moonlight-ios/Limelight/ViewControllers/MainFrameViewController.m

//  MainFrameViewController.m
//  Moonlight
//
//  Created by Diego Waxemberg on 1/17/14.
//  Copyright (c) 2014 Moonlight Stream. All rights reserved.
//

@import ImageIO;

#import "MainFrameViewController.h"
#import "CryptoManager.h"
#import "HttpManager.h"
#import "Connection.h"
#import "StreamManager.h"
#import "Utils.h"
#import "UIComputerView.h"
#import "UIAppView.h"
#import "DataManager.h"
#import "TemporarySettings.h"
#import "WakeOnLanManager.h"
#import "AppListResponse.h"
#import "ServerInfoResponse.h"
#import "StreamFrameViewController.h"
#import "LoadingFrameViewController.h"
#import "ComputerScrollView.h"
#import "TemporaryApp.h"
#import "IdManager.h"
#import "ConnectionHelper.h"

#if !TARGET_OS_TV
#import "SettingsViewController.h"
#else
#import <sys/utsname.h>
#endif

#import <VideoToolbox/VideoToolbox.h>

@implementation MainFrameViewController {
    NSOperationQueue* _opQueue;
    TemporaryHost* _selectedHost;
    NSString* _uniqueId;
    NSData* _clientCert;
    DiscoveryManager* _discMan;
    AppAssetManager* _appManager;
    StreamConfiguration* _streamConfig;
    UIAlertController* _pairAlert;
    LoadingFrameViewController* _loadingFrame;
    UIScrollView* hostScrollView;
    FrontViewPosition currentPosition;
    NSArray* _sortedAppList;
    NSCache* _boxArtCache;
    bool _background;
#if TARGET_OS_TV
    UITapGestureRecognizer* _menuRecognizer;
#endif
}
static NSMutableSet* hostList;

- (void)showPIN:(NSString *)PIN {
    dispatch_async(dispatch_get_main_queue(), ^{
        self->_pairAlert = [UIAlertController alertControllerWithTitle:@"Pairing"
                                                               message:[NSString stringWithFormat:@"Enter the following PIN on the host machine: %@", PIN]
                                                        preferredStyle:UIAlertControllerStyleAlert];
        [self->_pairAlert addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDestructive handler:^(UIAlertAction* action) {
            self->_pairAlert = nil;
            [self->_discMan startDiscovery];
            [self hideLoadingFrame: ^{
                [self showHostSelectionView];
            }];
        }]];
        [[self activeViewController] presentViewController:self->_pairAlert animated:YES completion:nil];
    });
}

- (void)displayPairingFailureDialog:(NSString *)message {
    UIAlertController* failedDialog = [UIAlertController alertControllerWithTitle:@"Pairing Failed"
                                                                          message:message
                                                                   preferredStyle:UIAlertControllerStyleAlert];
    [Utils addHelpOptionToDialog:failedDialog];
    [failedDialog addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
    
    [_discMan startDiscovery];
    
    [self hideLoadingFrame: ^{
        [self showHostSelectionView];
        [[self activeViewController] presentViewController:failedDialog animated:YES completion:nil];
    }];
}

- (void)pairFailed:(NSString *)message {
    dispatch_async(dispatch_get_main_queue(), ^{
        if (self->_pairAlert != nil) {
            [self->_pairAlert dismissViewControllerAnimated:YES completion:^{
                [self displayPairingFailureDialog:message];
            }];
            self->_pairAlert = nil;
        }
    });
}

- (void)pairSuccessful:(NSData*)serverCert {
    dispatch_async(dispatch_get_main_queue(), ^{
        // Store the cert from pairing with the host
        self->_selectedHost.serverCert = serverCert;
        
        [self->_pairAlert dismissViewControllerAnimated:YES completion:nil];
        self->_pairAlert = nil;
        
        [self->_discMan startDiscovery];
        [self alreadyPaired];
    });
}

- (void)disableUpButton {
#if !TARGET_OS_TV
    [self->_upButton setTitle:nil];
#endif
}

- (void)enableUpButton {
#if !TARGET_OS_TV
    [self->_upButton setTitle:@"Select New Host"];
#endif
}

- (void)alreadyPaired {
    BOOL usingCachedAppList = false;
    
    // Capture the host here because it can change once we
    // leave the main thread
    TemporaryHost* host = _selectedHost;
    
    if ([host.appList count] > 0) {
        usingCachedAppList = true;
        dispatch_async(dispatch_get_main_queue(), ^{
            if (host != self->_selectedHost) {
                [self hideLoadingFrame: nil];
                return;
            }
            
            [self updateAppsForHost:host];
            [self hideLoadingFrame: nil];
        });
    }
    Log(LOG_I, @"Using cached app list: %d", usingCachedAppList);
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        // Exempt this host from discovery while handling the applist query
        [self->_discMan removeHostFromDiscovery:host];
        
        AppListResponse* appListResp = [ConnectionHelper getAppListForHostWithHostIP:host.activeAddress serverCert:host.serverCert uniqueID:self->_uniqueId];
        
        [self->_discMan addHostToDiscovery:host];

        if (![appListResp isStatusOk] || [appListResp getAppList] == nil) {
            Log(LOG_W, @"Failed to get applist: %@", appListResp.statusMessage);
            dispatch_async(dispatch_get_main_queue(), ^{
                if (host != self->_selectedHost) {
                    [self hideLoadingFrame: nil];
                    return;
                }
                
