SDLProxy.m

// SDLProxy.m

#import "SDLProxy.h"

#import <ExternalAccessory/ExternalAccessory.h>
#import <UIKit/UIKit.h>
#import <objc/runtime.h>

#import "SDLAbstractTransport.h"
#import "SDLAudioStreamingState.h"
#import "SDLDebugTool.h"
#import "SDLEncodedSyncPData.h"
#import "SDLFileType.h"
#import "SDLFunctionID.h"
#import "SDLGlobals.h"
#import "SDLHMILevel.h"
#import "SDLJsonDecoder.h"
#import "SDLJsonEncoder.h"
#import "SDLLanguage.h"
#import "SDLLayoutMode.h"
#import "SDLLockScreenManager.h"
#import "SDLLockScreenManager.h"
#import "SDLNames.h"
#import "SDLOnHMIStatus.h"
#import "SDLOnSystemRequest.h"
#import "SDLPolicyDataParser.h"
#import "SDLPolicyDataParser.h"
#import "SDLProtocol.h"
#import "SDLProtocolMessage.h"
#import "SDLProtocolMessage.h"
#import "SDLPutFile.h"
#import "SDLRegisterAppInterfaceResponse.h"
#import "SDLRPCPayload.h"
#import "SDLRPCRequestFactory.h"
#import "SDLRPCResponse.h"
#import "SDLRequestType.h"
#import "SDLSiphonServer.h"
#import "SDLStreamingMediaManager.h"
#import "SDLSystemContext.h"
#import "SDLSystemRequest.h"
#import "SDLTimer.h"
#import "SDLURLSession.h"


typedef void (^URLSessionTaskCompletionHandler)(NSData *data, NSURLResponse *response, NSError *error);
typedef void (^URLSessionDownloadTaskCompletionHandler)(NSURL *location, NSURLResponse *response, NSError *error);

NSString *const SDLProxyVersion = @"4.1.4";
const float startSessionTime = 10.0;
const float notifyProxyClosedDelay = 0.1;
const int POLICIES_CORRELATION_ID = 65535;


@interface SDLProxy () {
    SDLLockScreenManager *_lsm;
}

@property (strong, nonatomic) NSMutableSet *mutableProxyListeners;
@property (nonatomic, strong, readwrite, nullable) SDLStreamingMediaManager *streamingMediaManager;
@property (nonatomic, strong, nullable) SDLDisplayCapabilities* displayCapabilities;

@end


@implementation SDLProxy

#pragma mark - Object lifecycle
- (instancetype)initWithTransport:(SDLAbstractTransport *)transport protocol:(SDLAbstractProtocol *)protocol delegate:(NSObject<SDLProxyListener> *)theDelegate {
    if (self = [super init]) {
        _debugConsoleGroupName = @"default";
        _lsm = [[SDLLockScreenManager alloc] init];
        _alreadyDestructed = NO;

        _mutableProxyListeners = [NSMutableSet setWithObject:theDelegate];
        _protocol = protocol;
        _transport = transport;
        _transport.delegate = protocol;
        [_protocol.protocolDelegateTable addObject:self];
        _protocol.transport = transport;

        [self.transport connect];

        [SDLDebugTool logInfo:@"SDLProxy initWithTransport"];
        [[EAAccessoryManager sharedAccessoryManager] registerForLocalNotifications];
    }

    return self;
}

- (void)destructObjects {
    if (!_alreadyDestructed) {
        _alreadyDestructed = YES;

        [[NSNotificationCenter defaultCenter] removeObserver:self];
        [[EAAccessoryManager sharedAccessoryManager] unregisterForLocalNotifications];

        [[SDLURLSession defaultSession] cancelAllTasks];

        [self.protocol dispose];
        [self.transport dispose];

        _transport = nil;
        _protocol = nil;
        _mutableProxyListeners = nil;
        _streamingMediaManager = nil;
        _displayCapabilities = nil;
    }
}

