/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/

#import "RCTRefreshControl.h"
#import "RCTRefreshableProtocol.h"

#import "RCTUtils.h"

@interface RCTRefreshControl () <RCTRefreshableProtocol>
@end

@implementation RCTRefreshControl {
BOOL _isInitialRender;
BOOL _currentRefreshingState;
UInt64 _currentRefreshingStateClock;
UInt64 _currentRefreshingStateTimestamp;
BOOL _refreshingProgrammatically;
NSString *_title;
UIColor *_titleColor;
CGFloat _progressViewOffset;
}

- (instancetype)init
{
if ((self = [super init])) {
[self addTarget:self action:@selector(refreshControlValueChanged) forControlEvents:UIControlEventValueChanged];
_currentRefreshingStateClock = 1;
_currentRefreshingStateTimestamp = 0;
_isInitialRender = true;
_currentRefreshingState = false;
}
return self;
}

RCT_NOT_IMPLEMENTED(-(instancetype)initWithCoder : (NSCoder *)aDecoder)

- (void)layoutSubviews
{
[super layoutSubviews];
[self _applyProgressViewOffset];

// Fix for bug #7976
if (self.backgroundColor == nil) {
self.backgroundColor = [UIColor clearColor];
}

// If the control is refreshing when mounted we need to call
// beginRefreshing in layoutSubview or it doesn't work.
if (_currentRefreshingState && _isInitialRender) {
[self beginRefreshingProgrammatically];
}
_isInitialRender = false;
}

- (void)beginRefreshingProgrammatically
{
UInt64 beginRefreshingTimestamp = _currentRefreshingStateTimestamp;
_refreshingProgrammatically = YES;

// Fix for bug #24855
[self sizeToFit];

if (self.scrollView) {
// When using begin refreshing we need to adjust the ScrollView content offset manually.
UIScrollView *scrollView = (UIScrollView *)self.scrollView;

CGPoint offset = {scrollView.contentOffset.x, scrollView.contentOffset.y - self.frame.size.height};

// `beginRefreshing` must be called after the animation is done. This is why it is impossible
// to use `setContentOffset` with `animated:YES`.
[UIView animateWithDuration:0.25
delay:0
options:UIViewAnimationOptionBeginFromCurrentState
animations:^(void) {
[scrollView setContentOffset:offset];
}
completion:^(__unused BOOL finished) {
if (beginRefreshingTimestamp == self->_currentRefreshingStateTimestamp) {
[super beginRefreshing];
[self setCurrentRefreshingState:super.refreshing];
}
}];
} else if (beginRefreshingTimestamp == self->_currentRefreshingStateTimestamp) {
[super beginRefreshing];
[self setCurrentRefreshingState:super.refreshing];
}
}

- (void)endRefreshingProgrammatically
{
// The contentOffset of the scrollview MUST be greater than the contentInset before calling
// endRefreshing otherwise the next pull to refresh will not work properly.
UIScrollView *scrollView = self.scrollView;
if (scrollView && _refreshingProgrammatically && scrollView.contentOffset.y < -scrollView.contentInset.top) {
UInt64 endRefreshingTimestamp = _currentRefreshingStateTimestamp;
CGPoint offset = {scrollView.contentOffset.x, -scrollView.contentInset.top};
[UIView animateWithDuration:0.25
delay:0
options:UIViewAnimationOptionBeginFromCurrentState
animations:^(void) {
[scrollView setContentOffset:offset];
}
completion:^(__unused BOOL finished) {
if (endRefreshingTimestamp == self->_currentRefreshingStateTimestamp) {
[super endRefreshing];
[self setCurrentRefreshingState:super.refreshing];
}
}];
} else {
[super endRefreshing];
}
}

- (void)_applyProgressViewOffset
{
// progressViewOffset must be converted from the ScrollView parent's coordinate space to
// the coordinate space of the RefreshControl. This ensures that the control respects any
// offset in the view hierarchy, and that progressViewOffset is not inadvertently applied
// multiple times.
UIView *scrollView = self.superview;
UIView *target = scrollView.superview;
CGPoint rawOffset = CGPointMake(0, _progressViewOffset);
CGPoint converted = [self convertPoint:rawOffset fromView:target];
self.frame = CGRectOffset(self.frame, 0, converted.y);
}

- (NSString *)title
{
return _title;
}

- (void)setTitle:(NSString *)title
{
_title = title;
[self _updateTitle];
}

- (void)setTitleColor:(UIColor *)color
{
_titleColor = color;
[self _updateTitle];
}

- (void)_updateTitle
{
if (!_title) {
return;
}

NSMutableDictionary *attributes = [NSMutableDictionary dictionary];
if (_titleColor) {
attributes[NSForegroundColorAttributeName] = _titleColor;
}

self.attributedTitle = [[NSAttributedString alloc] initWithString:_title attributes:attributes];
}

- (void)setRefreshing:(BOOL)refreshing
{
if (_currentRefreshingState != refreshing) {
[self setCurrentRefreshingState:refreshing];

if (refreshing) {
if (!_isInitialRender) {
[self beginRefreshingProgrammatically];
}
} else {
[self endRefreshingProgrammatically];
}
}
}

- (void)setCurrentRefreshingState:(BOOL)refreshing
{
_currentRefreshingState = refreshing;
_currentRefreshingStateTimestamp = _currentRefreshingStateClock++;
}

- (void)setProgressViewOffset:(CGFloat)offset
{
_progressViewOffset = offset;
[self _applyProgressViewOffset];
}

- (void)refreshControlValueChanged
{
[self setCurrentRefreshingState:super.refreshing];
_refreshingProgrammatically = NO;

if (_onRefresh) {
_onRefresh(nil);
}
}

@end