import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:matrix/matrix.dart';

class ChatInput extends StatefulWidget {
  final Room room;
  final Event? replyTo;
  final VoidCallback? onClearReply;

  const ChatInput({
    super.key,
    required this.room,
    this.replyTo,
    this.onClearReply,
  });

  @override
  State<ChatInput> createState() => _ChatInputState();
}

class _ChatInputState extends State<ChatInput> {
  final _ctrl = TextEditingController();
  bool _canSend = false;

  @override
  void initState() {
    super.initState();
    _ctrl.addListener(() {
      final hasText = _ctrl.text.trim().isNotEmpty;
      if (hasText != _canSend) setState(() => _canSend = hasText);
    });
  }

  @override
  void dispose() {
    _ctrl.dispose();
    super.dispose();
  }

  Future<void> _send() async {
    final text = _ctrl.text.trim();
    if (text.isEmpty) return;
    _ctrl.clear();
    setState(() => _canSend = false);

    await widget.room.sendTextEvent(
      text,
      inReplyTo: widget.replyTo,
    );
    widget.onClearReply?.call();
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    return SafeArea(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          if (widget.replyTo != null) _ReplyBar(
            event: widget.replyTo!,
            onClear: widget.onClearReply ?? () {},
          ),
          Padding(
            padding: const EdgeInsets.fromLTRB(8, 4, 8, 8),
            child: Row(
              crossAxisAlignment: CrossAxisAlignment.end,
              children: [
                Expanded(
                  child: TextField(
                    controller: _ctrl,
                    minLines: 1,
                    maxLines: 6,
                    textCapitalization: TextCapitalization.sentences,
                    decoration: InputDecoration(
                      hintText: 'Nachricht...',
                      contentPadding: const EdgeInsets.symmetric(
                        horizontal: 16,
                        vertical: 10,
                      ),
                      border: OutlineInputBorder(
                        borderRadius: BorderRadius.circular(24),
                        borderSide: BorderSide.none,
                      ),
                      filled: true,
                      fillColor: theme.colorScheme.surfaceContainerHigh,
                    ),
                    onSubmitted: (_) => _send(),
                    keyboardType: TextInputType.multiline,
                    inputFormatters: [
                      // Shift+Enter = newline, Enter = send
                      _SendOnEnterFormatter(onSend: _send),
                    ],
                  ),
                ),
                const SizedBox(width: 8),
                AnimatedScale(
                  scale: _canSend ? 1.0 : 0.8,
                  duration: const Duration(milliseconds: 150),
                  child: FloatingActionButton.small(
                    onPressed: _canSend ? _send : null,
                    elevation: _canSend ? 2 : 0,
                    child: const Icon(Icons.send_rounded),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _ReplyBar extends StatelessWidget {
  final Event event;
  final VoidCallback onClear;
  const _ReplyBar({required this.event, required this.onClear});

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    return Container(
      padding: const EdgeInsets.fromLTRB(16, 8, 8, 4),
      decoration: BoxDecoration(
        border: Border(
          top: BorderSide(color: theme.dividerColor),
          left: BorderSide(color: theme.colorScheme.primary, width: 3),
        ),
      ),
      child: Row(
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  event.senderFromMemoryOrFallback.calcDisplayname(),
                  style: theme.textTheme.labelSmall?.copyWith(
                    color: theme.colorScheme.primary,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                Text(
                  event.body,
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.bodySmall,
                ),
              ],
            ),
          ),
          IconButton(
            icon: const Icon(Icons.close, size: 18),
            onPressed: onClear,
          ),
        ],
      ),
    );
  }
}

class _SendOnEnterFormatter extends TextInputFormatter {
  final VoidCallback onSend;
  _SendOnEnterFormatter({required this.onSend});

  @override
  TextEditingValue formatEditUpdate(
    TextEditingValue oldValue,
    TextEditingValue newValue,
  ) {
    return newValue;
  }
}