- (void)dispose {
    if (self.transport != nil) {
        [self.transport disconnect];
    }

    [self destructObjects];
}

- (void)dealloc {
    [self destructObjects];
    [SDLDebugTool logInfo:@"SDLProxy Dealloc" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:_debugConsoleGroupName];
}

- (void)notifyProxyClosed {
    if (_isConnected) {
        _isConnected = NO;
        [self invokeMethodOnDelegates:@selector(onProxyClosed) withObject:nil];
    }
}

#pragma mark - Accessors

- (NSSet *)proxyListeners {
    return [self.mutableProxyListeners copy];
}

#pragma mark - Methods

- (void)sendMobileHMIState {
    UIApplicationState appState = [UIApplication sharedApplication].applicationState;
    SDLOnHMIStatus *HMIStatusRPC = [[SDLOnHMIStatus alloc] init];

    HMIStatusRPC.audioStreamingState = [SDLAudioStreamingState NOT_AUDIBLE];
    HMIStatusRPC.systemContext = [SDLSystemContext MAIN];

    switch (appState) {
        case UIApplicationStateActive: {
            HMIStatusRPC.hmiLevel = [SDLHMILevel FULL];
        } break;
        case UIApplicationStateBackground: // Fallthrough
        case UIApplicationStateInactive: {
            HMIStatusRPC.hmiLevel = [SDLHMILevel BACKGROUND];
        } break;
        default:
            break;
    }

    NSString *log = [NSString stringWithFormat:@"Sending new mobile hmi state: %@", HMIStatusRPC.hmiLevel.value];
    [SDLDebugTool logInfo:log withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    [self sendRPC:HMIStatusRPC];
}


#pragma mark - Setters / Getters

- (NSString *)proxyVersion {
    return SDLProxyVersion;
}

- (SDLStreamingMediaManager *)streamingMediaManager {
    if (_streamingMediaManager == nil) {
        if (self.displayCapabilities == nil) {
            @throw [NSException exceptionWithName:NSInvalidArgumentException reason:@"SDLStreamingMediaManager must be accessed only after a successful RegisterAppInterfaceResponse" userInfo:nil];
        }
        _streamingMediaManager = [[SDLStreamingMediaManager alloc] initWithProtocol:self.protocol displayCapabilities:self.displayCapabilities];
        [self.protocol.protocolDelegateTable addObject:_streamingMediaManager];
    }

    return _streamingMediaManager;
}


#pragma mark - SDLProtocolListener Implementation
- (void)onProtocolOpened {
    _isConnected = YES;
    [SDLDebugTool logInfo:@"StartSession (request)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    [self.protocol sendStartSessionWithType:SDLServiceType_RPC];

    if (self.startSessionTimer == nil) {
        self.startSessionTimer = [[SDLTimer alloc] initWithDuration:startSessionTime repeat:NO];
        __weak typeof(self) weakSelf = self;
        self.startSessionTimer.elapsedBlock = ^{
            [SDLDebugTool logInfo:@"Start Session Timeout" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:weakSelf.debugConsoleGroupName];
            [weakSelf performSelector:@selector(notifyProxyClosed) withObject:nil afterDelay:notifyProxyClosedDelay];
        };
    }
    [self.startSessionTimer start];
}

- (void)onProtocolClosed {
    [self notifyProxyClosed];
}

- (void)onError:(NSString *)info exception:(NSException *)e {
    [self invokeMethodOnDelegates:@selector(onError:) withObject:e];
}

- (void)handleProtocolStartSessionACK:(SDLServiceType)serviceType sessionID:(Byte)sessionID version:(Byte)version {
    // Turn off the timer, the start session response came back
    [self.startSessionTimer cancel];

    NSString *logMessage = [NSString stringWithFormat:@"StartSession (response)\nSessionId: %d for serviceType %d", sessionID, serviceType];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    if (serviceType == SDLServiceType_RPC) {
        [self invokeMethodOnDelegates:@selector(onProxyOpened) withObject:nil];
    }
}

