<?php
/**
 * A-07 Google Tools.
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Apps\Google;

defined( 'ABSPATH' ) || exit;

use ForensixDigital\Apps\AppDefinition;
use ForensixDigital\Apps\AppInterface;
use ForensixDigital\Core\Plugin;
use ForensixDigital\Rest\Api;
use ForensixDigital\Services\Entitlements\Edition;
use ForensixDigital\Services\Http\Http;
use ForensixDigital\Services\Permissions\Capabilities;
use ForensixDigital\Services\Settings\Settings;

/**
 * Guides the owner through Search Console and Analytics (or Tag Manager) setup, prints the
 * codes they paste, and checks the pages for missing, doubled or conflicting tags. It prints
 * nothing until a code is saved, never prints a tag another plugin already prints, and does not
 * connect to a Google account.
 */
final class GoogleApp implements AppInterface {

	public const ID = 'google';

	/**
	 * Registry entry.
	 */
	public static function definition(): AppDefinition {
		return new AppDefinition(
			array(
				'id'                   => self::ID,
				'name'                 => __( 'Google tools', 'forensix-digital' ),
				'description'          => __( 'Step-by-step help to connect your site to Google Search Console and Google Analytics, and a check that finds missing or doubled tags.', 'forensix-digital' ),
				'category'             => 'tools',
				'edition'              => Edition::FREE,
				'features'             => array(
					'F-GOOGLE-01' => Edition::FREE,
					'F-GOOGLE-02' => Edition::FREE,
					'F-GOOGLE-03' => Edition::FREE,
				),
				'deactivation_effects' => array(
					__( 'The tags and the verification line this app added are removed from your pages. Tags added by other plugins stay.', 'forensix-digital' ),
					__( 'Your saved codes stay, so turning the app on again brings the tags back.', 'forensix-digital' ),
				),
				'factory'              => static fn(): self => new self(),
			)
		);
	}

	/**
	 * Settings service with the scope declared.
	 */
	private static function settings(): Settings {
		$settings = Plugin::container()->get( Settings::class );
		$settings->register( GoogleConfig::SCOPE, GoogleConfig::defaults(), array( GoogleConfig::class, 'sanitize' ) );
		return $settings;
	}

	/**
	 * Hooks the app while it is active.
	 */
	public function register(): void {
		add_action( 'wp_head', array( $this, 'print_head' ), 1 );
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_tags' ), 1 );
		add_action( 'wp_body_open', array( $this, 'print_body' ), 1 );
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
		add_filter( 'forensix_admin_screens', array( $this, 'add_screen' ) );
	}

	/**
	 * Whether tags may be printed for this visitor.
	 *
	 * @param array<string, mixed> $values Saved settings.
	 */
	private static function should_print( array $values ): bool {
		if ( is_admin() || is_feed() || is_robots() || is_customize_preview() ) {
			return false;
		}
		return ! empty( $values['track_editors'] ) || ! ( is_user_logged_in() && current_user_can( 'edit_posts' ) );
	}

	/**
	 * Prints the verification line. It goes to everyone, including editors, because Google reads
	 * it as a visitor.
	 */
	public function print_head(): void {
		$tag = GoogleOutput::meta( self::settings()->all( GoogleConfig::SCOPE ), GoogleCheck::foreign() );
		echo $tag; // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Escaped inside GoogleOutput; the code is validated against an exact pattern.
	}

	/**
	 * Hands the Analytics and Tag Manager scripts to WordPress.
	 */
	public function enqueue_tags(): void {
		$values = self::settings()->all( GoogleConfig::SCOPE );
		if ( ! self::should_print( $values ) ) {
			return;
		}
		$args = array(
			'strategy'  => 'async',
			'in_footer' => false,
		);
		foreach ( GoogleOutput::scripts( $values, GoogleCheck::foreign() ) as $script ) {
			wp_enqueue_script( $script['handle'], $script['src'], array(), null, $args ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- A Google-hosted loader has no version of ours; null keeps the address as Google documents it.
			wp_add_inline_script( $script['handle'], $script['inline'] );
		}
	}

