import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:lucide_icons/lucide_icons.dart';

import '../../core/theme/design_tokens.dart';

enum MessageComposerMode { text, holdToSpeak }

enum MessageComposerProcess { idle, recording, transcribing }

const messageComposerContainerKey = ValueKey('message_composer_container');
const messageComposerPlusButtonKey = ValueKey('message_composer_plus_button');
const messageComposerRightButtonKey = ValueKey('message_composer_right_button');
const messageComposerHoldAreaKey = ValueKey('message_composer_hold_area');
const messageComposerRecordingHintKey = ValueKey(
  'message_composer_recording_hint',
);
const _holdActivateDurationMs = 120;

class MessageComposer extends StatelessWidget {
  const MessageComposer({
    super.key,
    required this.mode,
    required this.process,
    required this.hasMessage,
    required this.isWaitingAgent,
    required this.iconSize,
    required this.composerMinHeight,
    required this.onTapPlus,
    required this.onTapRightAction,
    required this.onHoldToSpeakStart,
    required this.onHoldToSpeakEnd,
    required this.onHoldToSpeakMoveUpdate,
    required this.onHoldToSpeakCancel,
    required this.textInputChild,
    required this.recordingAnimation,
    this.holdToSpeakText = '按住说话',
    this.recordingText = '松手发送',
    this.transcribingText = '语音识别中...',
    this.recordingHintText = '松开发送，上滑取消',
    this.showRecordingInlineFeedback = true,
  });

  final MessageComposerMode mode;
  final MessageComposerProcess process;
  final bool hasMessage;
  final bool isWaitingAgent;
  final double iconSize;
  final double composerMinHeight;
  final VoidCallback onTapPlus;
  final VoidCallback onTapRightAction;
  final VoidCallback onHoldToSpeakStart;
  final VoidCallback onHoldToSpeakEnd;
  final ValueChanged<LongPressMoveUpdateDetails> onHoldToSpeakMoveUpdate;
  final VoidCallback onHoldToSpeakCancel;
  final Widget textInputChild;
  final Widget recordingAnimation;
  final String holdToSpeakText;
  final String recordingText;
  final String transcribingText;
  final String recordingHintText;
  final bool showRecordingInlineFeedback;

  bool get _isHoldMode => mode == MessageComposerMode.holdToSpeak;

  bool get _isRecording => process == MessageComposerProcess.recording;

  bool get _isTranscribing => process == MessageComposerProcess.transcribing;

  @override
  Widget build(BuildContext context) {
    return Container(
      key: messageComposerContainerKey,
      padding: const EdgeInsets.symmetric(
        horizontal: AppSpacing.md,
        vertical: AppSpacing.xs,
      ),
      decoration: BoxDecoration(
        color: AppColors.white,
        borderRadius: BorderRadius.circular(AppRadius.full),
        border: Border.all(color: AppColors.slate200),
        boxShadow: const [
          BoxShadow(
            color: AppColors.slate200,
            blurRadius: AppRadius.lg,
            offset: Offset(AppSpacing.none, AppSpacing.xs),
          ),
          BoxShadow(
            color: AppColors.white,
            blurRadius: AppRadius.md,
            offset: Offset(AppSpacing.none, -AppSpacing.xs),
          ),
        ],
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          IgnorePointer(
            ignoring: _isRecording && _isHoldMode,
            child: Opacity(
              opacity: _isRecording && _isHoldMode ? AppSpacing.none : 1,
              child: IconButton(
                key: messageComposerPlusButtonKey,
                visualDensity: VisualDensity.compact,
                onPressed: onTapPlus,
                icon: Icon(
                  LucideIcons.plus,
                  size: iconSize,
                  color: AppColors.slate500,
                ),
              ),
            ),
          ),
          const SizedBox(width: AppSpacing.sm),
          Expanded(child: _buildCenterArea()),
          const SizedBox(width: AppSpacing.sm),
          IconButton(
            key: messageComposerRightButtonKey,
            visualDensity: VisualDensity.compact,
            onPressed: onTapRightAction,
            icon: _isTranscribing
                ? const SizedBox(
                    width: AppSpacing.lg,
                    height: AppSpacing.lg,
                    child: CircularProgressIndicator(
                      strokeWidth: AppSpacing.xs / 2,
                      color: AppColors.blue600,
                    ),
                  )
                : Icon(
                    _resolveRightIcon(),
                    size: iconSize,
                    color: _resolveRightIconColor(),
                  ),
          ),
        ],
      ),
    );
  }

  Widget _buildCenterArea() {
    return SizedBox(
      height: composerMinHeight,
      child: AnimatedSwitcher(
        duration: const Duration(milliseconds: 180),
        switchInCurve: Curves.easeOut,
        switchOutCurve: Curves.easeOut,
        child: _isHoldMode
            ? _buildHoldToSpeakArea(key: const ValueKey('hold_mode'))
            : _buildTextInputArea(key: const ValueKey('text_mode')),
      ),
    );
  }

  Widget _buildTextInputArea({required Key key}) {
    return SizedBox(key: key, height: composerMinHeight, child: textInputChild);
  }

  Widget _buildHoldToSpeakArea({required Key key}) {
    return RawGestureDetector(
      key: messageComposerHoldAreaKey,
      behavior: HitTestBehavior.opaque,
      gestures: {
        LongPressGestureRecognizer:
            GestureRecognizerFactoryWithHandlers<LongPressGestureRecognizer>(
              () => LongPressGestureRecognizer(
                duration: const Duration(milliseconds: _holdActivateDurationMs),
              ),
              (instance) {
                instance.onLongPressStart = (_) => onHoldToSpeakStart();
                instance.onLongPressEnd = (_) => onHoldToSpeakEnd();
                instance.onLongPressMoveUpdate = onHoldToSpeakMoveUpdate;
                instance.onLongPressCancel = onHoldToSpeakCancel;
              },
            ),
      },
      child: Container(
        key: key,
        width: double.infinity,
        height: composerMinHeight,
        alignment: Alignment.center,
        child: _buildHoldToSpeakContent(),
      ),
    );
  }

  Widget _buildHoldToSpeakContent() {
    if (_isRecording) {
      if (!showRecordingInlineFeedback) {
        return Align(
          alignment: Alignment.center,
          child: Text(
            recordingText,
            style: const TextStyle(color: AppColors.slate700),
          ),
        );
      }
      return Column(
        mainAxisAlignment: MainAxisAlignment.center,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          recordingAnimation,
          const SizedBox(height: AppSpacing.xs),
          Text(
            recordingHintText,
            key: messageComposerRecordingHintKey,
            style: const TextStyle(color: AppColors.slate500),
          ),
        ],
      );
    }

    if (_isTranscribing) {
      return Align(
        alignment: Alignment.center,
        child: Text(
          transcribingText,
          style: const TextStyle(color: AppColors.slate500),
        ),
      );
    }

    return Align(
      alignment: Alignment.center,
      child: Text(
        holdToSpeakText,
        style: const TextStyle(color: AppColors.slate500),
      ),
    );
  }

  IconData _resolveRightIcon() {
    if (isWaitingAgent) {
      return LucideIcons.square;
    }
    if (hasMessage) {
      return LucideIcons.send;
    }
    return _isHoldMode ? LucideIcons.keyboard : LucideIcons.mic;
  }

  Color _resolveRightIconColor() {
    if (isWaitingAgent || hasMessage) {
      return AppColors.blue600;
    }
    return AppColors.slate500;
  }
}