import 'package:collection/collection.dart';
import 'package:flutter/cupertino.dart';
import 'package:imessage/message_header.dart';
import 'package:imessage/message_input.dart';
import 'package:imessage/message_widget.dart';
import 'package:stream_chat_flutter/stream_chat_flutter.dart'
    show Message, StreamChatCore;

class MessageListView extends StatelessWidget {
  const MessageListView({Key key, this.messages}) : super(key: key);
  final List<Message> messages;

  @override
  Widget build(BuildContext context) {
    final entries = groupBy(messages,
            (Message message) => message.createdAt.toString().substring(0, 10))
        .entries
        .toList();
    return Column(
      children: [
        Expanded(
          child: SizedBox(
              height: MediaQuery.of(context).size.height * 0.9,
              child: Align(
                alignment: FractionalOffset.topCenter,
                child: ListView.builder(
                    reverse: true,
                    itemCount: entries.length,
                    itemBuilder: (context, index) {
                      return Column(
                        children: [
                          Padding(
                            padding:
                                const EdgeInsets.fromLTRB(8.0, 24.0, 8.0, 8.0),
                            child: MessageHeader(
                                rawTimeStamp: entries[index].key), //date
                          ),
                          ...entries[index]
                              .value //messages
                              .map((message) {
                                return MessageWidget(
                                  alignment: isReceived(message, context)
                                      ? Alignment.centerLeft
                                      : Alignment.topRight,
                                  color: isReceived(message, context)
                                      ? CupertinoColors.systemGrey5
                                      : CupertinoColors.systemBlue,
                                  messageColor: isReceived(message, context)
                                      ? CupertinoColors.black
                                      : CupertinoColors.white,
                                  message: message,
                                );
                              })
                              .toList()
                              .reversed,
                        ],
                      );
                    }),
              )),
        ),
        MessageInput()
      ],
    );
  }

  bool isReceived(Message message, BuildContext context) {
    final currentUserId = StreamChatCore.of(context).user.id;
    return message.user.id == currentUserId;
  }

  bool isSameDay(Message message) =>
      message.createdAt.day == DateTime.now().day;
}