import 'package:flutter/material.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:shadcn_ui/shadcn_ui.dart';
import '../../core/app_colors.dart';
import '../../core/app_theme.dart';
import '../../core/navigation_provider.dart';
import '../../providers/data_providers.dart';
import '../../providers/consultation_provider.dart';

/// 问诊对话页 — 完整的 AI 分身聊天界面
class DoctorChatPage extends ConsumerStatefulWidget {
  final String id;
  const DoctorChatPage({super.key, required this.id});

  @override
  ConsumerState<DoctorChatPage> createState() => _DoctorChatPageState();
}

class _DoctorChatPageState extends ConsumerState<DoctorChatPage> {
  final _textCtrl = TextEditingController();
  final _scrollCtrl = ScrollController();

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ref.read(consultationChatProvider.notifier).init(widget.id);
    });
  }

  @override
  void dispose() {
    ref.read(consultationChatProvider.notifier).stop();
    _textCtrl.dispose();
    _scrollCtrl.dispose();
    super.dispose();
  }

  void _send() {
    final text = _textCtrl.text.trim();
    if (text.isEmpty) return;
    _textCtrl.clear();
    ref.read(consultationChatProvider.notifier).sendMessage(text);
  }

  String _statusText(String status) {
    switch (status) {
      case 'AiTalking':
        return 'AI分身对话中';
      case 'WaitingDoctor':
        return '已转接医生，请耐心等待';
      case 'DoctorReplied':
        return '医生已回复';
      case 'Closed':
        return '对话已结束';
      default:
        return '';
    }
  }

  @override
  Widget build(BuildContext context) {
    final state = ref.watch(consultationChatProvider);
    final canSend = state.status == 'AiTalking' && !state.isSending;

    return GradientScaffold(
      appBar: AppBar(
        backgroundColor: Colors.white,
        title: Column(children: [
          Text(state.doctorName.isNotEmpty ? '${state.doctorName} · ${state.doctorDepartment}' : '问诊对话',
              style: const TextStyle(fontSize: 19, fontWeight: FontWeight.w600, color: Color(0xFF1A1A1A))),
          if (state.doctorName.isNotEmpty)
            Text(_statusText(state.status), style: const TextStyle(fontSize: 15, color: AppColors.textSecondary)),
        ]),
        centerTitle: true,
        actions: [
          Container(
            margin: const EdgeInsets.only(right: 12),
            padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
            decoration: BoxDecoration(
              color: Colors.white,
              borderRadius: BorderRadius.circular(12),
            ),
            child: Text('剩余${state.quotaRemaining}/${state.quotaTotal}次',
                style: const TextStyle(fontSize: 15, color: AppColors.textPrimary, fontWeight: FontWeight.w500)),
          ),
        ],
      ),
      body: state.isLoading
          ? const Center(child: CircularProgressIndicator(color: AppTheme.primaryLight))
          : Column(children: [
              Expanded(child: _buildMessageList(state)),
              _buildInputBar(canSend),
            ]),
    );
  }

  Widget _buildMessageList(ConsultationChatState state) {
    if (state.messages.isEmpty) {
      return const Center(
          child: Text('暂无消息', style: TextStyle(color: Color(0xFFBBBBBB))));
    }
    return ListView.builder(
      controller: _scrollCtrl,
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      itemCount: state.messages.length,
      itemBuilder: (ctx, i) => _buildBubble(state, state.messages[i]),
    );
  }

  Widget _buildBubble(ConsultationChatState state, ConsultationMsg msg) {
    final isUser = msg.senderType == 'User';
    final isAi = msg.senderType == 'Ai';

    return Align(
      alignment: isUser ? Alignment.centerRight : Alignment.centerLeft,
      child: Container(
        margin: const EdgeInsets.only(bottom: 12),
        padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 14),
        constraints: BoxConstraints(maxWidth: MediaQuery.of(context).size.width * 0.82),
        decoration: BoxDecoration(
          color: isUser ? AppTheme.primary : const Color(0xFFFEFEFF),
          borderRadius: BorderRadius.only(
            topLeft: Radius.circular(isUser ? 20 : 4),
            topRight: Radius.circular(isUser ? 4 : 20),
            bottomLeft: const Radius.circular(20),
            bottomRight: const Radius.circular(20),
          ),
          border: isUser ? null : Border.all(color: const Color(0xFFD8DCFD), width: 1.5),
          boxShadow: isUser
              ? []
              : [BoxShadow(color: AppTheme.primary.withAlpha(12), blurRadius: 10, offset: const Offset(0, 3))],
        ),
        child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
          if (!isUser && msg.senderName != null) ...[
            Row(children: [
              const CircleAvatar(radius: 10, backgroundColor: Color(0xFFF0F2FF),
                  child: Icon(Icons.smart_toy, size: 15, color: AppTheme.primaryLight)),
              const SizedBox(width: 6),
              Text(msg.senderName!, style: const TextStyle(fontSize: 15, color: Color(0xFF9E9E9E))),
            ]),
            const SizedBox(height: 8),
          ],
          if (isUser)
            Text(msg.content, style: const TextStyle(fontSize: 19, color: Colors.white, height: 1.4))
          else
            MarkdownBody(
              data: msg.content,
              selectable: true,
              styleSheet: MarkdownStyleSheet(
                p: const TextStyle(fontSize: 19, color: Color(0xFF1A1A1A), height: 1.5),
              ),
            ),
          if (isAi) ...[
            const SizedBox(height: 8),
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
              decoration: BoxDecoration(
                color: const Color(0xFFFFF8E1),
                borderRadius: BorderRadius.circular(6),
              ),
              child: Text('🏷️ 以上为AI分析，具体请咨询${state.doctorName}',
                  style: const TextStyle(fontSize: 13, color: Color(0xFFF9A825))),
            ),
          ],
        ]),
      ),
    );
  }

  Widget _buildInputBar(bool canSend) {
    return Container(
      padding: const EdgeInsets.fromLTRB(12, 8, 12, 10),
      decoration: BoxDecoration(
        color: Colors.white,
        border: const Border(top: BorderSide(color: Color(0xFFEEEEEE))),
      ),
      child: Row(crossAxisAlignment: CrossAxisAlignment.end, children: [
        Expanded(
          child: Container(
            constraints: const BoxConstraints(maxHeight: 120),
            decoration: BoxDecoration(
              color: AppColors.backgroundSoft,
              borderRadius: BorderRadius.circular(20),
            ),
            child: TextField(
              controller: _textCtrl,
              enabled: canSend,
              maxLines: null,
              style: const TextStyle(fontSize: 18),
              decoration: InputDecoration(
                hintText: canSend ? '描述您的症状...' : '对话已结束',
                hintStyle: const TextStyle(fontSize: 18, color: Color(0xFFBBBBBB)),
                contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
                border: const OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
                enabledBorder: const OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
                focusedBorder: const OutlineInputBorder(borderRadius: BorderRadius.all(Radius.circular(20)), borderSide: BorderSide.none),
              ),
              onSubmitted: (_) => _send(),
            ),
          ),
        ),
        const SizedBox(width: 8),
        GestureDetector(
          onTap: canSend ? _send : null,
          child: Container(
            width: 40, height: 40,
            decoration: BoxDecoration(
              color: canSend ? AppColors.blueMeasure : const Color(0xFFCCCCCC),
              borderRadius: BorderRadius.circular(20),
            ),
            child: const Icon(Icons.send_rounded, size: 20, color: Colors.white),
          ),
        ),
      ]),
    );
  }
}