<?php
/**
 * A deterministic fake of Google's OAuth, Admin, Data and Search Console
 * APIs, plus the relay, for demo mode.
 *
 * @package Tagsmith
 */

declare(strict_types=1);

namespace Tagsmith\Demo;

use Tagsmith\Plugin;

defined( 'ABSPATH' ) || exit;

require_once __DIR__ . '/FakeData.php';
require_once __DIR__ . '/FakeReports.php';
require_once __DIR__ . '/FakeSearchConsole.php';

/**
 * Answers every Google/relay HTTP call the plugin makes, from a
 * `pre_http_request` filter, with plausible, deterministic data derived
 * from the request itself. Used by the Playground preview, e2e tests and
 * screenshots (see demo/tagsmith-demo.php). Report generation lives in
 * FakeReports and FakeSearchConsole; the pools they draw from are in
 * FakeData.
 */
class FakeGoogle {

	/**
	 * The demo GA4 property id.
	 *
	 * @var string
	 */
	public const PROPERTY_ID = 'properties/100000001';

	/**
	 * The demo GA4 measurement id.
	 *
	 * @var string
	 */
	public const MEASUREMENT_ID = 'G-DEMO000001';

	/**
	 * Answers a request, or null when the URL isn't one FakeGoogle handles.
	 *
	 * @param string               $url  Request URL.
	 * @param array<string, mixed> $args wp_remote_request() args (method, body, headers…).
	 * @return array<string, mixed>|null A WP HTTP response array, or null.
	 */
	public static function respond( string $url, array $args ): ?array {
		$host = (string) wp_parse_url( $url, PHP_URL_HOST );

		if ( '' === $host ) {
			return null;
		}

		$relay_host = (string) wp_parse_url( Plugin::relay_url(), PHP_URL_HOST );

		if ( 'oauth2.googleapis.com' === $host || ( '' !== $relay_host && 0 === strcasecmp( $host, $relay_host ) ) ) {
			return self::auth( $url );
		}

		if ( 'analyticsadmin.googleapis.com' === $host ) {
			return self::admin( $url );
		}

		if ( 'analyticsdata.googleapis.com' === $host ) {
			return self::data( $url, $args );
		}

		if ( 'searchconsole.googleapis.com' === $host ) {
			return self::gsc( $url, $args );
		}

		return null;
	}

	/**
	 * Token/refresh/revoke.
	 *
	 * @param string $url Request URL.
	 * @return array<string, mixed>
	 */
	private static function auth( string $url ): array {
		if ( false !== strpos( $url, '/revoke' ) ) {
			return self::ok( array() );
		}

		return self::ok(
			array(
				'access_token' => 'demo-token',
				'expires_in'   => 3600,
				'scope'        => 'openid email https://www.googleapis.com/auth/analytics.readonly https://www.googleapis.com/auth/webmasters.readonly',
			)
		);
	}

	/**
	 * Account summaries and web data streams.
	 *
	 * @param string $url Request URL.
	 * @return array<string, mixed>
	 */
	private static function admin( string $url ): array {
		if ( false !== strpos( $url, 'dataStreams' ) ) {
			return self::ok(
				array(
					'dataStreams' => array(
						array(
							'name'          => self::PROPERTY_ID . '/dataStreams/1',
							'type'          => 'WEB_DATA_STREAM',
							'displayName'   => 'Demo Site',
							'webStreamData' => array(
								'measurementId' => self::MEASUREMENT_ID,
								'defaultUri'    => home_url(),
							),
						),
					),
				)
			);
		}

		return self::ok(
			array(
				'accountSummaries' => array(
					array(
						'account'           => 'accounts/1000000001',
						'displayName'       => 'Demo Account',
						'propertySummaries' => array(
							array(
								'property'    => self::PROPERTY_ID,
								'displayName' => 'Demo Site',
							),
						),
					),
				),
			)
		);
	}

	/**
	 * Runs runReport, batchRunReports or runRealtimeReport.
	 *
	 * @param string               $url  Request URL.
	 * @param array<string, mixed> $args Request args.
	 * @return array<string, mixed>
	 */
	private static function data( string $url, array $args ): array {
		$body = self::decode_body( $args );

		if ( false !== strpos( $url, ':batchRunReports' ) ) {
			$requests = array_values( (array) ( $body['requests'] ?? array() ) );

			return self::ok(
				array(
					'reports' => array_map(
						static fn( $request ): array => FakeReports::report( is_array( $request ) ? $request : array(), false ),
						$requests
					),
				)
			);
		}

		$is_realtime = false !== strpos( $url, ':runRealtimeReport' );

		return self::ok( FakeReports::report( $body, $is_realtime ) );
	}

	/**
	 * Verified sites and searchAnalytics.query.
	 *
	 * @param string               $url  Request URL.
	 * @param array<string, mixed> $args Request args.
	 * @return array<string, mixed>
	 */
	private static function gsc( string $url, array $args ): array {
		if ( false !== strpos( $url, '/searchAnalytics/query' ) ) {
			return self::ok( FakeSearchConsole::query( self::decode_body( $args ) ) );
		}

		return self::ok(
			array(
				'siteEntry' => array_map(
					static fn( string $site_url ): array => array(
						'siteUrl'         => $site_url,
						'permissionLevel' => 'siteOwner',
					),
					self::search_console_sites()
				),
			)
		);
	}

	/**
	 * The Search Console properties of the demo's Google account: a
	 * `sc-domain:` property when the site's host is a real-looking domain,
	 * and the URL-prefix property for the site (with a trailing slash, as
	 * Search Console lists it). The demo seeds one of these as gsc_site
	 * (tagsmith_demo_gsc_site() in tagsmith-demo.php), so the Health
	 * tab finds the site it selected. A bare IP or a host with a port, such
	 * as Playground's `127.0.0.1:9400`, only has the URL-prefix property.
	 *
	 * @return string[]
	 */
	private static function search_console_sites(): array {
		$home  = home_url();
		$host  = (string) wp_parse_url( $home, PHP_URL_HOST );
		$sites = array();

		if ( 1 === preg_match( '/^[a-z0-9.-]+\.[a-z]{2,}$/i', $host ) ) {
			$sites[] = 'sc-domain:' . strtolower( $host );
		}

		$sites[] = rtrim( $home, '/' ) . '/';

		return $sites;
	}

	/**
	 * Decodes a request's JSON body.
	 *
	 * @param array<string, mixed> $args wp_remote_request() args.
	 * @return array<string, mixed>
	 */
	private static function decode_body( array $args ): array {
		$raw = $args['body'] ?? null;

		if ( is_array( $raw ) ) {
			return $raw;
		}

		if ( ! is_string( $raw ) || '' === $raw ) {
			return array();
		}

		$decoded = json_decode( $raw, true );

		return is_array( $decoded ) ? $decoded : array();
	}

	/**
	 * Wraps a decoded body into a WP HTTP response array.
	 *
	 * @param array<string, mixed> $body Response body.
	 * @return array<string, mixed>
	 */
	private static function ok( array $body ): array {
		return array(
			'headers'  => array(),
			'body'     => (string) wp_json_encode( $body ),
			'response' => array(
				'code'    => 200,
				'message' => 'OK',
			),
			'cookies'  => array(),
			'filename' => null,
		);
	}
}