IM-ios/AIIM/Controller/chat/chetCell/ChatMessageModel.m

//
//  ChatMessageModel.m
//  AIIM
//
//  Created by qitewei on 2025/5/14.
//

#import "ChatMessageModel.h"
#import "CryptoAES.h"
#import "ChatsStore.h"
#import "AVFoundation/AVFoundation.h"
#import "FileNetApi.h"
#import <SDWebImage/SDImageCache.h>

@implementation ChatMessageModel

+ (instancetype)modelWithDictionary:(NSDictionary *)dict {
    ChatMessageModel *model = [[ChatMessageModel alloc] init];
    [model setupWithDictionary:dict];
    return model;
}

- (void)setupWithDictionary:(NSDictionary *)dict {
    
    NSMutableDictionary * mutableDict = [NSMutableDictionary dictionaryWithDictionary:dict];
    [mutableDict jk_each:^(id k, id v) {
        if ([v isKindOfClass:[NSNull class]]) {
            [mutableDict setObject:@"" forKey:k];
        }
    }];
    
    //原消息
    self.formerMessage = dict;
    self.chatId = mutableDict[@"chatId"];
    // 消息类型
    NSInteger type = [mutableDict[@"messageType"] integerValue];
    self.messageType = (ChatMessageType)type;
    self.type = [mutableDict[@"type"] integerValue];
    self.nickName = mutableDict[@"fromName"]?:@"";
    self.avatar = mutableDict[@"fromAvatar"]?:@"";
    
    // 通用内容
//    self.content = mutableDict[@"content"] ?: @"";//本地明文存储
    self.content =[CryptoAES.shareInstance decryptDataL:mutableDict[@"content"] ?: @""];//本地加密存储
    
    
    self.msgId = mutableDict[@"id"];
    self.fromId = mutableDict[@"fromId"];
    // 发送方标识
    NSDictionary *userinfo = [UDManager.shareInstance getDDManager:dkuserinfo];
    NSString *userId = userinfo[@"id"];
    if([self.fromId isEqualToString:userId]){
        self.isSender=true;
    }
    else{
        self.isSender=false;
    }
    
    // 处理媒体尺寸
    CGFloat width = [mutableDict[@"width"] floatValue];
    CGFloat height = [mutableDict[@"height"] floatValue];
    if (width > 0 && height > 0) {
        self.mediaSize = CGSizeMake(width, height);
    } else {
        // 默认尺寸
        self.mediaSize = CGSizeMake(200, 150);
    }
    self.placeholderImage = kImageMake(@"pictrue_placeholder");
    
    // 文件消息
    NSDictionary * extend = [mutableDict[@"extend"] isKindOfClass:NSDictionary.class]?mutableDict[@"extend"]:@{};

    self.fileName = extend[@"fileName"] ?: @"未知文件";
    self.fileSize = extend[@"size"] ?: @"0KB";
    
    
    self.url = extend[@"url"] ?: @"";
    NSCharacterSet *allowedCharacters = [NSCharacterSet URLQueryAllowedCharacterSet];
    self.url = [self.url stringByAddingPercentEncodingWithAllowedCharacters:allowedCharacters];
    self.localurl = extend[@"localurl"] ?: @"";
    
    self.quoteMessage = ![extend jk_hasKey:@"quoteMessage"] ?NULL: [ChatMessageModel modelWithDictionary:extend[@"quoteMessage"]];
    
    // 语音消息
    NSInteger duration = [extend[@"time"] integerValue];
    if (duration<=60) {
        self.voiceDuration = duration;
    }else{
        self.voiceDuration = duration/1000;
    }
    self.voiceWidth = self.voiceDuration==0?0:[self voiceBubbleWidth];
    
    //文件传输成功或失败
    self.fileError = 0;
    NSInteger fileError = [extend[@"fileError"] integerValue];
    if (fileError!=0) {
        self.fileError = fileError;
    }
    else{
        if(self.url.length>0){
            self.fileError = 0;
        }
    }
    
