ListController.m

/*
     File: ListController.m
 Abstract: Manages the List tab.
  Version: 1.4
 
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 */
 
#import "ListController.h"
 
#import "NetworkManager.h"
 
#include <sys/socket.h>
#include <sys/dirent.h>
 
#include <CFNetwork/CFNetwork.h>
 
#pragma mark * ListController
 
@interface ListController () <UITextFieldDelegate, UITableViewDelegate, UITableViewDataSource, NSStreamDelegate>
 
// thinsg for IB
 
@property (nonatomic, strong, readwrite) IBOutlet UITextField *               urlText;
@property (nonatomic, strong, readwrite) IBOutlet UIActivityIndicatorView *   activityIndicator;
@property (nonatomic, strong, readwrite) IBOutlet UITableView *               tableView;
@property (nonatomic, strong, readwrite) IBOutlet UIBarButtonItem *           listOrCancelButton;
 
- (IBAction)listOrCancelAction:(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, strong, readwrite) NSMutableData *   listData;
@property (nonatomic, strong, readwrite) NSMutableArray *  listEntries;
@property (nonatomic, copy,   readwrite) 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];
    [[NetworkManager sharedInstance] didStartNetworkOperation];
}
 
- (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];
    [[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!
 
    // 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 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.
 
        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;
    }
    [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];
        }
    }
    
    // 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];
        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], (CFIndex) ([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:(__bridge NSDictionary *) thisEntry encoding:NSUTF8StringEncoding];
                
                [newEntries addObject:entryToAdd];
            }
            
            // We consume the bytes regardless of whether we get an entry.
            
            offset += (NSUInteger) 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 < 0) {
                [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:(NSUInteger) 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 (NSInteger) ([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 >= 0);
    assert( (NSUInteger) 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"];
        }
        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"];
        }
        assert(cell != nil);
 
        listEntry = [self.listEntries objectAtIndex:((NSUInteger) 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
 
- (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 List to start listing"];
}
 
- (void)viewDidUnload
{
    [super viewDidUnload];
 
    self.urlText = nil;
    self.activityIndicator = nil;
    self.tableView = nil;
    self.listOrCancelButton = nil;
}
 
- (void)dealloc
{
    [self stopReceiveWithStatus:@"Stopped"];
}
 
@end