//
//  NSString+Message.m
//  TLChat
//
//  Created by 李伯坤 on 16/3/15.
//  Copyright © 2016年 李伯坤. All rights reserved.
//

#import "NSString+Message.h"
#import "TLExpressionHelper.h"

@implementation NSString (Message)

- (NSAttributedString *)toMessageString;
{
    //1、创建一个可变的属性字符串
    NSMutableAttributedString *attributeString = [[NSMutableAttributedString alloc] initWithString:self];
    [attributeString addAttribute:NSFontAttributeName value:[UIFont fontTextMessageText] range:NSMakeRange(0, self.length)];
    //2、通过正则表达式来匹配字符串
    NSString *regex_emoji = @"\\[[a-zA-Z0-9\\/\\u4e00-\\u9fa5]+\\]"; //匹配表情
    
    NSError *error = nil;
    NSRegularExpression *re = [NSRegularExpression regularExpressionWithPattern:regex_emoji options:NSRegularExpressionCaseInsensitive error:&error];
    if (!re) {
        NSLog(@"[NSString toMessageString]: %@", [error localizedDescription]);
        return attributeString;
    }
    
    NSArray *resultArray = [re matchesInString:self options:0 range:NSMakeRange(0, self.length)];
    //3、获取所有的表情以及位置
    //用来存放字典，字典中存储的是图片和图片对应的位置
    NSMutableArray *imageArray = [NSMutableArray arrayWithCapacity:resultArray.count];
    //根据匹配范围来用图片进行相应的替换
    for(NSTextCheckingResult *match in resultArray) {
        //获取数组元素中得到range
        NSRange range = [match range];
        //获取原字符串中对应的值
        NSString *subStr = [self substringWithRange:range];
        
        TLExpressionGroupModel *group = [[TLExpressionHelper sharedHelper] defaultFaceGroup];
        for (TLExpressionModel *emoji in group.data) {
            if ([emoji.name isEqualToString:subStr]) {
                //face[i][@"png"]就是我们要加载的图片
                //新建文字附件来存放我们的图片,iOS7才新加的对象
                NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
                //给附件添加图片
                textAttachment.image = [UIImage imageNamed:emoji.name];
                //调整一下图片的位置,如果你的图片偏上或者偏下，调整一下bounds的y值即可
                textAttachment.bounds = CGRectMake(0, -4, 20, 20);
                //把附件转换成可变字符串，用于替换掉源字符串中的表情文字
                NSAttributedString *imageStr = [NSAttributedString attributedStringWithAttachment:textAttachment];
                //把图片和图片对应的位置存入字典中
                NSMutableDictionary *imageDic = [NSMutableDictionary dictionaryWithCapacity:2];
                [imageDic setObject:imageStr forKey:@"image"];
                [imageDic setObject:[NSValue valueWithRange:range] forKey:@"range"];
                //把字典存入数组中
                [imageArray addObject:imageDic];
            }
        }
    }
    
    //4、从后往前替换，否则会引起位置问题
    for (int i = (int)imageArray.count -1; i >= 0; i--) {
        NSRange range;
        [imageArray[i][@"range"] getValue:&range];
        //进行替换
        [attributeString replaceCharactersInRange:range withAttributedString:imageArray[i][@"image"]];
    }
    return attributeString;
}


@end