/* HBQueueController

    This file is part of the HandBrake source code.
    Homepage: <http://handbrake.fr/>.
    It may be used under the terms of the GNU General Public License. */

#import "HBQueueController.h"

#import "HBController.h"
#import "HBAppDelegate.h"

#import "HBQueueOutlineView.h"

#import "NSArray+HBAdditions.h"
#import "HBUtilities.h"

#import "HBDockTile.h"

#import "HBOutputRedirect.h"
#import "HBJobOutputFileWriter.h"
#import "HBPreferencesController.h"

@import HandBrakeKit;

// Pasteboard type for or drag operations
#define DragDropSimplePboardType    @"HBQueueCustomOutlineViewPboardType"

// DockTile update frequency in total percent increment
#define dockTileUpdateFrequency     0.1f

@interface HBQueueController () <NSOutlineViewDataSource, HBQueueOutlineViewDelegate>

/// Whether the window is visible or occluded,
/// useful to avoid updating the UI needlessly
@property (nonatomic) BOOL visible;

// Progress
@property (nonatomic, strong) NSString *progressInfo;

@property (nonatomic, readonly) HBDockTile *dockTile;
@property (nonatomic, readwrite) double dockIconProgress;

@property (unsafe_unretained) IBOutlet NSTextField *progressTextField;
@property (unsafe_unretained) IBOutlet NSTextField *countTextField;
@property (unsafe_unretained) IBOutlet HBQueueOutlineView *outlineView;

@property (nonatomic, readonly) NSMutableDictionary *descriptions;

@property (nonatomic, readonly) HBDistributedArray<HBJob *> *jobs;
@property (nonatomic)   HBJob *currentJob;
@property (nonatomic)   HBJobOutputFileWriter *currentLog;

@property (nonatomic, readwrite) BOOL stop;

@property (nonatomic, readwrite) NSUInteger pendingItemsCount;
@property (nonatomic, readwrite) NSUInteger completedItemsCount;

@property (nonatomic) NSArray<HBJob *> *dragNodesArray;

@end

@implementation HBQueueController

- (instancetype)initWithURL:(NSURL *)queueURL;
{
    NSParameterAssert(queueURL);

    if (self = [super initWithWindowNibName:@"Queue"])
    {
        // Cached queue items descriptions
        _descriptions = [[NSMutableDictionary alloc] init];

        // Load the dockTile and instiante initial text fields
        _dockTile = [[HBDockTile alloc] initWithDockTile:[[NSApplication sharedApplication] dockTile]
                                                  image:[[NSApplication sharedApplication] applicationIconImage]];

        int loggingLevel = [[[NSUserDefaults standardUserDefaults] objectForKey:@"LoggingLevel"] intValue];

        // Init a separate instance of libhb for the queue
        _core = [[HBCore alloc] initWithLogLevel:loggingLevel name:@"QueueCore"];
        _core.automaticallyPreventSleep = NO;

        // Progress
        _progressInfo = @"";
        if (NSAppKitVersionNumber < NSAppKitVersionNumber10_10)
        {
            _visible = YES;
        }

        // Load the queue from disk.
        _jobs = [[HBDistributedArray alloc] initWithURL:queueURL class:[HBJob class]];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reloadQueue) name:HBDistributedArrayChanged object:_jobs];
    }

    return self;
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)windowDidLoad
{
    // lets setup our queue list outline view for drag and drop here
    [self.outlineView registerForDraggedTypes:@[DragDropSimplePboardType]];
    [self.outlineView setDraggingSourceOperationMask:NSDragOperationEvery forLocal:YES];
    [self.outlineView setVerticalMotionCanBeginDrag:YES];

    [self updateQueueStats];
}

#pragma mark Toolbar

- (BOOL)validateMenuItem:(NSMenuItem *)menuItem
{
    SEL action = menuItem.action;

    if (action == @selector(rip:))
    {
        if (self.core.state == HBStateIdle)
        {
            menuItem.title = NSLocalizedString(@"Start Encoding", nil);

            return (self.pendingItemsCount > 0);
        }
        else if (self.core.state != HBStateIdle)
        {
            menuItem.title = NSLocalizedString(@"Stop Encoding", nil);

            return YES;
        }
    }

    if (action == @selector(pause:))
    {
        if (self.core.state != HBStatePaused)
        {
            menuItem.title = NSLocalizedString(@"Pause Encoding", nil);
        }
        else
        {
            menuItem.title = NSLocalizedString(@"Resume Encoding", nil);
        }

        return (self.core.state == HBStateWorking || self.core.state == HBStatePaused);
    }

    if (action == @selector(editSelectedQueueItem:) ||
        action == @selector(removeSelectedQueueItem:) ||
        action == @selector(revealSelectedQueueItems:))
    {
        return (self.outlineView.selectedRow != -1 || self.outlineView.clickedRow != -1);
    }

    if (action == @selector(resetJobState:))
    {
        return self.outlineView.targetedRowIndexes.count > 0;
    }

    if (action == @selector(clearAll:))
    {
        return self.jobs.count > 0;
    }

    if (action == @selector(clearCompleted:))
    {
        return self.completedItemsCount > 0;
    }

    return YES;
}

- (BOOL)validateToolbarItem:(NSToolbarItem *)theItem
{
    SEL action = theItem.action;
    HBState s = self.core.state;

    if (action == @selector(toggleStartCancel:))
    {
        if ((s == HBStateScanning) || (s == HBStatePaused) || (s == HBStateWorking) || (s == HBStateMuxing))
        {
            theItem.image = [NSImage imageNamed:@"stopencode"];
            theItem.label = NSLocalizedString(@"Stop", @"");
            theItem.toolTip = NSLocalizedString(@"Stop Encoding", @"");
            return YES;
        }
        else
        {
            theItem.image = [NSImage imageNamed:@"encode"];
            theItem.label = NSLocalizedString(@"Start", @"");
            theItem.toolTip = NSLocalizedString(@"Start Encoding", @"");
            return (self.pendingItemsCount > 0);
        }
    }

    if (action == @selector(togglePauseResume:))
    {
        if (s == HBStatePaused)
        {
            theItem.image = [NSImage imageNamed:@"encode"];
            theItem.label = NSLocalizedString(@"Resume", @"");
            theItem.toolTip = NSLocalizedString(@"Resume Encoding", @"");
            return YES;
        }
        else
        {
            theItem.image = [NSImage imageNamed:@"pauseencode"];
            theItem.label = NSLocalizedString(@"Pause", @"");
            theItem.toolTip = NSLocalizedString(@"Pause Encoding", @"");
            return (s == HBStateWorking || s == HBStateMuxing);
        }
    }

    return NO;
}

#pragma mark - Public methods

- (void)addJob:(HBJob *)item
{
    NSParameterAssert(item);
    [self addJobsFromArray:@[item]];
}

