OrderedListStyle.mm

#import "StyleHeaders.h"
#import "EnrichedTextInputView.h"
#import "FontExtension.h"
#import "OccurenceUtils.h"
#import "ParagraphsUtils.h"
#import "TextInsertionUtils.h"

@implementation OrderedListStyle {
  EnrichedTextInputView *_input;
}

+ (StyleType)getStyleType { return OrderedList; }

- (CGFloat)getHeadIndent {
  // lists are drawn manually
  // margin before marker + gap between marker and paragraph
  return [_input->config orderedListMarginLeft] + [_input->config orderedListGapWidth];
}

- (instancetype)initWithInput:(id)input {
  self = [super init];
  _input = (EnrichedTextInputView *)input;
  return self;
}

- (void)applyStyle:(NSRange)range {
  BOOL isStylePresent = [self detectStyle:range];
  if(range.length >= 1) {
    isStylePresent ? [self removeAttributes:range] : [self addAttributes:range];
  } else {
    isStylePresent ? [self removeTypingAttributes] : [self addTypingAttributes];
  }
}

// we assume correct paragraph range is already given
- (void)addAttributes:(NSRange)range {
  NSTextList *numberBullet = [[NSTextList alloc] initWithMarkerFormat:NSTextListMarkerDecimal options:0];
  NSArray *paragraphs = [ParagraphsUtils getSeparateParagraphsRangesIn:_input->textView range:range];
  // if we fill empty lines with zero width spaces, we need to offset later ranges
  NSInteger offset = 0;
  // needed for range adjustments
  NSRange preModificationRange = _input->textView.selectedRange;
  
  // let's not emit some weird selection changes or text/html changes
  _input->blockEmitting = YES;
  
  for(NSValue *value in paragraphs) {
    // take previous offsets into consideration
    NSRange fixedRange = NSMakeRange([value rangeValue].location + offset, [value rangeValue].length);
    
    // length 0 with first line, length 1 and newline with some empty lines in the middle
    if(fixedRange.length == 0 ||
      (fixedRange.length == 1 &&
      [[NSCharacterSet newlineCharacterSet] characterIsMember: [_input->textView.textStorage.string characterAtIndex:fixedRange.location]])
    ) {
      [TextInsertionUtils insertText:@"\u200B" at:fixedRange.location additionalAttributes:nullptr input:_input withSelection:NO];
      fixedRange = NSMakeRange(fixedRange.location, fixedRange.length + 1);
      offset += 1;
    }
    
    [_input->textView.textStorage enumerateAttribute:NSParagraphStyleAttributeName inRange:fixedRange options:0
      usingBlock:^(id  _Nullable value, NSRange range, BOOL * _Nonnull stop) {
        NSMutableParagraphStyle *pStyle = [(NSParagraphStyle *)value mutableCopy];
        pStyle.textLists = @[numberBullet];
        pStyle.headIndent = [self getHeadIndent];
        pStyle.firstLineHeadIndent = [self getHeadIndent];
        [_input->textView.textStorage addAttribute:NSParagraphStyleAttributeName value:pStyle range:range];
      }
    ];
  }
  
  // back to emitting
  _input->blockEmitting = NO;
  
  if(preModificationRange.length == 0) {
    // fix selection if only one line was possibly made a list and filled with a space
    _input->textView.selectedRange = preModificationRange;
  } else {
    // in other cases, fix the selection with newly made offsets
    _input->textView.selectedRange = NSMakeRange(preModificationRange.location, preModificationRange.length + offset);
  }
  
  // also add typing attributes
  NSMutableDictionary *typingAttrs = [_input->textView.typingAttributes mutableCopy];
  NSMutableParagraphStyle *pStyle = [typingAttrs[NSParagraphStyleAttributeName] mutableCopy];
  pStyle.textLists = @[numberBullet];
  pStyle.headIndent = [self getHeadIndent];
  pStyle.firstLineHeadIndent = [self getHeadIndent];
  typingAttrs[NSParagraphStyleAttributeName] = pStyle;
  _input->textView.typingAttributes = typingAttrs;
}

// does pretty much the same as normal addAttributes, just need to get the range
- (void)addTypingAttributes {
  [self addAttributes:_input->textView.selectedRange];
}

- (void)removeAttributes:(NSRange)range {
  NSArray *paragraphs = [ParagraphsUtils getSeparateParagraphsRangesIn:_input->textView range:range];
  
  [_input->textView.textStorage beginEditing];
  
  for(NSValue *value in paragraphs) {
    NSRange range = [value rangeValue];
    [_input->textView.textStorage enumerateAttribute:NSParagraphStyleAttributeName inRange:range options:0
      usingBlock:^(id  _Nullable value, NSRange range, BOOL * _Nonnull stop) {
        NSMutableParagraphStyle *pStyle = [(NSParagraphStyle *)value mutableCopy];
        pStyle.textLists = @[];
        pStyle.headIndent = 0;
        pStyle.firstLineHeadIndent = 0;
        [_input->textView.textStorage addAttribute:NSParagraphStyleAttributeName value:pStyle range:range];
      }
    ];
  }
  
