<?php
/**
 * Adds the FullSession script to the front end.
 *
 * @package FullSession
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Decides whether to track the current page and prints the loader with its config.
 */
class FullSession_Tracker {

	const HANDLE = 'fullsession-loader';

	/**
	 * Register hooks.
	 */
	public static function init() {
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'enqueue' ), 5 );
	}

	/**
	 * Whether the script should be added to the current page.
	 *
	 * @return bool
	 */
	public static function should_track() {
		$settings = FullSession_Settings::get();

		if ( ! $settings['enabled'] || ! FullSession_Settings::is_connected() ) {
			return false;
		}
		if ( is_admin() || is_customize_preview() ) {
			return false;
		}
		if ( self::is_excluded_user( $settings['excluded_roles'] ) ) {
			return false;
		}
		if ( self::is_excluded_url( $settings['excluded_urls'] ) ) {
			return false;
		}

		/**
		 * Filters whether FullSession records the current page.
		 *
		 * @param bool $track Whether to add the script.
		 */
		return (bool) apply_filters( 'fullsession_should_track', true );
	}

	/**
	 * Whether the logged-in user has one of the excluded roles.
	 *
	 * @param string[] $excluded_roles Roles not to record.
	 * @return bool
	 */
	private static function is_excluded_user( $excluded_roles ) {
		if ( ! is_user_logged_in() || empty( $excluded_roles ) ) {
			return false;
		}
		$user = wp_get_current_user();
		if ( array_intersect( (array) $user->roles, $excluded_roles ) ) {
			return true;
		}
		// Network admins often have no role on a sub-site. Treat them as administrators.
		return is_multisite() && is_super_admin( $user->ID ) && in_array( 'administrator', $excluded_roles, true );
	}

	/**
	 * Whether the current request path matches an excluded URL pattern.
	 *
	 * @param string $excluded_urls Patterns, one per line.
	 * @return bool
	 */
	private static function is_excluded_url( $excluded_urls ) {
		$patterns = FullSession_Settings::parse_url_patterns( $excluded_urls );
		if ( empty( $patterns ) || ! isset( $_SERVER['REQUEST_URI'] ) ) {
			return false;
		}
		$uri  = sanitize_text_field( wp_unslash( $_SERVER['REQUEST_URI'] ) );
		$path = wp_parse_url( $uri, PHP_URL_PATH );
		$path = $path ? rawurldecode( $path ) : '/';

		if ( FullSession_Settings::path_matches( $path, $patterns ) ) {
			return true;
		}

		// Also match paths relative to the site, so `/about` works for a site in a
		// subfolder (e.g. example.com/shop/about, or a multisite sub-site).
		$home_path = untrailingslashit( (string) wp_parse_url( home_url(), PHP_URL_PATH ) );
		if ( '' !== $home_path && 0 === stripos( $path . '/', $home_path . '/' ) ) {
			return FullSession_Settings::path_matches( substr( $path, strlen( $home_path ) ), $patterns );
		}

		return false;
	}

	/**
	 * Enqueue the loader and pass it the config.
	 */
	public static function enqueue() {
		if ( ! self::should_track() ) {
			return;
		}

		wp_enqueue_script( self::HANDLE, FULLSESSION_URL . 'assets/js/fullsession-loader.js', array(), FULLSESSION_VERSION, false );
		wp_add_inline_script( self::HANDLE, 'window.fullsessionConfig = ' . self::encode( self::config() ) . ';', 'before' );
	}

	/**
	 * Config passed to fullsession-loader.js.
	 *
	 * @return array
	 */
	private static function config() {
		$settings = FullSession_Settings::get();

		$config = array(
			'customerId'      => $settings['customer_id'],
			'scriptUrl'       => FULLSESSION_SCRIPT_URL,
			'consentMode'     => $settings['consent_mode'],
			'consentCategory' => $settings['consent_category'],
			'calls'           => array(),
		);

		if ( $settings['identify_users'] && is_user_logged_in() ) {
			$user   = wp_get_current_user();
			$traits = array();
			if ( $settings['identify_send_name_email'] ) {
				$traits['name']  = $user->display_name;
				$traits['email'] = $user->user_email;
			}
			$config['calls'][] = array( 'identify', array( (string) $user->ID, (object) $traits ) );

			$roles = (array) $user->roles;
			if ( $roles ) {
				$config['calls'][] = array( 'setSessionAttributes', array( array( 'wp_role' => implode( ',', $roles ) ) ) );
			}
		}

		/**
		 * Filters the custom events sent on this page load.
		 *
		 * @param array $events List of array( 'name' => string, 'data' => array ) items.
		 */
		$events = apply_filters( 'fullsession_page_events', array() );
		foreach ( (array) $events as $event ) {
			if ( ! empty( $event['name'] ) && ! empty( $event['data'] ) ) {
				$config['calls'][] = array( 'event', array( (string) $event['name'], (object) $event['data'] ) );
			}
		}

		// This page now carries data for this visitor only (identity or their shop events).
		// Ask page cache plugins not to store it, so it's never served to someone else.
		if ( $config['calls'] && ! defined( 'DONOTCACHEPAGE' ) ) {
			define( 'DONOTCACHEPAGE', true ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedConstantFound -- Standard constant read by page cache plugins.
		}

		return $config;
	}

	/**
	 * JSON for an inline script. Escapes `<`, `>` and `&` so values can't close the script tag.
	 *
	 * @param mixed $data Data.
	 * @return string
	 */
	public static function encode( $data ) {
		return (string) wp_json_encode( $data, JSON_HEX_TAG | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE );
	}
}