/*!
 * iOS SDK
 *
 * Tencent is pleased to support the open source community by making
 * Hippy available.
 *
 * Copyright (C) 2019 THL A29 Limited, a Tencent company.
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#import "HippyTextView.h"

#import "HippyConvert.h"
#import "HippyShadowText.h"
#import "HippyText.h"
#import "HippyUtils.h"
#import "HippyTextSelection.h"
#import "UIView+Hippy.h"

@implementation HippyUITextView {
    BOOL _jsRequestingFirstResponder;
}

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

- (void)hippyWillMakeFirstResponder {
    _jsRequestingFirstResponder = YES;
}

- (BOOL)canBecomeFirstResponder {
    // return _jsRequestingFirstResponder;
    return YES;
}

- (BOOL)becomeFirstResponder {
    if (_responderDelegate && [_responderDelegate respondsToSelector:@selector(textview_becomeFirstResponder)]) {
        [_responderDelegate textview_becomeFirstResponder];
    }

    return [super becomeFirstResponder];
}

- (BOOL)resignFirstResponder {
    if (_responderDelegate && [_responderDelegate respondsToSelector:@selector(textview_resignFirstResponder)]) {
        [_responderDelegate textview_resignFirstResponder];
    }
    return [super resignFirstResponder];
}

- (void)hippyDidMakeFirstResponder {
    _jsRequestingFirstResponder = YES;
}

- (void)didMoveToWindow {
    if (_jsRequestingFirstResponder) {
        [self becomeFirstResponder];
        [self hippyDidMakeFirstResponder];
    }
}

- (void)setCanEdit:(BOOL)canEdit {
    _canEdit = canEdit;
    [self setEditable:canEdit];
}

@end

@interface HippyTextView () <HippyUITextViewResponseDelegate>

/// ParagraphStyle for TextView and PlaceholderView,
/// used for lineHeight config and etc.
@property (nonatomic, strong) NSMutableParagraphStyle *paragraphStyle;

@end

@implementation HippyTextView {
    NSString *_placeholder;
    UITextView *_placeholderView;
    HippyText *_richTextView;
    NSAttributedString *_pendingAttributedText;
    UIScrollView *_scrollView;

    UITextRange *_previousSelectionRange;
    NSUInteger _previousTextLength;
    CGFloat _previousContentHeight;
    NSString *_predictedText;

    BOOL _blockTextShouldChange;
    BOOL _nativeUpdatesInFlight;
    NSInteger _nativeEventCount;

    CGSize _previousContentSize;
    BOOL _viewDidCompleteInitialLayout;
}

@dynamic lineHeight;
@dynamic lineSpacing;
@dynamic lineHeightMultiple;

#pragma mark - Keyboard Events

- (void)keyboardWillShow:(NSNotification *)aNotification {
    [super keyboardWillShow:aNotification];
    //获取键盘的高度
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
    CGFloat keyboardHeight = keyboardRect.size.height;
    if (self.isFirstResponder && _onKeyboardWillShow) {
        _onKeyboardWillShow(@{ @"keyboardHeight": @(keyboardHeight) });
    }
}

- (void)keyboardWillHide:(NSNotification *)aNotification {
    [super keyboardWillHide:aNotification];
    if (_onKeyboardWillHide) {
        _onKeyboardWillHide(@{});
    }
}

- (void)keyboardHeightChanged:(NSNotification *)aNotification {
    [super keyboardHeightChanged:aNotification];
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
    CGFloat keyboardHeight = keyboardRect.size.height;
    if (self.isFirstResponder && _onKeyboardHeightChanged) {
        _onKeyboardHeightChanged(@{ @"keyboardHeight": @(keyboardHeight) });
    }
}

- (instancetype)init {
    if ((self = [super initWithFrame:CGRectZero])) {
        [self setContentInset:UIEdgeInsetsZero];
        _placeholderTextColor = [self defaultPlaceholderTextColor];
        _blurOnSubmit = NO;

        _textView = [[HippyUITextView alloc] initWithFrame:CGRectZero];
        _textView.responderDelegate = self;
        _textView.backgroundColor = [UIColor clearColor];
        _textView.textColor = [UIColor blackColor];
        _textView.scrollsToTop = NO;
        _textView.scrollEnabled = NO;
        _textView.delegate = self;

