/*
* 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 <React/RCTUITextView.h>

#import <React/RCTUtils.h>
#import <React/UIView+React.h>

#import <React/RCTBackedTextInputDelegateAdapter.h>
#import <React/RCTTextAttributes.h>

@implementation RCTUITextView {
UILabel *_placeholderView;
UITextView *_detachedTextView;
RCTBackedTextViewDelegateAdapter *_textInputDelegateAdapter;
NSDictionary<NSAttributedStringKey, id> *_defaultTextAttributes;
}

static UIFont *defaultPlaceholderFont()
{
return [UIFont systemFontOfSize:17];
}

static UIColor *defaultPlaceholderColor()
{
// Default placeholder color from UITextField.
return [UIColor colorWithRed:0 green:0 blue:0.0980392 alpha:0.22];
}

- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(textDidChange)
name:UITextViewTextDidChangeNotification
object:self];

_placeholderView = [[UILabel alloc] initWithFrame:self.bounds];
_placeholderView.isAccessibilityElement = NO;
_placeholderView.numberOfLines = 0;
[self addSubview:_placeholderView];

_textInputDelegateAdapter = [[RCTBackedTextViewDelegateAdapter alloc] initWithTextView:self];

self.backgroundColor = [UIColor clearColor];
self.textColor = [UIColor blackColor];
// This line actually removes 5pt (default value) left and right padding in UITextView.
self.textContainer.lineFragmentPadding = 0;
self.scrollsToTop = NO;
self.scrollEnabled = YES;
}

return self;
}

- (void)setDelegate:(id<UITextViewDelegate>)delegate
{
// Delegate is set inside `[RCTBackedTextViewDelegateAdapter initWithTextView]` and
// it cannot be changed from outside.
if (super.delegate) {
return;
}
[super setDelegate:delegate];
}

#pragma mark - Accessibility

- (void)setIsAccessibilityElement:(BOOL)isAccessibilityElement
{
// UITextView is accessible by default (some nested views are) and disabling that is not supported.
// On iOS accessible elements cannot be nested, therefore enabling accessibility for some container view
// (even in a case where this view is a part of public API of TextInput on iOS) shadows some features implemented
// inside the component.
}

- (NSString *)accessibilityLabel
{
NSMutableString *accessibilityLabel = [NSMutableString new];

NSString *superAccessibilityLabel = [super accessibilityLabel];
if (superAccessibilityLabel.length > 0) {
[accessibilityLabel appendString:superAccessibilityLabel];
}

if (self.placeholder.length > 0 && self.attributedText.string.length == 0) {
if (accessibilityLabel.length > 0) {
[accessibilityLabel appendString:@" "];
}
[accessibilityLabel appendString:self.placeholder];
}

return accessibilityLabel;
}

#pragma mark - Properties

- (void)setPlaceholder:(NSString *)placeholder
{
_placeholder = placeholder;
[self _updatePlaceholder];
}

- (void)setPlaceholderColor:(UIColor *)placeholderColor
{
_placeholderColor = placeholderColor;
[self _updatePlaceholder];
}

- (void)setDefaultTextAttributes:(NSDictionary<NSAttributedStringKey, id> *)defaultTextAttributes
{
if ([_defaultTextAttributes isEqualToDictionary:defaultTextAttributes]) {
return;
}

_defaultTextAttributes = defaultTextAttributes;
self.typingAttributes = defaultTextAttributes;
[self _updatePlaceholder];
}

- (NSDictionary<NSAttributedStringKey, id> *)defaultTextAttributes
{
return _defaultTextAttributes;
}

- (void)textDidChange
{
_textWasPasted = NO;
[self _invalidatePlaceholderVisibility];
}

#pragma mark - Overrides

- (void)setFont:(UIFont *)font
{
[super setFont:font];
[self _updatePlaceholder];
}

- (void)setTextAlignment:(NSTextAlignment)textAlignment
{
[super setTextAlignment:textAlignment];
_placeholderView.textAlignment = textAlignment;
}

- (void)setAttributedText:(NSAttributedString *)attributedText
{
[super setAttributedText:attributedText];
[self textDidChange];
}

- (void)setSelectedTextRange:(UITextRange *)selectedTextRange notifyDelegate:(BOOL)notifyDelegate
{
if (!notifyDelegate) {
// We have to notify an adapter that following selection change was initiated programmatically,
// so the adapter must not generate a notification for it.
[_textInputDelegateAdapter skipNextTextInputDidChangeSelectionEventWithTextRange:selectedTextRange];
}

[super setSelectedTextRange:selectedTextRange];
}

- (void)paste:(id)sender
{
_textWasPasted = YES;
[super paste:sender];
}

// Turn off scroll animation to fix flaky scrolling.
// This is only necessary for iOS <= 13.
#if defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && __IPHONE_OS_VERSION_MAX_ALLOWED < 140000
- (void)setContentOffset:(CGPoint)contentOffset animated:(__unused BOOL)animated
{
[super setContentOffset:contentOffset animated:NO];
}
#endif

