<?php

defined( 'ABSPATH' ) || exit;

class AIEO_GSC {

	const SETTINGS_OPT = 'aieo_gsc_settings'; 
	const TOKENS_OPT   = 'aieo_gsc_tokens';   

	
	const STATE_META = 'aieo_gsc_oauth_state';
	const STATE_TTL  = 15 * MINUTE_IN_SECONDS;

	
	const STATE_TRANSIENT = 'aieo_gsc_oauth_state';

	
	const LAST_ERROR_OPT = 'aieo_gsc_last_error';

	
	const LAST_SYNC_OPT = 'aieo_gsc_history_last_sync';

	
	const QUERIES_CACHE = 'aieo_gsc_queries_cache';

	
	const SITES_CACHE = 'aieo_gsc_sites';
	const SITES_TTL   = 12 * HOUR_IN_SECONDS;

	const SCOPE      = 'https://www.googleapis.com/auth/webmasters.readonly';
	const AUTH_URL   = 'https://accounts.google.com/o/oauth2/v2/auth';
	const TOKEN_URL  = 'https://oauth2.googleapis.com/token';
	const REVOKE_URL = 'https://oauth2.googleapis.com/revoke';
	const API_BASE   = 'https://www.googleapis.com/webmasters/v3';
	const INSPECT_URL = 'https://searchconsole.googleapis.com/v1/urlInspection/index:inspect';
	const TIMEOUT    = 30;

	
	const RECONNECT_REASONS = array( 'invalid_grant', 'unauthorized_client', 'UNAUTHENTICATED', 'aieo_gsc_refresh' );

	
	
	

	public static function settings() {
		$s = get_option( self::SETTINGS_OPT, array() );
		return is_array( $s ) ? $s : array();
	}

	
	public static function save_settings( $client_id, $client_secret, $property = null ) {
		$s       = self::settings();
		$cid     = sanitize_text_field( (string) $client_id );
		$changed = (string) ( $s['client_id'] ?? '' ) !== $cid;

		$s['client_id']     = $cid;
		$s['client_secret'] = sanitize_text_field( (string) $client_secret );
		if ( $changed ) {
			unset( $s['property'] );
		}
		if ( null !== $property ) {
			$s['property'] = self::sanitize_property( (string) $property );
		}
		update_option( self::SETTINGS_OPT, $s, false );

		if ( $changed ) {
			delete_option( self::TOKENS_OPT );
			self::forget_connection_state();
			delete_transient( self::SITES_CACHE );
		}
		return $changed;
	}

	
	public static function set_property( $property ) {
		$s   = self::settings();
		$old = isset( $s['property'] ) ? (string) $s['property'] : '';

		$s['property'] = self::sanitize_property( (string) $property );
		update_option( self::SETTINGS_OPT, $s, false );

		if ( $s['property'] === $old ) {
			return false;
		}
		
		
		
		self::forget_connection_state();
		return true;
	}

	public static function property() {
		$s = self::settings();
		return isset( $s['property'] ) ? (string) $s['property'] : '';
	}

	public static function is_configured() {
		$s = self::settings();
		return ! empty( $s['client_id'] ) && ! empty( $s['client_secret'] );
	}

	public static function is_connected() {
		$t = get_option( self::TOKENS_OPT, array() );
		return is_array( $t ) && ! empty( $t['refresh_token'] );
	}

	
	public static function redirect_uri() {
		return admin_url( 'admin-post.php?action=aieo_gsc_oauth' );
	}

	
	public static function disconnect( $revoke = true ) {
		$refresh = self::stored_refresh();
		if ( $revoke && '' !== $refresh ) {
			wp_remote_post( self::REVOKE_URL, array(
				'timeout' => 5,
				'body'    => array( 'token' => $refresh ),
			) );
		}
		delete_option( self::TOKENS_OPT );
		$s = self::settings();
		if ( isset( $s['property'] ) ) {
			unset( $s['property'] );
			update_option( self::SETTINGS_OPT, $s, false );
		}
		self::forget_connection_state();
		delete_transient( self::SITES_CACHE );
	}

	
	private static function forget_connection_state() {
		delete_option( self::LAST_SYNC_OPT );
		delete_option( self::LAST_ERROR_OPT );
		delete_transient( self::QUERIES_CACHE );
	}

	
	