        _scrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
        _scrollView.scrollsToTop = NO;
        [_scrollView addSubview:_textView];

        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(textFieldEditChanged:)
                                                     name:UITextViewTextDidChangeNotification
                                                   object:_textView];
        [self addSubview:_scrollView];
    }
    return self;
}

HIPPY_NOT_IMPLEMENTED(-(instancetype)initWithFrame : (CGRect)frame)
HIPPY_NOT_IMPLEMENTED(-(instancetype)initWithCoder : (NSCoder *)aDecoder)

- (void)insertHippySubview:(UIView *)subview atIndex:(NSInteger)index {
    [super insertHippySubview:subview atIndex:index];
    if ([subview isKindOfClass:[HippyText class]]) {
        if (_richTextView) {
            HippyLogError(@"Tried to insert a second <Text> into <TextInput> - there can only be one.");
        }
        _richTextView = (HippyText *)subview;

        if (subview.backgroundColor) {
            NSMutableDictionary<NSString *, id> *attrs = [_textView.typingAttributes mutableCopy];
            attrs[NSBackgroundColorAttributeName] = subview.backgroundColor;
            _textView.typingAttributes = attrs;
        }

        [self performTextUpdate];
    }
}

- (void)removeHippySubview:(UIView *)subview {
    [super removeHippySubview:subview];
    if (_richTextView == subview) {
        _richTextView = nil;
        [self performTextUpdate];
    }
}

- (void)didUpdateHippySubviews {
    // Do nothing, as we don't allow non-text subviews
}

- (void)setMostRecentEventCount:(NSInteger)mostRecentEventCount {
    _mostRecentEventCount = mostRecentEventCount;

    // Props are set after uiBlockToAmendWithShadowViewRegistry, which means that
    // at the time performTextUpdate is called, _mostRecentEventCount will be
    // behind _eventCount, with the result that performPendingTextUpdate will do
    // nothing. For that reason we call it again here after mostRecentEventCount
    // has been set.
    [self performPendingTextUpdate];
}

- (void)performTextUpdate {
    if (_richTextView) {
        _pendingAttributedText = _richTextView.textStorage;
        [self performPendingTextUpdate];
    } else if (!self.text) {
        _textView.attributedText = nil;
    }
}

static NSAttributedString *removeHippyTagFromString(NSAttributedString *string) {
    if (string.length == 0) {
        return string;
    } else {
        NSMutableAttributedString *mutableString = [[NSMutableAttributedString alloc] initWithAttributedString:string];
        [mutableString removeAttribute:HippyHippyTagAttributeName range:NSMakeRange(0, mutableString.length)];
        return mutableString;
    }
}

- (void)performPendingTextUpdate {
    if (!_pendingAttributedText || _mostRecentEventCount < _nativeEventCount || _nativeUpdatesInFlight) {
        return;
    }

    // The underlying <Text> node that produces _pendingAttributedText has a hippy tag attribute on it that causes the
    // -isEqualToAttributedString: comparison below to spuriously fail. We don't want that comparison to fail unless it
    // needs to because when the comparison fails, we end up setting attributedText on the text view, which clears
    // autocomplete state for CKJ text input.
    //
    // TODO: Kill this after we finish passing all style/attribute info into JS.
    _pendingAttributedText = removeHippyTagFromString(_pendingAttributedText);

    if ([_textView.attributedText isEqualToAttributedString:_pendingAttributedText]) {
        _pendingAttributedText = nil;  // Don't try again.
        return;
    }

    // When we update the attributed text, there might be pending autocorrections
    // that will get accepted by default. In order for this to not garble our text,
    // we temporarily block all textShouldChange events so they are not applied.
    _blockTextShouldChange = YES;

    UITextRange *selection = _textView.selectedTextRange;
    NSInteger oldTextLength = _textView.attributedText.length;

