import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../core/app_colors.dart';
import '../core/app_design_tokens.dart';
import '../providers/ai_consent_provider.dart';
import '../providers/auth_provider.dart';
import '../pages/settings/ai_consent_details_page.dart';

class AiConsentGate extends ConsumerStatefulWidget {
  final Widget child;
  const AiConsentGate({super.key, required this.child});

  @override
  ConsumerState<AiConsentGate> createState() => _AiConsentGateState();
}

class _AiConsentGateState extends ConsumerState<AiConsentGate> {
  String? _loadedUserId;

  @override
  Widget build(BuildContext context) {
    final user = ref.watch(authProvider).user;
    if (user == null || user.id.isEmpty) return widget.child;

    if (_loadedUserId != user.id) {
      _loadedUserId = user.id;
      Future<void>.microtask(
        () => ref.read(aiConsentProvider.notifier).load(user.id),
      );
    }

    final consent = ref.watch(aiConsentProvider);
    if (consent.userId != user.id || consent.isLoading) {
      return const Scaffold(backgroundColor: Colors.white);
    }
    if (consent.granted) return widget.child;

    return Scaffold(
      backgroundColor: AppColors.background,
      body: Center(
        child: Padding(
          padding: const EdgeInsets.all(24),
          child: _ConsentCard(userId: user.id),
        ),
      ),
    );
  }
}

class _ConsentCard extends ConsumerWidget {
  final String userId;
  const _ConsentCard({required this.userId});

  Future<void> _grant(BuildContext context, WidgetRef ref) async {
    await ref.read(aiConsentProvider.notifier).grant(userId);
  }

  Future<void> _decline(BuildContext context, WidgetRef ref) async {
    await ref.read(authProvider.notifier).logout();
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Card(
      elevation: 0,
      color: Colors.white,
      shape: RoundedRectangleBorder(borderRadius: AppRadius.xlBorder),
      child: Padding(
        padding: const EdgeInsets.fromLTRB(22, 24, 22, 20),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            const Icon(Icons.auto_awesome, size: 40, color: AppColors.primary),
            const SizedBox(height: 14),
            const Text(
              'AI 健康服务授权',
              textAlign: TextAlign.center,
              style: TextStyle(fontSize: 21, fontWeight: FontWeight.w700),
            ),
            const SizedBox(height: 14),
            const Text(
              '小脉健康的核心功能使用第三方 AI 服务。经你同意后，你主动输入的健康信息、对话内容、图片和报告可能会发送给相关 AI 服务，用于健康记录、饮食识别、报告整理和 AI 回复。',
              style: TextStyle(
                fontSize: 15,
                height: 1.6,
                color: AppColors.textSecondary,
              ),
            ),
            const SizedBox(height: 10),
            const Text(
              'AI 生成内容仅供健康管理参考，不能替代医生诊断或治疗。',
              style: TextStyle(
                fontSize: 14,
                height: 1.5,
                color: AppColors.textSecondary,
              ),
            ),
            const SizedBox(height: 10),
            TextButton(
              onPressed: () {
                Navigator.of(context).push(
                  MaterialPageRoute<void>(
                    builder: (_) => const AiConsentDetailsPage(),
                  ),
                );
              },
              child: const Text('查看《AI 数据处理说明》'),
            ),
            const SizedBox(height: 8),
            FilledButton(
              onPressed: () => _grant(context, ref),
              child: const Text('同意并继续'),
            ),
            const SizedBox(height: 8),
            OutlinedButton(
              onPressed: () => _decline(context, ref),
              child: const Text('不同意并退出'),
            ),
          ],
        ),
      ),
    );
  }
}