	

	
	public static function last_error() {
		$e = get_option( self::LAST_ERROR_OPT, array() );
		if ( ! is_array( $e ) || empty( $e['message'] ) ) {
			return array();
		}
		return array(
			'code'    => (string) ( $e['code'] ?? '' ),
			'message' => (string) $e['message'],
			'at'      => (int) ( $e['at'] ?? 0 ),
		);
	}

	public static function record_error( $code, $message ) {
		update_option( self::LAST_ERROR_OPT, array(
			'code'    => (string) $code,
			'message' => (string) $message,
			'at'      => time(),
		), false );
	}

	public static function clear_error() {
		delete_option( self::LAST_ERROR_OPT );
	}

	
	public static function error_reason( $error ) {
		if ( ! is_wp_error( $error ) ) {
			return '';
		}
		$data = $error->get_error_data();
		if ( is_array( $data ) && ! empty( $data['reason'] ) ) {
			return (string) $data['reason'];
		}
		return (string) $error->get_error_code();
	}

	
	public static function needs_reconnect( $error ) {
		$reason = is_wp_error( $error ) ? self::error_reason( $error ) : (string) $error;
		return in_array( $reason, self::RECONNECT_REASONS, true );
	}

	
	
	

	
	public static function auth_url() {
		$uid = get_current_user_id();
		if ( ! self::is_configured() || ! $uid ) {
			return '';
		}
		$s     = self::settings();
		$state = wp_generate_password( 24, false );
		update_user_meta( $uid, self::STATE_META, array(
			'state'   => $state,
			'expires' => time() + self::STATE_TTL,
		) );
		$args = array(
			'client_id'              => $s['client_id'],
			'redirect_uri'           => self::redirect_uri(),
			'response_type'          => 'code',
			'scope'                  => self::SCOPE,
			'access_type'            => 'offline',
			'include_granted_scopes' => 'true',
			'prompt'                 => 'consent', 
			'state'                  => $state,
		);
		return self::AUTH_URL . '?' . http_build_query( $args );
	}

	
	public static function handle_callback( $code, $state ) {
		$checked = self::consume_state( get_current_user_id(), (string) $state );
		if ( is_wp_error( $checked ) ) {
			return $checked;
		}
		if ( '' === (string) $code ) {
			return new WP_Error( 'aieo_gsc_nocode', __( 'Google did not return an authorization code.', 'ai-eshop-optimizer' ) );
		}
		$s    = self::settings();
		$resp = wp_remote_post( self::TOKEN_URL, array(
			'timeout' => self::TIMEOUT,
			'body'    => array(
				'code'          => (string) $code,
				'client_id'     => $s['client_id'],
				'client_secret' => $s['client_secret'],
				'redirect_uri'  => self::redirect_uri(),
				'grant_type'    => 'authorization_code',
			),
		) );
		$data = self::decode( $resp );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		if ( empty( $data['access_token'] ) ) {
			return new WP_Error( 'aieo_gsc_token', __( 'Google did not return an access token. Re-check the client credentials + redirect URI.', 'ai-eshop-optimizer' ) );
		}
		$tokens = array(
			'access_token'  => (string) $data['access_token'],
			'refresh_token' => ! empty( $data['refresh_token'] ) ? (string) $data['refresh_token'] : self::stored_refresh(),
			'scope'         => (string) ( $data['scope'] ?? self::SCOPE ),
			'expires_at'    => time() + (int) ( $data['expires_in'] ?? 3600 ) - 60,
		);
		if ( '' === $tokens['refresh_token'] ) {
			return new WP_Error( 'aieo_gsc_norefresh', __( 'Google did not return a refresh token. Remove the app from your Google account’s third-party access and reconnect (we request offline access).', 'ai-eshop-optimizer' ) );
		}
		update_option( self::TOKENS_OPT, $tokens, false );
		
		
		
		self::clear_error();
		return true;
	}

	
	private static function consume_state( $user_id, $state ) {
		$pending = $user_id ? get_user_meta( $user_id, self::STATE_META, true ) : array();
		if ( is_array( $pending ) && ! empty( $pending['state'] ) && (int) ( $pending['expires'] ?? 0 ) >= time() ) {
			if ( ! hash_equals( (string) $pending['state'], $state ) ) {
				return new WP_Error( 'aieo_gsc_state', __( 'The Google sign-in could not be verified (state mismatch). Please try again.', 'ai-eshop-optimizer' ) );
			}
			delete_user_meta( $user_id, self::STATE_META );
			return true;
		}
		if ( $user_id && ! empty( $pending ) ) {
			delete_user_meta( $user_id, self::STATE_META ); 
		}
		$legacy = (string) get_transient( self::STATE_TRANSIENT );
		if ( '' !== $legacy && hash_equals( $legacy, $state ) ) {
			delete_transient( self::STATE_TRANSIENT );
			return true;
		}
		return new WP_Error( 'aieo_gsc_state_expired', __( 'This Google sign-in has expired, or was started by a different WordPress user. Click “Connect Google Search Console” again and finish within 15 minutes.', 'ai-eshop-optimizer' ) );
	}

