/*

     File: AppController.m

 Abstract: UIApplication's delegate class, the central controller of the application.

  Version: 2.1

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 */

#import "AppController.h"

#import "TapViewController.h"

#import "PickerViewController.h"

// The Bonjour service type consists of an IANA service name (see RFC 6335) 

// prefixed by an underscore (as per RFC 2782).

//

// <http://www.ietf.org/rfc/rfc6335.txt>

// 

// <http://www.ietf.org/rfc/rfc2782.txt>

// 

// See Section 5.1 of RFC 6335 for the specifics requirements.

// 

// To avoid conflicts, you must register your service type with IANA before 

// shipping.

// 

// To help network administrators indentify your service, you should choose a 

// service name that's reasonably human readable.

static NSString * kWiTapBonjourType = @"_witap2._tcp.";

@interface AppController () <

    UIApplicationDelegate, 

    TapViewControllerDelegate, 

    PickerDelegate, 

    NSNetServiceDelegate,

    NSStreamDelegate

>

@property (nonatomic, strong, readwrite) TapViewController *    tapViewController;

@property (nonatomic, strong, readwrite) NSNetService *         server;

@property (nonatomic, assign, readwrite) BOOL                   isServerStarted;

@property (nonatomic, copy,   readwrite) NSString *             registeredName;

@property (nonatomic, strong, readwrite) NSInputStream *        inputStream;

@property (nonatomic, strong, readwrite) NSOutputStream *       outputStream;

@property (nonatomic, assign, readwrite) NSUInteger             streamOpenCount;

@property (nonatomic, strong, readwrite) PickerViewController * picker;

@end

#pragma mark -

@implementation AppController

@synthesize window = _window;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

{

    #pragma unused(application)

    #pragma unused(launchOptions)

    // Get the root view controller (set up by the storyboard)

    self.tapViewController = (TapViewController *) self.window.rootViewController;

    assert([self.tapViewController isKindOfClass:[TapViewController class]]);

    self.tapViewController.delegate = self;

    // Show our window

    self.window.rootViewController = self.tapViewController;

    [self.window makeKeyAndVisible];

    // Create and advertise our server.  We only want the service to be registered on 

    // local networks so we pass in the "local." domain.

    self.server = [[NSNetService alloc] initWithDomain:@"local." type:kWiTapBonjourType name:[UIDevice currentDevice].name port:0];

    self.server.includesPeerToPeer = YES;

    [self.server setDelegate:self];

    [self.server publishWithOptions:NSNetServiceListenForConnections];

    self.isServerStarted = YES;

    // Set up for a new game, which presents a Bonjour browser that displays other 

    // available games.

    [self setupForNewGame];

    return YES;

}

- (void)applicationDidEnterBackground:(UIApplication *)application

{

    #pragma unused(application)

    // If there's a game playing, shut it down.  Whether this is the right thing to do 

    // depends on your app.  In some cases it might be more sensible to leave the connection 

    // in place for a short while to see if the user comes back to the app.  This issue is 

    // discussed in more depth in Technote 2277 "Networking and Multitasking".

    //

    // <https://developer.apple.com/library/ios/#technotes/tn2277/_index.html>

    if (self.inputStream) {

        [self setupForNewGame];

    }

    // Quiesce the server and service browser, if any.

    [self.server stop];

    self.isServerStarted = NO;

    self.registeredName = nil;

    if (self.picker != nil) {

        [self.picker stop];

    }

}

- (void)applicationWillEnterForeground:(UIApplication *)application

{

    #pragma unused(application)

    // Quicken the server.  Once this is done it will quicken the picker, if there's one up.

    assert( ! self.isServerStarted );

    [self.server publishWithOptions:NSNetServiceListenForConnections];

    self.isServerStarted = YES;

    if (self.registeredName != nil) {

        [self startPicker];

    }

}

- (void)setupForNewGame

{

    // Reset our tap view state to avoid old taps appearing in the new game.

    [self.tapViewController resetTouches];

    // If there's a connection, shut it down.

    [self closeStreams];

    // If our server is deregistered, reregister it.

    if ( ! self.isServerStarted ) {

        [self.server publishWithOptions:NSNetServiceListenForConnections];

        self.isServerStarted = YES;

    }

    // And show the service picker.

    [self presentPicker];

}

#pragma mark - Picker management

- (void)startPicker

{

    assert(self.registeredName != nil);

    // Tell the picker about our registration.  It uses this to a) filter out our game 

    // from the results, and b) display our game name in its table view header.

    self.picker.localService = self.server;

    // Start it up.

