//
//  PSTCollectionViewFlowLayout.h
//  PSPDFKit
//
//  Copyright (c) 2012-2013 Peter Steinberger. All rights reserved.
//

#import "PSTCollectionViewLayout.h"

extern NSString *const PSTCollectionElementKindSectionHeader;
extern NSString *const PSTCollectionElementKindSectionFooter;

typedef NS_ENUM(NSInteger, PSTCollectionViewScrollDirection) {
    PSTCollectionViewScrollDirectionVertical,
    PSTCollectionViewScrollDirectionHorizontal
};

@protocol PSTCollectionViewDelegateFlowLayout <PSTCollectionViewDelegate>
@optional

- (CGSize)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath;
- (UIEdgeInsets)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section;
- (CGFloat)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section;
- (CGFloat)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section;
- (CGSize)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section;
- (CGSize)collectionView:(PSTCollectionView *)collectionView layout:(PSTCollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section;

@end

@class PSTGridLayoutInfo;

@interface PSTCollectionViewFlowLayout : PSTCollectionViewLayout

@property (nonatomic) CGFloat minimumLineSpacing;
@property (nonatomic) CGFloat minimumInteritemSpacing;
@property (nonatomic) CGSize itemSize; // for the cases the delegate method is not implemented
@property (nonatomic) PSTCollectionViewScrollDirection scrollDirection; // default is PSTCollectionViewScrollDirectionVertical
@property (nonatomic) CGSize headerReferenceSize;
@property (nonatomic) CGSize footerReferenceSize;

@property (nonatomic) UIEdgeInsets sectionInset;

/*
 Row alignment options exits in the official UICollectionView, but hasn't been made public API.
 
 Here's a snippet to test this on UICollectionView:

 NSMutableDictionary *rowAlign = [[flowLayout valueForKey:@"_rowAlignmentsOptionsDictionary"] mutableCopy];
 rowAlign[@"UIFlowLayoutCommonRowHorizontalAlignmentKey"] = @(1);
 rowAlign[@"UIFlowLayoutLastRowHorizontalAlignmentKey"] = @(3);
 [flowLayout setValue:rowAlign forKey:@"_rowAlignmentsOptionsDictionary"];
 */
@property (nonatomic, strong) NSDictionary *rowAlignmentOptions;

@end

// @steipete addition, private API in UICollectionViewFlowLayout
extern NSString *const PSTFlowLayoutCommonRowHorizontalAlignmentKey;
extern NSString *const PSTFlowLayoutLastRowHorizontalAlignmentKey;
extern NSString *const PSTFlowLayoutRowVerticalAlignmentKey;

typedef NS_ENUM(NSInteger, PSTFlowLayoutHorizontalAlignment) {
    PSTFlowLayoutHorizontalAlignmentLeft,
    PSTFlowLayoutHorizontalAlignmentCentered,
    PSTFlowLayoutHorizontalAlignmentRight,
    PSTFlowLayoutHorizontalAlignmentJustify // 3; default except for the last row
};
// TODO: settings for UIFlowLayoutRowVerticalAlignmentKey


/*
@interface PSTCollectionViewFlowLayout (Private)

- (CGSize)synchronizeLayout;

// For items being inserted or deleted, the collection view calls some different methods, which you should override to provide the appropriate layout information.
- (PSTCollectionViewLayoutAttributes *)initialLayoutAttributesForFooterInInsertedSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)initialLayoutAttributesForHeaderInInsertedSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)initialLayoutAttributesForInsertedItemAtIndexPath:(NSIndexPath *)indexPath;
- (PSTCollectionViewLayoutAttributes *)finalLayoutAttributesForFooterInDeletedSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)finalLayoutAttributesForHeaderInDeletedSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)finalLayoutAttributesForDeletedItemAtIndexPath:(NSIndexPath *)indexPath;

- (void)_updateItemsLayout;
- (void)_getSizingInfos;
- (void)_updateDelegateFlags;

- (PSTCollectionViewLayoutAttributes *)layoutAttributesForFooterInSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)layoutAttributesForHeaderInSection:(NSInteger)section;
- (PSTCollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath usingData:(id)data;
- (PSTCollectionViewLayoutAttributes *)layoutAttributesForFooterInSection:(NSInteger)section usingData:(id)data;
- (PSTCollectionViewLayoutAttributes *)layoutAttributesForHeaderInSection:(NSInteger)section usingData:(id)data;

- (id)indexesForSectionFootersInRect:(CGRect)rect;
- (id)indexesForSectionHeadersInRect:(CGRect)rect;
- (id)indexPathsForItemsInRect:(CGRect)rect usingData:(id)arg2;
- (id)indexesForSectionFootersInRect:(CGRect)rect usingData:(id)arg2;
- (id)indexesForSectionHeadersInRect:(CGRect)arg1 usingData:(id)arg2;
- (CGRect)_frameForItemAtSection:(int)arg1 andRow:(int)arg2 usingData:(id)arg3;
- (CGRect)_frameForFooterInSection:(int)arg1 usingData:(id)arg2;
- (CGRect)_frameForHeaderInSection:(int)arg1 usingData:(id)arg2;
- (void)_invalidateLayout;
- (NSIndexPath *)indexPathForItemAtPoint:(CGPoint)arg1;
- (PSTCollectionViewLayoutAttributes *)_layoutAttributesForItemsInRect:(CGRect)arg1;
- (CGSize)collectionViewContentSize;
- (void)finalizeCollectionViewUpdates;
- (PSTCollectionViewLayoutAttributes *)layoutAttributesForSupplementaryViewOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath;
- (void)_invalidateButKeepDelegateInfo;
- (void)_invalidateButKeepAllInfo;
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)arg1;
- (id)layoutAttributesForElementsInRect:(CGRect)arg1;
- (void)invalidateLayout;
- (id)layoutAttributesForItemAtIndexPath:(id)arg1;

@end
*/