	/**
	 * Prints the Tag Manager fallback after the opening body tag.
	 */
	public function print_body(): void {
		$values = self::settings()->all( GoogleConfig::SCOPE );
		if ( ! self::should_print( $values ) ) {
			return;
		}
		echo GoogleOutput::body( $values, GoogleCheck::foreign() ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- Escaped inside GoogleOutput.
	}

	/**
	 * Registers the REST routes.
	 */
	public function register_routes(): void {
		$can = static fn(): bool => current_user_can( Capabilities::MANAGE_SETTINGS );
		register_rest_route(
			Api::NAMESPACE,
			'/google',
			array(
				array(
					'methods'             => 'GET',
					'callback'            => array( $this, 'show' ),
					'permission_callback' => $can,
				),
				array(
					'methods'             => 'POST',
					'callback'            => array( $this, 'save' ),
					'permission_callback' => $can,
				),
			)
		);
		register_rest_route(
			Api::NAMESPACE,
			'/google/check',
			array(
				'methods'             => 'POST',
				'callback'            => array( $this, 'check' ),
				'permission_callback' => $can,
			)
		);
	}

	/**
	 * Saved codes, the last check and what the screen needs for its guidance.
	 */
	public function show(): \WP_REST_Response {
		return new \WP_REST_Response(
			array(
				'values' => self::settings()->all( GoogleConfig::SCOPE ),
				'check'  => GoogleCheck::last(),
				'host'   => (string) wp_parse_url( home_url(), PHP_URL_HOST ),
				'url'    => home_url( '/' ),
			)
		);
	}

	/**
	 * Saves the codes.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @phpstan-param \WP_REST_Request<array<string, mixed>> $request
	 */
	public function save( \WP_REST_Request $request ): \WP_REST_Response {
		$settings = self::settings();
		$settings->update( GoogleConfig::SCOPE, (array) $request->get_json_params() );
		return new \WP_REST_Response(
			array(
				'ok'      => true,
				'message' => __( 'Saved. Empty the cache of your caching plugin, then run the check below.', 'forensix-digital' ),
				'values'  => $settings->all( GoogleConfig::SCOPE ),
			)
		);
	}

	/**
	 * Checks the pages now.
	 */
	public function check(): \WP_REST_Response {
		$values  = self::settings()->all( GoogleConfig::SCOPE );
		$outcome = ( new GoogleCheck( Plugin::container()->get( Http::class ) ) )->run( $values );
		return new \WP_REST_Response(
			array(
				'ok'    => true,
				'check' => $outcome,
			)
		);
	}

	/**
	 * Adds the page to the Forensix menu.
	 *
	 * @param array $screens Screens.
	 * @phpstan-param array<string, array{key: string, title: string, capability: string}> $screens
	 * @return array<string, array{key: string, title: string, capability: string}>
	 */
	public function add_screen( array $screens ): array {
		$screens['forensix-google'] = array(
			'key'        => 'google',
			'title'      => __( 'Google tools', 'forensix-digital' ),
			'capability' => Capabilities::MANAGE_SETTINGS,
		);
		return $screens;
	}

	/**
	 * Nothing to set up.
	 */
	public function activate(): void {}

	/**
	 * Removes the hooks, so the tags disappear from the pages.
	 */
	public function deactivate(): void {
		remove_action( 'wp_head', array( $this, 'print_head' ), 1 );
		remove_action( 'wp_enqueue_scripts', array( $this, 'enqueue_tags' ), 1 );
		remove_action( 'wp_body_open', array( $this, 'print_body' ), 1 );
		remove_action( 'rest_api_init', array( $this, 'register_routes' ) );
		remove_filter( 'forensix_admin_screens', array( $this, 'add_screen' ) );
	}

	/**
	 * Deletes the saved codes and the last check.
	 */
	public function delete_data(): void {
		delete_option( Settings::OPTION_PREFIX . GoogleConfig::SCOPE );
		delete_option( GoogleCheck::OPTION );
	}
}