    _textView.attributedText = _pendingAttributedText;
    _predictedText = _pendingAttributedText.string;
    _pendingAttributedText = nil;

    if (selection.empty) {
        // maintain cursor position relative to the end of the old text
        NSInteger start = [_textView offsetFromPosition:_textView.beginningOfDocument toPosition:selection.start];
        NSInteger offsetFromEnd = oldTextLength - start;
        NSInteger newOffset = _textView.attributedText.length - offsetFromEnd;
        UITextPosition *position = [_textView positionFromPosition:_textView.beginningOfDocument offset:newOffset];
        _textView.selectedTextRange = [_textView textRangeFromPosition:position toPosition:position];
    }

    [_textView layoutIfNeeded];

    [self updatePlaceholderVisibility];

    _blockTextShouldChange = NO;
}

- (void)updateFrames {
    // Adjust the insets so that they are as close as possible to single-line
    // HippyTextField defaults, using the system defaults of font size 17 and a
    // height of 31 points.
    //
    // We apply the left inset to the frame since a negative left text-container
    // inset mysteriously causes the text to be hidden until the text view is
    // first focused.
    UIEdgeInsets adjustedFrameInset = UIEdgeInsetsZero;
    adjustedFrameInset.left = [self contentInset].left - 5;

    UIEdgeInsets adjustedTextContainerInset = [self contentInset];
    //  adjustedTextContainerInset.top += 5;
    adjustedTextContainerInset.left = 0;

    CGRect frame = UIEdgeInsetsInsetRect(self.bounds, adjustedFrameInset);
    _textView.frame = frame;
    _placeholderView.frame = frame;
    _scrollView.frame = frame;
    [self updateContentSize];

    _textView.textContainerInset = adjustedTextContainerInset;
    _placeholderView.textContainerInset = adjustedTextContainerInset;
}

- (void)updateContentSize {
    CGSize contentSize = (CGSize) { CGRectGetMaxX(_scrollView.frame), INFINITY };
    contentSize.height = [_textView sizeThatFits:contentSize].height;
    
    if (_viewDidCompleteInitialLayout && _onContentSizeChange && !CGSizeEqualToSize(_previousContentSize, contentSize)) {
        _previousContentSize = contentSize;
        _onContentSizeChange(@{
            @"contentSize": @ {
                @"height": @(contentSize.height),
                @"width": @(contentSize.width),
            },
            @"target": self.hippyTag,
        });
    }
    
    CGSize viewSize = CGSizeMake(CGRectGetWidth(_scrollView.frame), MAX(contentSize.height, self.frame.size.height));
    _scrollView.contentSize = viewSize;
    _textView.frame = (CGRect) { CGPointZero, viewSize };
}

- (void)updatePlaceholder {
    [_placeholderView removeFromSuperview];
    _placeholderView = nil;

    if (_placeholder) {
        _placeholderView = [[UITextView alloc] initWithFrame:self.bounds];
        _placeholderView.userInteractionEnabled = NO;
        _placeholderView.backgroundColor = [UIColor clearColor];
        _placeholderView.scrollEnabled = NO;
        _placeholderView.editable = NO;
        _placeholderView.scrollsToTop = NO;
        NSMutableAttributedString *attrStr = [[NSMutableAttributedString alloc] initWithString:_placeholder
                                                                                    attributes:@{
            NSFontAttributeName: (_textView.font ? _textView.font : [self defaultPlaceholderFont]),
            NSForegroundColorAttributeName: _placeholderTextColor 
        }];
        if (self.paragraphStyle) {
            // Apply paragraph style to the entire string
            [attrStr addAttribute:NSParagraphStyleAttributeName
                            value:self.paragraphStyle
                            range:NSMakeRange(0, attrStr.length)];
        }
        _placeholderView.textAlignment = _textView.textAlignment;
        _placeholderView.attributedText = attrStr;

        [self insertSubview:_placeholderView belowSubview:_textView];
        [self updatePlaceholderVisibility];
    }
}

- (UIFont *)font {
    return _textView.font;
}

- (void)setFont:(UIFont *)font {
    _textView.font = font;
    [self updatePlaceholder];
}

- (void)setLineHeight:(NSNumber *)lineHeight {
    // create paragraphStyle, update placeholder and textView
    if (!self.paragraphStyle) {
        self.paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    }
    self.paragraphStyle.minimumLineHeight = [lineHeight doubleValue];
    self.paragraphStyle.maximumLineHeight = [lineHeight doubleValue];
    