- (void)addJobsFromArray:(NSArray<HBJob *> *)items;
{
    NSParameterAssert(items);
    if (items.count)
    {
        [self addQueueItems:items];
    }
}

- (BOOL)jobExistAtURL:(NSURL *)url
{
    NSParameterAssert(url);

    for (HBJob *item in self.jobs)
    {
        if ([item.completeOutputURL isEqualTo:url])
        {
            return YES;
        }
    }
    return NO;
}

- (NSUInteger)count
{
    return self.jobs.count;
}

/**
 * This method will clear the queue of any encodes that are not still pending
 * this includes both successfully completed encodes as well as canceled encodes
 */
- (void)removeCompletedJobs
{
    [self.jobs beginTransaction];
    NSIndexSet *indexes = [self.jobs indexesOfObjectsUsingBlock:^BOOL(HBJob *item) {
        return (item.state == HBJobStateCompleted || item.state == HBJobStateCanceled);
    }];
    [self removeQueueItemsAtIndexes:indexes];
    [self.jobs commit];
}

/**
 * This method will clear the queue of all encodes. effectively creating an empty queue
 */
- (void)removeAllJobs
{
    [self.jobs beginTransaction];
    [self removeQueueItemsAtIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, self.jobs.count)]];
    [self.jobs commit];
}

/**
 * This method will set any item marked as encoding back to pending
 * currently used right after a queue reload
 */
- (void)setEncodingJobsAsPending
{
    [self.jobs beginTransaction];

    NSMutableIndexSet *indexes = [NSMutableIndexSet indexSet];
    NSUInteger idx = 0;
    for (HBJob *job in self.jobs)
    {
        // We want to keep any queue item that is pending or was previously being encoded
        if (job.state == HBJobStateWorking)
        {
            job.state = HBJobStateReady;
            [indexes addIndex:idx];
        }
        idx++;
    }
    [self reloadQueueItemsAtIndexes:indexes];
    [self.jobs commit];
}

#pragma mark - Private queue editing methods

/**
 *  Reloads the queue, this is called
 *  when another HandBrake instances modifies the queue
 */
- (void)reloadQueue
{
    [self updateQueueStats];
    [self.outlineView reloadData];
    [self.window.undoManager removeAllActions];
}

- (void)reloadQueueItemAtIndex:(NSUInteger)idx
{
    [self reloadQueueItemsAtIndexes:[NSIndexSet indexSetWithIndex:idx]];
}

- (void)reloadQueueItemsAtIndexes:(NSIndexSet *)indexes
{
    NSMutableIndexSet *outlineIndexes = [NSMutableIndexSet indexSet];
    [outlineIndexes addIndex:0];
    [outlineIndexes addIndex:2];
    [self.outlineView reloadDataForRowIndexes:indexes columnIndexes:outlineIndexes];
    [self updateQueueStats];
}

- (void)addQueueItems:(NSArray *)items
{
    NSParameterAssert(items);
    NSIndexSet *indexes = [NSIndexSet indexSetWithIndexesInRange:NSMakeRange(self.jobs.count, items.count)];
    [self addQueueItems:items atIndexes:indexes];
}

- (void)addQueueItems:(NSArray *)items atIndexes:(NSIndexSet *)indexes
{
    NSParameterAssert(items);
    NSParameterAssert(indexes);
    [self.jobs beginTransaction];
    [self.outlineView beginUpdates];

    // Forward
    NSUInteger currentIndex = indexes.firstIndex;
    NSUInteger currentObjectIndex = 0;
    while (currentIndex != NSNotFound)
    {
        [self.jobs insertObject:items[currentObjectIndex] atIndex:currentIndex];
        currentIndex = [indexes indexGreaterThanIndex:currentIndex];
        currentObjectIndex++;
    }

    [self.outlineView insertItemsAtIndexes:indexes
                                  inParent:nil
                             withAnimation:NSTableViewAnimationSlideDown];

    NSUndoManager *undo = self.window.undoManager;
    [[undo prepareWithInvocationTarget:self] removeQueueItemsAtIndexes:indexes];

    if (!undo.isUndoing)
    {
        if (items.count == 1)
        {
            [undo setActionName:NSLocalizedString(@"Add Job To Queue", nil)];
        }
        else
        {
            [undo setActionName:NSLocalizedString(@"Add Jobs To Queue", nil)];
        }
    }

    [self.outlineView endUpdates];
    [self updateQueueStats];
    [self.jobs commit];
}

- (void)removeQueueItemAtIndex:(NSUInteger)index
{
    [self removeQueueItemsAtIndexes:[NSIndexSet indexSetWithIndex:index]];
}

- (void)removeQueueItemsAtIndexes:(NSIndexSet *)indexes
{
    NSParameterAssert(indexes);

    if (indexes.count == 0)
    {
        return;
    }

    [self.jobs beginTransaction];
    [self.outlineView beginUpdates];

    NSArray<HBJob *> *removeJobs = [self.jobs objectsAtIndexes:indexes];

    if (self.jobs.count > indexes.lastIndex)
    {
        [self.jobs removeObjectsAtIndexes:indexes];
    }

    for (HBJob *job in removeJobs)
    {
        [self.descriptions removeObjectForKey:job.uuid];
    }

    [self.outlineView removeItemsAtIndexes:indexes inParent:nil withAnimation:NSTableViewAnimationSlideUp];
    [self.outlineView selectRowIndexes:[NSIndexSet indexSetWithIndex:indexes.firstIndex] byExtendingSelection:NO];

    NSUndoManager *undo = self.window.undoManager;
    [[undo prepareWithInvocationTarget:self] addQueueItems:removeJobs atIndexes:indexes];

    if (!undo.isUndoing)
    {
        if (indexes.count == 1)
        {
            [undo setActionName:NSLocalizedString(@"Remove Job From Queue", nil)];
        }
        else
        {
            [undo setActionName:NSLocalizedString(@"Remove Jobs From Queue", nil)];
        }
    }

    [self.outlineView endUpdates];
    [self updateQueueStats];
    [self.jobs commit];
}

- (void)moveQueueItems:(NSArray *)items toIndex:(NSUInteger)index
{
    [self.jobs beginTransaction];
    [self.outlineView beginUpdates];

    NSMutableArray *source = [NSMutableArray array];
    NSMutableArray *dest = [NSMutableArray array];

    for (id object in items.reverseObjectEnumerator)
    {
        NSUInteger sourceIndex = [self.jobs indexOfObject:object];
        [self.jobs removeObjectAtIndex:sourceIndex];


        if (sourceIndex < index)
        {
            index--;
        }

        [self.jobs insertObject:object atIndex:index];

