import 'package:flutter/material.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../../core/app_colors.dart';
import '../../core/app_theme.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.sizeOf(context).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: AppColors.iconBg,
                    child: Icon(
                      Icons.forum_outlined,
                      size: 15,
                      color: AppColors.primary,
                    ),
                  ),
                  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: AppColors.divider)),
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.end,
        children: [
          Expanded(
            child: Container(
              constraints: const BoxConstraints(maxHeight: 120),
              decoration: BoxDecoration(
                color: AppColors.backgroundSoft,
                borderRadius: BorderRadius.circular(20),
                border: Border.all(color: AppColors.border),
              ),
              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(color: AppColors.border),
                  ),
                  enabledBorder: const OutlineInputBorder(
                    borderRadius: BorderRadius.all(Radius.circular(20)),
                    borderSide: BorderSide(color: AppColors.border),
                  ),
                  focusedBorder: const OutlineInputBorder(
                    borderRadius: BorderRadius.all(Radius.circular(20)),
                    borderSide: BorderSide(color: AppColors.primary),
                  ),
                ),
                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,
              ),
            ),
          ),
        ],
      ),
    );
  }
}