AI-Health/health_app/lib/widgets/ai_consent_gate.dart

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

import '../core/app_colors.dart';
import '../core/app_design_tokens.dart';
import '../core/navigation_provider.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 || user.role != 'User') {
      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);
    final currentRoute = ref.watch(currentRouteProvider).name;
    final isConsentInformationRoute =
        currentRoute == 'aiConsentDetails' || currentRoute == 'staticText';
    if (consent.userId != user.id || consent.isLoading) {
      return const Scaffold(
        body: Center(
          child: CircularProgressIndicator(color: AppColors.primary),
        ),
      );
    }
    if (consent.granted || isConsentInformationRoute) return widget.child;

    return Scaffold(
      body: DecoratedBox(
        decoration: const BoxDecoration(gradient: AppColors.bgGradient),
        child: SafeArea(
          child: Center(
            child: SingleChildScrollView(
              padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 20),
              child: ConstrainedBox(
                constraints: const BoxConstraints(maxWidth: 400),
                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 {
    final succeeded = await ref.read(aiConsentProvider.notifier).grant(userId);
    if (!succeeded && context.mounted) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Authorization could not be saved.')),
      );
    }
  }

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

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final consent = ref.watch(aiConsentProvider);
    return Container(
      padding: const EdgeInsets.fromLTRB(20, 10, 20, 20),
      decoration: BoxDecoration(
        color: Colors.white.withValues(alpha: 0.96),
        borderRadius: AppRadius.cardBorder,
        border: Border.all(color: AppColors.primaryLight, width: 1),
        boxShadow: AppShadows.panel,
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          Align(
            child: Image.asset(
              'assets/branding/health_login_character_transparent.png',
              height: 112,
              fit: BoxFit.contain,
            ),
          ),
          const SizedBox(height: 2),
          Align(
            child: Container(
              padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
              decoration: BoxDecoration(
                color: AppColors.primarySoft,
                borderRadius: AppRadius.pillBorder,
              ),
              child: const Text(
                'AI Service',
                style: TextStyle(
                  fontSize: 13,
                  fontWeight: FontWeight.w600,
                  color: AppColors.primaryDark,
                ),
              ),
            ),
          ),
          const SizedBox(height: 14),
          Padding(
            padding: const EdgeInsets.symmetric(horizontal: 2),
            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: consent.isSaving
                      ? null
                      : () => _grant(context, ref),
                  child: const Text('同意并继续'),
                ),
                const SizedBox(height: 8),
                OutlinedButton(
                  onPressed: consent.isSaving
                      ? null
                      : () => _decline(context, ref),
                  child: const Text('不同意并退出'),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}