        [source addObject:@(index)];
        [dest addObject:@(sourceIndex)];

        [self.outlineView moveItemAtIndex:sourceIndex inParent:nil toIndex:index inParent:nil];
    }

    NSUndoManager *undo = self.window.undoManager;
    [[undo prepareWithInvocationTarget:self] moveQueueItemsAtIndexes:source toIndexes:dest];

    if (!undo.isUndoing)
    {
        if (items.count == 1)
        {
            [undo setActionName:NSLocalizedString(@"Move Job in Queue", nil)];
        }
        else
        {
            [undo setActionName:NSLocalizedString(@"Move Jobs in Queue", nil)];
        }
    }

    [self.outlineView endUpdates];
    [self.jobs commit];
}

- (void)moveQueueItemsAtIndexes:(NSArray *)source toIndexes:(NSArray *)dest
{
    [self.jobs beginTransaction];
    [self.outlineView beginUpdates];

    NSMutableArray *newSource = [NSMutableArray array];
    NSMutableArray *newDest = [NSMutableArray array];

    for (NSInteger idx = source.count - 1; idx >= 0; idx--)
    {
        NSUInteger sourceIndex = [source[idx] integerValue];
        NSUInteger destIndex = [dest[idx] integerValue];

        [newSource addObject:@(destIndex)];
        [newDest addObject:@(sourceIndex)];

        id obj = [self.jobs objectAtIndex:sourceIndex];
        [self.jobs removeObjectAtIndex:sourceIndex];
        [self.jobs insertObject:obj atIndex:destIndex];

        [self.outlineView moveItemAtIndex:sourceIndex inParent:nil toIndex:destIndex inParent:nil];
    }

    NSUndoManager *undo = self.window.undoManager;
    [[undo prepareWithInvocationTarget:self] moveQueueItemsAtIndexes:newSource toIndexes:newDest];

    if (!undo.isUndoing)
    {
        if (source.count == 1)
        {
            [undo setActionName:NSLocalizedString(@"Move Job in Queue", nil)];
        }
        else
        {
            [undo setActionName:NSLocalizedString(@"Move Jobs in Queue", nil)];
        }
    }

    [self.outlineView endUpdates];
    [self.jobs commit];
}

- (void)windowDidChangeOcclusionState:(NSNotification *)notification
{
    if ([self.window occlusionState] & NSWindowOcclusionStateVisible)
    {
        self.visible = YES;
        self.progressTextField.stringValue = self.progressInfo;
    }
    else
    {
        self.visible = NO;
    }
}

- (void)updateProgress:(NSString *)info progress:(double)progress hidden:(BOOL)hidden
{
    self.progressInfo = info;
    if (self.visible)
    {
        self.progressTextField.stringValue = info;
    }
    [self.controller setQueueInfo:info progress:progress hidden:hidden];
}

/**
 *  Updates the queue status label.
 */
- (void)updateQueueStats
{
    // lets get the stats on the status of the queue array
    NSUInteger pendingCount = 0;
    NSUInteger completedCount = 0;

    for (HBJob *job in self.jobs)
    {
        if (job.state == HBJobStateReady)
        {
            pendingCount++;
        }
        if (job.state == HBJobStateCompleted)
        {
            completedCount++;
        }
    }

    NSString *string;
    if (pendingCount == 0)
    {
        string = NSLocalizedString(@"No encode pending", @"");
    }
    else if (pendingCount == 1)
    {
        string = [NSString stringWithFormat: NSLocalizedString(@"%d encode pending", @""), pendingCount];
    }
    else
    {
        string = [NSString stringWithFormat: NSLocalizedString(@"%d encodes pending", @""), pendingCount];
    }

    self.countTextField.stringValue = string;
    [self.controller setQueueState:pendingCount];

    self.pendingItemsCount = pendingCount;
    self.completedItemsCount = completedCount;
}

#pragma mark - Queue Job Processing

- (BOOL)_isDiskSpaceLowAtURL:(NSURL *)url
{
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"HBQueuePauseIfLowSpace"])
    {
        NSURL *volumeURL = nil;
        NSDictionary<NSURLResourceKey, id> *attrs = [url resourceValuesForKeys:@[NSURLIsVolumeKey, NSURLVolumeURLKey] error:NULL];
        long long minCapacity = [[[NSUserDefaults standardUserDefaults] stringForKey:@"HBQueueMinFreeSpace"] longLongValue] * 1000000000;

        volumeURL = [attrs[NSURLIsVolumeKey] boolValue] ? url : attrs[NSURLVolumeURLKey];

        if (volumeURL)
        {
            if ([volumeURL respondsToSelector:@selector(removeCachedResourceValueForKey:)])
            {
                [volumeURL removeCachedResourceValueForKey:NSURLVolumeAvailableCapacityKey];
            }
            attrs = [volumeURL resourceValuesForKeys:@[NSURLVolumeAvailableCapacityKey] error:NULL];

            if (attrs[NSURLVolumeAvailableCapacityKey])
            {
                if ([attrs[NSURLVolumeAvailableCapacityKey] longLongValue] < minCapacity)
                {
                    return YES;
                }
            }
        }
    }

    return NO;
}

/**
 * Used to get the next pending queue item and return it if found
 */
- (HBJob *)getNextPendingQueueItem
{
    for (HBJob *job in self.jobs)
    {
        if (job.state == HBJobStateReady)
        {
            return job;
        }
    }
    return nil;
}

/**
 *  Starts the queue
 */
- (void)encodeNextQueueItem
{
    [self.jobs beginTransaction];
    self.currentJob = nil;

    // since we have completed an encode, we go to the next
    if (self.stop)
    {
        [HBUtilities writeToActivityLog:"Queue manually stopped"];

        self.stop = NO;
        [self.core allowSleep];
    }
    else
    {
        // Check to see if there are any more pending items in the queue
        HBJob *nextJob = [self getNextPendingQueueItem];

        if (nextJob && [self _isDiskSpaceLowAtURL:nextJob.outputURL])
        {
            // Disk space is low, show an alert
            [HBUtilities writeToActivityLog:"Queue Stopped, low space on destination disk"];

            [self queueLowDiskSpaceAlert];
        }
        // If we still have more pending items in our queue, lets go to the next one
        else if (nextJob)
        {
            // now we mark the queue item as working so another instance can not come along and try to scan it while we are scanning
            nextJob.state = HBJobStateWorking;

