//
//  NSString+RAJavascript.m
//  APEX CRM
//
//  Created by Jack on 2018/12/1.
//  Copyright © 2018年 USAI. All rights reserved.
//

#import "NSString+RAJavascript.h"

@implementation NSString (RAJavascript)


- (unsigned char)ra_hexCharFromInt:(int)value
{
    if (value <= 9) return (unsigned char)(value + 48);
    return (unsigned char)((value - 10) + 97);
}

- (NSString *)ra_unicodeStringForChar:(unichar)ch
{
    unsigned char uni[] = {
        [self ra_hexCharFromInt:((ch >> 12) & 0x0f)],
        [self ra_hexCharFromInt:((ch >> 8) & 0x0f)],
        [self ra_hexCharFromInt:((ch >> 4) & 0x0f)],
        [self ra_hexCharFromInt:(ch & 0x0f)],
        0
    };
    return [NSString stringWithUTF8String:(char*)uni];
}

- (NSString *)ra_stringByEscapingForJavascriptWithDelimiter:(unichar)delimiter wrapWithDelimiters:(BOOL)wrap
{
    NSMutableString *js = [[NSMutableString alloc] init];
    
    if (wrap)
    {
        [js appendFormat:@"%C", delimiter];
    }
    
    int lastWritePosition = 0;
    int skipped = 0;
    NSInteger length = self.length;
    unichar *chars = malloc(sizeof(unichar) * length);
    unichar c;
    [self getCharacters:chars range:NSMakeRange(0, length)];
    NSString *escapedValue;
    
    for (int i = 0; i < length; i++)
    {
        c = chars[i];
        
        switch (c)
        {
            case L'\t':
                escapedValue = @"\\t";
                break;
            case L'\n':
                escapedValue = @"\\n";
                break;
            case L'\r':
                escapedValue = @"\\r";
                break;
            case L'\f':
                escapedValue = @"\\f";
                break;
            case L'\b':
                escapedValue = @"\\b";
                break;
            case L'\\':
                escapedValue = @"\\\\";
                break;
            case 0x0085:
                escapedValue = @"\\u0085";
                break;
            case 0x2028:
                escapedValue = @"\\u2028";
                break;
            case 0x2029:
                escapedValue = @"\\u2029";
                break;
            case L'\'':
                escapedValue = (delimiter == L'\'') ? @"\\'" : nil;
                break;
            case L'"':
                escapedValue = (delimiter == '"') ? @"\\\"" : nil;
                break;
            default:
                escapedValue = (c <= 0x001f) ? [self ra_unicodeStringForChar:c] : nil;
                break;
        }
        
        if (escapedValue)
        {
            if (skipped > 0)
            {
                [js appendString:[self substringWithRange:NSMakeRange(lastWritePosition, skipped)]];
                skipped = 0;
            }
            
            [js appendString:escapedValue];
            lastWritePosition = i + 1;
        }
        else
        {
            skipped++;
        }
    }
    
    if (skipped > 0)
    {
        if (lastWritePosition == 0)
        {
            [js appendString:self];
        }
        else
        {
            [js appendString:[self substringWithRange:NSMakeRange(lastWritePosition, skipped)]];
        }
    }
    
    free(chars);
    
    if (wrap)
    {
        [js appendFormat:@"%C", delimiter];
    }
    
    return js;
}



@end