- (void)onProtocolMessageReceived:(SDLProtocolMessage *)msgData {
    @try {
        [self handleProtocolMessage:msgData];
    } @catch (NSException *e) {
        NSString *logMessage = [NSString stringWithFormat:@"Proxy: Failed to handle protocol message %@", e];
        [SDLDebugTool logInfo:logMessage withType:SDLDebugType_Debug toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    }
}


#pragma mark - Message sending and recieving
- (void)sendRPC:(SDLRPCMessage *)message {
    @try {
        [self.protocol sendRPC:message];
    } @catch (NSException *exception) {
        NSString *logMessage = [NSString stringWithFormat:@"Proxy: Failed to send RPC message: %@", message.name];
        [SDLDebugTool logInfo:logMessage withType:SDLDebugType_Debug toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    }
}

- (void)sendRPCRequest:(SDLRPCMessage *)msg {
    if ([msg isKindOfClass:SDLRPCRequest.class]) {
        [self sendRPC:msg];
    }
}

- (void)handleProtocolMessage:(SDLProtocolMessage *)incomingMessage {
    // Convert protocol message to dictionary
    NSDictionary *rpcMessageAsDictionary = [incomingMessage rpcDictionary];
    [self handleRPCDictionary:rpcMessageAsDictionary];
}

- (void)handleRPCDictionary:(NSDictionary *)dict {
    SDLRPCMessage *message = [[SDLRPCMessage alloc] initWithDictionary:[dict mutableCopy]];
    NSString *functionName = [message getFunctionName];
    NSString *messageType = [message messageType];

    // If it's a response, append response
    if ([messageType isEqualToString:NAMES_response]) {
        BOOL notGenericResponseMessage = ![functionName isEqualToString:@"GenericResponse"];
        if (notGenericResponseMessage) {
            functionName = [NSString stringWithFormat:@"%@Response", functionName];
        }
    }

    // From the function name, create the corresponding RPCObject and initialize it
    NSString *functionClassName = [NSString stringWithFormat:@"SDL%@", functionName];
    SDLRPCMessage *newMessage = [[NSClassFromString(functionClassName) alloc] initWithDictionary:[dict mutableCopy]];

    // Log the RPC message
    NSString *logMessage = [NSString stringWithFormat:@"%@", newMessage];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    // Intercept and handle several messages ourselves
    if ([functionName isEqualToString:NAMES_OnAppInterfaceUnregistered] || [functionName isEqualToString:NAMES_UnregisterAppInterface]) {
        [self handleRPCUnregistered:dict];
    }

    if ([functionName isEqualToString:@"RegisterAppInterfaceResponse"]) {
        [self handleRegisterAppInterfaceResponse:(SDLRPCResponse *)newMessage];
    }

    if ([functionName isEqualToString:@"EncodedSyncPDataResponse"]) {
        [SDLDebugTool logInfo:@"EncodedSyncPData (response)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    }

    if ([functionName isEqualToString:@"OnEncodedSyncPData"]) {
        [self handleSyncPData:newMessage];
    }

    if ([functionName isEqualToString:@"OnSystemRequest"]) {
        [self handleSystemRequest:dict];
    }

    if ([functionName isEqualToString:@"SystemRequestResponse"]) {
        [self handleSystemRequestResponse:newMessage];
    }

    // Formulate the name of the method to call and invoke the method on the delegate(s)
    NSString *handlerName = [NSString stringWithFormat:@"on%@:", functionName];
    SEL handlerSelector = NSSelectorFromString(handlerName);
    [self invokeMethodOnDelegates:handlerSelector withObject:newMessage];

    // When an OnHMIStatus notification comes in, after passing it on (above), generate an "OnLockScreenNotification"
    if ([functionName isEqualToString:@"OnHMIStatus"]) {
        [self handleAfterHMIStatus:newMessage];
    }