            // Tell HB to output a new activity log file for this encode
            self.currentLog = [[HBJobOutputFileWriter alloc] initWithJob:nextJob];
            if (self.currentLog)
            {
                [[HBOutputRedirect stderrRedirect] addListener:self.currentLog];
                [[HBOutputRedirect stdoutRedirect] addListener:self.currentLog];
            }

            self.currentJob = nextJob;
            [self reloadQueueItemAtIndex:[self.jobs indexOfObject:nextJob]];

            // now we can go ahead and scan the new pending queue item
            [self encodeJob:nextJob];

            // erase undo manager history
            [self.window.undoManager removeAllActions];
        }
        else
        {
            [HBUtilities writeToActivityLog:"Queue Done, there are no more pending encodes"];

            // Since there are no more items to encode, go to queueCompletedAlerts
            // for user specified alerts after queue completed
            [self queueCompletedAlerts];

            [self.core allowSleep];
        }
    }
    [self.jobs commit];
}

- (void)completedJob:(HBJob *)job result:(HBCoreResult)result;
{
    NSParameterAssert(job);
    [self.jobs beginTransaction];

    // Since we are done with this encode, tell output to stop writing to the
    // individual encode log.
    [[HBOutputRedirect stderrRedirect] removeListener:self.currentLog];
    [[HBOutputRedirect stdoutRedirect] removeListener:self.currentLog];

    self.currentLog = nil;

    // Check to see if the encode state has not been canceled
    // to determine if we should send it to external app.
    if (result != HBCoreResultCanceled)
    {
        // Send to tagger
        [self sendToExternalApp:job];
    }

    // Mark the encode just finished
    switch (result) {
        case HBCoreResultDone:
            job.state = HBJobStateCompleted;
            break;
        case HBCoreResultCanceled:
            job.state = HBJobStateCanceled;
            break;
        default:
            job.state = HBJobStateFailed;
            break;
    }

    if ([self.jobs containsObject:job])
    {
        [self reloadQueueItemAtIndex:[self.jobs indexOfObject:job]];
    }
    [self.window.toolbar validateVisibleItems];
    [self.jobs commit];

    // Update UI
    NSString *info = nil;
    switch (result) {
        case HBCoreResultDone:
            info = NSLocalizedString(@"Encode Finished.", @"");
            [self jobCompletedAlerts:job result:result];
            break;
        case HBCoreResultCanceled:
            info = NSLocalizedString(@"Encode Canceled.", @"");
            break;
        default:
            info = NSLocalizedString(@"Encode Failed.", @"");
            [self jobCompletedAlerts:job result:result];
            break;
    }
    [self updateProgress:info progress:1.0 hidden:YES];

    // Restore dock icon
    [self.dockTile updateDockIcon:-1.0 withETA:@""];
    self.dockIconProgress = 0;
}

/**
 * Here we actually tell hb_scan to perform the source scan, using the path to source and title number
 */
- (void)encodeJob:(HBJob *)job
{
    NSParameterAssert(job);

    // Progress handler
    void (^progressHandler)(HBState state, HBProgress progress, NSString *info) = ^(HBState state, HBProgress progress, NSString *info)
    {
        [self updateProgress:info progress:0 hidden:NO];
    };

    // Completion handler
    void (^completionHandler)(HBCoreResult result) = ^(HBCoreResult result)
    {
        if (result == HBCoreResultDone)
        {
            [self realEncodeJob:job];
        }
        else
        {
            [self completedJob:job result:result];
            [self encodeNextQueueItem];
        }
    };

    // Only scan 10 previews before an encode - additional previews are
    // only useful for autocrop and static previews, which are already taken care of at this point
    [self.core scanURL:job.fileURL
            titleIndex:job.titleIdx
              previews:10
           minDuration:0
       progressHandler:progressHandler
     completionHandler:completionHandler];
}

/**
 * This assumes that we have re-scanned and loaded up a new queue item to send to libhb
 */
- (void)realEncodeJob:(HBJob *)job
{
    NSParameterAssert(job);

    // Reset the title in the job.
    job.title = self.core.titles[0];

    HBStateFormatter *formatter = [[HBStateFormatter alloc] init];
    formatter.title = job.outputFileName;
    self.core.stateFormatter = formatter;

    // Progress handler
    void (^progressHandler)(HBState state, HBProgress progress, NSString *info) = ^(HBState state, HBProgress progress, NSString *info)
    {
        if (state == HBStateWorking)
        {
            // Update dock icon
            if (self.dockIconProgress < 100.0 * progress.percent)
            {
                [self.dockTile updateDockIcon:progress.percent hours:progress.hours minutes:progress.minutes seconds:progress.seconds];
                self.dockIconProgress += dockTileUpdateFrequency;
            }
        }
        else if (state == HBStateMuxing)
        {
            [self.dockTile updateDockIcon:1.0 withETA:@""];
        }

        // Update UI
        [self updateProgress:info progress:progress.percent hidden:NO];
    };

    // Completion handler
    void (^completionHandler)(HBCoreResult result) = ^(HBCoreResult result)
    {
        [self completedJob:job result:result];
        [self encodeNextQueueItem];
    };

    // We should be all setup so let 'er rip
    [self.core encodeJob:job progressHandler:progressHandler completionHandler:completionHandler];

    // We are done using the title, remove it from the job
    job.title = nil;
}

/**
 * Cancels the current job
 */
- (void)doCancelCurrentJob
{
    if (self.core.state == HBStateScanning)
    {
        [self.core cancelScan];
    }
    else
    {
        [self.core cancelEncode];
    }
}

/**
 * Cancels the current job and starts processing the next in queue.
 */
- (void)cancelCurrentJobAndContinue
{
    [self doCancelCurrentJob];
}

/**
 * Cancels the current job and stops libhb from processing the remaining encodes.
 */
- (void)cancelCurrentJobAndStop
{
    self.stop = YES;
    [self doCancelCurrentJob];
}

/**
 * Finishes the current job and stops libhb from processing the remaining encodes.
 */
- (void)finishCurrentAndStop
{
    self.stop = YES;
}

#pragma mark - Encode Done Actions

#define SERVICE_NAME @"Encode Done"

/**
 *  Register a test notification and make
 *  it enabled by default
 */
- (NSDictionary *)registrationDictionaryForGrowl
{
    return @{GROWL_NOTIFICATIONS_ALL: @[SERVICE_NAME],
             GROWL_NOTIFICATIONS_DEFAULT: @[SERVICE_NAME]};
}

- (void)showNotificationWithTitle:(NSString *)title description:(NSString *)description url:(NSURL *)fileURL
{
    [GrowlApplicationBridge notifyWithTitle:title
                                description:description
                           notificationName:SERVICE_NAME
                                   iconData:nil
                                   priority:0
                                   isSticky:YES
                               clickContext:fileURL.path];
}