                UIAlertController* applistAlert = [UIAlertController alertControllerWithTitle:@"Connection Interrupted"
                                                                                      message:appListResp.statusMessage
                                                                               preferredStyle:UIAlertControllerStyleAlert];
                [Utils addHelpOptionToDialog:applistAlert];
                [applistAlert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
                [self hideLoadingFrame: ^{
                    [self showHostSelectionView];
                    [[self activeViewController] presentViewController:applistAlert animated:YES completion:nil];
                }];
                host.state = StateOffline;
            });
        } else {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self updateApplist:[appListResp getAppList] forHost:host];

                if (host != self->_selectedHost) {
                    [self hideLoadingFrame: nil];
                    return;
                }
                
                [self updateAppsForHost:host];
                [self->_appManager stopRetrieving];
                [self->_appManager retrieveAssetsFromHost:host];
                [self hideLoadingFrame: nil];
            });
        }
    });
}

- (void) updateApplist:(NSSet*) newList forHost:(TemporaryHost*)host {
    DataManager* database = [[DataManager alloc] init];
    
    for (TemporaryApp* app in newList) {
        BOOL appAlreadyInList = NO;
        for (TemporaryApp* savedApp in host.appList) {
            if ([app.id isEqualToString:savedApp.id]) {
                savedApp.name = app.name;
                savedApp.hdrSupported = app.hdrSupported;
                appAlreadyInList = YES;
                break;
            }
        }
        if (!appAlreadyInList) {
            app.host = host;
            [host.appList addObject:app];
        }
    }
    
    BOOL appWasRemoved;
    do {
        appWasRemoved = NO;
        
        for (TemporaryApp* app in host.appList) {
            appWasRemoved = YES;
            for (TemporaryApp* mergedApp in newList) {
                if ([mergedApp.id isEqualToString:app.id]) {
                    appWasRemoved = NO;
                    break;
                }
            }
            if (appWasRemoved) {
                // Removing the app mutates the list we're iterating (which isn't legal).
                // We need to jump out of this loop and restart enumeration.
                
                [host.appList removeObject:app];
                
                // It's important to remove the app record from the database
                // since we'll have a constraint violation now that appList
                // doesn't have this app in it.
                [database removeApp:app];
                
                break;
            }
        }
        
        // Keep looping until the list is no longer being mutated
    } while (appWasRemoved);

    [database updateAppsForExistingHost:host];
    
    // This host may be eligible for a shortcut now that the app list
    // has been populated
    [self updateHostShortcuts];
}

- (void)showHostSelectionView {
#if TARGET_OS_TV
    // Remove the menu button intercept to allow the app to exit
    // when at the host selection view.
    [self.navigationController.view removeGestureRecognizer:_menuRecognizer];
#endif
    
    [_appManager stopRetrieving];
    _selectedHost = nil;
    _sortedAppList = nil;
    
    self.title = @"Select Host";
    [self disableUpButton];
    
    [self.collectionView reloadData];
    [self.view addSubview:hostScrollView];
}

- (void) receivedAssetForApp:(TemporaryApp*)app {
    // Update the box art cache now so we don't have to do it
    // on the main thread
    [self updateBoxArtCacheForApp:app];
    
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.collectionView reloadData];
    });
}

- (void)displayDnsFailedDialog {
    UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"Network Error"
                                                                   message:@"Failed to resolve host."
                                                            preferredStyle:UIAlertControllerStyleAlert];
    [Utils addHelpOptionToDialog:alert];
    [alert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
    [[self activeViewController] presentViewController:alert animated:YES completion:nil];
}

- (void) hostClicked:(TemporaryHost *)host view:(UIView *)view {
    // Treat clicks on offline hosts to be long clicks
    // This shows the context menu with wake, delete, etc. rather
    // than just hanging for a while and failing as we would in this
    // code path.
    if (host.state != StateOnline && view != nil) {
        [self hostLongClicked:host view:view];
        return;
    }
    
    Log(LOG_D, @"Clicked host: %@", host.name);
    _selectedHost = host;
    self.title = host.name;
    [self enableUpButton];
    [self disableNavigation];
    
#if TARGET_OS_TV
    // Intercept the menu key to go back to the host page
    [self.navigationController.view addGestureRecognizer:_menuRecognizer];
#endif
    
    // If we are online, paired, and have a cached app list, skip straight
    // to the app grid without a loading frame. This is the fast path that users
    // should hit most. Check for a valid view because we don't want to hit the fast
    // path after coming back from streaming, since we need to fetch serverinfo too
    // so that our active game data is correct.
    if (host.state == StateOnline && host.pairState == PairStatePaired && host.appList.count > 0 && view != nil) {
        [self alreadyPaired];
        return;
    }
    
    [self showLoadingFrame: ^{
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            HttpManager* hMan = [[HttpManager alloc] initWithHost:host.activeAddress uniqueId:self->_uniqueId serverCert:host.serverCert];
            ServerInfoResponse* serverInfoResp = [[ServerInfoResponse alloc] init];
            
            // Exempt this host from discovery while handling the serverinfo request
            [self->_discMan removeHostFromDiscovery:host];
            [hMan executeRequestSynchronously:[HttpRequest requestForResponse:serverInfoResp withUrlRequest:[hMan newServerInfoRequest:false]
                                                                fallbackError:401 fallbackRequest:[hMan newHttpServerInfoRequest]]];
            [self->_discMan addHostToDiscovery:host];
            
            if (![serverInfoResp isStatusOk]) {
                Log(LOG_W, @"Failed to get server info: %@", serverInfoResp.statusMessage);
                dispatch_async(dispatch_get_main_queue(), ^{
                    if (host != self->_selectedHost) {
                        [self hideLoadingFrame:nil];
                        return;
                    }
                    