    [self.picker start];

}

- (void)presentPicker

{

    if (self.picker != nil) {

        // If the picker is already on screen then we're here because of a connection failure. 

        // In that case we just cancel the picker's connection UI and the user can choose another 

        // service.

        [self.picker cancelConnect];

    } else {

        // Create the service picker and put it up on screen.  We only start the picker 

        // if our server has completed its registration (the picker needs to know our 

        // service name so that it can exclude us from the list).  If that's not the 

        // case then the picker remains stopped until -serverDidStart: runs.

        self.picker = [self.tapViewController.storyboard instantiateViewControllerWithIdentifier:@"picker"];

        assert([self.picker isKindOfClass:[PickerViewController class]]);

        self.picker.type = kWiTapBonjourType;

        self.picker.delegate = self;

        if (self.registeredName != nil) {

            [self startPicker];

        }

        [self.tapViewController presentViewController:self.picker animated:NO completion:nil];

    }

}

- (void)dismissPicker

{

    assert(self.picker != nil);

    [self.tapViewController dismissViewControllerAnimated:NO completion:nil];

    [self.picker stop];

    self.picker = nil;

}

- (void)pickerViewController:(PickerViewController *)controller connectToService:(NSNetService *)service

    // Called by the picker when the user has chosen a service for us to connect to. 

    // The picker is already displaying its connection-in-progress UI.

{

    BOOL                success;

    NSInputStream *     inStream;

    NSOutputStream *    outStream;

    assert(controller == self.picker);

    #pragma unused(controller)

    assert(service != nil);

    assert(self.inputStream == nil);

    assert(self.outputStream == nil);

    // Create and open streams for the service.

    // 

    // -getInputStream:outputStream: just creates the streams, it doesn't hit the 

    // network, and thus it shouldn't fail under normal circumstances (in fact, its 

    // CFNetService equivalent, CFStreamCreatePairWithSocketToNetService, returns no status 

    // at all).  So, I didn't spend too much time worrying about the error case here.  If 

    // we do get an error, you end up staying in the picker.  OTOH, actual connection errors 

    // get handled via the NSStreamEventErrorOccurred event.

    success = [service getInputStream:&inStream outputStream:&outStream];

    if ( ! success ) {

        [self setupForNewGame];

    } else {

        self.inputStream  = inStream;

        self.outputStream = outStream;

        [self openStreams];

    }

}

- (void)pickerViewControllerDidCancelConnect:(PickerViewController *)controller

    // Called by the picker when the user taps the Cancel button in its 

    // connection-in-progress UI.  We respond by closing our in-progress connection.

{

    #pragma unused(controller)

    [self closeStreams];

}

#pragma mark - Connection management

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode

{

    #pragma unused(stream)

    switch(eventCode) {

        case NSStreamEventOpenCompleted: {

            self.streamOpenCount += 1;

            assert(self.streamOpenCount <= 2);

            // Once both streams are open we hide the picker and the game is on.

            if (self.streamOpenCount == 2) {

                [self dismissPicker];

                [self.server stop];

                self.isServerStarted = NO;

                self.registeredName = nil;

            }

        } break;

        case NSStreamEventHasSpaceAvailable: {

            assert(stream == self.outputStream);

            // do nothing

        } break;

        case NSStreamEventHasBytesAvailable: {

            uint8_t     b;

            NSInteger   bytesRead;

            assert(stream == self.inputStream);

            bytesRead = [self.inputStream read:&b maxLength:sizeof(uint8_t)];

            if (bytesRead <= 0) {

                // Do nothing; we'll handle EOF and error in the 

                // NSStreamEventEndEncountered and NSStreamEventErrorOccurred case, 

                // respectively.

            } else {

                // We received a remote tap update, forward it to the appropriate view

                if ( (b >= 'A') && (b < ('A' + kTapViewControllerTapItemCount))) {

                    [self.tapViewController remoteTouchDownOnItem:b - 'A'];

                } else if ( (b >= 'a') && (b < ('a' + kTapViewControllerTapItemCount))) {

                    [self.tapViewController remoteTouchUpOnItem:b - 'a'];

                } else {

                    // Ignore the bogus input.  This is important because it allows us 

                    // to telnet in to the app in order to test its behaviour.  telnet 

                    // sends all sorts of odd characters, so ignoring them is a good thing.