  [_input->textView.textStorage endEditing];
    
  // also remove typing attributes
  NSMutableDictionary *typingAttrs = [_input->textView.typingAttributes mutableCopy];
  NSMutableParagraphStyle *pStyle = [typingAttrs[NSParagraphStyleAttributeName] mutableCopy];
  pStyle.textLists = @[];
  pStyle.headIndent = 0;
  pStyle.firstLineHeadIndent = 0;
  typingAttrs[NSParagraphStyleAttributeName] = pStyle;
  _input->textView.typingAttributes = typingAttrs;
}

// needed for the sake of style conflicts, needs to do exactly the same as removeAttribtues
- (void)removeTypingAttributes {
  [self removeAttributes:_input->textView.selectedRange];
}

- (BOOL)handleBackspaceInRange:(NSRange)range replacementText:(NSString *)text {
  if(
    [self detectStyle:_input->textView.selectedRange] &&
    NSEqualRanges(_input->textView.selectedRange, NSMakeRange(0, 0)) &&
    [text isEqualToString:@""]
  ) {
    // removing first list point by backspacing doesn't remove typing attributes because it doesn't run textViewDidChange
    // so we try guessing that a point should be deleted here
    NSRange paragraphRange = [_input->textView.textStorage.string paragraphRangeForRange:_input->textView.selectedRange];
    [self removeAttributes:paragraphRange];
    return YES;
  } else if(
    [self detectStyle:_input->textView.selectedRange] &&
    [text isEqualToString:@""]
  ) {
    // other case; make sure removing all the (non newline) text from a list item also removes the item itself
    NSRange paragraphRange = [_input->textView.textStorage.string paragraphRangeForRange:range];
    NSValue *nonNewlineVal = [ParagraphsUtils getNonNewlineRangesIn:_input->textView range:paragraphRange].firstObject;
    if(nonNewlineVal == nullptr) {
      return NO;
    }
    NSRange nonNewlineRange = [nonNewlineVal rangeValue];
    if(NSEqualRanges(range, nonNewlineRange)) {
      [self removeAttributes:range];
      [TextInsertionUtils replaceText:text at:range additionalAttributes:nullptr input:_input withSelection:YES];
      return YES;
    }
  }
  return NO;
}

- (BOOL)tryHandlingListShorcutInRange:(NSRange)range replacementText:(NSString *)text {
  NSRange paragraphRange = [_input->textView.textStorage.string paragraphRangeForRange:range];
  // a dot was added - check if we are both at the paragraph beginning + 1 character (which we want to be a dash)
  if([text isEqualToString:@"."] && range.location - 1 == paragraphRange.location) {
    unichar charBefore = [_input->textView.textStorage.string characterAtIndex:range.location - 1];
    if(charBefore == '1') {
      // we got a match - add a list if possible
      if([_input handleStyleBlocksAndConflicts:[[self class] getStyleType] range:paragraphRange]) {
        // don't emit some html updates during the replacing
        BOOL prevEmitHtml = _input->emitHtml;
        if(prevEmitHtml) {
          _input->emitHtml = NO;
        }
        
        // remove the number
        [TextInsertionUtils replaceText:@"" at:NSMakeRange(paragraphRange.location, 1) additionalAttributes:nullptr input:_input withSelection:YES];
        
        if(prevEmitHtml) {
          _input->emitHtml = YES;
        }
        
        // add attributes on the paragraph
        [self addAttributes:NSMakeRange(paragraphRange.location, paragraphRange.length - 1)];
        return YES;
      }
    }
  }
  return NO;
}

- (BOOL)styleCondition:(id _Nullable)value :(NSRange)range {
  NSParagraphStyle *paragraph = (NSParagraphStyle *)value;
  return paragraph != nullptr && paragraph.textLists.count == 1 && paragraph.textLists.firstObject.markerFormat == NSTextListMarkerDecimal;
}

- (BOOL)detectStyle:(NSRange)range {
  if(range.length >= 1) {
    return [OccurenceUtils detect:NSParagraphStyleAttributeName withInput:_input inRange:range
      withCondition: ^BOOL(id  _Nullable value, NSRange range) {
        return [self styleCondition:value :range];
      }
    ];
  } else {
    return [OccurenceUtils detect:NSParagraphStyleAttributeName withInput:_input atIndex:range.location checkPrevious:YES
      withCondition:^BOOL(id  _Nullable value, NSRange range) {
        return [self styleCondition:value :range];
      }
    ];
  }
}

- (BOOL)anyOccurence:(NSRange)range {
  return [OccurenceUtils any:NSParagraphStyleAttributeName withInput:_input inRange:range
    withCondition:^BOOL(id  _Nullable value, NSRange range) {
      return [self styleCondition:value :range];
    }
  ];
}

- (NSArray<StylePair *> *_Nullable)findAllOccurences:(NSRange)range {
  return [OccurenceUtils all:NSParagraphStyleAttributeName withInput:_input inRange:range
    withCondition:^BOOL(id  _Nullable value, NSRange range) {
      return [self styleCondition:value :range];
    }
  ];
}

@end