chats not displaying in my streambuilder widget

Question

im developing a chat app in flutter i've created a search funtion where users can search by name or email and send massage to them . but my problem is whenever i click at chat user it creats a chatroom where all massages should be . but when i send massage it displayes 0 massages , tho massages are there stored in my firestore database but unable to fetch them in my ui

here's my search.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:test_app/pages/chatroom.dart';
import 'package:test_app/pages/login.dart';

class search extends StatefulWidget {
  const search({Key? key}) : super(key: key);

  @override
  _searchState createState() => _searchState();
}

class _searchState extends State<search> {
  final TextEditingController _search = TextEditingController();
  final FirebaseAuth _auth = FirebaseAuth.instance;
  Map<String, dynamic>? userMap;
  bool isLoading = false;

  // chatroomid
  String chatRoomId(String user1, String user2) {
    if (user1[0].toLowerCase().codeUnits[0] >
        user2.toLowerCase().codeUnits[0]) {
      return "$user1$user2";
    } else {
      return "$user2$user1";
    }
  }

  onSearch() async {
    final aa = _auth.currentUser!.displayName!;
    if (aa.isEmpty) {
      print("is empty");
    } else {
      print(aa);
    }

    FirebaseFirestore _firestore = FirebaseFirestore.instance;
    setState(() {
      isLoading = true;
    });
    if (_search.text.contains("@")) {
      await _firestore
          .collection('users')
          .where("email", isEqualTo: _search.text)
          .get()
          .then((value) {
        setState(() {
          userMap = value.docs[0].data();
          isLoading = false;
        });
        print(userMap);
      });
    } else if (_search.text == "#dev_info") {
      Navigator.push(context, MaterialPageRoute(builder: (context) => Login()));
    } else {
      await _firestore
          .collection("users")
          .where("username", isGreaterThanOrEqualTo: _search.text)
          .get()
          .then((value) {
        setState(() {
          userMap = value.docs[0].data();
          isLoading = false;
        });
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.of(context).size;
    return Scaffold(
      body: isLoading
          ? Center(
              child: Container(
                height: size.height / 20,
                width: size.height / 20,
                child: CircularProgressIndicator(),
              ),
            )
          : Column(children: [
              SizedBox(
                height: 45,
              ),
              Container(
                height: size.height / 14,
                width: size.width,
                alignment: Alignment.center,
                child: Container(
                  height: size.height / 14,
                  width: size.width / 1.15,
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(32),
                  ),
                  child: TextFormField(
                    controller: _search,
                    decoration: InputDecoration(
                      hintStyle: TextStyle(fontSize: 17),
                      suffixIcon: Icon(
                        Icons.search,
                        color: Colors.black,
                      ),
                      contentPadding: EdgeInsets.all(18),
                      hintText: "search",
                      focusedBorder: OutlineInputBorder(
                          borderRadius: BorderRadius.all(Radius.circular(10.0)),
                          borderSide: BorderSide(
                              color: Color.fromARGB(255, 41, 40, 38))),
                    ),
                  ),
                ),
              ),
              SizedBox(
                height: 5,
              ),
              Container(
                alignment: Alignment.centerRight,
                height: size.height / 14,
                width: size.width / 1.15,
                child: ElevatedButton.icon(
                  onPressed: onSearch,
                  icon: const Icon(Icons.arrow_right_alt_rounded),
                  label: Text("search"),
                  style: ElevatedButton.styleFrom(
                    primary: Color.fromARGB(234, 47, 48, 48),
                  ),
                ),
              ),
              SizedBox(
                height: 15,
              ),
              userMap != null
                  ? PhysicalModel(
                      color: Color.fromARGB(255, 255, 254, 254),
                      elevation: 18,
                      shadowColor: Color.fromARGB(255, 75, 75, 73),
                      borderRadius: BorderRadius.circular(20),
                      child: ListTile(
                        tileColor:
                            Color.fromARGB(255, 255, 255, 255).withOpacity(0.5),
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(15),
                        ),
                        leading: CircleAvatar(
                          backgroundImage: NetworkImage(userMap!['photoUrl']),
                        ),
                        title: Text(
                          userMap!['username'],
                          style: TextStyle(
                            color: Colors.black,
                            fontSize: 17,
                            fontWeight: FontWeight.w500,
                          ),
                        ),
                        subtitle: Text(userMap!['tag']),
                        trailing: IconButton(
                          onPressed: () {
                            String roomId = chatRoomId(
                                "dkjsdhksjdhskjdh",
                                userMap!['username']);
                            Navigator.of(context).push(
                              MaterialPageRoute(
                                builder: (_) => ChatRoom(
                                  chatRoomId: roomId,
                                  userMap: userMap!,
                                ),
                              ),
                            );
                          },
                          icon: Icon(Icons.photo),
                        ),
                      ),
                    )
                  : Container(),
                       