- (void)selectAll:(id)sender
{
[super selectAll:sender];

// `selectAll:` does not work for UITextView when it's being called inside UITextView's delegate methods.
dispatch_async(dispatch_get_main_queue(), ^{
UITextRange *selectionRange = [self textRangeFromPosition:self.beginningOfDocument toPosition:self.endOfDocument];
[self setSelectedTextRange:selectionRange notifyDelegate:NO];
});
}

#pragma mark - Layout

- (CGFloat)preferredMaxLayoutWidth
{
// Returning size DOES contain `textContainerInset` (aka `padding`).
return _preferredMaxLayoutWidth ?: self.placeholderSize.width;
}

- (CGSize)placeholderSize
{
UIEdgeInsets textContainerInset = self.textContainerInset;
NSString *placeholder = self.placeholder ?: @"";
CGSize maxPlaceholderSize =
CGSizeMake(UIEdgeInsetsInsetRect(self.bounds, textContainerInset).size.width, CGFLOAT_MAX);
CGSize placeholderSize = [placeholder boundingRectWithSize:maxPlaceholderSize
options:NSStringDrawingUsesLineFragmentOrigin
attributes:[self _placeholderTextAttributes]
context:nil]
.size;
placeholderSize = CGSizeMake(RCTCeilPixelValue(placeholderSize.width), RCTCeilPixelValue(placeholderSize.height));
placeholderSize.width += textContainerInset.left + textContainerInset.right;
placeholderSize.height += textContainerInset.top + textContainerInset.bottom;
// Returning size DOES contain `textContainerInset` (aka `padding`; as `sizeThatFits:` does).
return placeholderSize;
}

- (CGSize)contentSize
{
CGSize contentSize = super.contentSize;
CGSize placeholderSize = _placeholderView.isHidden ? CGSizeZero : self.placeholderSize;
// When a text input is empty, it actually displays a placehoder.
// So, we have to consider `placeholderSize` as a minimum `contentSize`.
// Returning size DOES contain `textContainerInset` (aka `padding`).
return CGSizeMake(MAX(contentSize.width, placeholderSize.width), MAX(contentSize.height, placeholderSize.height));
}

- (void)layoutSubviews
{
[super layoutSubviews];

CGRect textFrame = UIEdgeInsetsInsetRect(self.bounds, self.textContainerInset);
CGFloat placeholderHeight = [_placeholderView sizeThatFits:textFrame.size].height;
textFrame.size.height = MIN(placeholderHeight, textFrame.size.height);
_placeholderView.frame = textFrame;
}

- (CGSize)intrinsicContentSize
{
// Returning size DOES contain `textContainerInset` (aka `padding`).
return [self sizeThatFits:CGSizeMake(self.preferredMaxLayoutWidth, CGFLOAT_MAX)];
}

- (CGSize)sizeThatFits:(CGSize)size
{
// Returned fitting size depends on text size and placeholder size.
CGSize textSize = [super sizeThatFits:size];
CGSize placeholderSize = self.placeholderSize;
// Returning size DOES contain `textContainerInset` (aka `padding`).
return CGSizeMake(MAX(textSize.width, placeholderSize.width), MAX(textSize.height, placeholderSize.height));
}

#pragma mark - Context Menu

- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
if (_contextMenuHidden) {
return NO;
}

return [super canPerformAction:action withSender:sender];
}

#pragma mark - Placeholder

- (void)_invalidatePlaceholderVisibility
{
BOOL isVisible = _placeholder.length != 0 && self.attributedText.length == 0;
_placeholderView.hidden = !isVisible;
}

- (void)_updatePlaceholder
{
_placeholderView.attributedText = [[NSAttributedString alloc] initWithString:_placeholder ?: @""
attributes:[self _placeholderTextAttributes]];
[self _invalidatePlaceholderVisibility];
}

- (NSDictionary<NSAttributedStringKey, id> *)_placeholderTextAttributes
{
NSMutableDictionary<NSAttributedStringKey, id> *textAttributes =
[_defaultTextAttributes mutableCopy] ?: [NSMutableDictionary new];

[textAttributes setValue:self.placeholderColor ?: defaultPlaceholderColor() forKey:NSForegroundColorAttributeName];

if (![textAttributes objectForKey:NSFontAttributeName]) {
[textAttributes setValue:defaultPlaceholderFont() forKey:NSFontAttributeName];
}

return textAttributes;
}

#pragma mark - Caret Manipulation

- (CGRect)caretRectForPosition:(UITextPosition *)position
{
if (_caretHidden) {
return CGRectZero;
}

return [super caretRectForPosition:position];
}

#pragma mark - Utility Methods

@end