                    UIAlertController* applistAlert = [UIAlertController alertControllerWithTitle:@"Connection Failed"
                                                                            message:serverInfoResp.statusMessage
                                                                                   preferredStyle:UIAlertControllerStyleAlert];
                    [Utils addHelpOptionToDialog:applistAlert];
                    [applistAlert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
                    
                    // Only display an alert if this was the result of a real
                    // user action, not just passively entering the foreground again
                    [self hideLoadingFrame: ^{
                        [self showHostSelectionView];
                        if (view != nil) {
                            [[self activeViewController] presentViewController:applistAlert animated:YES completion:nil];
                        }
                    }];
                    
                    host.state = StateOffline;
                });
            } else {
                // Update the host object with this data
                [serverInfoResp populateHost:host];
                if (host.pairState == PairStatePaired) {
                    Log(LOG_I, @"Already Paired");
                    [self alreadyPaired];
                }
                // Only pair when this was the result of explicit user action
                else if (view != nil) {
                    Log(LOG_I, @"Trying to pair");
                    // Polling the server while pairing causes the server to screw up
                    [self->_discMan stopDiscoveryBlocking];
                    PairManager* pMan = [[PairManager alloc] initWithManager:hMan clientCert:self->_clientCert callback:self];
                    [self->_opQueue addOperation:pMan];
                }
                else {
                    // Not user action, so just return to host screen
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [self hideLoadingFrame:^{
                            [self showHostSelectionView];
                        }];
                    });
                }
            }
        });
    }];
}

- (UIViewController*) activeViewController {
    UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController;

    while (topController.presentedViewController) {
        topController = topController.presentedViewController;
    }

    return topController;
}

- (void)hostLongClicked:(TemporaryHost *)host view:(UIView *)view {
    Log(LOG_D, @"Long clicked host: %@", host.name);
    NSString* message;
    
    switch (host.state) {
        case StateOffline:
            message = @"Offline";
            break;
            
        case StateOnline:
            if (host.pairState == PairStatePaired) {
                message = @"Online - Paired";
            }
            else {
                message = @"Online - Not Paired";
            }
            break;
        
        case StateUnknown:
            message = @"Connecting";
            break;
            
        default:
            break;
    }
    
    UIAlertController* longClickAlert = [UIAlertController alertControllerWithTitle:host.name message:message preferredStyle:UIAlertControllerStyleActionSheet];
    if (host.state != StateOnline) {
        [longClickAlert addAction:[UIAlertAction actionWithTitle:@"Wake" style:UIAlertActionStyleDefault handler:^(UIAlertAction* action){
            UIAlertController* wolAlert = [UIAlertController alertControllerWithTitle:@"Wake-On-LAN" message:@"" preferredStyle:UIAlertControllerStyleAlert];
            [wolAlert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
            if (host.mac == nil || [host.mac isEqualToString:@"00:00:00:00:00:00"]) {
                wolAlert.message = @"Host MAC unknown, unable to send WOL Packet";
            } else {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                    [WakeOnLanManager wakeHost:host];
                });
                wolAlert.message = @"Successfully sent wake-up request. It may take a few moments for the PC to wake. If it never wakes up, ensure it's properly configured for Wake-on-LAN.";
            }
            [[self activeViewController] presentViewController:wolAlert animated:YES completion:nil];
        }]];
        
#if !TARGET_OS_TV
        [longClickAlert addAction:[UIAlertAction actionWithTitle:@"Connection Help" style:UIAlertActionStyleDefault handler:^(UIAlertAction* action){
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"https://github.com/moonlight-stream/moonlight-docs/wiki/Troubleshooting"]];
        }]];
#endif
    }
    [longClickAlert addAction:[UIAlertAction actionWithTitle:@"Remove Host" style:UIAlertActionStyleDestructive handler:^(UIAlertAction* action) {
        [self->_discMan removeHostFromDiscovery:host];
        DataManager* dataMan = [[DataManager alloc] init];
        [dataMan removeHost:host];
        @synchronized(hostList) {
            [hostList removeObject:host];
            [self updateAllHosts:[hostList allObjects]];
        }
        
    }]];
    [longClickAlert addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]];
    
    // these two lines are required for iPad support of UIAlertSheet
    longClickAlert.popoverPresentationController.sourceView = view;
    
    longClickAlert.popoverPresentationController.sourceRect = CGRectMake(view.bounds.size.width / 2.0, view.bounds.size.height / 2.0, 1.0, 1.0); // center of the view
    [[self activeViewController] presentViewController:longClickAlert animated:YES completion:^{
        [self updateHosts];
    }];
}