- (void)growlNotificationWasClicked:(id)clickContext
{
    // Show the file in Finder when a done notification was clicked.
    if ([clickContext isKindOfClass:[NSString class]] && [clickContext length])
    {
        NSURL *fileURL = [NSURL fileURLWithPath:clickContext];
        [[NSWorkspace sharedWorkspace] activateFileViewerSelectingURLs:@[fileURL]];
    }
}

/**
 *  Sends the URL to the external app
 *  selected in the preferences.
 *
 *  @param job the job of the file to send
 */
- (void)sendToExternalApp:(HBJob *)job
{
    // This end of encode action is called as each encode rolls off of the queue
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"HBSendToAppEnabled"] == YES)
    {
#ifdef __SANDBOX_ENABLED__
        BOOL accessingSecurityScopedResource = [job.outputURL startAccessingSecurityScopedResource];
#endif

        NSWorkspace *workspace = [NSWorkspace sharedWorkspace];
        NSString *app = [workspace fullPathForApplication:[[NSUserDefaults standardUserDefaults] objectForKey:@"HBSendToApp"]];

        if (app)
        {
            if (![workspace openFile:job.completeOutputURL.path withApplication:app])
            {
                [HBUtilities writeToActivityLog:"Failed to send file to: %s", app];
            }
        }
        else
        {
            [HBUtilities writeToActivityLog:"Send file to: app not found"];
        }

#ifdef __SANDBOX_ENABLED__
        if (accessingSecurityScopedResource)
        {
            [job.outputURL stopAccessingSecurityScopedResource];
        }
#endif
    }
}

/**
 *  Runs the alert for a single job
 */
- (void)jobCompletedAlerts:(HBJob *)job result:(HBCoreResult)result
{
    // Both the Notification and Sending to tagger can be done as encodes roll off the queue
    if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionNotification ||
        [[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionAlertAndNotification)
    {
        // If Play System Alert has been selected in Preferences
        if ([[NSUserDefaults standardUserDefaults] boolForKey:@"HBAlertWhenDoneSound"] == YES)
        {
            NSBeep();
        }

        NSString *title;
        NSString *description;
        if (result == HBCoreResultDone)
        {
            title = NSLocalizedString(@"Put down that cocktail…", nil);
            description = [NSString stringWithFormat:NSLocalizedString(@"Your encode %@ is done!", nil),
                                     job.outputFileName];

        }
        else
        {
            title = NSLocalizedString(@"Encode failed", nil);
            description = [NSString stringWithFormat:NSLocalizedString(@"Your encode %@ couldn't be completed.", nil),
                           job.outputFileName];
        }

        [self showNotificationWithTitle:title
                            description:description
                                    url:job.completeOutputURL];
    }
}

/**
 *  Runs the global queue completed alerts
 */
- (void)queueCompletedAlerts
{
    // If Play System Alert has been selected in Preferences
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"HBAlertWhenDoneSound"] == YES)
    {
        NSBeep();
    }

    // If Alert Window or Window and Notification has been selected
    if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionAlert ||
        [[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionAlertAndNotification)
    {
        // On Screen Notification
        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:NSLocalizedString(@"Put down that cocktail…", @"")];
        [alert setInformativeText:NSLocalizedString(@"Your HandBrake queue is done!", @"")];
        [NSApp requestUserAttention:NSCriticalRequest];
        [alert runModal];
    }

    // If sleep has been selected
    if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionSleep)
    {
        // Sleep
        NSDictionary *errorDict;
        NSAppleScript *scriptObject = [[NSAppleScript alloc] initWithSource:
                                       @"tell application \"Finder\" to sleep"];
        [scriptObject executeAndReturnError: &errorDict];
    }
    // If Shutdown has been selected
    if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionShutDown)
    {
        // Shut Down
        NSDictionary *errorDict;
        NSAppleScript *scriptObject = [[NSAppleScript alloc] initWithSource:@"tell application \"Finder\" to shut down"];
        [scriptObject executeAndReturnError: &errorDict];
    }
}

- (void)queueLowDiskSpaceAlert
{
    NSAlert *alert = [[NSAlert alloc] init];
    [alert setMessageText:NSLocalizedString(@"Your destination disk is almost full.", @"")];
    [alert setInformativeText:NSLocalizedString(@"You need to make more space available on your destination disk.", @"")];
    [NSApp requestUserAttention:NSCriticalRequest];
    [alert runModal];
}

#pragma mark - Queue Item Controls

- (void)HB_deleteSelectionFromTableView:(NSTableView *)tableView
{
    [self removeSelectedQueueItem:tableView];
}

/**
 * Delete encodes from the queue window and accompanying array
 * Also handling first cancelling the encode if in fact its currently encoding.
 */
- (IBAction)removeSelectedQueueItem:(id)sender
{
    if ([self.jobs beginTransaction] == HBDistributedArrayContentReload)
    {
        // Do not execture the action if the array changed.
        [self.jobs commit];
        return;
    }

    NSMutableIndexSet *targetedRows = [[self.outlineView targetedRowIndexes] mutableCopy];

    if (targetedRows.count)
    {
        // if this is a currently encoding job, we need to be sure to alert the user,
        // to let them decide to cancel it first, then if they do, we can come back and
        // remove it
        NSIndexSet *workingIndexes = [self.jobs indexesOfObjectsUsingBlock:^BOOL(HBJob *item) {
            return item.state == HBJobStateWorking;
        }];

        if ([targetedRows containsIndexes:workingIndexes])
        {
            [targetedRows removeIndexes:workingIndexes];
            NSArray<HBJob *> *workingJobs = [self.jobs filteredArrayUsingBlock:^BOOL(HBJob *item) {
                return item.state == HBJobStateWorking;
            }];

            if ([workingJobs containsObject:self.currentJob])
            {
                NSString *alertTitle = [NSString stringWithFormat:NSLocalizedString(@"Stop This Encode and Remove It?", nil)];

                // Which window to attach the sheet to?
                NSWindow *targetWindow = self.window;
                if ([sender respondsToSelector: @selector(window)])
                {
                    targetWindow = [sender window];
                }

                NSAlert *alert = [[NSAlert alloc] init];
                [alert setMessageText:alertTitle];
                [alert setInformativeText:NSLocalizedString(@"Your movie will be lost if you don't continue encoding.", nil)];
                [alert addButtonWithTitle:NSLocalizedString(@"Keep Encoding", nil)];
                [alert addButtonWithTitle:NSLocalizedString(@"Stop Encoding and Delete", nil)];
                [alert setAlertStyle:NSCriticalAlertStyle];

