/*

 Copyright (C) 2014 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 */

#import "AAPLExistingImageCollectionView.h"

#import "AAPLExistingImageCollectionViewCell.h"

#import "AAPLImage.h"

static NSString * const cellReuseIdentifier = @"imageCell";

@interface AAPLExistingImageCollectionView()

@property (strong, atomic) NSMutableArray *imageRecords;

@property (strong, atomic) dispatch_queue_t updateArrayQueue;

@property (strong, atomic) NSIndexPath *currentLoadingIndex;

@end

#pragma mark -

@implementation AAPLExistingImageCollectionView

- (instancetype) initWithCoder:(NSCoder *)aDecoder

{

    self = [super initWithCoder:aDecoder];

    if(self)

    {

        self.dataSource = self;

        _imageRecords = [[NSMutableArray alloc] init];

        _updateArrayQueue = dispatch_queue_create("UpdateCollectionViewQueue", DISPATCH_QUEUE_SERIAL);

    }

    return self;

}

- (NSUInteger) count

{

    return [self.imageRecords count];

}

- (void) addImageFromRecord:(CKRecord *)toAdd

{

    AAPLImage *fetchedImage = [[AAPLImage alloc] initWithRecord:toAdd];

    // Ensures that only one object will be added to the imageRecords array at a time

    dispatch_async(self.updateArrayQueue, ^{

        [self.imageRecords addObject:fetchedImage];

        dispatch_async(dispatch_get_main_queue(), ^{

            [self reloadData];

        });

    });

}

- (void) cellAtIndex:(NSIndexPath *)index isLoading:(BOOL)loading

{

    if(loading == YES) self.currentLoadingIndex = index;

    else self.currentLoadingIndex = nil;

    dispatch_async(dispatch_get_main_queue(), ^{

        [self reloadData];

    });

}

- (CKRecordID *) getRecordIDAtIndex:(NSIndexPath *)index

{

    // returns the recordID of the item in imageRecords at the given index

    AAPLImage *AAPLImageAtIndex = self.imageRecords[index.row];

    return [[AAPLImageAtIndex record] recordID];

}

#pragma mark UICollectionViewDataSource

- (NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

    return [self.imageRecords count];

}

// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:

- (AAPLExistingImageCollectionViewCell *) collectionView:(AAPLExistingImageCollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

    AAPLExistingImageCollectionViewCell *cell = [self dequeueReusableCellWithReuseIdentifier:cellReuseIdentifier forIndexPath:indexPath];

    if (cell == nil)

    {

        cell = [[AAPLExistingImageCollectionViewCell alloc] init];

    }

    cell.thumbnailImage.image = [self.imageRecords[indexPath.row] thumbnail];

    if(indexPath && [indexPath isEqual:self.currentLoadingIndex]) [cell setLoading:YES];

    else [cell setLoading:NO];

    return cell;

}

@end