import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:lucide_icons/lucide_icons.dart';
import '../../../../core/api/api_exception.dart';
import '../../../../core/di/injection.dart';
import '../../../../core/theme/design_tokens.dart';
import '../../../chat/data/models/chat_list_item.dart';
import '../../../chat/presentation/bloc/chat_bloc.dart';
import '../../../chat/data/tools/route_navigation_tool.dart';
import '../../../messages/data/inbox_api.dart';
import '../../data/voice_recorder.dart';
import '../../../chat/ui/widgets/ui_schema_renderer.dart';
import '../../../../shared/widgets/toast/toast.dart';
import '../../../../shared/widgets/toast/toast_type.dart';
import 'home_sheet.dart';

/// 布局常量
const _headerHeight = 60.0;
const _defaultPadding = 20.0;
const _itemSpacing = 16.0;
const _inputPadding = 16.0;
const _iconSize = 24.0;
const _messagePaddingH = 13.0;
const _messagePaddingV = 9.0;
const _cornerRadius = 12.0;
const _inputMinHeight = 48.0;
const _inputRadius = 24.0;
const _scrollDurationMs = 300;
const _rippleDurationMs = 1200;
const _recordingDotSize = 10.0;
const _transcribingSpinnerSize = 18.0;
const _transcribingStrokeWidth = 2.0;
const _inputActionButtonKey = ValueKey('home_input_action_button');
const _inputActionIconKey = ValueKey('home_input_action_icon');

/// 颜色常量
const _chatBgColor = Color(0xFFF8FAFC);
const _userBubbleColor = Color(0xFFEAF1FB);

class HomeScreen extends StatefulWidget {
  final VoiceRecorder? voiceRecorder;
  final Future<String> Function(String filePath)? onTranscribeAudio;
  final Future<void> Function(String transcript)? onAutoSendTranscript;
  final ChatBloc? chatBloc;
  final bool autoLoadHistory;

  const HomeScreen({
    super.key,
    this.voiceRecorder,
    this.onTranscribeAudio,
    this.onAutoSendTranscript,
    this.chatBloc,
    this.autoLoadHistory = true,
  });

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen>
    with SingleTickerProviderStateMixin {
  final TextEditingController _messageController = TextEditingController();
  final ScrollController _scrollController = ScrollController();
  late final ChatBloc _chatBloc;
  late final VoiceRecorder _voiceRecorder;
  late final InboxApi _inboxApi;
  late final Future<String> Function(String filePath) _transcribeAudio;
  late final Future<void> Function(String transcript) _autoSendTranscript;
  late final AnimationController _listeningAnimationController;
  bool _isRecording = false;
  bool _isTranscribing = false;
  int _unreadCount = 0;

  bool get _hasMessage => _messageController.text.trim().isNotEmpty;

  @override
  void initState() {
    super.initState();
    _messageController.addListener(_onMessageChanged);
    _chatBloc = widget.chatBloc ?? ChatBloc();
    _voiceRecorder = widget.voiceRecorder ?? RecordVoiceRecorder();
    _inboxApi = sl<InboxApi>();
    _transcribeAudio =
        widget.onTranscribeAudio ?? _chatBloc.transcribeAudioFile;
    _autoSendTranscript = widget.onAutoSendTranscript ?? _chatBloc.sendMessage;
    _listeningAnimationController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: _rippleDurationMs),
    );
    if (widget.autoLoadHistory) {
      _chatBloc.loadHistory();
    }
    _loadUnreadCount();
  }

  Future<void> _loadUnreadCount() async {
    try {
      final messages = await _inboxApi.getMessages(isRead: false);
      if (mounted) {
        setState(() => _unreadCount = messages.length);
      }
    } catch (_) {
      // Ignore errors
    }
  }

  @override
  void dispose() {
    _messageController.removeListener(_onMessageChanged);
    _messageController.dispose();
    _scrollController.dispose();
    _listeningAnimationController.dispose();
    _voiceRecorder.dispose();
    if (widget.chatBloc == null) {
      _chatBloc.close();
    }
    RouteNavigationTool.instance.clearNavigator();
    super.dispose();
  }

  void _onMessageChanged() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    RouteNavigationTool.instance.bindNavigator((target, {replace = false}) {
      if (!mounted) {
        return;
      }
      if (replace) {
        context.go(target);
      } else {
        context.push(target);
      }
    });

