/SimpleFTPSample/ListController.m

/*
    File:       ListController.m

    Contains:   Manages the List tab.

    Written by: DTS

    Copyright:  Copyright (c) 2010 Apple Inc. All Rights Reserved.

    Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc.
                ("Apple") in consideration of your agreement to the following
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                original Apple software (the "Apple Software"), to use,
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                without modifications, in source and/or binary forms; provided
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                or logos of Apple Inc. may be used to endorse or promote
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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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                IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT,
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*/

#import "ListController.h"

#import "AppDelegate.h"

#include <sys/socket.h>
#include <sys/dirent.h>

#include <CFNetwork/CFNetwork.h>

#pragma mark * ListController

@interface ListController ()

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

@property (nonatomic, readonly) BOOL              isReceiving;
@property (nonatomic, retain)   NSInputStream *   networkStream;
@property (nonatomic, retain)   NSMutableData *   listData;
@property (nonatomic, retain)   NSMutableArray *  listEntries;
@property (nonatomic, copy)     NSString *        status;

- (void)_updateStatus:(NSString *)statusString;

@end

@implementation ListController

#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.listEntries removeAllObjects];
    [self.tableView reloadData];
    [self _updateStatus:@"Receiving"];
    self.listOrCancelButton.title = @"Cancel";
    [self.activityIndicator startAnimating];
    [[AppDelegate sharedAppDelegate] didStartNetworking];
}

- (void)_updateStatus:(NSString *)statusString
{
    assert(statusString != nil);
    self.status = statusString;
    [self.tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:[NSIndexPath indexPathForRow:0 inSection:0]] withRowAnimation:UITableViewRowAnimationNone];
}

- (void)_addListEntries:(NSArray *)newEntries
{
    assert(self.listEntries != nil);
    
    [self.listEntries addObjectsFromArray:newEntries];
    [self.tableView reloadData];
}

- (void)_receiveDidStopWithStatus:(NSString *)statusString
{
    if (statusString == nil) {
        statusString = @"List succeeded";
    }
    [self _updateStatus:statusString];
    self.listOrCancelButton.title = @"List";
    [self.activityIndicator stopAnimating];
    [[AppDelegate sharedAppDelegate] didStopNetworking];
}

#pragma mark * Core transfer code

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

@synthesize networkStream   = _networkStream;
@synthesize listData        = _listData;
@synthesize listEntries     = _listEntries;

- (BOOL)isReceiving
{
    return (self.networkStream != nil);
}

- (void)_startReceive
    // Starts a connection to download the current URL.
{
    BOOL                success;
    NSURL *             url;
    CFReadStreamRef     ftpStream;
    
    assert(self.networkStream == nil);      // don't tap receive twice in a row!

    // First get and check the URL.
    
    url = [[AppDelegate sharedAppDelegate] smartURLForString:self.urlText.text];
    success = (url != nil);

    // If the URL is bogus, let the user know.  Otherwise kick off the connection.
    
    if ( ! success) {
        [self _updateStatus:@"Invalid URL"];
    } else {

        // Create the mutable data into which we will receive the listing.

        self.listData = [NSMutableData data];
        assert(self.listData != nil);

        // Open a CFFTPStream for the URL.

        ftpStream = CFReadStreamCreateWithFTPURL(NULL, (CFURLRef) url);
        assert(ftpStream != NULL);
        
        self.networkStream = (NSInputStream *) ftpStream;
        
        self.networkStream.delegate = self;
        [self.networkStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
        [self.networkStream open];
        
        // Have to release ftpStream to balance out the create.  self.networkStream 
        // has retained this for our persistent use.
        
        CFRelease(ftpStream);
        
        // 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;
    }
    [self _receiveDidStopWithStatus:statusString];
    self.listData = nil;
}

- (NSDictionary *)_entryByReencodingNameInEntry:(NSDictionary *)entry encoding:(NSStringEncoding)newEncoding
    // CFFTPCreateParsedResourceListing always interprets the file name as MacRoman, 
    // which is clearly bogus <rdar://problem/7420589>.  This code attempts to fix 
    // that by converting the Unicode name back to MacRoman (to get the original bytes; 
    // this works because there's a lossless round trip between MacRoman and Unicode) 
    // and then reconverting those bytes to Unicode using the encoding provided. 
{
    NSDictionary *  result;
    NSString *      name;
    NSData *        nameData;
    NSString *      newName;
    
    newName = nil;
    
    // Try to get the name, convert it back to MacRoman, and then reconvert it 
    // with the preferred encoding.
    
    name = [entry objectForKey:(id) kCFFTPResourceName];
    if (name != nil) {
        assert([name isKindOfClass:[NSString class]]);
        
        nameData = [name dataUsingEncoding:NSMacOSRomanStringEncoding];
        if (nameData != nil) {
            newName = [[[NSString alloc] initWithData:nameData encoding:newEncoding] autorelease];
        }
    }
    
    // If the above failed, just return the entry unmodified.  If it succeeded, 
    // make a copy of the entry and replace the name with the new name that we 
    // calculated.
    
