Envelope/mobile/lib/views/main/conversation_create_add_users.dart

import 'package:Envelope/models/conversations.dart';
import 'package:Envelope/views/main/conversation_create_add_users_list.dart';
import 'package:Envelope/views/main/conversation_detail.dart';
import 'package:flutter/material.dart';
import '/models/friends.dart';
import '/views/main/friend_list_item.dart';

class ConversationAddFriendsList extends StatefulWidget {
  final List<Friend> friends;
  final String title;
  const ConversationAddFriendsList({
    Key? key,
    required this.friends,
    required this.title,
  }) : super(key: key);

  @override
  State<ConversationAddFriendsList> createState() => _ConversationAddFriendsListState();
}

class _ConversationAddFriendsListState extends State<ConversationAddFriendsList> {
  List<Friend> friends = [];
  List<Friend> friendsSelected = [];

  @override
  void initState() {
    super.initState();
    friends.addAll(widget.friends);
    setState(() {});
  }

  void filterSearchResults(String query) {
    List<Friend> dummySearchList = [];
    dummySearchList.addAll(widget.friends);

    if(query.isNotEmpty) {
      List<Friend> dummyListData = [];
      for (Friend friend in dummySearchList) {
        if (friend.username.toLowerCase().contains(query)) {
          dummyListData.add(friend);
        }
      }
      setState(() {
        friends.clear();
        friends.addAll(dummyListData);
      });
      return;
    }

    setState(() {
      friends.clear();
      friends.addAll(widget.friends);
    });
  }

  Widget list() {
    if (friends.isEmpty) {
      return const Center(
          child: Text('No Friends'),
      );
    }

    return ListView.builder(
        itemCount: friends.length,
        shrinkWrap: true,
        padding: const EdgeInsets.only(top: 16),
        physics: const BouncingScrollPhysics(),
        itemBuilder: (context, i) {
          return ConversationAddFriendItem(
              friend: friends[i],
              isSelected: (bool value) {
                setState(() {
                  widget.friends[i].selected = value;
                  if (value) {
                    friendsSelected.add(friends[i]);
                    return;
                  }
                  friendsSelected.remove(friends[i]);
                });
              }
          );
        },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
            elevation: 0,
            automaticallyImplyLeading: false,
            flexibleSpace: SafeArea(
                child: Container(
                    padding: const EdgeInsets.only(right: 16),
                    child: Row(
                        children: <Widget>[
                          IconButton(
                              onPressed: (){
                                Navigator.pop(context);
                              },
                              icon: const Icon(Icons.arrow_back),
                          ),
                          const SizedBox(width: 2,),
                          Expanded(
                              child: Column(
                                  crossAxisAlignment: CrossAxisAlignment.start,
                                  mainAxisAlignment: MainAxisAlignment.center,
                                  children: <Widget>[
                                    Text(
                                        friendsSelected.isEmpty ?
                                        'Select Friends' :
                                        '${friendsSelected.length} Friends Selected',
                                        style: const TextStyle(
                                            fontSize: 16,
                                            fontWeight: FontWeight.w600
                                        ),
                                    ),
                                  ],
                              ),
                          ),
                        ],
                    ),
                ),
          ),
        ),
        body: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Padding(
                  padding: const EdgeInsets.only(top: 20,left: 16,right: 16),
                  child: TextField(
                      decoration: const InputDecoration(
                              hintText: "Search...",
                                prefixIcon: Icon(
                                    Icons.search,
                                    size: 20
                                ),
                        ),
                        onChanged: (value) => filterSearchResults(value.toLowerCase())
                    ),
                ),
                Padding(
                        padding: const EdgeInsets.only(top: 0,left: 16,right: 16),
                        child: list(),
                ),
            ],
        ),
        floatingActionButton: Padding(
           padding: const EdgeInsets.only(right: 10, bottom: 10),
            child: FloatingActionButton(
                onPressed: () async {
                  Conversation conversation = await createConversation(widget.title, friendsSelected);

                  friendsSelected = [];
                  Navigator.of(context).popUntil((route) => route.isFirst);
                  Navigator.push(context, MaterialPageRoute(builder: (context){
                    return ConversationDetail(
                        conversation: conversation,
                    );
                  }));
                },
                backgroundColor: Theme.of(context).colorScheme.primary,
                child: friendsSelected.isEmpty ?
                  const Text('Skip') :
                  const Icon(Icons.add, size: 30),
            ),
        ),
    );
  }
}