                [alert beginSheetModalForWindow:targetWindow
                                  modalDelegate:self
                                 didEndSelector:@selector(didDimissCancelCurrentJob:returnCode:contextInfo:)
                                    contextInfo:NULL];
            }
        }

        // remove the non working items immediately
        [self removeQueueItemsAtIndexes:targetedRows];
    }
    [self.jobs commit];
}

- (void)didDimissCancelCurrentJob:(NSAlert *)alert
                       returnCode:(NSInteger)returnCode
                      contextInfo:(void *)contextInfo
{
    if (returnCode == NSAlertSecondButtonReturn)
    {
        [self.jobs beginTransaction];

        NSInteger index = [self.jobs indexOfObject:self.currentJob];
        [self cancelCurrentJobAndContinue];

        [self removeQueueItemAtIndex:index];
        [self.jobs commit];
    }
}

/**
 * Show the finished encode in the finder
 */
- (IBAction)revealSelectedQueueItems:(id)sender
{
    NSIndexSet *targetedRows = [self.outlineView targetedRowIndexes];
    NSMutableArray *urls = [[NSMutableArray alloc] init];

    NSUInteger currentIndex = [targetedRows firstIndex];
    while (currentIndex != NSNotFound) {
        NSURL *url = [[self.jobs objectAtIndex:currentIndex] completeOutputURL];
        [urls addObject:url];
        currentIndex = [targetedRows indexGreaterThanIndex:currentIndex];
    }

    [[NSWorkspace sharedWorkspace] activateFileViewerSelectingURLs:urls];
}

- (void)remindUserOfSleepOrShutdown
{
    if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionSleep)
    {
        // Warn that computer will sleep after encoding
        NSBeep();
        [NSApp requestUserAttention:NSCriticalRequest];

        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:NSLocalizedString(@"The computer will sleep after encoding is done.", @"")];
        [alert setInformativeText:NSLocalizedString(@"You have selected to sleep the computer after encoding. To turn off sleeping, go to the HandBrake preferences.", @"")];
        [alert addButtonWithTitle:NSLocalizedString(@"OK", @"")];
        [alert addButtonWithTitle:NSLocalizedString(@"Preferences…",@"")];

        NSInteger response = [alert runModal];
        if (response == NSAlertSecondButtonReturn)
        {
            [self.delegate showPreferencesWindow:nil];
        }
    }
    else if ([[NSUserDefaults standardUserDefaults] integerForKey:@"HBAlertWhenDone"] == HBDoneActionShutDown)
    {
        // Warn that computer will shut down after encoding
        NSBeep();
        [NSApp requestUserAttention:NSCriticalRequest];

        NSAlert *alert = [[NSAlert alloc] init];
        [alert setMessageText:NSLocalizedString(@"The computer will shut down after encoding is done.", @"")];
        [alert setInformativeText:NSLocalizedString(@"You have selected to shut down the computer after encoding. To turn off shut down, go to the HandBrake preferences.", @"")];
        [alert addButtonWithTitle:NSLocalizedString(@"OK", @"")];
        [alert addButtonWithTitle:NSLocalizedString(@"Preferences…", @"")];

        NSInteger response = [alert runModal];
        if (response == NSAlertSecondButtonReturn)
        {
            [self.delegate showPreferencesWindow:nil];
        }
    }
}

/**
 * Rip: puts up an alert before ultimately calling doRip
 */
- (IBAction)rip:(id)sender
{
    // Rip or Cancel ?
    if (self.core.state == HBStateWorking || self.core.state == HBStatePaused || self.core.state == HBStateSearching)
    {
        [self cancelRip:sender];
    }
    // If there are pending jobs in the queue, then this is a rip the queue
    else if (self.pendingItemsCount > 0)
    {
        // We check to see if we need to warn the user that the computer will go to sleep
        // or shut down when encoding is finished
        [self remindUserOfSleepOrShutdown];

        [self.core preventSleep];
        [self encodeNextQueueItem];
    }
}

/**
 * Displays an alert asking user if the want to cancel encoding of current job.
 * Cancel: returns immediately after posting the alert. Later, when the user
 * acknowledges the alert, doCancelCurrentJob is called.
 */
- (IBAction)cancelRip:(id)sender
{
    // Which window to attach the sheet to?
    NSWindow *window = self.window;
    if ([sender respondsToSelector:@selector(window)])
    {
        window = [sender window];
    }

    NSAlert *alert = [[NSAlert alloc] init];
    [alert setMessageText:NSLocalizedString(@"You are currently encoding. What would you like to do?", nil)];
    [alert setInformativeText:NSLocalizedString(@"Your encode will be canceled if you don't continue encoding.", nil)];
    [alert addButtonWithTitle:NSLocalizedString(@"Continue Encoding", nil)];
    [alert addButtonWithTitle:NSLocalizedString(@"Cancel Current and Stop", nil)];
    [alert addButtonWithTitle:NSLocalizedString(@"Cancel Current and Continue", nil)];
    [alert addButtonWithTitle:NSLocalizedString(@"Finish Current and Stop", nil)];
    [alert setAlertStyle:NSCriticalAlertStyle];

    [alert beginSheetModalForWindow:window
                      modalDelegate:self
                     didEndSelector:@selector(didDimissCancel:returnCode:contextInfo:)
                        contextInfo:nil];
}

- (void)didDimissCancel:(NSAlert *)alert
             returnCode:(NSInteger)returnCode
            contextInfo:(void *)contextInfo
{
    if (returnCode == NSAlertSecondButtonReturn)
    {
        [self cancelCurrentJobAndStop];
    }
    else if (returnCode == NSAlertThirdButtonReturn)
    {
        [self cancelCurrentJobAndContinue];
    }
    else if (returnCode == NSAlertThirdButtonReturn + 1)
    {
        [self finishCurrentAndStop];
    }
}

/**
 * Starts or cancels the processing of jobs depending on the current state
 */
- (IBAction)toggleStartCancel:(id)sender
{
    HBState s = self.core.state;
    if ((s == HBStatePaused) || (s == HBStateWorking) || (s == HBStateMuxing))
    {
        [self cancelRip:self];
    }
    else if (self.pendingItemsCount > 0)
    {
        [self rip:self];
    }
}

/**
 * Toggles the pause/resume state of libhb
 */
- (IBAction)togglePauseResume:(id)sender
{
    HBState s = self.core.state;
    if (s == HBStatePaused)
    {
        [self.core resume];
        [self.core preventSleep];
    }
    else if (s == HBStateWorking || s == HBStateMuxing)
    {
        [self.core pause];
        [self.core allowSleep];
    }
}