- (void) addHostClicked {
    Log(LOG_D, @"Clicked add host");
    UIAlertController* alertController = [UIAlertController alertControllerWithTitle:@"Host Address" message:@"Please enter a hostname or IP address" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction* action){
        NSString* hostAddress = ((UITextField*)[[alertController textFields] objectAtIndex:0]).text;
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
            [self->_discMan discoverHost:hostAddress withCallback:^(TemporaryHost* host, NSString* error){
                if (host != nil) {
                    dispatch_async(dispatch_get_main_queue(), ^{
                        @synchronized(hostList) {
                            [hostList addObject:host];
                        }
                        [self updateHosts];
                    });
                } else {
                    UIAlertController* hostNotFoundAlert = [UIAlertController alertControllerWithTitle:@"Add Host" message:error preferredStyle:UIAlertControllerStyleAlert];
                    [Utils addHelpOptionToDialog:hostNotFoundAlert];
                    [hostNotFoundAlert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
                    dispatch_async(dispatch_get_main_queue(), ^{
                        [[self activeViewController] presentViewController:hostNotFoundAlert animated:YES completion:nil];
                    });
                }
            }];});
    }]];
    [alertController addTextFieldWithConfigurationHandler:nil];
    [[self activeViewController] presentViewController:alertController animated:YES completion:nil];
}

- (void) prepareToStreamApp:(TemporaryApp *)app {
    _streamConfig = [[StreamConfiguration alloc] init];
    _streamConfig.host = app.host.activeAddress;
    _streamConfig.appID = app.id;
    _streamConfig.appName = app.name;
    _streamConfig.serverCert = app.host.serverCert;
    
    DataManager* dataMan = [[DataManager alloc] init];
    TemporarySettings* streamSettings = [dataMan getSettings];
    
    _streamConfig.frameRate = [streamSettings.framerate intValue];
    if (@available(iOS 10.3, *)) {
        // Don't stream more FPS than the display can show
        if (_streamConfig.frameRate > [UIScreen mainScreen].maximumFramesPerSecond) {
            _streamConfig.frameRate = (int)[UIScreen mainScreen].maximumFramesPerSecond;
            Log(LOG_W, @"Clamping FPS to maximum refresh rate: %d", _streamConfig.frameRate);
        }
    }
    
    _streamConfig.height = [streamSettings.height intValue];
    _streamConfig.width = [streamSettings.width intValue];
#if TARGET_OS_TV
    // Don't allow streaming 4K on the Apple TV HD
    struct utsname systemInfo;
    uname(&systemInfo);
    if (strcmp(systemInfo.machine, "AppleTV5,3") == 0 && _streamConfig.height >= 2160) {
        Log(LOG_W, @"4K streaming not supported on Apple TV HD");
        _streamConfig.width = 1920;
        _streamConfig.height = 1080;
    }
#endif
    
    _streamConfig.bitRate = [streamSettings.bitrate intValue];
    _streamConfig.streamingRemotely = streamSettings.streamingRemotely;
    _streamConfig.optimizeGameSettings = streamSettings.optimizeGames;
    _streamConfig.playAudioOnPC = streamSettings.playAudioOnPC;
    _streamConfig.allowHevc = streamSettings.useHevc;
    
    // multiController must be set before calling getConnectedGamepadMask
    _streamConfig.multiController = streamSettings.multiController;
    _streamConfig.gamepadMask = [ControllerSupport getConnectedGamepadMask:_streamConfig];
    

    // Probe for supported channel configurations
    Log(LOG_I, @"Audio device supports %d channels", [AVAudioSession sharedInstance].maximumOutputNumberOfChannels);
    if ([AVAudioSession sharedInstance].maximumOutputNumberOfChannels >= 6) {
        _streamConfig.audioChannelCount = 6;
        _streamConfig.audioChannelMask = 0xFC;
    }
    else {
        _streamConfig.audioChannelCount = 2;
        _streamConfig.audioChannelMask = 0x3;
    }
    
    // HDR requires HDR10 game, HDR10 display, and HEVC Main10 decoder on the client.
    // It additionally requires an HEVC Main10 encoder on the server (GTX 1000+).
    //
    // It should also be a user preference, since some games may require higher peak
    // brightness than the iOS device can support to look correct in HDR mode.
    if (@available(iOS 11.3, *)) {
        _streamConfig.enableHdr =
            app.hdrSupported && // App supported
            (app.host.serverCodecModeSupport & 0x200) != 0 && // HEVC Main10 encoding on host PC GPU
            VTIsHardwareDecodeSupported(kCMVideoCodecType_HEVC) && // Decoder supported
            (AVPlayer.availableHDRModes & AVPlayerHDRModeHDR10) != 0 && // Display supported
            streamSettings.enableHdr; // User wants it enabled
    }
}

- (void) appClicked:(TemporaryApp *)app {
    Log(LOG_D, @"Clicked app: %@", app.name);
    
    [_appManager stopRetrieving];
    
#if !TARGET_OS_TV
    if (currentPosition != FrontViewPositionLeft) {
        // This must not be animated because we need the position
        // to change (and notify our callback to save settings data)
        // before we call prepareToStreamApp.
        [[self revealViewController] revealToggleAnimated:NO];
    }
#endif
    
    TemporaryApp* currentApp = [self findRunningApp:app.host];
    if (currentApp != nil) {
        UIAlertController* alertController = [UIAlertController
                                              alertControllerWithTitle: app.name
                                              message: [app.id isEqualToString:currentApp.id] ? @"" : [NSString stringWithFormat:@"%@ is currently running", currentApp.name]preferredStyle:UIAlertControllerStyleAlert];
        [alertController addAction:[UIAlertAction
                                    actionWithTitle:[app.id isEqualToString:currentApp.id] ? @"Resume App" : @"Resume Running App" style:UIAlertActionStyleDefault handler:^(UIAlertAction* action){
                                        Log(LOG_I, @"Resuming application: %@", currentApp.name);
                                        [self prepareToStreamApp:currentApp];
                                        [self performSegueWithIdentifier:@"createStreamFrame" sender:nil];
                                    }]];
        [alertController addAction:[UIAlertAction actionWithTitle:
                                    [app.id isEqualToString:currentApp.id] ? @"Quit App" : @"Quit Running App and Start" style:UIAlertActionStyleDestructive handler:^(UIAlertAction* action){
                                        Log(LOG_I, @"Quitting application: %@", currentApp.name);
                                        [self showLoadingFrame: ^{
                                            dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                                                HttpManager* hMan = [[HttpManager alloc] initWithHost:app.host.activeAddress uniqueId:self->_uniqueId serverCert:app.host.serverCert];
                                                HttpResponse* quitResponse = [[HttpResponse alloc] init];
                                                HttpRequest* quitRequest = [HttpRequest requestForResponse: quitResponse withUrlRequest:[hMan newQuitAppRequest]];
                                                