    return BlocProvider.value(
      value: _chatBloc,
      child: BlocConsumer<ChatBloc, ChatState>(
        listener: (context, state) {
          if (state.error != null) {
            Toast.show(context, state.error!, type: ToastType.error);
          }
        },
        builder: (context, state) {
          return Scaffold(
            backgroundColor: _chatBgColor,
            body: SafeArea(
              child: Column(
                children: [
                  _buildHeader(context),
                  Expanded(child: _buildChatArea(context, state)),
                  _buildInputContainer(context, state),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  Widget _buildHeader(BuildContext context) {
    return SizedBox(
      height: _headerHeight,
      child: Padding(
        padding: const EdgeInsets.symmetric(horizontal: _defaultPadding),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            IconButton(
              icon: const Icon(
                LucideIcons.settings,
                size: _iconSize,
                color: AppColors.slate900,
              ),
              onPressed: () => context.push('/settings'),
            ),
            Row(
              children: [
                IconButton(
                  icon: const Icon(
                    LucideIcons.calendar,
                    size: _iconSize,
                    color: AppColors.slate900,
                  ),
                  onPressed: () => context.push('/calendar/dayweek?from=home'),
                ),
                const SizedBox(width: _itemSpacing),
                IconButton(
                  icon: Stack(
                    clipBehavior: Clip.none,
                    children: [
                      const Icon(
                        LucideIcons.messageSquare,
                        size: _iconSize,
                        color: AppColors.slate900,
                      ),
                      if (_unreadCount > 0)
                        Positioned(
                          right: -4,
                          top: -4,
                          child: Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 4,
                              vertical: 2,
                            ),
                            decoration: BoxDecoration(
                              color: AppColors.red500,
                              borderRadius: BorderRadius.circular(8),
                            ),
                            constraints: const BoxConstraints(
                              minWidth: 16,
                              minHeight: 16,
                            ),
                            child: Text(
                              _unreadCount > 99
                                  ? '99+'
                                  : _unreadCount.toString(),
                              style: const TextStyle(
                                fontSize: 10,
                                fontWeight: FontWeight.w600,
                                color: AppColors.white,
                              ),
                              textAlign: TextAlign.center,
                            ),
                          ),
                        ),
                    ],
                  ),
                  onPressed: () => context.push('/messages/invites'),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildChatArea(BuildContext context, ChatState state) {
    final showWaitingIndicator =
        state.isWaitingFirstToken || state.isStreaming || state.isCancelling;

    if (state.isLoadingHistory && state.items.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    }

    if (state.items.isEmpty) {
      return Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          const Expanded(
            child: Center(
              child: Text(
                '开始对话吧',
                style: TextStyle(fontSize: 16, color: AppColors.slate400),
              ),
            ),
          ),
          if (showWaitingIndicator) _buildWaitingIndicator(),
        ],
      );
    }

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        Expanded(
          child: RefreshIndicator(
            onRefresh: () => _onRefresh(context),
            child: ListView.builder(
              controller: _scrollController,
              physics: const AlwaysScrollableScrollPhysics(),
              padding: const EdgeInsets.all(_defaultPadding),
              itemCount: state.items.length + (state.hasEarlierHistory ? 1 : 0),
              itemBuilder: (context, index) {
                if (index == 0 && state.hasEarlierHistory) {
                  return _buildLoadMoreButton(context, state.isLoadingHistory);
                }

                final itemIndex = state.hasEarlierHistory ? index - 1 : index;
                final item = state.items[itemIndex];

                final showDateDivider =
                    itemIndex == 0 ||
                    !_isSameDay(
                      state.items[itemIndex - 1].timestamp,
                      item.timestamp,
                    );

                return Column(
                  crossAxisAlignment: CrossAxisAlignment.stretch,
                  children: [
                    if (showDateDivider) _buildDateDivider(item.timestamp),
                    Padding(
                      padding: const EdgeInsets.only(bottom: _itemSpacing),
                      child: _buildChatItem(item),
                    ),
                  ],
                );
              },
            ),
          ),
        ),
        if (showWaitingIndicator) _buildWaitingIndicator(),
      ],
    );
  }

  Widget _buildWaitingIndicator() {
    return Padding(
      padding: const EdgeInsets.fromLTRB(
        _defaultPadding,
        0,
        _defaultPadding,
        _defaultPadding,
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: const [
          SizedBox(
            width: _transcribingSpinnerSize,
            height: _transcribingSpinnerSize,
            child: CircularProgressIndicator(
              strokeWidth: _transcribingStrokeWidth,
              color: AppColors.blue600,
            ),
          ),
          SizedBox(width: 8),
          Text(
            '正在思考...',
            style: TextStyle(fontSize: 14, color: AppColors.slate500),
          ),
        ],
      ),
    );
  }

  bool _isSameDay(DateTime a, DateTime b) {
    return a.year == b.year && a.month == b.month && a.day == b.day;
  }

