import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:image_picker/image_picker.dart';

import 'home_composer_stack.dart';

class HomeInputHost extends StatefulWidget {
  const HomeInputHost({
    super.key,
    required this.selectedImages,
    required this.onRemoveImage,
    required this.isRecording,
    required this.isCancelGestureActive,
    required this.isTranscribing,
    required this.isWaitingAgent,
    required this.messageController,
    required this.onTapPlus,
    required this.onStopGenerating,
    required this.onHoldToSpeakStart,
    required this.onHoldToSpeakEnd,
    required this.onHoldToSpeakMoveUpdate,
    required this.onHoldToSpeakCancel,
    required this.onSubmitText,
    required this.keyboardInset,
  });

  final List<XFile> selectedImages;
  final ValueChanged<int> onRemoveImage;
  final bool isRecording;
  final bool isCancelGestureActive;
  final bool isTranscribing;
  final bool isWaitingAgent;
  final TextEditingController messageController;
  final VoidCallback onTapPlus;
  final VoidCallback onStopGenerating;
  final VoidCallback onHoldToSpeakStart;
  final VoidCallback onHoldToSpeakEnd;
  final ValueChanged<LongPressMoveUpdateDetails> onHoldToSpeakMoveUpdate;
  final VoidCallback onHoldToSpeakCancel;
  final Future<void> Function(String text) onSubmitText;
  final double keyboardInset;

  @override
  State<HomeInputHost> createState() => HomeInputHostState();
}

class HomeInputHostState extends State<HomeInputHost> {
  final FocusNode _messageFocusNode = FocusNode();
  Timer? _keyboardShowFallbackTimer;
  bool _isHoldToSpeakMode = true;

  void unfocusInput() {
    _messageFocusNode.unfocus();
  }

  @override
  void initState() {
    super.initState();
    _messageFocusNode.addListener(_handleMessageFocusChanged);
  }

  @override
  void dispose() {
    _keyboardShowFallbackTimer?.cancel();
    _messageFocusNode.removeListener(_handleMessageFocusChanged);
    _messageFocusNode.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return HomeComposerStack(
      selectedImages: widget.selectedImages,
      onRemoveImage: widget.onRemoveImage,
      isHoldToSpeakMode: _isHoldToSpeakMode,
      isRecording: widget.isRecording,
      isCancelGestureActive: widget.isCancelGestureActive,
      isTranscribing: widget.isTranscribing,
      isWaitingAgent: widget.isWaitingAgent,
      messageController: widget.messageController,
      messageFocusNode: _messageFocusNode,
      onTapPlus: widget.onTapPlus,
      onTapRightAction: _onRightActionTap,
      onHoldToSpeakStart: widget.onHoldToSpeakStart,
      onHoldToSpeakEnd: widget.onHoldToSpeakEnd,
      onHoldToSpeakMoveUpdate: widget.onHoldToSpeakMoveUpdate,
      onHoldToSpeakCancel: widget.onHoldToSpeakCancel,
      onSubmit: _onSubmit,
      keyboardInset: widget.keyboardInset,
    );
  }

  void _onRightActionTap() {
    if (widget.isTranscribing || widget.isRecording) {
      return;
    }
    if (widget.isWaitingAgent) {
      widget.onStopGenerating();
      return;
    }
    final draft = widget.messageController.text.trim();
    if (draft.isNotEmpty) {
      _onSubmit();
      return;
    }
    _toggleInputMode();
  }

  void _toggleInputMode() {
    if (widget.isRecording || widget.isTranscribing) {
      return;
    }
    final switchToText = _isHoldToSpeakMode;
    setState(() {
      _isHoldToSpeakMode = !_isHoldToSpeakMode;
    });
    if (!switchToText) {
      _messageFocusNode.unfocus();
      _keyboardShowFallbackTimer?.cancel();
      return;
    }
    WidgetsBinding.instance.addPostFrameCallback((_) {
      if (!mounted || _isHoldToSpeakMode) {
        return;
      }
      _messageFocusNode.requestFocus();
    });
  }

  void _handleMessageFocusChanged() {
    if (!_messageFocusNode.hasFocus || _isHoldToSpeakMode) {
      _keyboardShowFallbackTimer?.cancel();
      return;
    }
    _scheduleKeyboardShowFallback();
  }

  void _scheduleKeyboardShowFallback() {
    if (!_supportsProgrammaticKeyboardShow() || _isKeyboardVisible()) {
      return;
    }
    _keyboardShowFallbackTimer?.cancel();
    _keyboardShowFallbackTimer = Timer(const Duration(milliseconds: 120), () {
      if (!mounted || !_messageFocusNode.hasFocus || _isHoldToSpeakMode) {
        return;
      }
      if (_isKeyboardVisible()) {
        return;
      }
      SystemChannels.textInput.invokeMethod<void>('TextInput.show');
    });
  }

  bool _supportsProgrammaticKeyboardShow() {
    if (kIsWeb) {
      return false;
    }
    return defaultTargetPlatform == TargetPlatform.android ||
        defaultTargetPlatform == TargetPlatform.iOS;
  }

  bool _isKeyboardVisible() {
    final mediaQuery = MediaQuery.maybeOf(context);
    if (mediaQuery == null) {
      return false;
    }
    return mediaQuery.viewInsets.bottom > 0;
  }

  void _onSubmit() {
    final draft = widget.messageController.text.trim();
    if (draft.isEmpty) {
      return;
    }
    widget.onSubmitText(draft);
  }
}