    [self updateParagraphAndFontStyleForTextView:_textView];
    [self updatePlaceholder];
}

- (void)setLineSpacing:(NSNumber *)lineSpacing {
    // create paragraphStyle, update placeholder and textView
    if (!self.paragraphStyle) {
        self.paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    }
    self.paragraphStyle.lineSpacing = [lineSpacing doubleValue];
    
    [self updateParagraphAndFontStyleForTextView:_textView];
    [self updatePlaceholder];
}

- (void)setLineHeightMultiple:(NSNumber *)lineHeightMultiple {
    // create paragraphStyle, update placeholder and textView
    if (!self.paragraphStyle) {
        self.paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    }
    self.paragraphStyle.lineHeightMultiple = [lineHeightMultiple doubleValue];
    
    [self updateParagraphAndFontStyleForTextView:_textView];
    [self updatePlaceholder];
}

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

- (void)setPlaceholderTextColor:(UIColor *)placeholderTextColor {
    if (placeholderTextColor) {
        _placeholderTextColor = placeholderTextColor;
    } else {
        _placeholderTextColor = [self defaultPlaceholderTextColor];
    }
    [self updatePlaceholder];
}

- (void)setContentInset:(UIEdgeInsets)contentInset {
    [super setContentInset:contentInset];
    [self updateFrames];
}

- (void)checkMaxLengthAndAlterTextView:(UITextView *)textField {
    //TODO: This old special logic needs to be optimized.
    if (self.isFirstResponder && self.maxLength) {
        NSInteger theMaxLength = self.maxLength.integerValue;
        NSString *toBeString = textField.text;
        NSString *lang = [textField.textInputMode primaryLanguage];
        if ([lang isEqualToString:@"zh-Hans"])  // 简体中文输入
        {
            UITextRange *selectedRange = [textField markedTextRange];
            UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];
            
            if (!position) {
                if (toBeString.length > theMaxLength) {
                    NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:theMaxLength];
                    if (rangeIndex.length == 1) {
                        textField.text = [toBeString substringToIndex:theMaxLength];
                    } else {
                        NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange(0, theMaxLength)];
                        textField.text = [toBeString substringWithRange:rangeRange];
                    }
                }
            }

        } else {
            if (toBeString.length > theMaxLength) {
                NSRange rangeIndex = [toBeString rangeOfComposedCharacterSequenceAtIndex:theMaxLength];
                if (rangeIndex.length == 1) {
                    textField.text = [toBeString substringToIndex:theMaxLength];
                } else {
                    NSRange rangeRange = [toBeString rangeOfComposedCharacterSequencesForRange:NSMakeRange(0, theMaxLength)];
                    textField.text = [toBeString substringWithRange:rangeRange];
                }
            }
        }
    }
}

- (void)textFieldEditChanged:(NSNotification *)obj {
    [self checkMaxLengthAndAlterTextView:(UITextView *)obj.object];
}

- (NSString *)text {
    return _textView.text;
}

- (void)setSelection:(HippyTextSelection *)selection {
    if (!selection) {
        return;
    }

    UITextRange *currentSelection = _textView.selectedTextRange;
    UITextPosition *start = [_textView positionFromPosition:_textView.beginningOfDocument offset:selection.start];
    UITextPosition *end = [_textView positionFromPosition:_textView.beginningOfDocument offset:selection.end];
    UITextRange *selectedTextRange = [_textView textRangeFromPosition:start toPosition:end];

    NSInteger eventLag = _nativeEventCount - _mostRecentEventCount;
    if (eventLag == 0 && ![currentSelection isEqual:selectedTextRange]) {
        _previousSelectionRange = selectedTextRange;
        _textView.selectedTextRange = selectedTextRange;
    } else if (eventLag > HippyTextUpdateLagWarningThreshold) {
        HippyLogWarn(@"Native TextInput(%@) is %ld events ahead of JS - try to make your JS faster.", self.text, (long)eventLag);
    }
}

