/*

     File: GetController.m

 Abstract: Manages the Get tab.

  Version: 1.4

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

 Inc. ("Apple") in consideration of your agreement to the following

 terms, and your use, installation, modification or redistribution of

 this Apple software constitutes acceptance of these terms.  If you do

 not agree with these terms, please do not use, install, modify or

 redistribute this Apple software.

 In consideration of your agreement to abide by the following terms, and

 subject to these terms, Apple grants you a personal, non-exclusive

 license, under Apple's copyrights in this original Apple software (the

 "Apple Software"), to use, reproduce, modify and redistribute the Apple

 Software, with or without modifications, in source and/or binary forms;

 provided that if you redistribute the Apple Software in its entirety and

 without modifications, you must retain this notice and the following

 text and disclaimers in all such redistributions of the Apple Software.

 Neither the name, trademarks, service marks or logos of Apple Inc. may

 be used to endorse or promote products derived from the Apple Software

 without specific prior 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 COMBINATION WITH YOUR PRODUCTS.

 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,

 MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED

 AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),

 STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE

 POSSIBILITY OF SUCH DAMAGE.

 Copyright (C) 2013 Apple Inc. All Rights Reserved.

 */

#import "GetController.h"

#import "NetworkManager.h"

#include <CFNetwork/CFNetwork.h>

#pragma mark * GetController

@interface GetController () <UITextFieldDelegate, NSStreamDelegate>

// things for IB

@property (nonatomic, strong, readwrite) IBOutlet UITextField *               urlText;

@property (nonatomic, strong, readwrite) IBOutlet UIImageView *               imageView;

@property (nonatomic, strong, readwrite) IBOutlet UILabel *                   statusLabel;

@property (nonatomic, strong, readwrite) IBOutlet UIActivityIndicatorView *   activityIndicator;

@property (nonatomic, strong, readwrite) IBOutlet UIBarButtonItem *           getOrCancelButton;

- (IBAction)getOrCancelAction:(id)sender;

// Properties that don't need to be seen by the outside world.

@property (nonatomic, assign, readonly ) BOOL              isReceiving;

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

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

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

@end

@implementation GetController

#pragma mark * Status management

// These methods are used by the core transfer code to update the UI.

- (void)receiveDidStart

{

    // Clear the current image so that we get a nice visual cue if the receive fails.

    self.imageView.image = [UIImage imageNamed:@"NoImage.png"];

    self.statusLabel.text = @"Receiving";

    self.getOrCancelButton.title = @"Cancel";

    [self.activityIndicator startAnimating];

    [[NetworkManager sharedInstance] didStartNetworkOperation];

}

- (void)updateStatus:(NSString *)statusString

{

    assert(statusString != nil);

    self.statusLabel.text = statusString;

}

- (void)receiveDidStopWithStatus:(NSString *)statusString

{

    if (statusString == nil) {

        assert(self.filePath != nil);

        self.imageView.image = [UIImage imageWithContentsOfFile:self.filePath];

        statusString = @"GET succeeded";

    }

    self.statusLabel.text = statusString;

    self.getOrCancelButton.title = @"Get";

    [self.activityIndicator stopAnimating];

    [[NetworkManager sharedInstance] didStopNetworkOperation];

}

#pragma mark * Core transfer code

// This is the code that actually does the networking.

- (BOOL)isReceiving

{

    return (self.networkStream != nil);

}

- (void)startReceive

    // Starts a connection to download the current URL.

{

    BOOL                success;

    NSURL *             url;

    assert(self.networkStream == nil);      // don't tap receive twice in a row!

    assert(self.fileStream == nil);         // ditto

    assert(self.filePath == nil);           // ditto

    // First get and check the URL.

    url = [[NetworkManager sharedInstance] smartURLForString:self.urlText.text];

    success = (url != nil);

    // If the URL is bogus, let the user know.  Otherwise kick off the connection.

    if ( ! success) {

        self.statusLabel.text = @"Invalid URL";

    } else {

        // Open a stream for the file we're going to receive into.

        self.filePath = [[NetworkManager sharedInstance] pathForTemporaryFileWithPrefix:@"Get"];

        assert(self.filePath != nil);

        self.fileStream = [NSOutputStream outputStreamToFileAtPath:self.filePath append:NO];

        assert(self.fileStream != nil);

        [self.fileStream open];

        // Open a CFFTPStream for the URL.

        self.networkStream = CFBridgingRelease(

            CFReadStreamCreateWithFTPURL(NULL, (__bridge CFURLRef) url)

        );

        assert(self.networkStream != nil);

        self.networkStream.delegate = self;

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

        [self.networkStream open];

        // Tell the UI we're receiving.