    
    //合并转发
    self.forwardMsgArray = extend[@"messageList"] ?:@[];
    
    // 通话记录
    self.callDuration = [mutableDict[@"duration"] integerValue];
    self.isCallSuccess = [mutableDict[@"result"] boolValue];
    self.isVideo = [mutableDict[@"video"] boolValue];
    
    //@相关
    self.atAll = extend[@"atAll"]?[extend[@"atAll"] boolValue]:NO;
    self.atUserIds = extend[@"atUserIds"]?:@[];
    
    // 时间戳（如果需要）
    self.timestamp = [mutableDict[@"timestamp"] longLongValue];
    self.localtime = [mutableDict[@"localtime"] longLongValue];
    self.formatterTime = [self timeF:self.timestamp];
    // 其他自定义字段...
    self.readStatus = [self getReadStatus];
}

- (void)exchangeModelWithModel:(ChatMessageModel *)model{
    self.msgId = model.msgId;
    self.formerMessage = model.formerMessage;
    
    if(self.messageType!=model.messageType){
        self.cellHeight=0;
    }
    self.messageType = model.messageType;
    
    self.type = model.type;
    self.isSender = model.isSender;
    self.content = model.content;
    self.msgId = model.msgId;
    self.mediaSize = model.mediaSize;
    self.placeholderImage = model.placeholderImage;
    self.fileName = model.fileName;
    self.fileSize = model.fileSize;
    self.url = model.url;
    self.localurl = model.localurl;
    //文件传输成功或失败
    self.fileError = model.fileError;
    
    // 通话记录
    self.callDuration = model.callDuration;
    self.isCallSuccess = model.isCallSuccess;
    self.isVideo = model.isVideo;
    self.avatar = model.avatar;
    self.nickName = model.nickName;
    
    //@相关
    self.atAll = model.atAll;
    self.atUserIds = model.atUserIds;
    
    // 时间戳（如果需要）
    self.timestamp = model.timestamp;
    self.localtime = model.localtime;
    self.formatterTime = model.formatterTime;
//    // 其他自定义字段...
    // 其他自定义字段...
    self.readStatus = [self getReadStatus];
}

-(NSString *)timeF:(NSInteger)time{
    //NSLog(@"time:%ld",(long)time);
    // 创建日期格式器
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"dd"]; // 设置你想要的日期格式
    
    
    long long timestamp =(long)time/1000; // 例如：2021-10-01 00:00:00 UTC
    // 转换为NSDate
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:timestamp];
    NSString *dateString = [formatter stringFromDate:date];
    
    
    NSDate *now = [NSDate date];
    NSTimeInterval trt = [now timeIntervalSince1970];
    date = [NSDate dateWithTimeIntervalSince1970:trt];
    NSString *tdateString = [formatter stringFromDate:date];
    
    
    NSInteger shijiancha = trt-timestamp;
    
    if(shijiancha<60){
        return NSLocalizedString(@"time-oneminint", @"");
    }
    if(shijiancha>24*3600||dateString.intValue!=tdateString.intValue){
        // 假设这是你的时间戳（以秒为单位）
        long long timestamp =(long)time/1000; // 例如：2021-10-01 00:00:00 UTC
        // 转换为NSDate
        NSDate *date = [NSDate dateWithTimeIntervalSince1970:timestamp];
        // 创建日期格式器
        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
        [formatter setDateFormat:@"yyyy-MM-dd HH:mm"]; // 设置你想要的日期格式
        // 转换为字符串
        NSString *dateString = [formatter stringFromDate:date];
        return dateString;
    }
    else{
        NSInteger xiaoshi = shijiancha/3600;
        NSInteger fenzhong = shijiancha/60;
        if(xiaoshi>0){
            // 假设这是你的时间戳（以秒为单位）
            long long timestamp =(long)time/1000; // 例如：2021-10-01 00:00:00 UTC
            // 转换为NSDate
            NSDate *date = [NSDate dateWithTimeIntervalSince1970:timestamp];
            // 创建日期格式器
            NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
            [formatter setDateFormat:@"HH:mm"]; // 设置你想要的日期格式
            // 转换为字符串
            NSString *dateString = [formatter stringFromDate:date];
            return dateString;
        }
        else{
            return [NSString stringWithFormat:@"%ld%@",(long)fenzhong,NSLocalizedString(@"time-outmin", @"")];
        }
    }
    
