session-ios/Session/Utilities/BackgroundPoller.swift
2022-05-04 16:36:15 +10:00

62 lines
3.2 KiB
Swift

import PromiseKit
import SessionSnodeKit
@objc(LKBackgroundPoller)
public final class BackgroundPoller : NSObject {
private static var promises: [Promise<Void>] = []
private override init() { }
@objc(pollWithCompletionHandler:)
public static func poll(completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
promises = []
promises.append(pollForMessages())
promises.append(contentsOf: pollForClosedGroupMessages())
let v2OpenGroupServers = Set(Storage.shared.getAllV2OpenGroups().values.map { $0.server })
v2OpenGroupServers.forEach { server in
let poller = OpenGroupPollerV2(for: server)
poller.stop()
promises.append(poller.poll(isBackgroundPoll: true))
}
when(resolved: promises).done { _ in
completionHandler(.newData)
}.catch { error in
SNLog("Background poll failed due to error: \(error)")
completionHandler(.failed)
}
}
private static func pollForMessages() -> Promise<Void> {
let userPublicKey = getUserHexEncodedPublicKey()
return getMessages(for: userPublicKey, authenticated: true)
}
private static func pollForClosedGroupMessages() -> [Promise<Void>] {
let publicKeys = Storage.shared.getUserClosedGroupPublicKeys()
return publicKeys.map { getMessages(for: $0, authenticated: false) }
}
private static func getMessages(for publicKey: String, authenticated: Bool) -> Promise<Void> {
return SnodeAPI.getSwarm(for: publicKey).then(on: DispatchQueue.main) { swarm -> Promise<Void> in
guard let snode = swarm.randomElement() else { throw SnodeAPI.Error.generic }
return attempt(maxRetryCount: 4, recoveringOn: DispatchQueue.main) {
return SnodeAPI.getRawMessages(from: snode, associatedWith: publicKey, authenticated: authenticated).then(on: DispatchQueue.main) { rawResponse -> Promise<Void> in
let (messages, lastRawMessage) = SnodeAPI.parseRawMessagesResponse(rawResponse, from: snode, associatedWith: publicKey)
let promises = messages.compactMap { json -> Promise<Void>? in
// Use a best attempt approach here; we don't want to fail the entire process if one of the
// messages failed to parse.
guard let envelope = SNProtoEnvelope.from(json),
let data = try? envelope.serializedData() else { return nil }
let job = MessageReceiveJob(data: data, serverHash: json["hash"] as? String, isBackgroundPoll: true)
return job.execute()
}
let namespace = authenticated ? SnodeAPI.defaultNamespace : SnodeAPI.closedGroupNamespace
// Now that the MessageReceiveJob's have been created we can update the `lastMessageHash` value
SnodeAPI.updateLastMessageHashValueIfPossible(for: snode, namespace: namespace, associatedWith: publicKey, from: lastRawMessage)
return when(fulfilled: promises) // The promise returned by MessageReceiveJob never rejects
}
}
}
}
}