/*

     File: SessionContainer.m

 Abstract:  This container class is used to encapsulate the Multipeer Connectivity API classes and their respective delegate callbacks.  The is the MOST IMPORTANT source file in the entire example.  In this class you see examples of managing MCSession state, sending and receving data based messages, and sending and receving URL resources via the convenience API. 

  Version: 1.0

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@import MultipeerConnectivity;

#import "SessionContainer.h"

#import "Transcript.h"

@interface SessionContainer()

// Framework UI class for handling incoming invitations

@property (retain, nonatomic) MCAdvertiserAssistant *advertiserAssistant;

@end

@implementation SessionContainer

// Session container designated initializer

- (id)initWithDisplayName:(NSString *)displayName serviceType:(NSString *)serviceType

{

    if (self = [super init]) {

        // Create the peer ID with user input display name.  This display name will be seen by other browsing peers

        MCPeerID *peerID = [[MCPeerID alloc] initWithDisplayName:displayName];

        // Create the session that peers will be invited/join into.  You can provide an optinal security identity for custom authentication.  Also you can set the encryption preference for the session.

        _session = [[MCSession alloc] initWithPeer:peerID securityIdentity:nil encryptionPreference:MCEncryptionRequired];

        // Set ourselves as the MCSessionDelegate

        _session.delegate = self;

        // Create the advertiser assistant for managing incoming invitation

        _advertiserAssistant = [[MCAdvertiserAssistant alloc] initWithServiceType:serviceType discoveryInfo:nil session:_session];

        // Start the assistant to begin advertising your peers availability

        [_advertiserAssistant start];

    }

    return self;

}

// On dealloc we should clean up the session by disconnecting from it.

- (void)dealloc

{

    [_advertiserAssistant stop];

    [_session disconnect];

}

// Helper method for human readable printing of MCSessionState.  This state is per peer.

- (NSString *)stringForPeerConnectionState:(MCSessionState)state

{

    switch (state) {

        case MCSessionStateConnected:

            return @"Connected";

        case MCSessionStateConnecting:

            return @"Connecting";

        case MCSessionStateNotConnected:

            return @"Not Connected";

    }

}

#pragma mark - Public methods

// Instance method for sending a string bassed text message to all remote peers

- (Transcript *)sendMessage:(NSString *)message

{

    // Convert the string into a UTF8 encoded data

    NSData *messageData = [message dataUsingEncoding:NSUTF8StringEncoding];

    // Send text message to all connected peers

    NSError *error;

    [self.session sendData:messageData toPeers:self.session.connectedPeers withMode:MCSessionSendDataReliable error:&error];

    // Check the error return to know if there was an issue sending data to peers.  Note any peers in the 'toPeers' array argument are not connected this will fail.

    if (error) {

        NSLog(@"Error sending message to peers [%@]", error);

        return nil;

    }

    else {

        // Create a new send transcript

        return [[Transcript alloc] initWithPeerID:_session.myPeerID message:message direction:TRANSCRIPT_DIRECTION_SEND];

    }

}

// Method for sending image resources to all connected remote peers.  Returns an progress type transcript for monitoring tranfer

- (Transcript *)sendImage:(NSURL *)imageUrl

{

    NSProgress *progress;

    // Loop on connected peers and send the image to each

    for (MCPeerID *peerID in _session.connectedPeers) {

//        imageUrl = [NSURL URLWithString:@"http://images.apple.com/home/images/promo_logic_pro.jpg"];

        // Send the resource to the remote peer.  The completion handler block will be called at the end of sending or if any errors occur

        progress = [self.session sendResourceAtURL:imageUrl withName:[imageUrl lastPathComponent] toPeer:peerID withCompletionHandler:^(NSError *error) {

            // Implement this block to know when the sending resource transfer completes and if there is an error.

            if (error) {

                NSLog(@"Send resource to peer [%@] completed with Error [%@]", peerID.displayName, error);

            }

            else {

                // Create an image transcript for this received image resource

                Transcript *transcript = [[Transcript alloc] initWithPeerID:_session.myPeerID imageUrl:imageUrl direction:TRANSCRIPT_DIRECTION_SEND];

                [self.delegate updateTranscript:transcript];