  Widget _buildDateDivider(DateTime date) {
    final now = DateTime.now();
    final weekdays = ['周一', '周二', '周三', '周四', '周五', '周六', '周日'];
    final weekday = weekdays[date.weekday - 1];

    // For all dates (today/yesterday/this year), use the same format
    // Only add year prefix for dates from previous years
    final label = date.year == now.year
        ? '${date.month}月${date.day}日 $weekday'
        : '${date.year}年${date.month}月${date.day}日 $weekday';

    return Container(
      padding: const EdgeInsets.symmetric(vertical: 12),
      alignment: Alignment.center,
      child: Text(
        label,
        style: const TextStyle(fontSize: 12, color: AppColors.slate400),
      ),
    );
  }

  Widget _buildLoadMoreButton(BuildContext context, bool isLoading) {
    return GestureDetector(
      onTap: isLoading ? null : () => _onLoadMore(context),
      child: Container(
        padding: const EdgeInsets.symmetric(vertical: 8),
        alignment: Alignment.center,
        child: isLoading
            ? const SizedBox(
                width: 14,
                height: 14,
                child: CircularProgressIndicator(
                  strokeWidth: 1.5,
                  color: AppColors.slate400,
                ),
              )
            : const Text(
                '查看历史',
                style: TextStyle(fontSize: 12, color: AppColors.slate400),
              ),
      ),
    );
  }

  Future<void> _onRefresh(BuildContext context) async {
    await context.read<ChatBloc>().loadMoreHistory();
  }

  void _onLoadMore(BuildContext context) {
    context.read<ChatBloc>().loadMoreHistory();
  }

  Widget _buildChatItem(ChatListItem item) {
    switch (item.type) {
      case ChatItemType.message:
        return _buildMessageItem(item as TextMessageItem);
      case ChatItemType.toolCall:
        return _buildToolCallItem(item as ToolCallItem);
      case ChatItemType.toolResult:
        return _buildToolResultItem(item as ToolResultItem);
    }
  }

  Widget _buildMessageItem(TextMessageItem item) {
    final isUser = item.sender == MessageSender.user;
    return Row(
      mainAxisAlignment: isUser
          ? MainAxisAlignment.end
          : MainAxisAlignment.start,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Flexible(
          child: Container(
            padding: const EdgeInsets.symmetric(
              horizontal: _messagePaddingH,
              vertical: _messagePaddingV,
            ),
            decoration: BoxDecoration(
              color: isUser ? _userBubbleColor : AppColors.white,
              borderRadius: BorderRadius.only(
                topLeft: const Radius.circular(_cornerRadius),
                topRight: const Radius.circular(_cornerRadius),
                bottomLeft: Radius.circular(isUser ? _cornerRadius : 0),
                bottomRight: Radius.circular(isUser ? 0 : _cornerRadius),
              ),
              border: isUser ? null : Border.all(color: AppColors.slate300),
            ),
            child: Text(
              item.content,
              style: const TextStyle(fontSize: 14, color: AppColors.slate900),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildToolCallItem(ToolCallItem item) {
    final (statusText, statusColor, statusIcon) = switch (item.status) {
      ToolCallStatus.pending => (
        '准备中...',
        AppColors.slate500,
        LucideIcons.clock,
      ),
      ToolCallStatus.executing => (
        '执行中...',
        AppColors.blue600,
        LucideIcons.loader,
      ),
      ToolCallStatus.error => (
        item.errorMessage ?? '执行失败',
        AppColors.red600,
        LucideIcons.alertCircle,
      ),
      ToolCallStatus.completed => (
        '已完成',
        AppColors.emerald600,
        LucideIcons.checkCircle,
      ),
    };

