<?php
/**
 * Sends registrations and logins to AdPix.
 *
 * @package AdPix\Analytics
 */

declare( strict_types = 1 );

namespace AdPix\Analytics\Controller\Integration;

use AdPix\Analytics\Contracts\BootableInterface;
use AdPix\Analytics\Contracts\SettingsRepositoryInterface;
use AdPix\Analytics\Model\Event;
use AdPix\Analytics\Model\Identity;
use AdPix\Analytics\Service\EventRecorder;
use WP_User;

defined( 'ABSPATH' ) || exit;

/**
 * Ties WordPress accounts to AdPix profiles.
 *
 * A registration is the moment an anonymous visitor becomes a known person, and it is the only
 * moment at which the browsing that led to it can still be joined to them — the anonymous id is in a
 * cookie on the request that creates the account. Sending it later would attribute the sign-up to
 * nothing.
 */
final class UserController implements BootableInterface {

	/**
	 * @var SettingsRepositoryInterface
	 */
	private $settings;

	/**
	 * @var EventRecorder
	 */
	private $recorder;

	/**
	 * @param SettingsRepositoryInterface $settings Configuration source.
	 * @param EventRecorder               $recorder Event sender.
	 */
	public function __construct( SettingsRepositoryInterface $settings, EventRecorder $recorder ) {
		$this->settings = $settings;
		$this->recorder = $recorder;
	}

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function boot(): void {
		if ( ! $this->settings->load()->flag( 'track_users' ) ) {
			return;
		}

		add_action( 'user_register', array( $this, 'on_register' ), 20, 1 );
		add_action( 'wp_login', array( $this, 'on_login' ), 20, 2 );
	}

	/**
	 * A new account was created.
	 *
	 * @param int $user_id New user id.
	 * @return void
	 */
	public function on_register( $user_id ): void {
		$user = get_userdata( (int) $user_id );

		if ( ! $user instanceof WP_User ) {
			return;
		}

		$identity = $this->identity_for( $user );

		$this->recorder->identify( $identity );

		$this->recorder->record(
			Event::create( 'sign_up', Event::stable_id( 'sign_up', (string) $user->ID ) )
				->with_identity( $identity )
				->with_properties( array( 'method' => 'wordpress' ) )
				->at( time() )
		);
	}

	/**
	 * Somebody signed in.
	 *
	 * @param string       $user_login Username.
	 * @param WP_User|null $user       The user.
	 * @return void
	 */
	public function on_login( $user_login, $user = null ): void {
		unset( $user_login );

		if ( ! $user instanceof WP_User ) {
			return;
		}

		$identity = $this->identity_for( $user );

		// Identify rather than an event. A login is not a conversion, but it is the best chance to
		// re-link this browser to a known person — a returning customer on a new device is otherwise a
		// second anonymous visitor until they buy something.
		$this->recorder->identify( $identity );
	}

	/**
	 * Build the identity for a user.
	 *
	 * @param WP_User $user The user.
	 * @return Identity
	 */
	private function identity_for( WP_User $user ): Identity {
		$traits = array(
			'name' => $user->display_name,
		);

		$role = is_array( $user->roles ) ? reset( $user->roles ) : '';
		if ( is_string( $role ) && '' !== $role ) {
			$traits['role'] = $role;
		}

		/**
		 * Filters the traits sent with a WordPress user.
		 *
		 * Anything added here is stored against the person's AdPix profile, so it should be an attribute
		 * the site owner has a reason to segment on rather than everything the site happens to know.
		 *
		 * @since 1.0.0
		 *
		 * @param array<string,mixed> $traits Profile attributes.
		 * @param WP_User             $user   The user.
		 */
		$traits = (array) apply_filters( 'adpix_analytics_user_traits', $traits, $user );

		return Identity::from(
			array(
				// The WordPress user id, not the email: it never changes, so a customer who updates their
				// address stays the same person rather than becoming a second profile.
				'external_id' => (string) $user->ID,
				'email'       => $user->user_email,
				'phone'       => (string) get_user_meta( $user->ID, 'billing_phone', true ),
				'traits'      => $traits,
			)
		);
	}
}