                                                // Exempt this host from discovery while handling the quit operation
                                                [self->_discMan removeHostFromDiscovery:app.host];
                                                [hMan executeRequestSynchronously:quitRequest];
                                                if (quitResponse.statusCode == 200) {
                                                    ServerInfoResponse* serverInfoResp = [[ServerInfoResponse alloc] init];
                                                    [hMan executeRequestSynchronously:[HttpRequest requestForResponse:serverInfoResp withUrlRequest:[hMan newServerInfoRequest:false]
                                                                                                        fallbackError:401 fallbackRequest:[hMan newHttpServerInfoRequest]]];
                                                    if (![serverInfoResp isStatusOk] || [[serverInfoResp getStringTag:@"state"] hasSuffix:@"_SERVER_BUSY"]) {
                                                        // On newer GFE versions, the quit request succeeds even though the app doesn't
                                                        // really quit if another client tries to kill your app. We'll patch the response
                                                        // to look like the old error in that case, so the UI behaves.
                                                        quitResponse.statusCode = 599;
                                                    }
                                                    else if ([serverInfoResp isStatusOk]) {
                                                        // Update the host object with this info
                                                        [serverInfoResp populateHost:app.host];
                                                    }
                                                }
                                                [self->_discMan addHostToDiscovery:app.host];

                                                // If it fails, display an error and stop the current operation
                                                if (quitResponse.statusCode != 200) {
                                                    UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"Quitting App Failed"
                                                                                                message:@"Failed to quit app. If this app was started by "
                                                             "another device, you'll need to quit from that device."
                                                                                         preferredStyle:UIAlertControllerStyleAlert];
                                                    [alert addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
                                                    dispatch_async(dispatch_get_main_queue(), ^{
                                                        [self updateAppsForHost:app.host];
                                                        [self hideLoadingFrame: ^{
                                                            [[self activeViewController] presentViewController:alert animated:YES completion:nil];
                                                        }];
                                                    });
                                                }
                                                else {
                                                    app.host.currentGame = @"0";
                                                    dispatch_async(dispatch_get_main_queue(), ^{
                                                        // Refresh the UI
                                                        [self updateAppsForHost:app.host];
                                                        
                                                        // If it succeeds and we're to start streaming, segue to the stream
                                                        if (![app.id isEqualToString:currentApp.id]) {
                                                            [self prepareToStreamApp:app];
                                                            [self hideLoadingFrame: ^{
                                                                [self performSegueWithIdentifier:@"createStreamFrame" sender:nil];
                                                            }];
                                                        }
                                                        else {
                                                            // Otherwise, just hide the loading icon
                                                            [self hideLoadingFrame:nil];
                                                        }
                                                    });
                                                }
                                            });
                                        }];
                                        
                                    }]];
        [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]];
        [[self activeViewController] presentViewController:alertController animated:YES completion:nil];
    } else {
        [self prepareToStreamApp:app];
        [self performSegueWithIdentifier:@"createStreamFrame" sender:nil];
    }
}

- (TemporaryApp*) findRunningApp:(TemporaryHost*)host {
    for (TemporaryApp* app in host.appList) {
        if ([app.id isEqualToString:host.currentGame]) {
            return app;
        }
    }
    return nil;
}

#if !TARGET_OS_TV
- (void)revealController:(SWRevealViewController *)revealController didMoveToPosition:(FrontViewPosition)position {
    // If we moved back to the center position, we should save the settings
    if (position == FrontViewPositionLeft) {
        [(SettingsViewController*)[revealController rearViewController] saveSettings];
    }
    
    currentPosition = position;
}
#endif

#if TARGET_OS_TV
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    [self appClicked:_sortedAppList[indexPath.row]];
}
#endif

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    if ([segue.destinationViewController isKindOfClass:[StreamFrameViewController class]]) {
        StreamFrameViewController* streamFrame = segue.destinationViewController;
        streamFrame.streamConfig = _streamConfig;
    }
}

- (void) showLoadingFrame:(void (^)(void))completion {
    [_loadingFrame showLoadingFrame:completion];
}

- (void) hideLoadingFrame:(void (^)(void))completion {
    [self enableNavigation];
    [_loadingFrame dismissLoadingFrame:completion];
}

- (void)adjustScrollViewForSafeArea:(UIScrollView*)view {
    if (@available(iOS 11.0, *)) {
        if (self.view.safeAreaInsets.left >= 20 || self.view.safeAreaInsets.right >= 20) {
            view.contentInset = UIEdgeInsetsMake(0, 20, 0, 20);
        }
    }
}

// Adjust the subviews for the safe area on the iPhone X.
- (void)viewSafeAreaInsetsDidChange {
    [super viewSafeAreaInsetsDidChange];
    