/**
 *  Resets the job state to ready.
 */
- (IBAction)resetJobState:(id)sender
{
    if ([self.jobs beginTransaction] == HBDistributedArrayContentReload)
    {
        // Do not execture the action if the array changed.
        [self.jobs commit];
        return;
    }

    NSIndexSet *targetedRows = [self.outlineView targetedRowIndexes];
    NSMutableIndexSet *updatedIndexes = [NSMutableIndexSet indexSet];

    NSUInteger currentIndex = [targetedRows firstIndex];
    while (currentIndex != NSNotFound) {
        HBJob *job = self.jobs[currentIndex];

        if (job.state == HBJobStateCanceled || job.state == HBJobStateCompleted || job.state == HBJobStateFailed)
        {
            job.state = HBJobStateReady;
            [updatedIndexes addIndex:currentIndex];
        }
        currentIndex = [targetedRows indexGreaterThanIndex:currentIndex];
    }

    [self reloadQueueItemsAtIndexes:updatedIndexes];
    [self.jobs commit];
}

- (void)editQueueItem:(HBJob *)job
{
    NSParameterAssert(job);
    [self.jobs beginTransaction];

    if (job != self.currentJob)
    {
        job.state = HBJobStateWorking;
        [self.controller openJob:[job copy] completionHandler:^(BOOL result) {
            [self.jobs beginTransaction];
            if (result)
            {
                // Now that source is loaded and settings applied, delete the queue item from the queue
                NSInteger index = [self.jobs indexOfObject:job];
                job.state = HBJobStateReady;
                [self removeQueueItemAtIndex:index];
            }
            else
            {
                job.state = HBJobStateFailed;
                NSBeep();
            }
            [self.jobs commit];
        }];
    }
    else
    {
        NSBeep();
    }

    [self.jobs commit];
}

/**
 * Send the selected queue item back to the main window for rescan and possible edit.
 */
- (IBAction)editSelectedQueueItem:(id)sender
{
    if ([self.jobs beginTransaction] == HBDistributedArrayContentReload)
    {
        // Do not execture the action if the array changed.
        [self.jobs commit];
        return;
    }

    NSInteger row = self.outlineView.clickedRow;
    if (row != NSNotFound)
    {
        // if this is a currently encoding job, we need to be sure to alert the user,
        // to let them decide to cancel it first, then if they do, we can come back and
        // remove it
        HBJob *job = self.jobs[row];
        if (job == self.currentJob)
        {
            NSString *alertTitle = [NSString stringWithFormat:NSLocalizedString(@"Stop This Encode and Edit It?", nil)];

            // Which window to attach the sheet to?
            NSWindow *docWindow = self.window;
            if ([sender respondsToSelector: @selector(window)])
            {
                docWindow = [sender window];
            }

            NSAlert *alert = [[NSAlert alloc] init];
            [alert setMessageText:alertTitle];
            [alert setInformativeText:NSLocalizedString(@"Your movie will be lost if you don't continue encoding.", nil)];
            [alert addButtonWithTitle:NSLocalizedString(@"Keep Encoding", nil)];
            [alert addButtonWithTitle:NSLocalizedString(@"Stop Encoding and Edit", nil)];
            [alert setAlertStyle:NSCriticalAlertStyle];

            [alert beginSheetModalForWindow:docWindow
                              modalDelegate:self
                             didEndSelector:@selector(didDimissEditCurrentJob:returnCode:contextInfo:)
                                contextInfo:(__bridge void *)(job)];
        }
        else if (job.state != HBJobStateWorking)
        {
            [self editQueueItem:job];
        }
    }

    [self.jobs commit];
}

- (void)didDimissEditCurrentJob:(NSAlert *)alert
                       returnCode:(NSInteger)returnCode
                      contextInfo:(void *)contextInfo
{
    if (returnCode == NSAlertSecondButtonReturn)
    {
        HBJob *job = (__bridge HBJob *)contextInfo;
        [self editQueueItem:job];
    }
}

- (IBAction)clearAll:(id)sender
{
    [self.jobs beginTransaction];
    NSIndexSet *indexes = [self.jobs indexesOfObjectsUsingBlock:^BOOL(HBJob *item) {
        return (item.state != HBJobStateWorking);
    }];
    [self removeQueueItemsAtIndexes:indexes];
    [self.jobs commit];
}

- (IBAction)clearCompleted:(id)sender
{
    [self.jobs beginTransaction];
    NSIndexSet *indexes = [self.jobs indexesOfObjectsUsingBlock:^BOOL(HBJob *item) {
        return (item.state == HBJobStateCompleted);
    }];
    [self removeQueueItemsAtIndexes:indexes];
    [self.jobs commit];
}

#pragma mark -
#pragma mark NSOutlineView data source

- (id)outlineView:(NSOutlineView *)fOutlineView child:(NSInteger)index ofItem:(id)item
{
    if (item == nil)
    {
        return self.jobs[index];
    }

    // We are only one level deep, so we can't be asked about children
    NSAssert(NO, @"HBQueueController outlineView:child:ofItem: can't handle nested items.");
    return nil;
}

- (BOOL)outlineView:(NSOutlineView *)fOutlineView isItemExpandable:(id)item
{
    // Our outline view has no levels, but we can still expand every item. Doing so
    // just makes the row taller. See heightOfRowByItem below.
    return YES;
}

- (BOOL)outlineView:(NSOutlineView *)outlineView shouldExpandItem:(id)item
{
    // Our outline view has no levels, but we can still expand every item. Doing so
    // just makes the row taller. See heightOfRowByItem below.
    return ![(HBQueueOutlineView *)outlineView isDragging];
}

- (NSInteger)outlineView:(NSOutlineView *)fOutlineView numberOfChildrenOfItem:(id)item
{
    // Our outline view has no levels, so number of children will be zero for all
    // top-level items.
    if (item == nil)
    {
        return self.jobs.count;
    }
    else
    {
        return 0;
    }
}

#pragma mark NSOutlineView delegate

- (void)outlineViewItemDidCollapse:(NSNotification *)notification
{
    id item = notification.userInfo[@"NSObject"];
    NSInteger row = [self.outlineView rowForItem:item];
    [self.outlineView noteHeightOfRowsWithIndexesChanged:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(row,1)]];
}

- (void)outlineViewItemDidExpand:(NSNotification *)notification
{
    id item = notification.userInfo[@"NSObject"];
    NSInteger row = [self.outlineView rowForItem:item];
    [self.outlineView noteHeightOfRowsWithIndexesChanged:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(row,1)]];
}

