Swiftgram/submodules/TelegramCore/Sources/PeerLiveLocationsContext.swift

import Foundation
import Postbox
import SwiftSignalKit

import SyncCore

public func topPeerActiveLiveLocationMessages(viewTracker: AccountViewTracker, accountPeerId: PeerId, peerId: PeerId) -> Signal<(Peer?, [Message]), NoError> {
    return viewTracker.aroundMessageHistoryViewForLocation(.peer(peerId), index: .upperBound, anchorIndex: .upperBound, count: 50, fixedCombinedReadStates: nil, tagMask: .liveLocation, orderStatistics: [], additionalData: [.peer(accountPeerId)])
    |> map { (view, _, _) -> (Peer?, [Message]) in
        var accountPeer: Peer?
        for entry in view.additionalData {
            if case let .peer(id, peer) = entry {
                accountPeer = peer
                break
            }
        }
        
        let timestamp = Int32(CFAbsoluteTimeGetCurrent() + kCFAbsoluteTimeIntervalSince1970)
        var result: [Message] = []
        for entry in view.entries {
            for media in entry.message.media {
                if let location = media as? TelegramMediaMap, let liveBroadcastingTimeout = location.liveBroadcastingTimeout {
                    if entry.message.timestamp + liveBroadcastingTimeout > timestamp {
                        result.append(entry.message)
                    }
                } else {
                    assertionFailure()
                }
            }
        }
        return (accountPeer, result)
    }
}