    [self adjustScrollViewForSafeArea:self.collectionView];
    [self adjustScrollViewForSafeArea:self->hostScrollView];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.title = @"Select Host";
    
#if !TARGET_OS_TV
    // Set the side bar button action. When it's tapped, it'll show the sidebar.
    [_settingsButton setTarget:self.revealViewController];
    [_settingsButton setAction:@selector(revealToggle:)];
    
    // Set the host name button action. When it's tapped, it'll show the host selection view.
    [_upButton setTarget:self];
    [_upButton setAction:@selector(showHostSelectionView)];
    [self disableUpButton];
    
    // Set the gesture
    [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];
    
    // Get callbacks associated with the viewController
    [self.revealViewController setDelegate:self];
    
    // Disable bounce-back on reveal VC otherwise the settings will snap closed
    // if the user drags all the way off the screen opposite the settings pane.
    self.revealViewController.bounceBackOnOverdraw = NO;
#else
    // The settings button will direct the user into the Settings app on tvOS
    [_settingsButton setTarget:self];
    [_settingsButton setAction:@selector(openTvSettings:)];
    
    // Restore focus on the selected app on view controller pop navigation
    self.restoresFocusAfterTransition = NO;
    self.collectionView.remembersLastFocusedIndexPath = YES;
    
    _menuRecognizer = [[UITapGestureRecognizer alloc] init];
    [_menuRecognizer addTarget:self action: @selector(showHostSelectionView)];
    _menuRecognizer.allowedPressTypes = [[NSArray alloc] initWithObjects:[NSNumber numberWithLong:UIPressTypeMenu], nil];
    
    self.navigationController.navigationBar.titleTextAttributes = [NSDictionary dictionaryWithObject:[UIColor whiteColor] forKey:NSForegroundColorAttributeName];
#endif
    
    _loadingFrame = [self.storyboard instantiateViewControllerWithIdentifier:@"loadingFrame"];
    
    // Set the current position to the center
    currentPosition = FrontViewPositionLeft;
    
    // Set up crypto
    [CryptoManager generateKeyPairUsingSSL];
    _uniqueId = [IdManager getUniqueId];
    _clientCert = [CryptoManager readCertFromFile];

    _appManager = [[AppAssetManager alloc] initWithCallback:self];
    _opQueue = [[NSOperationQueue alloc] init];
    
    // Only initialize the host picker list once
    if (hostList == nil) {
        hostList = [[NSMutableSet alloc] init];
    }
    
    _boxArtCache = [[NSCache alloc] init];
        
    hostScrollView = [[ComputerScrollView alloc] init];
    hostScrollView.frame = CGRectMake(0, self.navigationController.navigationBar.frame.origin.y + self.navigationController.navigationBar.frame.size.height, self.view.frame.size.width, self.view.frame.size.height / 2);
    [hostScrollView setShowsHorizontalScrollIndicator:NO];
    hostScrollView.delaysContentTouches = NO;
    
    self.collectionView.delaysContentTouches = NO;
    self.collectionView.allowsMultipleSelection = NO;
#if !TARGET_OS_TV
    self.collectionView.multipleTouchEnabled = NO;
#endif
    
    [self retrieveSavedHosts];
    _discMan = [[DiscoveryManager alloc] initWithHosts:[hostList allObjects] andCallback:self];
    
    [self.view addSubview:hostScrollView];
}

#if TARGET_OS_TV
- (void)openTvSettings:(id)sender
{
    [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString] options:@{} completionHandler:nil];
}
#endif

-(void)beginForegroundRefresh:(bool)refreshAppList
{
    if (!_background) {
        // This will kick off box art caching
        [self updateHosts];
        
        [_discMan startDiscovery];
        
        // This will refresh the applist when a paired host is selected
        if (refreshAppList && _selectedHost != nil && _selectedHost.pairState == PairStatePaired) {
            [self hostClicked:_selectedHost view:nil];
        }
    }
}

-(void)handlePendingShortcutAction
{
    // Check if we have a pending shortcut action
    AppDelegate* delegate = (AppDelegate*)[UIApplication sharedApplication].delegate;
    if (delegate.pcUuidToLoad != nil) {
        // Find the host it corresponds to
        TemporaryHost* matchingHost = nil;
        for (TemporaryHost* host in hostList) {
            if ([host.uuid isEqualToString:delegate.pcUuidToLoad]) {
                matchingHost = host;
                break;
            }
        }
        
        // Clear the pending shortcut action
        delegate.pcUuidToLoad = nil;
        
        // Complete the request
        if (delegate.shortcutCompletionHandler != nil) {
            delegate.shortcutCompletionHandler(matchingHost != nil);
            delegate.shortcutCompletionHandler = nil;
        }
        
        if (matchingHost != nil && _selectedHost != matchingHost) {
            // Navigate to the host page
            [self hostClicked:matchingHost view:nil];
        }
    }
}

-(void)handleReturnToForeground
{
    _background = NO;
    
    [self beginForegroundRefresh: YES];
    
    // Check for a pending shortcut action when returning to foreground
    [self handlePendingShortcutAction];
}

-(void)handleEnterBackground
{
    _background = YES;
    
    [_discMan stopDiscovery];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    
#if !TARGET_OS_TV
    [[self revealViewController] setPrimaryViewController:self];
#endif
    
    [self.navigationController setNavigationBarHidden:NO animated:YES];
    
