import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_chat_bubble/bubble_type.dart';
import 'package:flutter_chat_bubble/chat_bubble.dart';
import 'package:flutter_chat_bubble/clippers/chat_bubble_clipper_6.dart';

class ChatDetail extends StatefulWidget {
  final friendUid;
  final friendName;

  const ChatDetail({Key? key, this.friendUid, this.friendName})
      : super(key: key);

  @override
  _ChatDetailState createState() => _ChatDetailState(friendUid, friendName);
}

class _ChatDetailState extends State<ChatDetail> {
  CollectionReference chats = FirebaseFirestore.instance.collection('chats');
  final friendUid;
  final friendName;
  final currentUserId = FirebaseAuth.instance.currentUser!.uid;
  var chatDocId;
  var _textController = new TextEditingController();

  _ChatDetailState(this.friendUid, this.friendName);

  @override
  void initState() {
    super.initState();
    chats
        .where('users', isEqualTo: {friendUid: null, currentUserId: null})
        .limit(1)
        .get()
        .then((QuerySnapshot querySnapshot) {
          if (querySnapshot.docs.isNotEmpty) {
            chatDocId = querySnapshot.docs.single.id;
          } else {
            chats.add({
              'users': {currentUserId: null, friendUid: null}
            }).then((value) => {chatDocId = value});
          }
        })
        .catchError((error) {});
  }

  void sendMessage(String msg) {
    if (msg == '') return;
    chats.doc(chatDocId).collection('messages').add({
      'createdOn': FieldValue.serverTimestamp(),
      'uid': currentUserId,
      'msg': msg
    }).then((value) {
      _textController.text = '';
    });
  }

  bool isSender(String friend) {
    return friend == currentUserId;
  }

  Alignment getAlignment(friend) {
    if (friend == currentUserId) {
      return Alignment.topRight;
    }
    return Alignment.topLeft;
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance
          .collection("chats")
          .doc(chatDocId)
          .collection('messages')
          .orderBy('createdOn', descending: true)
          .snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (snapshot.hasError) {
          return Center(
            child: Text("Error"),
          );
        }
        if (snapshot.connectionState == ConnectionState.waiting) {
          return Scaffold(
            backgroundColor: Colors.indigo.shade50,
          );
        }
        if (snapshot.hasData) {
          var data;
          return Container(
            decoration: BoxDecoration(
                image: DecorationImage(
              image: AssetImage("assets/images/chatscreen.png"),
              fit: BoxFit.cover,
            )),
            child: CupertinoPageScaffold(
                backgroundColor: Colors.transparent,
                navigationBar: CupertinoNavigationBar(
                  previousPageTitle: "Back",
                  middle: Text(friendName),
                  trailing: CupertinoButton(
                    padding: EdgeInsets.zero,
                    onPressed: () {},
                    child: Icon(Icons.person),
                  ),
                ),
                child: SafeArea(
                  child: Column(
                    children: [
                      Expanded(
                          child: ListView(
                        reverse: true,
                        children: snapshot.data!.docs
                            .map((DocumentSnapshot document) {
                          data = document.data()!;

                          return Padding(
                            padding:
                                const EdgeInsets.symmetric(horizontal: 8.0),
                            child: ChatBubble(
                              clipper: ChatBubbleClipper6(
                                nipSize: 0,
                                radius: 0,
                                type: BubbleType.receiverBubble,
                              ),
                              alignment: getAlignment(data['uid'].toString()),
                              margin: EdgeInsets.only(top: 20),
                              backGroundColor: isSender(data['uid'].toString())
                                  ? Color(0xFF08C187)
                                  : Color(0xffE7E7ED),
                              child: Container(
                                constraints: BoxConstraints(
                                  maxWidth:
                                      MediaQuery.of(context).size.width * 0.7,
                                ),
                                child: Column(
                                  children: [
                                    Row(
                                      mainAxisAlignment:
                                          MainAxisAlignment.start,
                                      children: [
                                        Text(
                                          data['msg'],
                                          style: TextStyle(
                                              color: isSender(
                                                      data['uid'].toString())
                                                  ? Colors.white
                                                  : Colors.black),
                                          maxLines: 100,
                                          overflow: TextOverflow.ellipsis,
                                        )
                                      ],
                                    ),
                                    Row(
                                      mainAxisAlignment: MainAxisAlignment.end,
                                      children: [
                                        Text(
                                            data['createdOn'] == null
                                                ? DateTime.now().toString()
                                                : data['createdOn']
                                                    .toDate()
                                                    .toString(),
                                            style: TextStyle(
                                                fontSize: 10,
                                                color: isSender(
                                                        data['uid'].toString())
                                                    ? Colors.white
                                                    : Colors.black)),
                                      ],
                                    )
                                  ],
                                ),
                              ),
                            ),
                          );
                        }).toList(),
                      )),
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                        children: [
                          Expanded(
                              child: CupertinoTextField(
                            controller: _textController,
                          )),
                          CupertinoButton(
                              onPressed: () =>
                                  sendMessage(_textController.text),
                              child: Icon(
                                Icons.send_sharp,
                              ))
                        ],
                      )
                    ],
                  ),
                )),
          );
        }
        return Container();
      },
    );
  }
}