/*

     File: AlbumContentsViewController.m

 Abstract: View controller to manaage displaying the contents of an album.

  Version: 1.1

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 */

#import "AlbumContentsViewController.h"

#import "MyPageViewController.h"

#import "PageViewControllerData.h"

@implementation AlbumContentsViewController

#pragma mark - View lifecycle

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

    self.title = [self.assetsGroup valueForProperty:ALAssetsGroupPropertyName];

    if (!self.assets) {

        _assets = [[NSMutableArray alloc] init];

    } else {

        [self.assets removeAllObjects];

    }

    ALAssetsGroupEnumerationResultsBlock assetsEnumerationBlock = ^(ALAsset *result, NSUInteger index, BOOL *stop) {

        if (result) {

            [self.assets addObject:result];

        }

    };

    ALAssetsFilter *onlyPhotosFilter = [ALAssetsFilter allPhotos];

    [self.assetsGroup setAssetsFilter:onlyPhotosFilter];

    [self.assetsGroup enumerateAssetsUsingBlock:assetsEnumerationBlock];

}

- (void)viewDidAppear:(BOOL)animated {

    [super viewDidAppear:animated];

    [self.collectionView reloadData];

}

#pragma mark - UICollectionViewDelegate

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

    return self.assets.count;

}

#define kImageViewTag 1 // the image view inside the collection view cell prototype is tagged with "1"

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"photoCell";

    UICollectionViewCell *cell = [cv dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

    // load the asset for this cell

    ALAsset *asset = self.assets[indexPath.row];

    CGImageRef thumbnailImageRef = [asset thumbnail];

    UIImage *thumbnail = [UIImage imageWithCGImage:thumbnailImageRef];

    // apply the image to the cell

    UIImageView *imageView = (UIImageView *)[cell viewWithTag:kImageViewTag];

    imageView.image = thumbnail;

    return cell;

}

#pragma mark - Segue support

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([[segue identifier] isEqualToString:@"showPhoto"]) {

        // hand off the assets of this album to our singleton data source

        [PageViewControllerData sharedInstance].photoAssets = self.assets;

        // start viewing the image at the appropriate cell index

        MyPageViewController *pageViewController = [segue destinationViewController];

        NSIndexPath *selectedCell = [self.collectionView indexPathsForSelectedItems][0];

        pageViewController.startingIndex = selectedCell.row;

    }

}

@end