import 'dart:async';

import 'package:flutter/material.dart';
import 'package:go_router/go_router.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';

import '../../../common/router/app_router.dart';
import 'auth_controller.dart';
import 'one_key_login_service.dart';

/// Shared login entry: launch the carrier-owned authorization page first and
/// use the Flutter SMS page only as a deliberate fallback.
abstract final class LoginLauncher {
  static final _service = OneKeyLoginService();
  static bool _starting = false;

  static Future<void> start(
    BuildContext context,
    WidgetRef ref, {
    String? next,
  }) async {
    if (_starting) return;
    _starting = true;
    final dismissLoading = _showLoading(context);
    try {
      final observer = _OneKeyLoginLifecycleObserver(_service);
      WidgetsBinding.instance.addObserver(observer);
      late final OneKeyLoginOutcome outcome;
      try {
        outcome = await _service.start(
          context: context,
          verifyToken: ref.read(authProvider.notifier).verifyOneKeyLogin,
          onNativeRequestDispatched: dismissLoading,
          onAuthPageOpened: dismissLoading,
        );
      } catch (_) {
        outcome = OneKeyLoginOutcome.fallback;
      } finally {
        WidgetsBinding.instance.removeObserver(observer);
      }
      if (!context.mounted) return;
      if (outcome == OneKeyLoginOutcome.success) {
        context.go(next?.isNotEmpty == true ? next! : AppRoutes.profile);
        return;
      }
      if (outcome == OneKeyLoginOutcome.fallback ||
          outcome == OneKeyLoginOutcome.unsupported) {
        final target = next == null || next.isEmpty
            ? AppRoutes.login
            : '${AppRoutes.login}?next=${Uri.encodeComponent(next)}';
        if (GoRouterState.of(context).matchedLocation != AppRoutes.login) {
          await context.push(target);
        }
      }
    } finally {
      dismissLoading();
      _starting = false;
    }
  }

  static VoidCallback _showLoading(BuildContext context) {
    var visible = true;
    unawaited(
      showDialog<void>(
        context: context,
        useRootNavigator: true,
        barrierDismissible: false,
        builder: (_) => const PopScope(
          canPop: false,
          child: Center(child: CircularProgressIndicator()),
        ),
      ),
    );
    return () {
      if (visible && context.mounted) {
        Navigator.of(context, rootNavigator: true).pop();
      }
      visible = false;
    };
  }
}

class _OneKeyLoginLifecycleObserver with WidgetsBindingObserver {
  _OneKeyLoginLifecycleObserver(this._service);
  final OneKeyLoginService _service;

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.resumed) _service.onAppResumed();
  }
}