            }

        }];

    }

    // Create an outgoing progress transcript.  For simplicity we will monitor a single NSProgress.  However users can measure each NSProgress returned individually as needed

    Transcript *transcript = [[Transcript alloc] initWithPeerID:_session.myPeerID imageName:[imageUrl lastPathComponent] progress:progress direction:TRANSCRIPT_DIRECTION_SEND];

    return transcript;

}

#pragma mark - MCSessionDelegate methods

// Override this method to handle changes to peer session state

- (void)session:(MCSession *)session peer:(MCPeerID *)peerID didChangeState:(MCSessionState)state

{

    NSLog(@"Peer [%@] changed state to %@", peerID.displayName, [self stringForPeerConnectionState:state]);

    NSString *adminMessage = [NSString stringWithFormat:@"'%@' is %@", peerID.displayName, [self stringForPeerConnectionState:state]];

    // Create an local transcript

    Transcript *transcript = [[Transcript alloc] initWithPeerID:peerID message:adminMessage direction:TRANSCRIPT_DIRECTION_LOCAL];

    // Notify the delegate that we have received a new chunk of data from a peer

    [self.delegate receivedTranscript:transcript];

}

// MCSession Delegate callback when receiving data from a peer in a given session

- (void)session:(MCSession *)session didReceiveData:(NSData *)data fromPeer:(MCPeerID *)peerID

{

    // Decode the incoming data to a UTF8 encoded string

    NSString *receivedMessage = [[NSString alloc] initWithData:data encoding: NSUTF8StringEncoding];

    // Create an received transcript

    Transcript *transcript = [[Transcript alloc] initWithPeerID:peerID message:receivedMessage direction:TRANSCRIPT_DIRECTION_RECEIVE];

    // Notify the delegate that we have received a new chunk of data from a peer

    [self.delegate receivedTranscript:transcript];

}

// MCSession delegate callback when we start to receive a resource from a peer in a given session

- (void)session:(MCSession *)session didStartReceivingResourceWithName:(NSString *)resourceName fromPeer:(MCPeerID *)peerID withProgress:(NSProgress *)progress

{

    NSLog(@"Start receiving resource [%@] from peer %@ with progress [%@]", resourceName, peerID.displayName, progress);

    // Create a resource progress transcript

    Transcript *transcript = [[Transcript alloc] initWithPeerID:peerID imageName:resourceName progress:progress direction:TRANSCRIPT_DIRECTION_RECEIVE];

    // Notify the UI delegate

    [self.delegate receivedTranscript:transcript];

}

// MCSession delegate callback when a incoming resource transfer ends (possibly with error)

- (void)session:(MCSession *)session didFinishReceivingResourceWithName:(NSString *)resourceName fromPeer:(MCPeerID *)peerID atURL:(NSURL *)localURL withError:(NSError *)error

{

    // If error is not nil something went wrong

    if (error)

    {

        NSLog(@"Error [%@] receiving resource from peer %@ ", [error localizedDescription], peerID.displayName);

    }

    else

    {

        // No error so this is a completed transfer.  The resources is located in a temporary location and should be copied to a permenant locatation immediately.

        // Write to documents directory

        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

        NSString *copyPath = [NSString stringWithFormat:@"%@/%@", [paths objectAtIndex:0], resourceName];

        if (![[NSFileManager defaultManager] copyItemAtPath:[localURL path] toPath:copyPath error:nil])

        {

            NSLog(@"Error copying resource to documents directory");

        }

        else {

            // Get a URL for the path we just copied the resource to

            NSURL *imageUrl = [NSURL fileURLWithPath:copyPath];

            // Create an image transcript for this received image resource

            Transcript *transcript = [[Transcript alloc] initWithPeerID:peerID imageUrl:imageUrl direction:TRANSCRIPT_DIRECTION_RECEIVE];

            [self.delegate updateTranscript:transcript];

        }

    }

}

// Streaming API not utilized in this sample code

- (void)session:(MCSession *)session didReceiveStream:(NSInputStream *)stream withName:(NSString *)streamName fromPeer:(MCPeerID *)peerID

{

    NSLog(@"Received data over stream with name %@ from peer %@", streamName, peerID.displayName);

}

@end