    return @"";
}

- (NSString *)getReadStatus{
    NSString * readStatus;
    self.readstate = 0;
    if(self.timestamp == 0){
        return @"";
    }
    if(self.messageType==11||self.messageType==12){
        return @"";
    }
    
    
    if(self.type==0){
        if (self.localtime != 0 && self.localtime == self.timestamp) {
            NSDate *now = [NSDate date];
            NSTimeInterval trt = [now timeIntervalSince1970];
            NSInteger time = trt*1000;
            NSInteger outTime =time-self.localtime;
            if(outTime>33000){
                if(self.messageType==1||self.messageType==2||self.messageType==5){
                    readStatus = @"正在发送";
                    self.readstate = 3;
                }else{
                    readStatus = @"发送失败";
                    self.readstate = 4;
                }
            }else{
                readStatus = @"正在发送";
                self.readstate = 3;
            }
        }
        else{
            //判断已读未读
            if(self.timestamp>ChatsStore.shareInstance.lastreadTime){
                readStatus = @"未读";
                self.readstate = 1;
            }
            else{
                readStatus = @"已读";
                self.readstate = 2;
            }
            if(self.fileError==1){
                readStatus = @"發送失敗，點擊重發";
                self.readstate = 4;
            }
        }
    }else{
        return @"";
    }
    
    return readStatus;
}

- (void)generateThumbnailWithCompletion:(void(^)(UIImage *thumbnail))completion {
    // 如果内存中已有缩略图，直接返回
    if (self.videoThumbnailImage) {
        if (completion) completion(self.videoThumbnailImage);
        return;
    }
    
    // 生成缓存 key，优先使用 msgId，如果没有则使用 URL 的 hash
    NSString *cacheKey = nil;
    if (self.msgId.length > 0) {
        cacheKey = [NSString stringWithFormat:@"video_thumbnail_%@", self.msgId];
    } else if (self.url.length > 0) {
        cacheKey = [NSString stringWithFormat:@"video_thumbnail_%lu", (unsigned long)[self.url hash]];
    }
    
    // 从 SDWebImage 缓存中查找
    if (cacheKey) {
        SDImageCache *imageCache = [SDImageCache sharedImageCache];
        UIImage *cachedImage = [imageCache imageFromCacheForKey:cacheKey];
        if (cachedImage) {
            NSLog(@"从缓存加载缩略图: %@", cacheKey);
            self.videoThumbnailImage = cachedImage;
            if (completion) completion(cachedImage);
            return;
        }
    }
    
    // 没有缓存，需要生成缩略图
    NSURL *videoURL = nil;
    if (self.localurl.length != 0 && [[NSFileManager defaultManager] fileExistsAtPath:self.localurl]) {
        // 从本地文件生成缩略图
        NSLog(@"generateThumbnailWithCompletion localurl:%@",self.localurl);
        videoURL = [NSURL fileURLWithPath:self.localurl];
        NSString *finalCacheKey = cacheKey;
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];
            
            AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
            generator.appliesPreferredTrackTransform = YES;

            CMTime acttime;
            NSError *error = nil;
            CGImageRef imageRef = [generator copyCGImageAtTime:CMTimeMake(0, 600) actualTime:&acttime error:&error];
            NSLog(@"error:%@",error);
            if (!error && imageRef) {
                UIImage *thumbnail = [[UIImage alloc] initWithCGImage:imageRef];
                CGImageRelease(imageRef);
                
                // 缓存到内存
                self.videoThumbnailImage = thumbnail;
                