        [self receiveDidStart];

    }

}

- (void)stopReceiveWithStatus:(NSString *)statusString

    // Shuts down the connection and displays the result (statusString == nil) 

    // or the error status (otherwise).

{

    if (self.networkStream != nil) {

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

        self.networkStream.delegate = nil;

        [self.networkStream close];

        self.networkStream = nil;

    }

    if (self.fileStream != nil) {

        [self.fileStream close];

        self.fileStream = nil;

    }

    [self receiveDidStopWithStatus:statusString];

    self.filePath = nil;

}

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

    // An NSStream delegate callback that's called when events happen on our 

    // network stream.

{

    #pragma unused(aStream)

    assert(aStream == self.networkStream);

    switch (eventCode) {

        case NSStreamEventOpenCompleted: {

            [self updateStatus:@"Opened connection"];

        } break;

        case NSStreamEventHasBytesAvailable: {

            NSInteger       bytesRead;

            uint8_t         buffer[32768];

            [self updateStatus:@"Receiving"];

            // Pull some data off the network.

            bytesRead = [self.networkStream read:buffer maxLength:sizeof(buffer)];

            if (bytesRead == -1) {

                [self stopReceiveWithStatus:@"Network read error"];

            } else if (bytesRead == 0) {

                [self stopReceiveWithStatus:nil];

            } else {

                NSInteger   bytesWritten;

                NSInteger   bytesWrittenSoFar;

                // Write to the file.

                bytesWrittenSoFar = 0;

                do {

                    bytesWritten = [self.fileStream write:&buffer[bytesWrittenSoFar] maxLength:(NSUInteger) (bytesRead - bytesWrittenSoFar)];

                    assert(bytesWritten != 0);

                    if (bytesWritten == -1) {

                        [self stopReceiveWithStatus:@"File write error"];

                        break;

                    } else {

                        bytesWrittenSoFar += bytesWritten;

                    }

                } while (bytesWrittenSoFar != bytesRead);

            }

        } break;

        case NSStreamEventHasSpaceAvailable: {

            assert(NO);     // should never happen for the output stream

        } break;

        case NSStreamEventErrorOccurred: {

            [self stopReceiveWithStatus:@"Stream open error"];

        } break;

        case NSStreamEventEndEncountered: {

            // ignore

        } break;

        default: {

            assert(NO);

        } break;

    }

}

#pragma mark * UI Actions

- (IBAction)getOrCancelAction:(id)sender

{

    #pragma unused(sender)

    if (self.isReceiving) {

        [self stopReceiveWithStatus:@"Cancelled"];

    } else {

        [self startReceive];

    }

}

- (void)textFieldDidEndEditing:(UITextField *)textField

    // A delegate method called by the URL text field when the editing is complete. 

    // We save the current value of the field in our settings.

{

    #pragma unused(textField)

    NSString *  newValue;

    NSString *  oldValue;

    assert(textField == self.urlText);

    newValue = self.urlText.text;

    oldValue = [[NSUserDefaults standardUserDefaults] stringForKey:@"GetURLText"];

    // Save the URL text if it's changed.

    assert(newValue != nil);        // what is UITextField thinking!?!

    assert(oldValue != nil);        // because we registered a default

    if ( ! [newValue isEqual:oldValue] ) {

        [[NSUserDefaults standardUserDefaults] setObject:newValue forKey:@"GetURLText"];

    }

}

- (BOOL)textFieldShouldReturn:(UITextField *)textField

    // A delegate method called by the URL text field when the user taps the Return 

    // key.  We just dismiss the keyboard.

{

    #pragma unused(textField)

    assert(textField == self.urlText);

    [self.urlText resignFirstResponder];

    return NO;

}

#pragma mark * View controller boilerplate

- (void)viewDidLoad

{    

    [super viewDidLoad];

    assert(self.urlText != nil);

    assert(self.imageView != nil);

    assert(self.statusLabel != nil);

    assert(self.activityIndicator != nil);

    assert(self.getOrCancelButton != nil);

    self.getOrCancelButton.possibleTitles = [NSSet setWithObjects:@"Get", @"Cancel", nil];

    self.urlText.text = [[NSUserDefaults standardUserDefaults] stringForKey:@"GetURLText"];

    self.activityIndicator.hidden = YES;

    self.statusLabel.text = @"Tap Get to start getting";

}

- (void)viewDidUnload

{

    [super viewDidUnload];

    self.urlText = nil;

    self.imageView = nil;

    self.statusLabel = nil;

    self.activityIndicator = nil;

    self.getOrCancelButton = nil;

}

- (void)dealloc

{

    [self stopReceiveWithStatus:@"Stopped"];

}

@end