//
//  ASTableLayoutController.m
//  AsyncDisplayKit
//
//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//

#import <AsyncDisplayKit/ASTableLayoutController.h>

#import <UIKit/UIKit.h>

#import <AsyncDisplayKit/ASAssert.h>
#import <AsyncDisplayKit/ASElementMap.h>

@interface ASTableLayoutController()
@end

@implementation ASTableLayoutController

- (instancetype)initWithTableView:(UITableView *)tableView
{
  if (!(self = [super init])) {
    return nil;
  }
  _tableView = tableView;
  return self;
}

#pragma mark - ASLayoutController

- (NSSet<ASCollectionElement *> *)elementsForScrolling:(ASScrollDirection)scrollDirection rangeMode:(ASLayoutRangeMode)rangeMode rangeType:(ASLayoutRangeType)rangeType map:(ASElementMap *)map
{
  CGRect bounds = _tableView.bounds;

  ASRangeTuningParameters tuningParameters = [self tuningParametersForRangeMode:rangeMode rangeType:rangeType];
  CGRect rangeBounds = CGRectExpandToRangeWithScrollableDirections(bounds, tuningParameters, ASScrollDirectionVerticalDirections, scrollDirection);
  NSArray *array = [_tableView indexPathsForRowsInRect:rangeBounds];
  return ASSetByFlatMapping(array, NSIndexPath *indexPath, [map elementForItemAtIndexPath:indexPath]);
}

- (void)allElementsForScrolling:(ASScrollDirection)scrollDirection rangeMode:(ASLayoutRangeMode)rangeMode displaySet:(NSSet<ASCollectionElement *> *__autoreleasing  _Nullable *)displaySet preloadSet:(NSSet<ASCollectionElement *> *__autoreleasing  _Nullable *)preloadSet map:(ASElementMap *)map
{
  if (displaySet == NULL || preloadSet == NULL) {
    return;
  }

  *displaySet = [self elementsForScrolling:scrollDirection rangeMode:rangeMode rangeType:ASLayoutRangeTypeDisplay map:map];
  *preloadSet = [self elementsForScrolling:scrollDirection rangeMode:rangeMode rangeType:ASLayoutRangeTypePreload map:map];
  return;
}

@end