	private static function stored_refresh() {
		$t = get_option( self::TOKENS_OPT, array() );
		return is_array( $t ) && ! empty( $t['refresh_token'] ) ? (string) $t['refresh_token'] : '';
	}

	
	public static function access_token() {
		$t = get_option( self::TOKENS_OPT, array() );
		if ( ! is_array( $t ) || empty( $t['refresh_token'] ) ) {
			return new WP_Error( 'aieo_gsc_disconnected', __( 'Google Search Console is not connected.', 'ai-eshop-optimizer' ) );
		}
		if ( ! empty( $t['access_token'] ) && ! empty( $t['expires_at'] ) && time() < (int) $t['expires_at'] ) {
			return (string) $t['access_token'];
		}
		$s    = self::settings();
		$resp = wp_remote_post( self::TOKEN_URL, array(
			'timeout' => self::TIMEOUT,
			'body'    => array(
				'client_id'     => $s['client_id'] ?? '',
				'client_secret' => $s['client_secret'] ?? '',
				'refresh_token' => (string) $t['refresh_token'],
				'grant_type'    => 'refresh_token',
			),
		) );
		$data = self::decode( $resp );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		if ( empty( $data['access_token'] ) ) {
			return new WP_Error( 'aieo_gsc_refresh', __( 'Could not refresh the Google access token. Reconnect Search Console.', 'ai-eshop-optimizer' ) );
		}
		$t['access_token'] = (string) $data['access_token'];
		$t['expires_at']   = time() + (int) ( $data['expires_in'] ?? 3600 ) - 60;
		update_option( self::TOKENS_OPT, $t, false );
		return $t['access_token'];
	}

	
	
	

	
	public static function list_sites() {
		$token = self::access_token();
		if ( is_wp_error( $token ) ) {
			return self::keep_sites( $token );
		}
		$resp = wp_remote_get( self::API_BASE . '/sites', array(
			'timeout' => self::TIMEOUT,
			'headers' => array( 'Authorization' => 'Bearer ' . $token ),
		) );
		$data = self::decode( $resp );
		if ( is_wp_error( $data ) ) {
			return self::keep_sites( $data );
		}
		$out = array();
		foreach ( (array) ( $data['siteEntry'] ?? array() ) as $e ) {
			$out[] = array(
				'siteUrl'         => (string) ( $e['siteUrl'] ?? '' ),
				'permissionLevel' => (string) ( $e['permissionLevel'] ?? '' ),
			);
		}
		return self::keep_sites( $out );
	}

	
	public static function saved_property_label( $property, $unloaded ) {
		
		return $unloaded ? (string) $property : sprintf( __( '%s (saved)', 'ai-eshop-optimizer' ), (string) $property );
	}

	
	public static function cached_sites() {
		$c = get_transient( self::SITES_CACHE );
		if ( ! is_array( $c ) ) {
			return null;
		}
		if ( isset( $c['error'] ) ) {
			return new WP_Error( (string) ( $c['code'] ?? 'aieo_gsc_sites' ), (string) $c['error'], array( 'reason' => (string) ( $c['reason'] ?? '' ) ) );
		}
		return isset( $c['sites'] ) && is_array( $c['sites'] ) ? $c['sites'] : null;
	}

	
	private static function keep_sites( $answer ) {
		$keep = is_wp_error( $answer )
			? array( 'error' => $answer->get_error_message(), 'code' => $answer->get_error_code(), 'reason' => self::error_reason( $answer ) )
			: array( 'sites' => $answer );
		set_transient( self::SITES_CACHE, $keep, self::SITES_TTL );
		return $answer;
	}