    if (newName == nil) {
        assert(NO);                 // in the debug builds, if this fails, we should investigate why
        result = (NSDictionary *) entry;
    } else {
        NSMutableDictionary *   newEntry;
        
        newEntry = [[entry mutableCopy] autorelease];
        assert(newEntry != nil);
        
        [newEntry setObject:newName forKey:(id) kCFFTPResourceName];
        
        result = newEntry;
    }
    
    return result;
}

- (void)_parseListData
{
    NSMutableArray *    newEntries;
    NSUInteger          offset;
    
    // We accumulate the new entries into an array to avoid a) adding items to the 
    // table one-by-one, and b) repeatedly shuffling the listData buffer around.
    
    newEntries = [NSMutableArray array];
    assert(newEntries != nil);
    
    offset = 0;
    do {
        CFIndex         bytesConsumed;
        CFDictionaryRef thisEntry;
        
        thisEntry = NULL;
        
        assert(offset <= self.listData.length);
        bytesConsumed = CFFTPCreateParsedResourceListing(NULL, &((const uint8_t *) self.listData.bytes)[offset], self.listData.length - offset, &thisEntry);
        if (bytesConsumed > 0) {

            // It is possible for CFFTPCreateParsedResourceListing to return a 
            // positive number but not create a parse dictionary.  For example, 
            // if the end of the listing text contains stuff that can't be parsed, 
            // CFFTPCreateParsedResourceListing returns a positive number (to tell 
            // the caller that it has consumed the data), but doesn't create a parse 
            // dictionary (because it couldn't make sense of the data).  So, it's 
            // important that we check for NULL.

            if (thisEntry != NULL) {
                NSDictionary *  entryToAdd;
                
                // Try to interpret the name as UTF-8, which makes things work properly 
                // with many UNIX-like systems, including the Mac OS X built-in FTP 
                // server.  If you have some idea what type of text your target system 
                // is going to return, you could tweak this encoding.  For example, 
                // if you know that the target system is running Windows, then 
                // NSWindowsCP1252StringEncoding would be a good choice here.
                // 
                // Alternatively you could let the user choose the encoding up 
                // front, or reencode the listing after they've seen it and decided 
                // it's wrong.
                //
                // Ain't FTP a wonderful protocol!

                entryToAdd = [self _entryByReencodingNameInEntry:(NSDictionary *) thisEntry encoding:NSUTF8StringEncoding];
                
                [newEntries addObject:entryToAdd];
            }
            
            // We consume the bytes regardless of whether we get an entry.
            
            offset += bytesConsumed;
        }
        
        if (thisEntry != NULL) {
            CFRelease(thisEntry);
        }
        
        if (bytesConsumed == 0) {
            // We haven't yet got enough data to parse an entry.  Wait for more data 
            // to arrive.
            break;
        } else if (bytesConsumed < 0) {
            // We totally failed to parse the listing.  Fail.
            [self _stopReceiveWithStatus:@"Listing parse failed"];
            break;
        }
    } while (YES);

    if (newEntries.count != 0) {
        [self _addListEntries:newEntries];
    }
    if (offset != 0) {
        [self.listData replaceBytesInRange:NSMakeRange(0, offset) withBytes:NULL length:0];
    }
}

- (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 {
                assert(self.listData != nil);
                
                // Append the data to our listing buffer.
                
                [self.listData appendBytes:buffer length:bytesRead];
                
                // Check the listing buffer for any complete entries and update 
                // the UI if we find any.
                
                [self _parseListData];
            }
        } 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)listOrCancelAction:(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:@"ListURLText"];

    // 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:@"ListURLText"];
    }
}

- (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 * Table view data source and delegate

- (NSInteger)tableView:(UITableView *)tv numberOfRowsInSection:(NSInteger)section
{
    #pragma unused(tv)
    #pragma unused(section)
    assert(tv == self.tableView);
    assert(section == 0);
    return self.listEntries.count + 1;
}

- (NSString *)_stringForNumber:(double)num asUnits:(NSString *)units
{
    NSString *  result;
    double      fractional;
    double      integral;
    
    fractional = modf(num, &integral);
    if ( (fractional < 0.1) || (fractional > 0.9) ) {
        result = [NSString stringWithFormat:@"%.0f %@", round(num), units];
    } else {
        result = [NSString stringWithFormat:@"%.1f %@", num, units];
    }
    return result;
}

- (NSString *)_stringForFileSize:(unsigned long long)fileSizeExact
{
    double  fileSize;
    NSString *  result;
    
    fileSize = (double) fileSizeExact;
    if (fileSizeExact == 1) {
        result = @"1 byte";
    } else if (fileSizeExact < 1024) {
        result = [NSString stringWithFormat:@"%llu bytes", fileSizeExact];
    } else if (fileSize < (1024.0 * 1024.0 * 0.1)) {
        result = [self _stringForNumber:fileSize / 1024.0 asUnits:@"KB"];
    } else if (fileSize < (1024.0 * 1024.0 * 1024.0 * 0.1)) {
        result = [self _stringForNumber:fileSize / (1024.0 * 1024.0) asUnits:@"MB"];
    } else {
        result = [self _stringForNumber:fileSize / (1024.0 * 1024.0 * 1024.0) asUnits:@"MB"];
    }
    return result;
}

static NSDateFormatter *    sDateFormatter;

