/*

     File: CollectionViewController.m

 Abstract: A simple view controller that manages a collection view controller and a medium rect ADBannerView

  Version: 2.2

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*/

#import <iAd/iAd.h>

#import "CollectionViewController.h"

@interface ImageViewCell : UICollectionViewCell

@property (nonatomic, readonly) UIImageView *imageView;

@end

@implementation ImageViewCell

- (instancetype)initWithFrame:(CGRect)frame

{

    self = [super initWithFrame:frame];

    if (self != nil) {

        _imageView = [[UIImageView alloc] initWithFrame:self.contentView.bounds];

        _imageView.contentMode = UIViewContentModeScaleAspectFit;

        [self.contentView addSubview:_imageView];

    }

    return self;

}

@end

@interface BannerViewCell : UICollectionViewCell

@property (nonatomic, retain) ADBannerView *bannerView;

@end

@implementation BannerViewCell

- (void)setBannerView:(ADBannerView *)bannerView

{

    [_bannerView removeFromSuperview];

    _bannerView = bannerView;

    [self.contentView addSubview:_bannerView];

    _bannerView.center = CGPointMake(CGRectGetMidX(self.contentView.bounds), CGRectGetMidY(self.contentView.bounds));

}

@end

@interface CollectionViewController () <ADBannerViewDelegate>

@end

@implementation CollectionViewController {

    ADBannerView *_banner;

    // We only want to insert/delete our banner if we are changing from Loaded to Non-loaded and vice versa, so we use this

    // ivar to track that state. If this wasn't a concern, we wouldn't need this ivar at all.

    BOOL _bannerWasLoaded;

}

- (void)viewDidLoad

{

    _banner = [[ADBannerView alloc] initWithAdType:ADAdTypeMediumRectangle];

    _banner.delegate = self;

    [self.collectionView registerClass:[ImageViewCell class] forCellWithReuseIdentifier:@"ImageView"];

    [self.collectionView registerClass:[BannerViewCell class] forCellWithReuseIdentifier:@"BannerView"];

}

#pragma mark - UICollectionViewDataSource

#define kBaseNumberOfItems 30

#define kNumberOfItemsWithBanners 33

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

{

    // We only have 1 banner, but we display it in one of 3 locations, so if the banner is loaded, we add 3 more items.

    return _banner.bannerLoaded ? kNumberOfItemsWithBanners : kBaseNumberOfItems;

}

- (UIImage *)makeArt:(NSInteger)index

{

    static UIImage *art[kBaseNumberOfItems];

    if (art[index] == nil) {

        UIGraphicsBeginImageContextWithOptions(CGSizeMake(300.0, 300.0), YES, 0.0);

        CGContextRef context = UIGraphicsGetCurrentContext();

        [[UIColor redColor] setFill];

        [[UIColor blueColor] setStroke];

        CGPoint center = CGPointMake(150.0, 150.0);

        CGContextMoveToPoint(context, center.x, center.y + 120.0);

        NSInteger numPoints = index * 2 + 3;

        for(int i = 1; i < numPoints; ++i)

        {

            CGFloat x = 120.0 * sinf(i * (numPoints - 1) * M_PI / numPoints);

            CGFloat y = 120.0 * cosf(i * (numPoints - 1) * M_PI / numPoints);

            CGContextAddLineToPoint(context, center.x + x, center.y + y);

        }

        CGContextClosePath(context);

        CGContextDrawPath(context, kCGPathEOFillStroke);

        art[index] = UIGraphicsGetImageFromCurrentImageContext();

        UIGraphicsEndImageContext();

    }

    return art[index];

}

#define kBannerLocation1 5

#define kBannerLocation2 16

#define kBannerLocation3 27

- (BOOL)isBannerItem:(NSIndexPath *)indexPath

{

    return (indexPath.item == kBannerLocation1) || (indexPath.item == kBannerLocation2) || (indexPath.item == kBannerLocation3);

}

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

{

    UICollectionViewCell *cell;

    if (_banner.bannerLoaded && [self isBannerItem:indexPath]) {

        BannerViewCell *bannerCell = [collectionView dequeueReusableCellWithReuseIdentifier:@"BannerView" forIndexPath:indexPath];

        bannerCell.bannerView = _banner;

        cell = bannerCell;

    } else {

        ImageViewCell *imageCell = [collectionView dequeueReusableCellWithReuseIdentifier:@"ImageView" forIndexPath:indexPath];

        NSInteger index = indexPath.item;

        if (index > kBannerLocation3) {

            index -= 3;

        } else if (index > kBannerLocation2) {

            index -= 2;

        } else if (index > kBannerLocation1) {

            index -= 1;

        }

        imageCell.imageView.image = [self makeArt:index];

        cell = imageCell;

    }

    return cell;

}

#pragma mark - ADBannerViewDelegate

- (void)bannerViewDidLoadAd:(ADBannerView *)banner

{

    if (!_bannerWasLoaded) {

        [self.collectionView performBatchUpdates:^{

            [self.collectionView insertItemsAtIndexPaths:@[ [NSIndexPath indexPathForItem:kBannerLocation1 inSection:0], [NSIndexPath indexPathForItem:kBannerLocation2 inSection:0], [NSIndexPath indexPathForItem:kBannerLocation3 inSection:0]]];

        } completion:nil];

    }

    _bannerWasLoaded = YES;

}

- (void)bannerView:(ADBannerView *)banner didFailToReceiveAdWithError:(NSError *)error

{

    if (_bannerWasLoaded) {

        [self.collectionView performBatchUpdates:^{

            [self.collectionView deleteItemsAtIndexPaths:@[ [NSIndexPath indexPathForItem:kBannerLocation1 inSection:0], [NSIndexPath indexPathForItem:kBannerLocation2 inSection:0], [NSIndexPath indexPathForItem:kBannerLocation3 inSection:0]]];

        } completion:nil];

    }

    _bannerWasLoaded = NO;

}

@end