#define HB_ROW_HEIGHT_TITLE_ONLY 17.0
#define HB_ROW_HEIGHT_PADDING 6.0

- (CGFloat)outlineView:(NSOutlineView *)outlineView heightOfRowByItem:(id)item
{
    if ([outlineView isItemExpanded:item])
    {
        // It is important to use a constant value when calculating the height. Querying the tableColumn width will not work, since it dynamically changes as the user resizes -- however, we don't get a notification that the user "did resize" it until after the mouse is let go. We use the latter as a hook for telling the table that the heights changed. We must return the same height from this method every time, until we tell the table the heights have changed. Not doing so will quicly cause drawing problems.
        NSTableColumn *tableColumnToWrap = (NSTableColumn *) [outlineView tableColumns][1];
        NSInteger columnToWrap = [outlineView.tableColumns indexOfObject:tableColumnToWrap];
        
        // Grab the fully prepared cell with our content filled in. Note that in IB the cell's Layout is set to Wraps.
        NSCell *cell = [outlineView preparedCellAtColumn:columnToWrap row:[outlineView rowForItem:item]];
        
        // See how tall it naturally would want to be if given a restricted with, but unbound height
        NSRect constrainedBounds = NSMakeRect(0, 0, tableColumnToWrap.width, CGFLOAT_MAX);
        NSSize naturalSize = [cell cellSizeForBounds:constrainedBounds];
        
        // Make sure we have a minimum height -- use the table's set height as the minimum.
        if (naturalSize.height > outlineView.rowHeight)
            return naturalSize.height + HB_ROW_HEIGHT_PADDING;
        else
            return outlineView.rowHeight;
    }
    else
    {
        return HB_ROW_HEIGHT_TITLE_ONLY;
    }
}

- (id)outlineView:(NSOutlineView *)fOutlineView objectValueForTableColumn:(NSTableColumn *)tableColumn byItem:(id)item
{
    if ([tableColumn.identifier isEqualToString:@"desc"])
    {
        HBJob *job = item;
        NSAttributedString *description = self.descriptions[job.uuid];

        if (description == nil)
        {
            description = job.attributedDescription;
            self.descriptions[job.uuid] = description;
        }

        return description;
    }
    else if ([tableColumn.identifier isEqualToString:@"icon"])
    {
        HBJob *job = item;
        if (job.state == HBJobStateCompleted)
        {
            return [NSImage imageNamed:@"EncodeComplete"];
        }
        else if (job.state == HBJobStateWorking)
        {
            return [NSImage imageNamed:@"EncodeWorking0"];
        }
        else if (job.state == HBJobStateCanceled)
        {
            return [NSImage imageNamed:@"EncodeCanceled"];
        }
        else if (job.state == HBJobStateFailed)
        {
            return [NSImage imageNamed:@"EncodeFailed"];
        }
        else
        {
            return [NSImage imageNamed:@"JobSmall"];
        }
    }
    else
    {
        return @"";
    }
}

/**
 * This method inserts the proper action icons into the far right of the queue window
 */
- (void)outlineView:(NSOutlineView *)outlineView willDisplayCell:(id)cell forTableColumn:(NSTableColumn *)tableColumn item:(id)item
{
    if ([tableColumn.identifier isEqualToString:@"action"])
    {
        [cell setEnabled: YES];
        BOOL highlighted = [outlineView isRowSelected:[outlineView rowForItem: item]] && [[outlineView window] isKeyWindow] && ([[outlineView window] firstResponder] == outlineView);

        HBJob *job = item;
        if (job.state == HBJobStateCompleted)
        {
            [cell setAction: @selector(revealSelectedQueueItems:)];
            if (highlighted)
            {
                [cell setImage:[NSImage imageNamed:@"RevealHighlight"]];
                [cell setAlternateImage:[NSImage imageNamed:@"RevealHighlightPressed"]];
            }
            else
            {
                [cell setImage:[NSImage imageNamed:@"Reveal"]];
            }
        }
        else
        {
            [cell setAction: @selector(removeSelectedQueueItem:)];
            if (highlighted)
            {
                [cell setImage:[NSImage imageNamed:@"DeleteHighlight"]];
                [cell setAlternateImage:[NSImage imageNamed:@"DeleteHighlightPressed"]];
            }
            else
            {
                [cell setImage:[NSImage imageNamed:@"Delete"]];
            }
        }
    }
}

- (void)outlineView:(NSOutlineView *)outlineView willDisplayOutlineCell:(id)cell forTableColumn:(NSTableColumn *)tableColumn item:(id)item
{
    // By default, the disclosure image gets centered vertically in the cell. We want
    // always at the top.
    if ([outlineView isItemExpanded:item])
    {
        [cell setImagePosition: NSImageAbove];
    }
    else
    {
        [cell setImagePosition: NSImageOnly];
    }
}

#pragma mark NSOutlineView drag & drop

- (BOOL)outlineView:(NSOutlineView *)outlineView writeItems:(NSArray *)items toPasteboard:(NSPasteboard *)pboard
{
    // Dragging is only allowed of the pending items.
    if ([items[0] state] != HBJobStateReady)
    {
        return NO;
    }

    self.dragNodesArray = items;

    // Provide data for our custom type, and simple NSStrings.
    [pboard declareTypes:@[DragDropSimplePboardType] owner:self];

    // the actual data doesn't matter since DragDropSimplePboardType drags aren't recognized by anyone but us!.
    [pboard setData:[NSData data] forType:DragDropSimplePboardType];

    return YES;
}

- (NSDragOperation)outlineView:(NSOutlineView *)outlineView validateDrop:(id <NSDraggingInfo>)info proposedItem:(id)item proposedChildIndex:(NSInteger)index
{
    // Don't allow dropping ONTO an item since they can't really contain any children.
    BOOL isOnDropTypeProposal = index == NSOutlineViewDropOnItemIndex;
    if (isOnDropTypeProposal)
    {
        return NSDragOperationNone;
    }
    
    // Don't allow dropping INTO an item since they can't really contain any children.
    if (item != nil)
    {
        index = [self.outlineView rowForItem:item] + 1;
        item = nil;
    }

    // We do not let the user drop a pending job before or *above*
    // already finished or currently encoding jobs.
    NSInteger encodingIndex = [self.jobs indexOfObject:self.currentJob];
    if (encodingIndex != NSNotFound && index <= encodingIndex)
    {
        return NSDragOperationNone;
        index = MAX(index, encodingIndex);
	}

    [outlineView setDropItem:item dropChildIndex:index];
    return NSDragOperationGeneric;
}

- (BOOL)outlineView:(NSOutlineView *)outlineView acceptDrop:(id <NSDraggingInfo>)info item:(id)item childIndex:(NSInteger)index
{
    [self moveQueueItems:self.dragNodesArray toIndex:index];
    return YES;
}

@end