    // Hide 1px border line
    UIImage* fakeImage = [[UIImage alloc] init];
    [self.navigationController.navigationBar setShadowImage:fakeImage];
    [self.navigationController.navigationBar setBackgroundImage:fakeImage forBarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
    
    // Check for a pending shortcut action when appearing
    [self handlePendingShortcutAction];
    
    [[NSNotificationCenter defaultCenter] addObserver: self
                                             selector: @selector(handleReturnToForeground)
                                                 name: UIApplicationDidBecomeActiveNotification
                                               object: nil];
    
    [[NSNotificationCenter defaultCenter] addObserver: self
                                             selector: @selector(handleEnterBackground)
                                                 name: UIApplicationWillResignActiveNotification
                                               object: nil];
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    // We can get here on home press while streaming
    // since the stream view segues to us just before
    // entering the background. We can't check the app
    // state here (since it's in transition), so we have
    // to use this function that will use our internal
    // state here to determine whether we're foreground.
    //
    // Note that this is neccessary here as we may enter
    // this view via an error dialog from the stream
    // view, so we won't get a return to active notification
    // for that which would normally fire beginForegroundRefresh.
    //
    // On tvOS, we'll get a viewWillAppear when returning from the
    // loading frame which will cause an infinite loop by starting
    // another loading frame. To avoid this, just don't refresh
    // if we're coming back from a loading frame view.
    [self beginForegroundRefresh: !([_loadingFrame isShown] || [_loadingFrame isBeingDismissed])];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
    
    // when discovery stops, we must create a new instance because
    // you cannot restart an NSOperation when it is finished
    [_discMan stopDiscovery];
    
    // Purge the box art cache
    [_boxArtCache removeAllObjects];
    
    // Remove our lifetime observers to avoid triggering them
    // while streaming
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void) retrieveSavedHosts {
    DataManager* dataMan = [[DataManager alloc] init];
    NSArray* hosts = [dataMan getHosts];
    @synchronized(hostList) {
        [hostList addObjectsFromArray:hosts];
        
        // Initialize the non-persistent host state
        for (TemporaryHost* host in hostList) {
            if (host.activeAddress == nil) {
                host.activeAddress = host.localAddress;
            }
            if (host.activeAddress == nil) {
                host.activeAddress = host.externalAddress;
            }
            if (host.activeAddress == nil) {
                host.activeAddress = host.address;
            }
            if (host.activeAddress == nil) {
                host.activeAddress = host.ipv6Address;
            }
        }
    }
}

- (void) updateAllHosts:(NSArray *)hosts {
    dispatch_async(dispatch_get_main_queue(), ^{
        Log(LOG_D, @"New host list:");
        for (TemporaryHost* host in hosts) {
            Log(LOG_D, @"Host: \n{\n\t name:%@ \n\t address:%@ \n\t localAddress:%@ \n\t externalAddress:%@ \n\t ipv6Address:%@ \n\t uuid:%@ \n\t mac:%@ \n\t pairState:%d \n\t online:%d \n\t activeAddress:%@ \n}", host.name, host.address, host.localAddress, host.externalAddress, host.ipv6Address, host.uuid, host.mac, host.pairState, host.state, host.activeAddress);
        }
        @synchronized(hostList) {
            [hostList removeAllObjects];
            [hostList addObjectsFromArray:hosts];
        }
        [self updateHosts];
    });
}

- (void)updateHostShortcuts {
    if (@available(iOS 9.0, *)) {
        NSMutableArray* quickActions = [[NSMutableArray alloc] init];
        
        @synchronized (hostList) {
            for (TemporaryHost* host in hostList) {
                // Pair state may be unknown if we haven't polled it yet, but the app list
                // count will persist from paired PCs
                if ([host.appList count] > 0) {
                    UIApplicationShortcutItem* shortcut = [[UIApplicationShortcutItem alloc]
                                                           initWithType:@"PC"
                                                           localizedTitle:host.name
                                                           localizedSubtitle:nil
                                                           icon:[UIApplicationShortcutIcon iconWithType:UIApplicationShortcutIconTypePlay]
                                                           userInfo:[NSDictionary dictionaryWithObject:host.uuid forKey:@"UUID"]];
                    [quickActions addObject: shortcut];
                }
            }
        }
        
        [UIApplication sharedApplication].shortcutItems = quickActions;
    }
}

- (void)updateHosts {
    Log(LOG_I, @"Updating hosts...");
    [[hostScrollView subviews] makeObjectsPerformSelector:@selector(removeFromSuperview)];
    UIComputerView* addComp = [[UIComputerView alloc] initForAddWithCallback:self];
    UIComputerView* compView;
    float prevEdge = -1;
    @synchronized (hostList) {
        // Sort the host list in alphabetical order
        NSArray* sortedHostList = [[hostList allObjects] sortedArrayUsingSelector:@selector(compareName:)];
        for (TemporaryHost* comp in sortedHostList) {
            compView = [[UIComputerView alloc] initWithComputer:comp andCallback:self];
            compView.center = CGPointMake([self getCompViewX:compView addComp:addComp prevEdge:prevEdge], hostScrollView.frame.size.height / 2);
            prevEdge = compView.frame.origin.x + compView.frame.size.width;
            [hostScrollView addSubview:compView];
            
            // Start jobs to decode the box art in advance
            for (TemporaryApp* app in comp.appList) {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
                    [self updateBoxArtCacheForApp:app];
                });
            }
        }
    }
    