                // 使用 SDWebImage 缓存到磁盘和内存
                if (finalCacheKey) {
                    SDImageCache *imageCache = [SDImageCache sharedImageCache];
                    [imageCache storeImage:thumbnail forKey:finalCacheKey completion:^{
                        NSLog(@"缩略图已缓存: %@", finalCacheKey);
                    }];
                }
                
                if (completion){
                    completion(thumbnail);
                }
            } else {
                if (completion) completion(nil);
            }
        });
    } else {
        // 从远程 URL 生成缩略图
        NSLog(@"generateThumbnailWithCompletion url");
        if (self.url.length == 0){
            if (completion) completion(nil);
            return;
        }
        
        NSDictionary *options = @{AVURLAssetAllowsCellularAccessKey: @YES,
                                  AVURLAssetPreferPreciseDurationAndTimingKey: @YES};
        AVURLAsset *asset = [AVURLAsset URLAssetWithURL:getURL(self.url) options:options];
        
        // 创建图像生成器
        AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:asset];
        generator.appliesPreferredTrackTransform = YES; // 应用视频的方向
        generator.maximumSize = CGSizeMake(320, 0);     // 设置最大尺寸，保持宽高比
        
        NSString *finalCacheKey = cacheKey;
        // 异步生成缩略图
        [generator generateCGImagesAsynchronouslyForTimes:@[[NSValue valueWithCMTime:kCMTimeZero]]
                                             completionHandler:^(CMTime requestedTime, CGImageRef image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error) {
            __block UIImage *thumbnail = nil;
            // 处理生成结果
            if (result == AVAssetImageGeneratorSucceeded && image) {
                // 创建UIImage
                thumbnail = [UIImage imageWithCGImage:image];
                self.videoThumbnailImage = thumbnail;
                
                // 使用 SDWebImage 缓存到磁盘和内存
                if (finalCacheKey) {
                    SDImageCache *imageCache = [SDImageCache sharedImageCache];
                    [imageCache storeImage:thumbnail forKey:finalCacheKey completion:^{
                        NSLog(@"缩略图已缓存: %@", finalCacheKey);
                    }];
                }
            }
            dispatch_async(dispatch_get_main_queue(), ^{
                if (completion) completion(thumbnail);
            });
        }];
    }
}

//下载视频文件
-(void)xiazaishipin:(void(^)(NSInteger persent))loading{
    NSLog(@"xiazaishipin--------");
    
    if(!self.isSender){
        NSString *localFileurl = [self.localurl stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLPathAllowedCharacterSet]];
        if (self.localurl.length != 0 && [[NSFileManager defaultManager] fileExistsAtPath:localFileurl]){
//            NSLog(@"文件已经存在本地");
            if (loading) {
                loading(100);
            }
        }
        else{
//            NSLog(@"文件不存在");
            if(self.url&&self.url.length != 0){
                
                NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
                NSURL *tempUrl = [NSURL URLWithString:self.url];
                NSString *fileName = tempUrl.lastPathComponent;
                NSString *fileExtension = [fileName pathExtension];
                NSString *newfileName = [NSString stringWithFormat:@"%@.%@", self.msgId,fileExtension];
                documentsDirectoryURL = [documentsDirectoryURL URLByAppendingPathComponent:newfileName];
                NSLog(@"文件已经存在本地1-:%@",documentsDirectoryURL.path);
                if ([[NSFileManager defaultManager] fileExistsAtPath:documentsDirectoryURL.path]){
                    NSLog(@"文件已经存在本地2-:%@",documentsDirectoryURL.path);
                    NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                    NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                    [extend setObject:documentsDirectoryURL.path forKey:@"localurl"];
                    [mutableDict setObject:extend forKey:@"extend"];
                    self.localurl = documentsDirectoryURL.path;
                    NSDictionary *NewMsg = [mutableDict copy];
                    [ChatsStore.shareInstance reciveMsg:NewMsg];
                    if (loading) {
                        loading(100);
                    }
                }
                else{
                    [FileNetApi downLoadWToken:getURL(self.url) thrid:self.msgId succ:^(int code, NSDictionary * res) {
                        if(res!=nil){
                            NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                            NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                            [extend setObject:res[@"filePath"] forKey:@"localurl"];
                            [mutableDict setObject:extend forKey:@"extend"];
                            self.localurl = res[@"filePath"];
                            NSDictionary *NewMsg = [mutableDict copy];
                            [ChatsStore.shareInstance reciveMsg:NewMsg];
                            if (loading) {
                                loading(100);
                            }
                        }
                        else{
                            if (code>=0&&code<200) {
                                if (loading) {
                                    loading(code);
                                }
                            }
                        }
                    } fail:^(NSError * _Nonnull error) {
                        NSLog(@"error:%@",error);
                    }];
                }
            }
            else{
                if (loading) {
                    loading(0);
                }
            }
        }
    }
    else{
        NSLog(@"downLoadWToken xiazaishipin-----");
    }
}