                }

            }

        } break;

        default:

            assert(NO);

            // fall through

        case NSStreamEventErrorOccurred:

            // fall through

        case NSStreamEventEndEncountered: {

            [self setupForNewGame];

        } break;

    }

}

- (void)openStreams

{

    assert(self.inputStream != nil);            // streams must exist but aren't open

    assert(self.outputStream != nil);

    assert(self.streamOpenCount == 0);

    [self.inputStream  setDelegate:self];

    [self.inputStream  scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

    [self.inputStream  open];

    [self.outputStream setDelegate:self];

    [self.outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

    [self.outputStream open];

}

- (void)closeStreams

{

    assert( (self.inputStream != nil) == (self.outputStream != nil) );      // should either have both or neither

    if (self.inputStream != nil) {

        [self.inputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

        [self.inputStream close];

        self.inputStream = nil;

        [self.outputStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

        [self.outputStream close];

        self.outputStream = nil;

    }

    self.streamOpenCount = 0;

}

- (void)send:(uint8_t)message

{

    assert(self.streamOpenCount == 2);

    // Only write to the stream if it has space available, otherwise we might block. 

    // In a real app you have to handle this case properly but in this sample code it's 

    // OK to ignore it; if the stream stops transferring data the user is going to have 

    // to tap a lot before we fill up our stream buffer (-:

    if ( [self.outputStream hasSpaceAvailable] ) {

        NSInteger   bytesWritten;

        bytesWritten = [self.outputStream write:&message maxLength:sizeof(message)];

        if (bytesWritten != sizeof(message)) {

            [self setupForNewGame];

        }

    }

}

- (void)tapViewController:(TapViewController *)controller localTouchDownOnItem:(NSUInteger)tapItemIndex

{

    assert(controller == self.tapViewController);

    #pragma unused(controller)

    [self send:(uint8_t) (tapItemIndex + 'A')];

}

- (void)tapViewController:(TapViewController *)controller localTouchUpOnItem:(NSUInteger)tapItemIndex

{

    assert(controller == self.tapViewController);

    #pragma unused(controller)

    [self send:(uint8_t) (tapItemIndex + 'a')];

}

- (void)tapViewControllerDidClose:(TapViewController *)controller

{

    assert(controller == self.tapViewController);

    #pragma unused(controller)

    [self setupForNewGame];

}

#pragma mark - QServer delegate

- (void)netServiceDidPublish:(NSNetService *)sender

{

    assert(sender == self.server);

    #pragma unused(sender)

    self.registeredName = self.server.name;

    if (self.picker != nil) {

        // If our server wasn't started when we brought up the picker, we 

        // left the picker stopped (because without our service name it can't 

        // filter us out of its list).  In that case we have to start the picker 

        // now.

        [self startPicker];

    }

}

- (void)netService:(NSNetService *)sender didAcceptConnectionWithInputStream:(NSInputStream *)inputStream outputStream:(NSOutputStream *)outputStream

{

    // Due to a bug <rdar://problem/15626440>, this method is called on some unspecified 

    // queue rather than the queue associated with the net service (which in this case 

    // is the main queue).  Work around this by bouncing to the main queue.

    [[NSOperationQueue mainQueue] addOperationWithBlock:^{

        assert(sender == self.server);

        #pragma unused(sender)

        assert(inputStream != nil);

        assert(outputStream != nil);

        assert( (self.inputStream != nil) == (self.outputStream != nil) );      // should either have both or neither

        if (self.inputStream != nil) {

            // We already have a game in place; reject this new one.

            [inputStream open];

            [inputStream close];

            [outputStream open];

            [outputStream close];

        } else {

            // Start up the new game.  Start by deregistering the server, to discourage 

            // other folks from connecting to us (and being disappointed when we reject 

            // the connection).

            [self.server stop];

            self.isServerStarted = NO;

            self.registeredName = nil;

            // Latch the input and output sterams and kick off an open.

            self.inputStream  = inputStream;

            self.outputStream = outputStream;

            [self openStreams];

        }

    }];

}

- (void)netService:(NSNetService *)sender didNotPublish:(NSDictionary *)errorDict

    // This is called when the server stops of its own accord.  The only reason 

    // that might happen is if the Bonjour registration fails when we reregister 

    // the server, and that's hard to trigger because we use auto-rename.  I've 

    // left an assert here so that, if this does happen, we can figure out why it 

    // happens and then decide how best to handle it.

{

    assert(sender == self.server);

    #pragma unused(sender)

    #pragma unused(errorDict)

    assert(NO);

}

@end