- (UITableViewCell *)tableView:(UITableView *)tv cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *   cell;
    NSDictionary *      listEntry;
    NSNumber *          typeNum;
    int                 type;
    NSNumber *          sizeNum;
    NSString *          sizeStr;
    NSNumber *          modeNum;
    char                modeCStr[12];
    NSDate *            date;
    NSString *          dateStr;
    
    #pragma unused(tv)
    assert(tv == self.tableView);
    assert(indexPath != nil);
    assert(indexPath.section == 0);
    assert(indexPath.row < (self.listEntries.count + 1));
    
    if (indexPath.row == 0) {
        cell = [self.tableView dequeueReusableCellWithIdentifier:@"StatusCell"];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"StatusCell"] autorelease];
        }
        assert(cell != nil);
        
        cell.textLabel.text = self.status;
        cell.textLabel.font = [UIFont systemFontOfSize:17.0f];
        cell.textLabel.textAlignment = UITextAlignmentCenter;
    } else {
        cell = [self.tableView dequeueReusableCellWithIdentifier:@"ListCell"];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"ListCell"] autorelease];
        }
        assert(cell != nil);

        listEntry = [self.listEntries objectAtIndex:indexPath.row - 1];
        assert([listEntry isKindOfClass:[NSDictionary class]]);
        
        // The first line of the cell is the item name.
        
        cell.textLabel.text = [listEntry objectForKey:(id) kCFFTPResourceName];
        
        // Use the second line of the cell to show various attributes.
        
        typeNum = [listEntry objectForKey:(id) kCFFTPResourceType];
        if (typeNum != nil) {
            assert([typeNum isKindOfClass:[NSNumber class]]);
            type = [typeNum intValue];
        } else {
            type = 0;
        }
        
        modeNum = [listEntry objectForKey:(id) kCFFTPResourceMode];
        if (modeNum != nil) {
            assert([modeNum isKindOfClass:[NSNumber class]]);
            
            strmode([modeNum intValue] + DTTOIF(type), modeCStr);
        } else {
            strlcat(modeCStr, "???????????", sizeof(modeCStr));
        }
        
        sizeNum = [listEntry objectForKey:(id) kCFFTPResourceSize];
        if (sizeNum != nil) {
            if (type == DT_REG) {
                assert([sizeNum isKindOfClass:[NSNumber class]]);
                sizeStr = [self _stringForFileSize:[sizeNum unsignedLongLongValue]];
            } else {
                sizeStr = @"-";
            }
        } else {
            sizeStr = @"?";
        }
        
        date = [listEntry objectForKey:(id) kCFFTPResourceModDate];
        if (date != nil) {
            if (sDateFormatter == nil) {
                sDateFormatter = [[NSDateFormatter alloc] init];
                assert(sDateFormatter != nil);
                
                sDateFormatter.dateStyle = NSDateFormatterShortStyle;
                sDateFormatter.timeStyle = NSDateFormatterShortStyle;
            }
            dateStr = [sDateFormatter stringFromDate:date];
        } else {
            dateStr = @"";
        }
        
        cell.detailTextLabel.text = [NSString stringWithFormat:@"%s %@ %@", modeCStr, sizeStr, dateStr];
    }
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
    
    return cell;
}

#pragma mark * View controller boilerplate

@synthesize urlText            = _urlText;
@synthesize activityIndicator  = _activityIndicator;
@synthesize tableView          = _tableView;
@synthesize listOrCancelButton = _listOrCancelButton;

@synthesize status             = _status;

- (void)viewDidLoad
{    
    [super viewDidLoad];
    assert(self.urlText != nil);
    assert(self.activityIndicator != nil);
    assert(self.tableView != nil);
    assert(self.listOrCancelButton != nil);
    
    self.listOrCancelButton.possibleTitles = [NSSet setWithObjects:@"List", @"Cancel", nil];

    if (self.listEntries == nil) {
        self.listEntries = [NSMutableArray array];
        assert(self.listEntries != nil);
    }

    self.urlText.text = [[NSUserDefaults standardUserDefaults] stringForKey:@"ListURLText"];
    
    self.activityIndicator.hidden = YES;
    [self _updateStatus:@"Tap a picture to start listing"];
}

- (void)viewDidUnload
{
    [super viewDidUnload];

    self.urlText = nil;
    self.activityIndicator = nil;
    self.tableView = nil;
    self.listOrCancelButton = nil;
}

- (void)dealloc
{
    [self _stopReceiveWithStatus:@"Stopped"];

    [self->_listEntries release];
    [self->_status release];

    [self->_urlText release];
    [self->_activityIndicator release];
    [self->_tableView release];
    [self->_listOrCancelButton release];

    [super dealloc];
}

@end