    // When an OnDriverDistraction notification comes in, after passing it on (above), generate an "OnLockScreenNotification"
    if ([functionName isEqualToString:@"OnDriverDistraction"]) {
        [self handleAfterDriverDistraction:newMessage];
    }
}

- (void)handleRpcMessage:(NSDictionary *)msg {
    [self handleRPCDictionary:msg];
}


#pragma mark - RPC Handlers
- (void)handleRPCUnregistered:(NSDictionary *)messageDictionary {
    NSString *logMessage = [NSString stringWithFormat:@"Unregistration forced by module. %@", messageDictionary];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    [self notifyProxyClosed];
}

- (void)handleRegisterAppInterfaceResponse:(SDLRPCResponse *)response {
    //Print Proxy Version To Console
    NSString *logMessage = [NSString stringWithFormat:@"Framework Version: %@", self.proxyVersion];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    if ([SDLGlobals globals].protocolVersion >= 4) {
        [self sendMobileHMIState];
        // Send SDL updates to application state
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sendMobileHMIState) name:UIApplicationDidBecomeActiveNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sendMobileHMIState) name:UIApplicationDidEnterBackgroundNotification object:nil];
    }
    
    // Extract the display capabilties to successfully build SDLStreamingMediaManager's video encoder.
    SDLRegisterAppInterfaceResponse* registerResponse = (SDLRegisterAppInterfaceResponse*)response;
    self.displayCapabilities = registerResponse.displayCapabilities;
}

- (void)handleSyncPData:(SDLRPCMessage *)message {
    // If URL != nil, perform HTTP Post and don't pass the notification to proxy listeners
    NSString *logMessage = [NSString stringWithFormat:@"OnEncodedSyncPData (notification)\n%@", message];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    NSString *urlString = (NSString *)[message getParameters:@"URL"];
    NSDictionary *encodedSyncPData = (NSDictionary *)[message getParameters:@"data"];
    NSNumber *encodedSyncPTimeout = (NSNumber *)[message getParameters:@"Timeout"];

    if (urlString && encodedSyncPData && encodedSyncPTimeout) {
        [self sendEncodedSyncPData:encodedSyncPData toURL:urlString withTimeout:encodedSyncPTimeout];
    }
}

- (void)handleSystemRequest:(NSDictionary *)dict {
    [SDLDebugTool logInfo:@"OnSystemRequest (notification)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    SDLOnSystemRequest *systemRequest = [[SDLOnSystemRequest alloc] initWithDictionary:[dict mutableCopy]];
    SDLRequestType *requestType = systemRequest.requestType;

    // Handle the various OnSystemRequest types
    if (requestType == [SDLRequestType PROPRIETARY]) {
        [self handleSystemRequestProprietary:systemRequest];
    } else if (requestType == [SDLRequestType LOCK_SCREEN_ICON_URL]) {
        [self handleSystemRequestLockScreenIconURL:systemRequest];
    } else if (requestType == [SDLRequestType HTTP]) {
        [self sdl_handleSystemRequestHTTP:systemRequest];
    } else if (requestType == [SDLRequestType LAUNCH_APP]) {
        [self sdl_handleSystemRequestLaunchApp:systemRequest];
    }
}

- (void)handleSystemRequestResponse:(SDLRPCMessage *)message {
    NSString *logMessage = [NSString stringWithFormat:@"SystemRequest (response)\n%@", message];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
}


#pragma mark Handle Post-Invoke of Delegate Methods
- (void)handleAfterHMIStatus:(SDLRPCMessage *)message {
    NSString *statusString = (NSString *)[message getParameters:NAMES_hmiLevel];
    SDLHMILevel *hmiLevel = [SDLHMILevel valueOf:statusString];
    _lsm.hmiLevel = hmiLevel;

    SEL callbackSelector = NSSelectorFromString(@"onOnLockScreenNotification:");
    [self invokeMethodOnDelegates:callbackSelector withObject:_lsm.lockScreenStatusNotification];
}

