for the search event.
	 *
	 * @see Conversions::prepare_request_data()
	 * @since 1.4.0
	 *
	 * @param Search $data Search data.
	 *
	 * @return array Prepared search event specific data.
	 */
	private function get_search_data( Search $data ) {
		return array(
			'event_id'    => $data->get_event_id(),
			'custom_data' => array(
				'search_string' => $data->get_search_query(),
			),
		);
	}

	/**
	 * Sends request to Pinterest Conversions API.
	 *
	 * @since 1.4.0
	 *
	 * @param string $event_name Event name.
	 * @param array  $data       Event data.
	 *
	 * @throws Throwable|Exception If any exception during the request happen.|If response was not successful enough.
	 * @return void
	 */
	private function send_request( string $event_name, array $data ) {
		$ad_account_id = Pinterest_For_WooCommerce()::get_setting( 'tracking_advertiser' );
		if ( empty( $ad_account_id ) ) {
			return;
		}

		$response = APIV5::send_conversions_api_event( $ad_account_id, $data );

		// Processing the call results.
		$is_error = isset( $response['code'] );
		// Successful requests do not have a code nor a message.
		if ( $is_error ) {
			throw new Exception(
				sprintf(
					/* translators: 1. the error message as returned by the Pinterest API */
					esc_html__( 'Error: $1%s', 'pinterest-for-woocommerce' ),
					esc_html( $response['message'] )
				),
				(int) $response['code']
			);
		} else {
			$data    = $response['events'][0] ?? array();
			$status  = $data['status'] ?? 'failed';
			$message = $data['error_message'] ?? $data['warning_message'] ?? 'Unknown';
			if ( 'failed' === $status ) {
				throw new Exception(
					sprintf(
						/* translators: 1. the error message as returned by the Pinterest API */
						esc_html__( 'Error: $1%s', 'pinterest-for-woocommerce' ),
						esc_html( $message )
					),
					0
				);
			}
		}
	}
}