- (void)setText:(NSString *)text {
    double version = UIDevice.currentDevice.systemVersion.doubleValue;
    if (version >= 10.0 && version < 12.0) {
        text = [text stringByReplacingOccurrencesOfString:@"జ్ఞ‌ా" withString:@" "];
    }

    NSInteger eventLag = _nativeEventCount - _mostRecentEventCount;
    if (eventLag == 0 && ![text isEqualToString:_textView.text]) {
        UITextRange *selection = _textView.selectedTextRange;
        NSInteger oldTextLength = _textView.text.length;

        _predictedText = text;
        // Use `attribuedText` instead of `text` to show paragraphStyle
        _textView.attributedText = [self attributedTextAfterApplyingParagraphStyle:text];
        [self textViewDidChange:_textView];
        if (selection.empty) {
            // maintain cursor position relative to the end of the old text
            NSInteger start = [_textView offsetFromPosition:_textView.beginningOfDocument toPosition:selection.start];
            NSInteger offsetFromEnd = oldTextLength - start;
            NSInteger newOffset = text.length - offsetFromEnd;
            UITextPosition *position = [_textView positionFromPosition:_textView.beginningOfDocument offset:newOffset];
            _textView.selectedTextRange = [_textView textRangeFromPosition:position toPosition:position];
        }

        [self updatePlaceholderVisibility];
        [self updateContentSize];  // keep the text wrapping when the length of
        // the textline has been extended longer than the length of textinputView
    } else if (eventLag > HippyTextUpdateLagWarningThreshold) {
        HippyLogWarn(@"Native TextInput(%@) is %ld events ahead of JS - try to make your JS faster.", self.text, (long)eventLag);
    }
}

- (void)setTextColor:(UIColor *)textColor {
    _textView.textColor = textColor;
}

- (UIColor *)textColor {
    return _textView.textColor;
}

- (void)updatePlaceholderVisibility {
    if (_textView.text.length > 0) {
        [_placeholderView setHidden:YES];
    } else {
        [_placeholderView setHidden:NO];
    }
}

- (void)setAutoCorrect:(BOOL)autoCorrect {
    _textView.autocorrectionType = (autoCorrect ? UITextAutocorrectionTypeYes : UITextAutocorrectionTypeNo);
}

- (BOOL)autoCorrect {
    return _textView.autocorrectionType == UITextAutocorrectionTypeYes;
}


#pragma mark - UITextViewDelegate

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
    if (_selectTextOnFocus) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [textView selectAll:nil];
        });
    }
    return YES;
}

- (void)textViewDidBeginEditing:(__unused UITextView *)textView {
    if (_clearTextOnFocus) {
        _textView.text = @"";
        [self updatePlaceholderVisibility];
    }
    // update typingAttributes
    [self updateTypingAttributes];
}

static BOOL findMismatch(NSString *first, NSString *second, NSRange *firstRange, NSRange *secondRange) {
    NSInteger firstMismatch = -1;
    for (NSUInteger ii = 0; ii < MAX(first.length, second.length); ii++) {
        if (ii >= first.length || ii >= second.length || [first characterAtIndex:ii] != [second characterAtIndex:ii]) {
            firstMismatch = ii;
            break;
        }
    }

    if (firstMismatch == -1) {
        return NO;
    }

    NSUInteger ii = second.length;
    NSUInteger lastMismatch = first.length;
    while (ii > firstMismatch && lastMismatch > firstMismatch) {
        if ([first characterAtIndex:(lastMismatch - 1)] != [second characterAtIndex:(ii - 1)]) {
            break;
        }
        ii--;
        lastMismatch--;
    }

    *firstRange = NSMakeRange(firstMismatch, lastMismatch - firstMismatch);
    *secondRange = NSMakeRange(firstMismatch, ii - firstMismatch);
    return YES;
}

