import 'package:aioa_mobile/features/assistant/application/leave_progress_controller.dart';
import 'package:aioa_mobile/features/assistant/data/leave_progress_repository.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:intl/intl.dart';

class AssistantPage extends ConsumerStatefulWidget {
  const AssistantPage({super.key});
  @override
  ConsumerState<AssistantPage> createState() => _AssistantPageState();
}

class _AssistantPageState extends ConsumerState<AssistantPage> {
  final _controller = TextEditingController();
  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final result = ref.watch(leaveProgressProvider);
    return Scaffold(
      appBar: AppBar(title: const Text('AI 流程助手')),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          const Text('询问本人请假流程进度，AI 只读查询，不会执行审批或修改申请。'),
          const SizedBox(height: 12),
          TextField(
            controller: _controller,
            minLines: 2,
            maxLines: 4,
            decoration: const InputDecoration(
              border: OutlineInputBorder(),
              hintText: '例如：我最近提交的年假审批到哪一步了？',
            ),
          ),
          const SizedBox(height: 10),
          FilledButton.icon(
            onPressed: result.isLoading
                ? null
                : () {
                    if (_controller.text.trim().isNotEmpty) {
                      ref
                          .read(leaveProgressProvider.notifier)
                          .ask(_controller.text);
                    }
                  },
            icon: const Icon(Icons.auto_awesome),
            label: const Text('查询进度'),
          ),
          const SizedBox(height: 16),
          result.when(
            loading: () => const Center(child: CircularProgressIndicator()),
            error: (e, _) => Card(
              child: Padding(
                padding: const EdgeInsets.all(16),
                child: Text('查询失败：$e'),
              ),
            ),
            data: (data) => data == null
                ? const SizedBox.shrink()
                : _Result(
                    data: data,
                    onSelect: (id) => ref
                        .read(leaveProgressProvider.notifier)
                        .ask('', selectedRequestId: id),
                  ),
          ),
        ],
      ),
    );
  }
}

class _Result extends StatelessWidget {
  const _Result({required this.data, required this.onSelect});
  final ProgressAnswer data;
  final ValueChanged<String> onSelect;
  @override
  Widget build(BuildContext context) {
    if (data.requiresSelection) {
      return Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Text('找到多条可能的申请，请选择：'),
          ...data.candidates.map(
            (c) => Card(
              child: ListTile(
                onTap: () => onSelect(c.id),
                title: Text('${_type(c.type)} · ${_status(c.status)}'),
                subtitle: Text(
                  '${DateFormat('MM-dd HH:mm').format(c.startsAt.toLocal())} — ${DateFormat('MM-dd HH:mm').format(c.endsAt.toLocal())}',
                ),
                trailing: const Icon(Icons.chevron_right),
              ),
            ),
          ),
        ],
      );
    }
    final request = data.request!;
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              '${_type(request.type)} · ${_status(request.status)}',
              style: Theme.of(context).textTheme.titleMedium,
            ),
            const SizedBox(height: 10),
            Text(data.answer ?? ''),
            if (data.activeTasks.isNotEmpty) ...[
              const SizedBox(height: 12),
              Text('当前节点：${data.activeTasks.join('、')}'),
            ],
            if (data.completedTasks.isNotEmpty)
              Text('已完成：${data.completedTasks.join('、')}'),
            const SizedBox(height: 12),
            OutlinedButton.icon(
              onPressed: () => context.push('/leave/${request.id}'),
              icon: const Icon(Icons.open_in_new),
              label: const Text('查看申请详情'),
            ),
          ],
        ),
      ),
    );
  }

  static String _type(String v) =>
      {'PERSONAL': '事假', 'SICK': '病假', 'ANNUAL': '年假'}[v] ?? v;
  static String _status(String v) =>
      {
        'DRAFT': '草稿',
        'PENDING': '审批中',
        'APPROVED': '已通过',
        'REJECTED': '已驳回',
        'WITHDRAWN': '已撤回',
      }[v] ??
      v;
}