Switch between streams flutter firebase - flutter

Question

I have a class of complains in which there is a field of status. This status can be pending , inprogress, completed , rejected. In UI I have designed buttons to filter complaints on the basis of status.
The issue that I am facing is that when I switch stream on button action. It still contains the data of previous stream.
Can anyone help me to have 2 streams and not either of it contains data of previous stream.
bool _isSwitched = false;
List<Complains> complains = [];
final Stream<QuerySnapshot> _all = FirebaseFirestore.instance
.collection('Complains').orderBy("startTime", descending: true)
.snapshots();
final Stream<QuerySnapshot> _pending = FirebaseFirestore.instance
.collection('Complains').where('status', isEqualTo: 'Pending').orderBy("startTime", descending: true)
.snapshots();
ElevatedButton(onPressed:(){
setState(() {
_isSwitched = !_isSwitched;
complains.clear();
complains2.clear();
});
} , child: Text("Switch Stream"),),
StreamBuilder<QuerySnapshot>(
initialData: null,
stream: _isSwitched?_all:_pending,
builder: (context, snapshot) {
if (snapshot.hasError) {
Text("Error");
}
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: CircularProgressIndicator(),
);
}
//length of stream is greater than 0
if (snapshot.data!.docs.length == 0) {
return Center(
child: Text("No Complains"),
);
}
for (var element in snapshot.data!.docs) {
Complains complain = Complains.fromMap(element.data() as Map<String, dynamic>);
_isSwitched?complains.add(complain):complains2.add(complain);
}
return ListView.builder(
itemBuilder: (context, index) {
return InkWell(
onTap: () {
},
child: Card(
margin: EdgeInsets.all(8.0),
elevation: 5,
color: Colors.white70,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(12.0))),
child: Container(
padding: EdgeInsets.all(20),
child:
Column(children: [
Text("Title\n ${complains[index].title}",style: TextStyle(fontStyle: FontStyle.italic),),
Table(
children: [
TableRow(children: [
Text("Name: " ),
Text("Address: "+ complains[index].address.toString(),),
]),
TableRow(children: [
Text("Priority: "+ complains[index].priority.toString(),),
Text("Status: "+complains[index].status.toString(),),
]),
TableRow(children: [
Text("Worker: "+ complains[index].worker.toString(),),
Text("Service: "+ complains[index].service.toString(),),
]),
],
),
],)
),
),
);
},
itemCount: _isSwitched?complains2.length:complains.length,
);
},
),
),