- (BOOL)textView:(HippyUITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    if (_onKeyPress) {
        NSString *resultKey = text;
        if ([text isEqualToString:@" "]) {
            resultKey = @"space";
        } else if ([text isEqualToString:@""]) {
            resultKey = @"backspace";
        } else if ([text isEqualToString:@"\n"]) {
            resultKey = @"enter";
        }
        _onKeyPress(@{ @"key": resultKey });
    }

    if (textView.textWasPasted) {
        textView.textWasPasted = NO;
    } else {
        if (_blurOnSubmit && [text isEqualToString:@"\n"]) {
            // TODO: the purpose of blurOnSubmit on HippyextField is to decide if the
            // field should lose focus when return is pressed or not. We're cheating a
            // bit here by using it on HippyextView to decide if return character should
            // submit the form, or be entered into the field.
            //
            // The reason this is cheating is because there's no way to specify that
            // you want the return key to be swallowed *and* have the field retain
            // focus (which was what blurOnSubmit was originally for). For the case
            // where _blurOnSubmit = YES, this is still the correct and expected
            // behavior though, so we'll leave the don't-blur-or-add-newline problem
            // to be solved another day.
            [self resignFirstResponder];
            if (_onBlur) {
                _onBlur(@{});
            }
            return NO;
        }
    }

    // So we need to track that there is a native update in flight just in case JS manages to come back around and update
    // things /before/ UITextView can update itself asynchronously.  If there is a native update in flight, we defer the
    // JS update when it comes in and apply the deferred update once textViewDidChange fires with the native update applied.
    if (_blockTextShouldChange) {
        return NO;
    }
    
    // maxlength related
    if (self.maxLength != nil) {
        if (textView.text.length > self.maxLength.integerValue &&
            text.length > range.length) {
            return NO;
        }
    }

    _nativeUpdatesInFlight = YES;

    if (range.location + range.length > _predictedText.length) {
        // _predictedText got out of sync in a bad way, so let's just force sync it.  Haven't been able to repro this, but
        // it's causing a real crash here: #6523822
        _predictedText = textView.text;
    }

    NSString *previousText = [_predictedText substringWithRange:range];
    if (_predictedText) {
        _predictedText = [_predictedText stringByReplacingCharactersInRange:range withString:text];
    } else {
        _predictedText = text;
    }

    if (_onTextInput) {
        _onTextInput(@{
            @"text": text,
            @"previousText": previousText ?: @"",
            @"range": @ { @"start": @(range.location), @"end": @(range.location + range.length) },
            @"eventCount": @(_nativeEventCount),
        });
    }
    
    return YES;
}

- (void)textViewDidChange:(UITextView *)textView {
    [self updatePlaceholderVisibility];
    [self updateContentSize];

    // Detect when textView updates happend that didn't invoke `shouldChangeTextInRange`
    // (e.g. typing simplified chinese in pinyin will insert and remove spaces without
    // calling shouldChangeTextInRange).  This will cause JS to get out of sync so we
    // update the mismatched range.
    NSRange currentRange;
    NSRange predictionRange;
    if (findMismatch(textView.text, _predictedText, &currentRange, &predictionRange)) {
        NSString *replacement = [textView.text substringWithRange:currentRange];
        [self textView:textView shouldChangeTextInRange:predictionRange replacementText:replacement];
        // JS will assume the selection changed based on the location of our shouldChangeTextInRange, so reset it.
        [self textViewDidChangeSelection:textView];
        _predictedText = textView.text;
    }

    _nativeUpdatesInFlight = NO;
    //  _nativeEventCount++;

    if (!self.hippyTag || !_onChangeText) {
        return;
    }
    
    // check maxLength before send event to js
    [self checkMaxLengthAndAlterTextView:textView];

    // When the context size increases, iOS updates the contentSize twice; once
    // with a lower height, then again with the correct height. To prevent a
    // spurious event from being sent, we track the previous, and only send the
    // update event if it matches our expectation that greater text length
    // should result in increased height. This assumption is, of course, not
    // necessarily true because shorter text might include more linebreaks, but
    // in practice this works well enough.
    NSUInteger textLength = textView.text.length;
    CGFloat contentHeight = textView.contentSize.height;
    if (textLength >= _previousTextLength) {
        contentHeight = MAX(contentHeight, _previousContentHeight);
    }
    _previousTextLength = textLength;
    _previousContentHeight = contentHeight;
    _onChangeText(@{
        @"text": self.text,
        @"contentSize": @ { @"height": @(contentHeight), @"width": @(textView.contentSize.width) },
        @"target": self.hippyTag,
        @"eventCount": @(_nativeEventCount),
    });
}