-(void)xiazaiwenjian:(void(^)(NSInteger persent))loading{
    NSLog(@"xiazaiwenjian---");
    if (self.isSender) {
        return;
    }
    else{
//        NSLog(@"self.localurl2:%@",self.localurl);
        if (self.localurl.length != 0 && [[NSFileManager defaultManager] fileExistsAtPath:self.localurl]){
//            NSLog(@"文件已经存在本地");
            self.customFileSize = [self getFileSize];
            if (loading) {
                loading(100);
            }
            return;
        }
        else{
            if(self.url&&self.url.length != 0){
                
                NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
                NSURL *tempUrl = [NSURL URLWithString:self.url];
                NSString *fileName = tempUrl.lastPathComponent;
                NSString *fileExtension = [fileName pathExtension];
                NSString *newfileName = [NSString stringWithFormat:@"%@.%@", self.msgId,fileExtension];
                documentsDirectoryURL = [documentsDirectoryURL URLByAppendingPathComponent:newfileName];
                NSLog(@"文件已经存在本地1-:%@",documentsDirectoryURL.path);
                if ([[NSFileManager defaultManager] fileExistsAtPath:documentsDirectoryURL.path]){
                    NSLog(@"文件已经存在本地2-:%@",documentsDirectoryURL.path);
                    NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                    NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                    [extend setObject:documentsDirectoryURL.path forKey:@"localurl"];
                    [mutableDict setObject:extend forKey:@"extend"];
                    self.localurl = documentsDirectoryURL.path;
                    NSDictionary *NewMsg = [mutableDict copy];
                    [ChatsStore.shareInstance reciveMsg:NewMsg];
                    self.customFileSize = [self getFileSize];
                    if (loading) {
                        loading(100);
                    }
                }
                else{
                    [FileNetApi downLoadWToken:getURL(self.url) thrid:self.msgId succ:^(int code, NSDictionary * res) {
                        if(res!=nil){
                            NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                            NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                            [extend setObject:res[@"filePath"] forKey:@"localurl"];
                            [mutableDict setObject:extend forKey:@"extend"];
                            self.localurl = res[@"filePath"];
                            NSDictionary *NewMsg = [mutableDict copy];
                            [ChatsStore.shareInstance reciveMsg:NewMsg];
                            self.customFileSize = [self getFileSize];
                            if (loading) {
                                loading(100);
                            }
                        }
                        else{
                            if (code>=0&&code<200) {
                                if (loading) {
                                    loading(code);
                                }
                            }
                        }
                    } fail:^(NSError * _Nonnull error) {
                        NSLog(@"error:%@",error);
                    }];
                }
            }
            else{
                if (loading) {
                    loading(0);
                }
            }
        }
    }
}