- (void)handleAfterDriverDistraction:(SDLRPCMessage *)message {
    NSString *stateString = (NSString *)[message getParameters:NAMES_state];
    BOOL state = [stateString isEqualToString:@"DD_ON"] ? YES : NO;
    _lsm.driverDistracted = state;

    SEL callbackSelector = NSSelectorFromString(@"onOnLockScreenNotification:");
    [self invokeMethodOnDelegates:callbackSelector withObject:_lsm.lockScreenStatusNotification];
}


#pragma mark OnSystemRequest Handlers
- (void)sdl_handleSystemRequestLaunchApp:(SDLOnSystemRequest *)request {
    NSURL *URLScheme = [NSURL URLWithString:request.url];
    if (URLScheme == nil) {
        [SDLDebugTool logInfo:[NSString stringWithFormat:@"Launch App failure: invalid URL sent from module: %@", request.url] withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return;
    }
    // If system version is less than 9.0 http://stackoverflow.com/a/5337804/1370927
    if (SDL_SYSTEM_VERSION_LESS_THAN(@"9.0")) {
        // Return early if we can't openURL because openURL will crash instead of fail silently in < 9.0
        if (![[UIApplication sharedApplication] canOpenURL:URLScheme]) {
            return;
        }
    }
    [[UIApplication sharedApplication] openURL:URLScheme];
}

- (void)handleSystemRequestProprietary:(SDLOnSystemRequest *)request {
    NSDictionary *JSONDictionary = [self validateAndParseSystemRequest:request];
    if (JSONDictionary == nil || request.url == nil) {
        return;
    }

    NSDictionary *requestData = JSONDictionary[@"HTTPRequest"];
    NSString *bodyString = requestData[@"body"];
    NSData *bodyData = [bodyString dataUsingEncoding:NSUTF8StringEncoding];

    // Parse and display the policy data.
    SDLPolicyDataParser *pdp = [[SDLPolicyDataParser alloc] init];
    NSData *policyData = [pdp unwrap:bodyData];
    if (policyData != nil) {
        [pdp parsePolicyData:policyData];
        NSString *logMessage = [NSString stringWithFormat:@"Policy Data from Module\n%@", pdp];
        [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
    }

    // Send the HTTP Request
    [self uploadForBodyDataDictionary:JSONDictionary
                            URLString:request.url
                    completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                        NSString *logMessage = nil;

                        if (error) {
                            logMessage = [NSString stringWithFormat:@"OnSystemRequest (HTTP response) = ERROR: %@", error];
                            [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                            return;
                        }

                        if (data == nil || data.length == 0) {
                            [SDLDebugTool logInfo:@"OnSystemRequest (HTTP response) failure: no data returned" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                            return;
                        }

                        // Show the HTTP response
                        [SDLDebugTool logInfo:@"OnSystemRequest (HTTP response)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

                        // Create the SystemRequest RPC to send to module.
                        SDLSystemRequest *request = [[SDLSystemRequest alloc] init];
                        request.correlationID = [NSNumber numberWithInt:POLICIES_CORRELATION_ID];
                        request.requestType = [SDLRequestType PROPRIETARY];
                        request.bulkData = data;

                        // Parse and display the policy data.
                        SDLPolicyDataParser *pdp = [[SDLPolicyDataParser alloc] init];
                        NSData *policyData = [pdp unwrap:data];
                        if (policyData) {
                            [pdp parsePolicyData:policyData];
                            logMessage = [NSString stringWithFormat:@"Policy Data from Cloud\n%@", pdp];
                            [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                        }

                        // Send and log RPC Request
                        logMessage = [NSString stringWithFormat:@"SystemRequest (request)\n%@\nData length=%lu", [request serializeAsDictionary:2], (unsigned long)data.length];
                        [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                        [self sendRPC:request];
                    }];
}

