Surface/lib/providers/channel.dart

122 lines
3.7 KiB
Dart

import 'package:flutter/material.dart';
import 'package:hive_flutter/hive_flutter.dart';
import 'package:provider/provider.dart';
import 'package:surface/providers/sn_network.dart';
import 'package:surface/types/chat.dart';
import 'package:surface/types/realm.dart';
class ChatChannelProvider extends ChangeNotifier {
static const kChatChannelBoxName = 'nex_chat_channels';
late final SnNetworkProvider _sn;
Box<SnChannel>? get _channelBox => Hive.box<SnChannel>(kChatChannelBoxName);
ChatChannelProvider(BuildContext context) {
_sn = context.read<SnNetworkProvider>();
_initializeLocalData();
}
Future<void> _initializeLocalData() async {
await Hive.openBox<SnChannel>(kChatChannelBoxName);
}
Future<void> _saveChannelToLocal(Iterable<SnChannel> channels) async {
if (_channelBox == null) return;
await _channelBox!.putAll({
for (final channel in channels) channel.key: channel,
});
}
Future<List<SnChannel>> _fetchChannelsFromServer({
String scope = 'global',
bool direct = false,
bool doNotSave = false,
}) async {
final resp = await _sn.client.get(
'/cgi/im/channels/$scope/me/available',
queryParameters: {
'direct': direct,
},
);
final out = List<SnChannel>.from(
resp.data?.map((e) => SnChannel.fromJson(e)) ?? [],
);
if (!doNotSave) _saveChannelToLocal(out);
return out;
}
/// The get channel method will return the channel with the given alias.
/// It will use the local storage as much as possible.
/// The alias should include the scope, formatted as `scope:alias`.
Future<SnChannel> getChannel(String key) async {
if (_channelBox != null) {
final local = _channelBox!.get(key);
if (local != null) return local;
}
var resp = await _sn.client.get('/cgi/im/channels/$key');
var out = SnChannel.fromJson(resp.data);
// Preload realm of the channel
if (out.realmId != null) {
resp = await _sn.client.get('/cgi/id/realms/${out.realmId}');
out = out.copyWith(realm: SnRealm.fromJson(resp.data));
}
_saveChannelToLocal([out]);
return out;
}
/// The fetch channel method return a stream, which will emit twice.
/// The first time is when the data was fetched from the local storage.
/// And the second time is when the data was fetched from the server.
/// But there is some exception that will only cause one of them to be emitted.
/// Like the local storage is broken or the server is down.
Stream<List<SnChannel>> fetchChannels() async* {
if (_channelBox != null) yield _channelBox!.values.toList();
var resp = await _sn.client.get('/cgi/id/realms/me/available');
final realms = List<SnRealm>.from(
resp.data?.map((e) => SnRealm.fromJson(e)) ?? [],
);
final realmMap = {
for (final realm in realms) realm.alias: realm,
};
final scopeToFetch = {'global', ...realms.map((e) => e.alias)};
final List<SnChannel> result = List.empty(growable: true);
final directMessages = await _fetchChannelsFromServer(
scope: scopeToFetch.first,
direct: true,
);
result.addAll(directMessages);
final nonBelongsChannels = await _fetchChannelsFromServer(
scope: scopeToFetch.first,
direct: false,
);
result.addAll(nonBelongsChannels);
for (final scope in scopeToFetch.skip(1)) {
final channel = await _fetchChannelsFromServer(
scope: scope,
direct: false,
doNotSave: true,
);
final out = channel.map((ele) => ele.copyWith(realm: realmMap[scope]));
_saveChannelToLocal(out);
result.addAll(out);
}
yield result;
}
@override
void dispose() {
_channelBox?.close();
super.dispose();
}
}