            ]),
    );
  }
}

here's my chatroom.dart

import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';

class ChatRoom extends StatelessWidget {
  final FirebaseAuth _auth = FirebaseAuth.instance;
  final FirebaseFirestore _firestore = FirebaseFirestore.instance;
  final TextEditingController _massage = TextEditingController();
  final Map<String, dynamic> userMap;
  final String chatRoomId;
  ChatRoom({required this.chatRoomId, required this.userMap});

  onSendMassage() async {
    if (_massage.text.isNotEmpty) {
      Map<String, dynamic> massages = {
        "sendby": _auth.currentUser!.displayName,
        "massage": _massage.text,
        "time": FieldValue.serverTimestamp(),
        "type": "text"
      };

      await _firestore
          .collection("chatroom")
          .doc(chatRoomId)
          .collection("chat")
          .add(massages);
      _massage.clear();
    } else {
      _firestore
          .collection('chatroom')
          .doc(chatRoomId)
          .collection('chats')
          .orderBy("time", descending: false)
          .snapshots();
      print("please input some massage");
    }
  }

  @override
  Widget build(BuildContext context) {
    final size = MediaQuery.of(context).size;
    return Scaffold(
      appBar: AppBar(
        leading: new Container(
          child: new IconButton(
            icon: new Icon(Icons.arrow_back_ios),
            onPressed: () {/* Your code */},
          ),
        ),
        title: Text('username'),
        backgroundColor: Colors.grey[850],
      ),
      body: SingleChildScrollView(
        child: Column(
          children: [
            Container(
              height: size.height / 1.25,
              width: size.width,
              child: StreamBuilder<QuerySnapshot>(
                stream: _firestore
                    .collection('chatroom')
                    .doc(chatRoomId)
                    .collection('chats')
                    .orderBy("time", descending: false)
                    .snapshots(),
                builder: (BuildContext context,
                    AsyncSnapshot<QuerySnapshot> snapshot) {
                  if (snapshot.data != null) {
                    return ListView.builder(
                      itemCount: snapshot.data!.docs.length,
                      itemBuilder: (context, index) {
                        return Center(
                            child: Text(
                          snapshot.data!.docs[index]['massage'],
                        ));
                      },
                    );
                  } else {
                    return Container(
                      child: Center(
                        child: Text('data'),
                      ),
                    );
                  }
                },
              ),
            ),
            Container(
              height: size.height / 10,
              width: size.width,
              alignment: Alignment.center,
              child: Container(
                height: size.height / 12,
                width: size.width / 1.1,
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    PhysicalModel(
                      color: Colors.white,
                      elevation: 42,
                      shadowColor: Color.fromARGB(255, 64, 64, 65),
                      borderRadius: BorderRadius.circular(20),
                      child: Container(
                        height: size.height / 16,
                        width: size.width / 1.3,
                        child: TextField(
                          controller: _massage,
                          decoration: InputDecoration(
                            contentPadding: const EdgeInsets.all(12),
                            border: InputBorder.none,
                            suffixIcon: IconButton(
                              onPressed: () {},
                              icon: Icon(Icons.photo),
                            ),
                            hintText: "Send Message",
                          ),
                        ),
                      ),
                    ),
                    IconButton(
                        icon: Icon(
                          Icons.arrow_circle_right_rounded,
                          size: 38,
                        ),
                        onPressed: onSendMassage),
                  ],
                ),
              ),
            )
          ],
        ),
      ),
    );
  }
} 

its my school project i need to submit before monday im down to provide any information you need to solve this bug