- (void)handleSystemRequestLockScreenIconURL:(SDLOnSystemRequest *)request {
    [[SDLURLSession defaultSession] dataFromURL:[NSURL URLWithString:request.url]
                              completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                  if (error != nil) {
                                      NSString *logMessage = [NSString stringWithFormat:@"OnSystemRequest failure (HTTP response), download task failed: %@", error.localizedDescription];
                                      [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                                      return;
                                  }

                                  UIImage *icon = [UIImage imageWithData:data];
                                  [self invokeMethodOnDelegates:@selector(onReceivedLockScreenIcon:) withObject:icon];
                              }];
}

- (void)sdl_handleSystemRequestHTTP:(SDLOnSystemRequest *)request {
    if (request.bulkData.length == 0) {
        // TODO: not sure how we want to handle http requests that don't have bulk data (maybe as GET?)
        return;
    }

    [self sdl_uploadData:request.bulkData
              toURLString:request.url
        completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
            NSString *logMessage = nil;
            if (error != nil) {
                logMessage = [NSString stringWithFormat:@"OnSystemRequest (HTTP response) = ERROR: %@", error.localizedDescription];
                [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                return;
            }

            if (data.length == 0) {
                [SDLDebugTool logInfo:@"OnSystemRequest (HTTP response) failure: no data returned" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
                return;
            }

            // Show the HTTP response
            NSString *responseLogString = [NSString stringWithFormat:@"OnSystemRequest (HTTP) response: %@", response];
            [SDLDebugTool logInfo:responseLogString withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

            // Create the SystemRequest RPC to send to module.
            SDLPutFile *putFile = [[SDLPutFile alloc] init];
            putFile.fileType = [SDLFileType JSON];
            putFile.correlationID = @(POLICIES_CORRELATION_ID);
            putFile.syncFileName = @"response_data";
            putFile.bulkData = data;

            // Send and log RPC Request
            logMessage = [NSString stringWithFormat:@"SystemRequest (request)\n%@\nData length=%lu", [request serializeAsDictionary:2], (unsigned long)data.length];
            [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
            [self sendRPC:putFile];
        }];
}

/**
 *  Determine if the System Request is valid and return it's JSON dictionary, if available.
 *
 *  @param request The system request to parse
 *
 *  @return A parsed JSON dictionary, or nil if it couldn't be parsed
 */
- (NSDictionary *)validateAndParseSystemRequest:(SDLOnSystemRequest *)request {
    NSString *urlString = request.url;
    SDLFileType *fileType = request.fileType;

    // Validate input
    if (urlString == nil || [NSURL URLWithString:urlString] == nil) {
        [SDLDebugTool logInfo:@"OnSystemRequest (notification) failure: url is nil" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return nil;
    }

    if (fileType != [SDLFileType JSON]) {
        [SDLDebugTool logInfo:@"OnSystemRequest (notification) failure: file type is not JSON" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return nil;
    }

    // Get data dictionary from the bulkData
    NSError *error = nil;
    NSDictionary *JSONDictionary = [NSJSONSerialization JSONObjectWithData:request.bulkData options:kNilOptions error:&error];
    if (error != nil) {
        [SDLDebugTool logInfo:@"OnSystemRequest failure: notification data is not valid JSON." withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return nil;
    }

    return JSONDictionary;
}

/**
 *  Start an upload for some data to a web address specified
 *
 *  @param data              The data to be passed to the server
 *  @param urlString         The URL the data should be POSTed to
 *  @param completionHandler A completion handler of what to do when the server responds
 */
- (void)sdl_uploadData:(NSData *_Nonnull)data toURLString:(NSString *_Nonnull)urlString completionHandler:(URLSessionTaskCompletionHandler _Nullable)completionHandler {
    // NSURLRequest configuration
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setValue:@"application/json" forHTTPHeaderField:@"content-type"];
    request.HTTPMethod = @"POST";

    // Logging
    NSString *logMessage = [NSString stringWithFormat:@"OnSystemRequest (HTTP Request) to URL %@", urlString];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    // Create the upload task
    [[SDLURLSession defaultSession] uploadWithURLRequest:request data:data completionHandler:completionHandler];
}