-(void)xiazaiyuyin:(void(^)(NSInteger persent))loading{
    NSLog(@"xiazaiwenjian---");
    if (self.isSender) {
        return;
    }
    else{
//        NSLog(@"self.localurl2:%@",self.localurl);
        if (self.localurl.length != 0 && [[NSFileManager defaultManager] fileExistsAtPath:self.localurl]){
//            NSLog(@"文件已经存在本地");
            if (loading) {
                loading(100);
            }
            return;
        }
        
        if(self.url&&self.url.length != 0){
            
            NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:NO error:nil];
            NSURL *tempUrl = [NSURL URLWithString:self.url];
            NSString *fileName = tempUrl.lastPathComponent;
            NSString *fileExtension = [fileName pathExtension];
            NSString *newfileName = [NSString stringWithFormat:@"%@.%@", self.msgId,fileExtension];
            documentsDirectoryURL = [documentsDirectoryURL URLByAppendingPathComponent:newfileName];
            NSLog(@"文件已经存在本地1-:%@",documentsDirectoryURL.path);
            if ([[NSFileManager defaultManager] fileExistsAtPath:documentsDirectoryURL.path]){
                NSLog(@"文件已经存在本地2-:%@",documentsDirectoryURL.path);
                NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                [extend setObject:documentsDirectoryURL.path forKey:@"localurl"];
                [mutableDict setObject:extend forKey:@"extend"];
                self.localurl = documentsDirectoryURL.path;
                NSDictionary *NewMsg = [mutableDict copy];
                [ChatsStore.shareInstance reciveMsg:NewMsg];
                if (loading) {
                    loading(100);
                }
            }
            else{
                [FileNetApi downLoadWToken:getURL(self.url) thrid:self.msgId succ:^(int code, NSDictionary * res) {
                    if(res!=nil){
                        NSMutableDictionary *mutableDict = [self.formerMessage mutableCopy];
                        NSMutableDictionary *extend = [self.formerMessage[@"extend"] mutableCopy];
                        [extend setObject:res[@"filePath"] forKey:@"localurl"];
                        [mutableDict setObject:extend forKey:@"extend"];
                        self.localurl = res[@"filePath"];
                        NSDictionary *NewMsg = [mutableDict copy];
                        [ChatsStore.shareInstance reciveMsg:NewMsg];
                        if (loading) {
                            loading(100);
                        }
                    }
                    else{
                        if (code>=0&&code<200) {
                            if (loading) {
                                loading(code);
                            }
                        }
                    }
                } fail:^(NSError * _Nonnull error) {
                    NSLog(@"error:%@",error);
                }];
            }
        }
        else{
            if (loading) {
                loading(0);
            }
        }
    }
}


-(void)setuploadPersent:(NSInteger)persent localtime:(NSInteger)localtime{
    if(self.uploadPersentChange && localtime==self.localtime){
        self.uploadPersentChange(persent,localtime);
    }
}



// 根据语音时长计算气泡宽度
- (CGFloat)voiceBubbleWidth {
    // 基础宽度
    CGFloat minWidth = 60.0f;
    CGFloat maxWidth = 200.0f;
    
    // 最大限制时长（如60秒）
    NSInteger maxDuration = 60;
    NSInteger duration = MIN(self.voiceDuration, maxDuration);
    
    // 线性增长计算
    CGFloat width = minWidth + (maxWidth - minWidth) * (duration / (CGFloat)maxDuration);
    
    return width;
}

- (NSString *)getFileSize {
    NSString *filePath = self.localurl;

    NSFileManager *fileManager = [NSFileManager defaultManager];

    // 获取文件属性
    NSError *error = nil;
    NSDictionary *attributes = [fileManager attributesOfItemAtPath:filePath error:&error];

    NSString *string = @"0KB";
    if (error) {
        NSLog(@"获取文件属性失败: %@", error);
    } else {
        // 获取文件大小（单位：字节）
        unsigned long long fileSize = [attributes fileSize];
        NSLog(@"文件大小: %llu 字节", fileSize);

        // 可选：转换为 KB、MB
        double fileSizeKB = fileSize / 1024.0;
        double fileSizeMB = fileSizeKB / 1024.0;
        NSLog(@"文件大小: %.2f KB (%.2f MB)", fileSizeKB, fileSizeMB);
        string = [NSString stringWithFormat:@"%.2fMB", fileSizeMB];
    }
    return string;
}

- (NSString *)customFileSize {
    if (!_customFileSize) {
        _customFileSize = [self getFileSize];
    }
    return _customFileSize;
}

@end