- (void)textViewDidChangeSelection:(HippyUITextView *)textView {
    if (_onSelectionChange && textView.selectedTextRange != _previousSelectionRange
        && ![textView.selectedTextRange isEqual:_previousSelectionRange]) {
        _previousSelectionRange = textView.selectedTextRange;

        UITextRange *selection = textView.selectedTextRange;
        NSInteger start = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selection.start];
        NSInteger end = [textView offsetFromPosition:textView.beginningOfDocument toPosition:selection.end];
        _onSelectionChange(@{
            @"selection": @ {
                @"start": @(start),
                @"end": @(end),
            },
        });

        if (_onChangeText) {
            _onChangeText(@{
                @"text": self.text,
            });
        }
    }
}


#pragma mark - Responder Chain

- (BOOL)isFirstResponder {
    return [_textView isFirstResponder];
}

- (BOOL)canBecomeFirstResponder {
    return [_textView canBecomeFirstResponder];
}

- (void)hippyWillMakeFirstResponder {
    [_textView hippyWillMakeFirstResponder];
}

- (void)hippyDidMakeFirstResponder {
    [_textView hippyDidMakeFirstResponder];
}

- (void)layoutSubviews {
    [super layoutSubviews];

    // Start sending content size updates only after the view has been laid out
    // otherwise we send multiple events with bad dimensions on initial render.
    _viewDidCompleteInitialLayout = YES;

    [self updateFrames];
}

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

- (UIColor *)defaultPlaceholderTextColor {
    return [UIColor colorWithRed:0.0 / 255.0 green:0.0 / 255.0 blue:0.098 / 255.0 alpha:0.22];
}

- (NSString *)value {
    return _textView.text;
}

- (void)setValue:(NSString *)value {
    [self setText:value];
}

- (void)setDefaultValue:(NSString *)defaultValue {
    if (defaultValue) {
        [self setText:defaultValue];
        _defaultValue = defaultValue;
    }
}

- (void)focus {
    [self becomeFirstResponder];
}

- (void)blur {
    [self resignFirstResponder];
}

- (void)clearText {
    [self setText:@""];
}

- (BOOL)becomeFirstResponder {
    [self setTextViewKeyboardAppearance];
    return [_textView becomeFirstResponder];
}

- (void)textview_becomeFirstResponder {
    if (_onFocus) {
        _onFocus(@{});
    }
}

- (void)textview_resignFirstResponder {
    if (_onBlur) {
        _onBlur(@{});
    }
}

- (BOOL)resignFirstResponder {
    _nativeEventCount = 0;
    [super resignFirstResponder];
    return [_textView resignFirstResponder];
}

- (void)setTextViewKeyboardAppearance {
    if (_textView) {
        _textView.keyboardAppearance = UIKeyboardAppearanceDefault;
    }
}

#pragma mark - ParagraphStyle Related

- (void)updateTypingAttributes {
    if (self.paragraphStyle) {
        // Set typingAttributes if needed
        NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
        attrs[NSParagraphStyleAttributeName] = self.paragraphStyle;
        if (_textView.font) {
            attrs[NSFontAttributeName] = _textView.font;
        }
        _textView.typingAttributes = attrs;
    }
}

- (NSAttributedString *)attributedTextAfterApplyingParagraphStyle:(NSString *)text {
    NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:text];
    
    if (self.paragraphStyle) {
        // add paragraph style to the entire string
        [attributedString addAttribute:NSParagraphStyleAttributeName
                                 value:self.paragraphStyle
                                 range:NSMakeRange(0, attributedString.length)];
    }
    if (_textView.font) {
        // add font style to the entire string
        [attributedString addAttribute:NSFontAttributeName
                                 value:_textView.font
                                 range:NSMakeRange(0, attributedString.length)];
    }
    return attributedString;
}

- (void)updateParagraphAndFontStyleForTextView:(UITextView *)textView {
    if (textView.text.length == 0) {
        return;
    }
    textView.attributedText = [self attributedTextAfterApplyingParagraphStyle:textView.text];
}

@end