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
      decoration: BoxDecoration(
        color: AppColors.blue50,
        borderRadius: BorderRadius.circular(8),
        border: Border.all(color: AppColors.slate300),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Icon(statusIcon, size: 16, color: statusColor),
          const SizedBox(width: 8),
          Text(
            item.toolName,
            style: const TextStyle(
              fontSize: 13,
              fontWeight: FontWeight.w500,
              color: AppColors.slate700,
            ),
          ),
          const SizedBox(width: 8),
          Text(statusText, style: TextStyle(fontSize: 12, color: statusColor)),
          if (item.toolName == 'front.navigate_to_route' &&
              item.status == ToolCallStatus.pending) ...[
            const SizedBox(width: 8),
            GestureDetector(
              onTap: () => _chatBloc.approveToolCall(item.callId),
              child: Container(
                padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                decoration: BoxDecoration(
                  color: AppColors.blue600,
                  borderRadius: BorderRadius.circular(6),
                ),
                child: const Text(
                  '同意',
                  style: TextStyle(fontSize: 11, color: AppColors.white),
                ),
              ),
            ),
          ],
        ],
      ),
    );
  }

  Widget _buildToolResultItem(ToolResultItem item) {
    return UiSchemaRenderer.render(item.uiCard);
  }

  Widget _buildInputContainer(BuildContext context, ChatState state) {
    final isWaitingAgent =
        state.isWaitingFirstToken || state.isStreaming || state.isCancelling;
    return Container(
      padding: const EdgeInsets.all(_inputPadding),
      color: _chatBgColor,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          GestureDetector(
            onTap: _isRecording
                ? _stopRecording
                : () => _showBottomSheet(context),
            child: Container(
              width: 36,
              height: 36,
              decoration: BoxDecoration(
                color: AppColors.white,
                shape: BoxShape.circle,
                border: Border.all(color: AppColors.slate300),
              ),
              child: Icon(
                _isRecording ? LucideIcons.square : LucideIcons.plus,
                size: 20,
                color: _isRecording ? AppColors.red600 : AppColors.slate500,
              ),
            ),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: Container(
              constraints: const BoxConstraints(minHeight: _inputMinHeight),
              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
              decoration: BoxDecoration(
                color: Colors.transparent,
                borderRadius: BorderRadius.circular(_inputRadius),
                border: Border.all(color: AppColors.slate300),
              ),
              child: Row(
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  Expanded(
                    child: _isRecording
                        ? _buildListeningIndicator()
                        : _isTranscribing
                        ? _buildTranscribingIndicator()
                        : TextField(
                            controller: _messageController,
                            minLines: 1,
                            maxLines: 3,
                            decoration: const InputDecoration(
                              hintText: '输入消息...',
                              border: InputBorder.none,
                              enabledBorder: InputBorder.none,
                              focusedBorder: InputBorder.none,
                              disabledBorder: InputBorder.none,
                              errorBorder: InputBorder.none,
                              focusedErrorBorder: InputBorder.none,
                              isDense: true,
                              contentPadding: EdgeInsets.zero,
                              filled: false,
                            ),
                            onSubmitted: (_) => _sendMessage(context),
                          ),
                  ),
                  const SizedBox(width: 8),
                  GestureDetector(
                    key: _inputActionButtonKey,
                    onTap: _isTranscribing
                        ? null
                        : _isRecording
                        ? () => _stopRecording(autoSendAfterTranscribe: true)
                        : isWaitingAgent
                        ? () => _onStopGenerating(context)
                        : _hasMessage
                        ? () => _sendMessage(context)
                        : _startRecording,
                    child: _isTranscribing
                        ? const SizedBox(
                            width: _transcribingSpinnerSize,
                            height: _transcribingSpinnerSize,
                            child: CircularProgressIndicator(
                              strokeWidth: _transcribingStrokeWidth,
                              color: AppColors.blue600,
                            ),
                          )
                        : Icon(
                            key: _inputActionIconKey,
                            _isRecording || isWaitingAgent
                                ? LucideIcons.square
                                : _hasMessage
                                ? LucideIcons.send
                                : LucideIcons.mic,
                            size: _iconSize,
                            color: _isRecording || isWaitingAgent || _hasMessage
                                ? AppColors.blue600
                                : AppColors.slate500,
                          ),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _sendMessage(BuildContext context) async {
    final content = _messageController.text.trim();
    if (content.isEmpty) return;
    FocusScope.of(context).unfocus();
    _messageController.clear();
    await context.read<ChatBloc>().sendMessage(content);

    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (_scrollController.hasClients) {
        _scrollController.animateTo(
          _scrollController.position.maxScrollExtent,
          duration: const Duration(milliseconds: _scrollDurationMs),
          curve: Curves.easeOut,
        );
      }
    });
  }

  Future<void> _onStopGenerating(BuildContext context) async {
    final canceled = await context.read<ChatBloc>().cancelCurrentRun();
    if (!mounted) {
      return;
    }
    if (canceled) {
      Toast.show(context, '已停止等待回复', type: ToastType.info);
    }
  }

