import 'dart:async';
import 'dart:collection';
import 'dart:math';

import 'package:fl_clash/common/common.dart';
import 'package:fl_clash/models/models.dart';
import 'package:fl_clash/widgets/fade_box.dart';
import 'package:flutter/material.dart';

class MessageManager extends StatefulWidget {
  final Widget child;

  const MessageManager({super.key, required this.child});

  @override
  State<MessageManager> createState() => MessageManagerState();
}

class MessageManagerState extends State<MessageManager> {
  final _messagesNotifier = ValueNotifier<List<CommonMessage>>([]);
  final _bufferMessages = Queue<CommonMessage>();
  final _activeTimers = <String, Timer>{};
  bool _isDisplayingMessage = false;

  @override
  void initState() {
    super.initState();
  }

  @override
  void dispose() {
    _messagesNotifier.dispose();
    for (final timer in _activeTimers.values) {
      timer.cancel();
    }
    _activeTimers.clear();
    _bufferMessages.clear();
    super.dispose();
  }

  void message(String text) {
    final commonMessage = CommonMessage(id: utils.uuidV4, text: text);
    _bufferMessages.add(commonMessage);
    commonPrint.log('message: $text');
    _processQueue();
  }

  void _cancelMessage(String id) {
    _bufferMessages.removeWhere((msg) => msg.id == id);
    if (_activeTimers.containsKey(id)) {
      _removeMessage(id);
    }
  }

  void _processQueue() {
    if (_isDisplayingMessage || _bufferMessages.isEmpty) {
      return;
    }
    _isDisplayingMessage = true;
    final message = _bufferMessages.removeFirst();
    _messagesNotifier.value = List.from(_messagesNotifier.value)..add(message);
    final timer = Timer(message.duration, () {
      _removeMessage(message.id);
    });
    _activeTimers[message.id] = timer;
  }

  void _removeMessage(String id) {
    _activeTimers.remove(id)?.cancel();
    final currentMessages = List<CommonMessage>.from(_messagesNotifier.value);
    currentMessages.removeWhere((msg) => msg.id == id);
    _messagesNotifier.value = currentMessages;
    _isDisplayingMessage = false;
    _processQueue();
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        widget.child,
        ValueListenableBuilder(
          valueListenable: _messagesNotifier,
          builder: (_, messages, _) {
            return Container(
              margin: EdgeInsets.only(
                top: kToolbarHeight + 12,
                left: 12,
                right: 12,
              ),
              child: FadeThroughBox(
                alignment: Alignment.topRight,
                child: messages.isEmpty
                    ? SizedBox()
                    : LayoutBuilder(
                        key: Key(messages.last.id),
                        builder: (_, constraints) {
                          return Dismissible(
                            key: ValueKey(messages.last.id),
                            onDismissed: (_) {
                              _cancelMessage(messages.last.id);
                            },
                            child: Card(
                              shape: const RoundedSuperellipseBorder(
                                borderRadius: BorderRadius.all(
                                  Radius.circular(14),
                                ),
                              ),
                              elevation: 10,
                              color: context.colorScheme.surfaceContainerHigh,
                              child: Container(
                                width: min(constraints.maxWidth, 500),
                                padding: EdgeInsets.symmetric(
                                  horizontal: 16,
                                  vertical: 8,
                                ),
                                child: Row(
                                  mainAxisAlignment:
                                      MainAxisAlignment.spaceBetween,
                                  children: [
                                    Flexible(
                                      child: Text(
                                        messages.last.text,
                                        maxLines: 3,
                                        overflow: TextOverflow.ellipsis,
                                      ),
                                    ),
                                    SizedBox(width: 16),
                                    IconButton(
                                      padding: EdgeInsets.all(2),
                                      visualDensity: VisualDensity.compact,
                                      onPressed: () {
                                        _cancelMessage(messages.last.id);
                                      },
                                      icon: Icon(Icons.close),
                                    ),
                                  ],
                                ),
                              ),
                            ),
                          );
                        },
                      ),
              ),
            );
          },
        ),
      ],
    );
  }
}