/**
 *  Start an upload for a body data dictionary, this is used by the "proprietary" system request needed for backward compatibility
 *
 *  @param dictionary        The system request dictionary that contains the HTTP data to be sent
 *  @param urlString         A string containing the URL to send the upload to
 *  @param completionHandler A completion handler returning the response from the server to the upload task
 */
- (void)uploadForBodyDataDictionary:(NSDictionary *)dictionary URLString:(NSString *)urlString completionHandler:(URLSessionTaskCompletionHandler)completionHandler {
    NSParameterAssert(dictionary != nil);
    NSParameterAssert(urlString != nil);
    NSParameterAssert(completionHandler != NULL);

    // Extract data from the dictionary
    NSDictionary *requestData = dictionary[@"HTTPRequest"];
    NSDictionary *headers = requestData[@"headers"];
    NSString *contentType = headers[@"ContentType"];
    NSTimeInterval timeout = [headers[@"ConnectTimeout"] doubleValue];
    NSString *method = headers[@"RequestMethod"];
    NSString *bodyString = requestData[@"body"];
    NSData *bodyData = [bodyString dataUsingEncoding:NSUTF8StringEncoding];

    // NSURLRequest configuration
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    [request setValue:contentType forHTTPHeaderField:@"content-type"];
    request.timeoutInterval = timeout;
    request.HTTPMethod = method;

    // Logging
    NSString *logMessage = [NSString stringWithFormat:@"OnSystemRequest (HTTP Request) to URL %@", urlString];
    [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    // Create the upload task
    [[SDLURLSession defaultSession] uploadWithURLRequest:request data:bodyData completionHandler:completionHandler];
}


#pragma mark - Delegate management

- (void)addDelegate:(NSObject<SDLProxyListener> *)delegate {
    @synchronized(self.mutableProxyListeners) {
        [self.mutableProxyListeners addObject:delegate];
    }
}

- (void)removeDelegate:(NSObject<SDLProxyListener> *)delegate {
    @synchronized(self.mutableProxyListeners) {
        [self.mutableProxyListeners removeObject:delegate];
    }
}

- (void)invokeMethodOnDelegates:(SEL)aSelector withObject:(id)object {
    dispatch_async(dispatch_get_main_queue(), ^{
        @autoreleasepool {
            for (id<SDLProxyListener> listener in self.proxyListeners) {
                if ([listener respondsToSelector:aSelector]) {
                    // HAX: http://stackoverflow.com/questions/7017281/performselector-may-cause-a-leak-because-its-selector-is-unknown
                    ((void (*)(id, SEL, id))[(NSObject *)listener methodForSelector:aSelector])(listener, aSelector, object);
                }
            }
        }
    });
}


#pragma mark - System Request and SyncP handling

- (void)sendEncodedSyncPData:(NSDictionary *)encodedSyncPData toURL:(NSString *)urlString withTimeout:(NSNumber *)timeout {
    // Configure HTTP URL & Request
    NSURL *url = [NSURL URLWithString:urlString];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    request.HTTPMethod = @"POST";
    [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
    request.timeoutInterval = 60;

    // Prepare the data in the required format
    NSString *encodedSyncPDataString = [[NSString stringWithFormat:@"%@", encodedSyncPData] componentsSeparatedByString:@"\""][1];
    NSArray *array = [NSArray arrayWithObject:encodedSyncPDataString];
    NSDictionary *dictionary = @{ @"data" : array };
    NSError *JSONSerializationError = nil;
    NSData *data = [NSJSONSerialization dataWithJSONObject:dictionary options:kNilOptions error:&JSONSerializationError];
    if (JSONSerializationError) {
        NSString *logMessage = [NSString stringWithFormat:@"Error formatting data for HTTP Request. %@", JSONSerializationError];
        [SDLDebugTool logInfo:logMessage withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return;
    }