  Widget _buildListeningIndicator() {
    return SizedBox(
      height: _inputMinHeight,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          AnimatedBuilder(
            animation: _listeningAnimationController,
            builder: (context, _) {
              final t = _listeningAnimationController.value;
              final waveA =
                  0.4 + 0.6 * (1 - ((t - 0.2).abs() * 2).clamp(0.0, 1.0));
              final waveB =
                  0.4 + 0.6 * (1 - ((t - 0.5).abs() * 2).clamp(0.0, 1.0));
              final waveC =
                  0.4 + 0.6 * (1 - ((t - 0.8).abs() * 2).clamp(0.0, 1.0));
              return Row(
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  _buildWaveDot(scale: waveA),
                  const SizedBox(width: 6),
                  _buildWaveDot(scale: waveB),
                  const SizedBox(width: 6),
                  _buildWaveDot(scale: waveC),
                ],
              );
            },
          ),
          const SizedBox(width: 10),
          const Text(
            '正在聆听...',
            style: TextStyle(fontSize: 14, color: AppColors.slate500),
          ),
        ],
      ),
    );
  }

  Widget _buildTranscribingIndicator() {
    return TweenAnimationBuilder<double>(
      tween: Tween<double>(begin: 0.0, end: 1.0),
      duration: const Duration(milliseconds: 180),
      builder: (context, value, child) {
        return Opacity(opacity: value, child: child);
      },
      child: const SizedBox(
        key: ValueKey('transcribing_indicator'),
        height: _inputMinHeight,
        child: Align(
          alignment: Alignment.centerLeft,
          child: Text(
            '语音识别中...',
            style: TextStyle(fontSize: 14, color: AppColors.slate500),
          ),
        ),
      ),
    );
  }

  Widget _buildWaveDot({required double scale}) {
    return Transform.scale(
      scale: scale,
      child: Container(
        width: _recordingDotSize,
        height: _recordingDotSize,
        decoration: const BoxDecoration(
          shape: BoxShape.circle,
          color: AppColors.red600,
        ),
      ),
    );
  }

  Future<void> _startRecording() async {
    try {
      await _voiceRecorder.start();
      _listeningAnimationController.repeat();
      if (!mounted) {
        return;
      }
      setState(() {
        _isRecording = true;
      });
    } catch (error) {
      if (!mounted) {
        return;
      }
      Toast.show(context, _readableError(error), type: ToastType.error);
    }
  }

  Future<void> _stopRecording({bool autoSendAfterTranscribe = false}) async {
    String? audioPath;
    try {
      audioPath = await _voiceRecorder.stop();
      _listeningAnimationController.stop();
      if (!mounted) {
        return;
      }
      setState(() {
        _isRecording = false;
        _isTranscribing = true;
      });
      if (audioPath == null || audioPath.isEmpty) {
        throw StateError('录音失败，请重试');
      }
      final transcript = await _transcribeAudio(audioPath);
      if (!mounted) {
        return;
      }
      final normalizedTranscript = transcript.trim();
      if (normalizedTranscript.isEmpty) {
        Toast.show(context, '未识别到有效语音，请靠近麦克风并连续说话后重试', type: ToastType.error);
        return;
      }
      _messageController.text = transcript;
      _messageController.selection = TextSelection.fromPosition(
        TextPosition(offset: transcript.length),
      );
      if (autoSendAfterTranscribe) {
        _messageController.clear();
        await _autoSendTranscript(normalizedTranscript);
      }
    } catch (error) {
      if (!mounted) {
        return;
      }
      Toast.show(context, _readableError(error), type: ToastType.error);
    } finally {
      try {
        if (audioPath != null) {
          final file = File(audioPath);
          if (await file.exists()) {
            await file.delete();
          }
        }
      } catch (_) {
        // Ignore temp file cleanup errors to avoid blocking UI state recovery.
      }
      if (mounted) {
        setState(() {
          _isTranscribing = false;
        });
      }
    }
  }

  String _readableError(Object error) {
    if (error is ApiException) {
      return error.message;
    }
    final raw = error.toString();
    if (raw.startsWith('Instance of')) {
      return '请求失败，请稍后重试';
    }
    return raw.replaceFirst('Bad state: ', '');
  }

  void _showBottomSheet(BuildContext context) {
    showModalBottomSheet(
      context: context,
      backgroundColor: Colors.transparent,
      isScrollControlled: true,
      builder: (context) => const HomeSheet(),
    );
  }
}