    // Create or delete host shortcuts as needed
    [self updateHostShortcuts];
    
    prevEdge = [self getCompViewX:addComp addComp:addComp prevEdge:prevEdge];
    addComp.center = CGPointMake(prevEdge, hostScrollView.frame.size.height / 2);
    
    [hostScrollView addSubview:addComp];
    [hostScrollView setContentSize:CGSizeMake(prevEdge + addComp.frame.size.width, hostScrollView.frame.size.height)];
}

- (float) getCompViewX:(UIComputerView*)comp addComp:(UIComputerView*)addComp prevEdge:(float)prevEdge {
    float padding;
    
#if TARGET_OS_TV
    padding = 100;
#else
    padding = addComp.frame.size.width / 2;
#endif
    
    if (prevEdge == -1) {
        return hostScrollView.frame.origin.x + comp.frame.size.width / 2 + padding;
    } else {
        return prevEdge + comp.frame.size.width / 2 + padding;
    }
}

// This function forces immediate decoding of the UIImage, rather
// than the default lazy decoding that results in janky scrolling.
+ (UIImage*) loadBoxArtForCaching:(TemporaryApp*)app {
    UIImage* boxArt;
    
    NSData* imageData = [NSData dataWithContentsOfFile:[AppAssetManager boxArtPathForApp:app]];
    if (imageData == nil) {
        // No box art on disk
        return nil;
    }
    
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)imageData, NULL);
    CGImageRef cgImage = CGImageSourceCreateImageAtIndex(source, 0, nil);
    
    size_t width = CGImageGetWidth(cgImage);
    size_t height = CGImageGetHeight(cgImage);
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef imageContext =  CGBitmapContextCreate(NULL, width, height, 8, width * 4, colorSpace,
                                                       kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little);
    CGColorSpaceRelease(colorSpace);

    CGContextDrawImage(imageContext, CGRectMake(0, 0, width, height), cgImage);
    
    CGImageRef outputImage = CGBitmapContextCreateImage(imageContext);

    boxArt = [UIImage imageWithCGImage:outputImage];
    
    CGImageRelease(outputImage);
    CGContextRelease(imageContext);
    
    CGImageRelease(cgImage);
    CFRelease(source);
    
    return boxArt;
}

- (void) updateBoxArtCacheForApp:(TemporaryApp*)app {
    if ([_boxArtCache objectForKey:app] == nil) {
        UIImage* image = [MainFrameViewController loadBoxArtForCaching:app];
        if (image != nil) {
            // Add the image to our cache if it was present
            [_boxArtCache setObject:image forKey:app];
        }
    }
}

- (void) updateAppsForHost:(TemporaryHost*)host {
    if (host != _selectedHost) {
        Log(LOG_W, @"Mismatched host during app update");
        return;
    }
    
    _sortedAppList = [host.appList allObjects];
    _sortedAppList = [_sortedAppList sortedArrayUsingSelector:@selector(compareName:)];
    
    [hostScrollView removeFromSuperview];
    [self.collectionView reloadData];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell* cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"AppCell" forIndexPath:indexPath];
    
    TemporaryApp* app = _sortedAppList[indexPath.row];
    UIAppView* appView = [[UIAppView alloc] initWithApp:app cache:_boxArtCache andCallback:self];
    
    if (appView.bounds.size.width > 10.0) {
        CGFloat scale = cell.bounds.size.width / appView.bounds.size.width;
        [appView setCenter:CGPointMake(appView.bounds.size.width / 2 * scale, appView.bounds.size.height / 2 * scale)];
        appView.transform = CGAffineTransformMakeScale(scale, scale);
    }
    
    [cell.subviews.firstObject removeFromSuperview]; // Remove a view that was previously added
    [cell addSubview:appView];

    
    UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:cell.bounds];
    cell.layer.masksToBounds = NO;
    cell.layer.shadowColor = [UIColor blackColor].CGColor;
    cell.layer.shadowOffset = CGSizeMake(1.0f, 5.0f);
    cell.layer.shadowOpacity = 0.5f;
    cell.layer.shadowPath = shadowPath.CGPath;
    
#if !TARGET_OS_TV
    cell.layer.borderWidth = 1;
    cell.layer.borderColor = [[UIColor colorWithRed:0 green:0 blue:0 alpha:0.3f] CGColor];
    cell.exclusiveTouch = YES;
#endif

    return cell;
}

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1; // App collection only
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    if (_selectedHost != nil && _sortedAppList != nil) {
        return _sortedAppList.count;
    }
    else {
        return 0;
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    
    // Purge the box art cache on low memory
    [_boxArtCache removeAllObjects];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [self.view endEditing:YES];
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    [textField resignFirstResponder];
    return YES;
}

#if !TARGET_OS_TV
- (BOOL)shouldAutorotate {
    return YES;
}
#endif

- (void) disableNavigation {
    self.navigationController.navigationBar.topItem.rightBarButtonItem.enabled = NO;
}

- (void) enableNavigation {
    self.navigationController.navigationBar.topItem.rightBarButtonItem.enabled = YES;
}

#if TARGET_OS_TV
- (BOOL)canBecomeFocused {
    return YES;
}
#endif

- (void)didUpdateFocusInContext:(UIFocusUpdateContext *)context withAnimationCoordinator:(UIFocusAnimationCoordinator *)coordinator {
    
#if !TARGET_OS_TV
    if (context.nextFocusedView != nil) {
        [context.nextFocusedView setAlpha:0.8];
    }
    [context.previouslyFocusedView setAlpha:1.0];
#endif
}

@end