    // Send the HTTP Request
    [[SDLURLSession defaultSession] uploadWithURLRequest:request
                                                    data:data
                                       completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
                                           [self syncPDataNetworkRequestCompleteWithData:data response:response error:error];
                                       }];

    [SDLDebugTool logInfo:@"OnEncodedSyncPData (HTTP request)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
}

// Handle the OnEncodedSyncPData HTTP Response
- (void)syncPDataNetworkRequestCompleteWithData:(NSData *)data response:(NSURLResponse *)response error:(NSError *)error {
    // Sample of response: {"data":["SDLKGLSDKFJLKSjdslkfjslkJLKDSGLKSDJFLKSDJF"]}
    [SDLDebugTool logInfo:@"OnEncodedSyncPData (HTTP response)" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];

    // Validate response data.
    if (data == nil || data.length == 0) {
        [SDLDebugTool logInfo:@"OnEncodedSyncPData (HTTP response) failure: no data returned" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
        return;
    }

    // Convert data to RPCRequest
    NSError *JSONConversionError = nil;
    NSDictionary *responseDictionary = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&JSONConversionError];
    if (!JSONConversionError) {
        SDLEncodedSyncPData *request = [[SDLEncodedSyncPData alloc] init];
        request.correlationID = [NSNumber numberWithInt:POLICIES_CORRELATION_ID];
        request.data = [responseDictionary objectForKey:@"data"];

        [self sendRPC:request];
    }
}


#pragma mark - PutFile Streaming
- (void)putFileStream:(NSInputStream *)inputStream withRequest:(SDLPutFile *)putFileRPCRequest {
    inputStream.delegate = self;
    objc_setAssociatedObject(inputStream, @"SDLPutFile", putFileRPCRequest, OBJC_ASSOCIATION_RETAIN);
    objc_setAssociatedObject(inputStream, @"BaseOffset", [putFileRPCRequest offset], OBJC_ASSOCIATION_RETAIN);

    [inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    [inputStream open];
}

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)eventCode {
    switch (eventCode) {
        case NSStreamEventHasBytesAvailable: {
            // Grab some bytes from the stream and send them in a SDLPutFile RPC Request
            NSUInteger currentStreamOffset = [[stream propertyForKey:NSStreamFileCurrentOffsetKey] unsignedIntegerValue];

            NSMutableData *buffer = [NSMutableData dataWithLength:[SDLGlobals globals].maxMTUSize];
            NSUInteger nBytesRead = [(NSInputStream *)stream read:(uint8_t *)buffer.mutableBytes maxLength:buffer.length];
            if (nBytesRead > 0) {
                NSData *data = [buffer subdataWithRange:NSMakeRange(0, nBytesRead)];
                NSUInteger baseOffset = [(NSNumber *)objc_getAssociatedObject(stream, @"BaseOffset") unsignedIntegerValue];
                NSUInteger newOffset = baseOffset + currentStreamOffset;

                SDLPutFile *putFileRPCRequest = (SDLPutFile *)objc_getAssociatedObject(stream, @"SDLPutFile");
                [putFileRPCRequest setOffset:[NSNumber numberWithUnsignedInteger:newOffset]];
                [putFileRPCRequest setLength:[NSNumber numberWithUnsignedInteger:nBytesRead]];
                [putFileRPCRequest setBulkData:data];

                [self sendRPC:putFileRPCRequest];
            }

            break;
        }
        case NSStreamEventEndEncountered: {
            // Cleanup the stream
            [stream close];
            [stream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

            break;
        }
        case NSStreamEventErrorOccurred: {
            [SDLDebugTool logInfo:@"Stream Event: Error" withType:SDLDebugType_RPC toOutput:SDLDebugOutput_All toGroup:self.debugConsoleGroupName];
            break;
        }
        default: {
            break;
        }
    }
}


#pragma mark - Siphon management
+ (void)enableSiphonDebug {
    [SDLSiphonServer enableSiphonDebug];
}

+ (void)disableSiphonDebug {
    [SDLSiphonServer disableSiphonDebug];
}

@end