/*

    File:       NetworkManager.m

    Contains:   Shared state and utilities for networking.

    Written by: DTS

    Copyright:  Copyright (c) 2009-2012 Apple Inc. All Rights Reserved.

    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.

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                original Apple software (the "Apple Software"), to use,

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                written permission from Apple.  Except as expressly stated in

                this notice, no other rights or licenses, express or implied,

                are granted by Apple herein, including but not limited to any

                patent rights that may be infringed by your derivative works or

                by other works in which the Apple Software may be incorporated.

                The Apple Software is provided by Apple on an "AS IS" basis. 

                APPLE MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING

                WITHOUT LIMITATION THE IMPLIED WARRANTIES OF NON-INFRINGEMENT,

                MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING

                THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN

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*/

#import "NetworkManager.h"

@interface NetworkManager ()

// read/write redeclaration of public read-only property

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

@end

@implementation NetworkManager

@synthesize networkOperationCount = _networkOperationCount;

+ (NetworkManager *)sharedInstance

{

    static dispatch_once_t  onceToken;

    static NetworkManager * sSharedInstance;

    dispatch_once(&onceToken, ^{

        sSharedInstance = [[NetworkManager alloc] init];

    });

    return sSharedInstance;

}

- (NSURL *)smartURLForString:(NSString *)str

{

    NSURL *     result;

    NSString *  trimmedStr;

    NSRange     schemeMarkerRange;

    NSString *  scheme;

    assert(str != nil);

    result = nil;

    trimmedStr = [str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

    if ( (trimmedStr != nil) && (trimmedStr.length != 0) ) {

        schemeMarkerRange = [trimmedStr rangeOfString:@"://"];

        if (schemeMarkerRange.location == NSNotFound) {

            result = [NSURL URLWithString:[NSString stringWithFormat:@"http://%@", trimmedStr]];

        } else {

            scheme = [trimmedStr substringWithRange:NSMakeRange(0, schemeMarkerRange.location)];

            assert(scheme != nil);

            if ( ([scheme compare:@"http"  options:NSCaseInsensitiveSearch] == NSOrderedSame)

              || ([scheme compare:@"https" options:NSCaseInsensitiveSearch] == NSOrderedSame) ) {

                result = [NSURL URLWithString:trimmedStr];

            } else {

                // It looks like this is some unsupported URL scheme.

            }

        }

    }

    return result;

}

- (NSString *)pathForTestImage:(NSUInteger)imageNumber

    // In order to fully test the send and receive code paths, we need some really big 

    // files.  Rather than carry theshe files around in our binary, we synthesise them. 

    // Specifically, for each test image, we expand the image by an order of magnitude, 

    // based on its image number.  That is, image 1 is not expanded, image 2 

    // gets expanded 10 times, and so on.  We expand the image by simply copying it 

    // to the temporary directory, writing the same data to the file over and over 

    // again.

{

    NSUInteger          power;

    NSUInteger          expansionFactor;

    NSString *          originalFilePath;

    NSString *          bigFilePath;

    NSFileManager *     fileManager;

    NSDictionary *      attrs;

    unsigned long long  originalFileSize;

    unsigned long long  bigFileSize;

    assert( (imageNumber >= 1) && (imageNumber <= 4) );

    // Argh, C has no built-in power operator, so I have to do 10 ** (imageNumber - 1)

    // in floating point and then cast back to integer.  Fortunately the range 

    // of values is small enough (1..1000) that floating point isn't going 

    // to cause me any problems.

    // On the simulator we expand by an extra order of magnitude; Macs are fast!

    power = imageNumber - 1;

    #if TARGET_IPHONE_SIMULATOR

        power += 1;

    #endif

    expansionFactor = (NSUInteger) pow(10, power);

    fileManager = [NSFileManager defaultManager];

    assert(fileManager != nil);

    // Calculate paths to both the original file and the expanded file.

    originalFilePath = [[NSBundle mainBundle] pathForResource:[NSString stringWithFormat:@"TestImage%zu", (size_t) imageNumber] ofType:@"png"];

    assert(originalFilePath != nil);

    bigFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"TestImage%zu.png", (size_t) imageNumber]];

    assert(bigFilePath != nil);

    // Get the sizes of each.

    attrs = [fileManager attributesOfItemAtPath:originalFilePath error:NULL];

    assert(attrs != nil);

    originalFileSize = [[attrs objectForKey:NSFileSize] unsignedLongLongValue];

    attrs = [fileManager attributesOfItemAtPath:bigFilePath error:NULL];

    if (attrs == NULL) {

        bigFileSize = 0;

    } else {

        bigFileSize = [[attrs objectForKey:NSFileSize] unsignedLongLongValue];

    }

    // If the expanded file is missing, or the wrong size, create it from scratch.

    if (bigFileSize != (originalFileSize * expansionFactor)) {

        NSOutputStream *    bigFileStream;

        NSData *            data;

        const uint8_t *     dataBuffer;

        NSUInteger          dataLength;

        NSUInteger          dataOffset;

        NSUInteger          counter;

        NSLog(@"%5zu - %@", (size_t) expansionFactor, bigFilePath);

        data = [NSData dataWithContentsOfMappedFile:originalFilePath];

        assert(data != nil);

        dataBuffer = [data bytes];

        dataLength = [data length];

        bigFileStream = [NSOutputStream outputStreamToFileAtPath:bigFilePath append:NO];

        assert(bigFileStream != NULL);

        [bigFileStream open];

        for (counter = 0; counter < expansionFactor; counter++) {

            dataOffset = 0;

            while (dataOffset != dataLength) {

                NSInteger       bytesWritten;

                bytesWritten = [bigFileStream write:&dataBuffer[dataOffset] maxLength:dataLength - dataOffset];

                assert(bytesWritten > 0);

                dataOffset += bytesWritten;

            }

        }

        [bigFileStream close];

    }

    return bigFilePath;

}

- (NSString *)pathForTemporaryFileWithPrefix:(NSString *)prefix

{

    NSString *  result;

    CFUUIDRef   uuid;

    CFStringRef uuidStr;

    uuid = CFUUIDCreate(NULL);

    assert(uuid != NULL);

    uuidStr = CFUUIDCreateString(NULL, uuid);

    assert(uuidStr != NULL);

    result = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"%@-%@", prefix, uuidStr]];

    assert(result != nil);

    CFRelease(uuidStr);

    CFRelease(uuid);

    return result;

}

- (void)didStartNetworkOperation

{

    // If you start a network operation off the main thread, you'll have to update this code 

    // to ensure that any observers of this property are thread safe.

    assert([NSThread isMainThread]);

    self.networkOperationCount += 1;

}

- (void)didStopNetworkOperation

{

    // If you stop a network operation off the main thread, you'll have to update this code 

    // to ensure that any observers of this property are thread safe.

    assert([NSThread isMainThread]);

    assert(self.networkOperationCount > 0);

    self.networkOperationCount -= 1;

}

@end