	
	public static function query( array $args = array() ) {
		$token = self::access_token();
		if ( is_wp_error( $token ) ) {
			return $token;
		}
		$property = self::property();
		if ( '' === $property ) {
			return new WP_Error( 'aieo_gsc_noprop', __( 'No Search Console property is selected.', 'ai-eshop-optimizer' ) );
		}
		$end   = isset( $args['end_date'] ) ? (string) $args['end_date'] : gmdate( 'Y-m-d', time() - 2 * DAY_IN_SECONDS );
		$start = isset( $args['start_date'] ) ? (string) $args['start_date'] : gmdate( 'Y-m-d', time() - 90 * DAY_IN_SECONDS );
		$body  = array(
			'startDate'  => $start,
			'endDate'    => $end,
			'dimensions' => isset( $args['dimensions'] ) && is_array( $args['dimensions'] ) ? array_values( $args['dimensions'] ) : array( 'query' ),
			'rowLimit'   => min( 25000, max( 1, (int) ( $args['row_limit'] ?? 1000 ) ) ),
			'startRow'   => max( 0, (int) ( $args['start_row'] ?? 0 ) ),
			'type'       => isset( $args['type'] ) ? (string) $args['type'] : 'web',
			'dataState'  => isset( $args['data_state'] ) ? (string) $args['data_state'] : 'final',
		);
		if ( ! empty( $args['filters'] ) && is_array( $args['filters'] ) ) {
			$body['dimensionFilterGroups'] = array( array( 'filters' => array_values( $args['filters'] ) ) );
		}
		$resp = wp_remote_post( self::API_BASE . '/sites/' . rawurlencode( $property ) . '/searchAnalytics/query', array(
			'timeout' => self::TIMEOUT,
			'headers' => array(
				'Authorization' => 'Bearer ' . $token,
				'Content-Type'  => 'application/json',
			),
			'body'    => wp_json_encode( $body ),
		) );
		$data = self::decode( $resp );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		$rows = array();
		foreach ( (array) ( $data['rows'] ?? array() ) as $r ) {
			$rows[] = array(
				'keys'        => array_map( 'strval', (array) ( $r['keys'] ?? array() ) ),
				'clicks'      => (int) round( (float) ( $r['clicks'] ?? 0 ) ),
				'impressions' => (int) round( (float) ( $r['impressions'] ?? 0 ) ),
				'ctr'         => round( (float) ( $r['ctr'] ?? 0 ), 4 ),
				'position'    => round( (float) ( $r['position'] ?? 0 ), 1 ),
			);
		}
		return array( 'rows' => $rows, 'range' => array( 'start' => $start, 'end' => $end ) );
	}

	
	public static function top_queries( $days = 90, $limit = 100, $dimensions = array( 'query' ) ) {
		return self::query( array(
			'start_date' => gmdate( 'Y-m-d', time() - max( 1, (int) $days ) * DAY_IN_SECONDS ),
			'end_date'   => gmdate( 'Y-m-d', time() - 2 * DAY_IN_SECONDS ),
			'dimensions' => $dimensions,
			'row_limit'  => (int) $limit,
		) );
	}

	
	public static function inspect_url( $url ) {
		$token = self::access_token();
		if ( is_wp_error( $token ) ) {
			return $token;
		}
		$property = self::property();
		if ( '' === $property ) {
			return new WP_Error( 'aieo_gsc_noprop', __( 'No Search Console property is selected.', 'ai-eshop-optimizer' ) );
		}
		$resp = wp_remote_post( self::INSPECT_URL, array(
			'timeout' => self::TIMEOUT,
			'headers' => array(
				'Authorization' => 'Bearer ' . $token,
				'Content-Type'  => 'application/json',
			),
			'body'    => wp_json_encode( array(
				'inspectionUrl' => (string) $url,
				'siteUrl'       => $property,
			) ),
		) );
		$data = self::decode( $resp );
		if ( is_wp_error( $data ) ) {
			return $data;
		}
		return isset( $data['inspectionResult'] ) && is_array( $data['inspectionResult'] ) ? $data['inspectionResult'] : $data;
	}

	
	
	

	
	private static function decode( $resp ) {
		if ( is_wp_error( $resp ) ) {
			return $resp;
		}
		$code = (int) wp_remote_retrieve_response_code( $resp );
		$data = json_decode( (string) wp_remote_retrieve_body( $resp ), true );
		if ( $code < 200 || $code >= 300 ) {
			$msg = is_array( $data ) && isset( $data['error']['message'] )
				? (string) $data['error']['message']
				: ( is_array( $data ) && isset( $data['error_description'] ) ? (string) $data['error_description'] : sprintf( 'HTTP %d', $code ) );
			$reason = '';
			if ( is_array( $data ) && isset( $data['error'] ) ) {
				$reason = is_array( $data['error'] ) ? (string) ( $data['error']['status'] ?? '' ) : (string) $data['error'];
			}
			return new WP_Error(
				'aieo_gsc_http',
				sprintf(  __( 'Google API error: %s', 'ai-eshop-optimizer' ), $msg ),
				array( 'google_status' => $code, 'reason' => $reason )
			);
		}
		return is_array( $data ) ? $data : array();
	}

	
	private static function sanitize_property( $p ) {
		$p = trim( (string) $p );
		if ( 0 === strpos( $p, 'sc-domain:' ) ) {
			return 'sc-domain:' . preg_replace( '/[^a-z0-9.-]/i', '', substr( $p, 10 ) );
		}
		return esc_url_raw( $p );
	}
}