ios-chat/wfuikit/WFChatUIKit/Utilities/WFCUMediaMessageDownloader.m

//
//  MediaMessageDownloader.m
//  WildFireChat
//
//  Created by heavyrain lee on 2018/8/29.
//  Copyright © 2018 WildFireChat. All rights reserved.
//

#import "WFCUMediaMessageDownloader.h"
#import "AFNetworking.h"

static WFCUMediaMessageDownloader *sharedSingleton = nil;

@interface WFCUMediaMessageDownloader()
@property(nonatomic, strong)NSMutableDictionary<NSString*, NSNumber*> *downloadingMessages;
@end



@implementation WFCUMediaMessageDownloader
+ (instancetype)sharedDownloader {
    if (sharedSingleton == nil) {
        @synchronized (self) {
            if (sharedSingleton == nil) {
                sharedSingleton = [[WFCUMediaMessageDownloader alloc] init];
                sharedSingleton.downloadingMessages = [[NSMutableDictionary alloc] init];
            }
        }
    }
    
    return sharedSingleton;
}

- (void)downloadFileWithURL:(NSString*)requestURLString
                 parameters:(NSDictionary *)parameters
                  savedPath:(NSString*)savedPath
            downloadSuccess:(void (^)(NSURLResponse *response, NSURL *filePath))success
            downloadFailure:(void (^)(NSError *error))failure
           downloadProgress:(void (^)(NSProgress *downloadProgress))progress

{
    
    AFHTTPRequestSerializer *serializer = [AFHTTPRequestSerializer serializer];
    NSMutableURLRequest *request =[serializer requestWithMethod:@"GET" URLString:requestURLString parameters:parameters error:nil];
    NSURLSessionDownloadTask *task = [[AFHTTPSessionManager manager] downloadTaskWithRequest:request progress:^(NSProgress * _Nonnull downloadProgress) {
        progress(downloadProgress);
    } destination:^NSURL * _Nonnull(NSURL * _Nonnull targetPath, NSURLResponse * _Nonnull response) {
        return [NSURL fileURLWithPath:savedPath];
    } completionHandler:^(NSURLResponse * _Nonnull response, NSURL * _Nullable filePath, NSError * _Nullable error) {
        if(error){
            failure(error);
        }else{
            success(response,filePath);
        }
    }];
    [task resume];
    
}

- (BOOL)tryDownload:(WFCCMessage *)msg
            success:(void(^)(long long messageUid, NSString *localPath))successBlock
              error:(void(^)(long long messageUid, int error_code))errorBlock {
    long long messageUid = msg.messageUid;
    
    if (!messageUid) {
        NSLog(@"Error, try download message have invalid uid");
        errorBlock(0, -2);
        return TRUE;
    }
    
    if (![msg.content isKindOfClass:[WFCCMediaMessageContent class]]) {
        NSLog(@"Error, try download message with id %lld, but it's not media message", messageUid);
        errorBlock(msg.messageUid, -1);
        return TRUE;
    }
    
    WFCCMediaMessageContent *mediaContent = (WFCCMediaMessageContent *)msg.content;
    if (mediaContent.localPath.length) {
        successBlock(msg.messageUid, mediaContent.localPath);
        return TRUE;
    }
    
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL isDir;
    NSError *error = nil;
    NSString *downloadDir = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject stringByAppendingString:@"/download"];
    if (![fileManager fileExistsAtPath:downloadDir isDirectory:&isDir]) {
        if(![fileManager createDirectoryAtPath:downloadDir withIntermediateDirectories:YES attributes:nil error:&error]) {
            errorBlock(msg.messageUid, -1);
            NSLog(@"Error, create download folder error");
            return YES;
        }
        if (error) {
            errorBlock(msg.messageUid, -1);
            NSLog(@"Error, create download folder error:%@", error);
            return YES;
        }
    }
    if (!isDir) {
        errorBlock(msg.messageUid, -1);
        NSLog(@"Error, create download folder error");
        return YES;
    }
    
    //通知UI开始显示下载动画
    [[NSNotificationCenter defaultCenter] postNotificationName:kMediaMessageStartDownloading object:@(messageUid)];
    
    
    if (self.downloadingMessages[mediaContent.remoteUrl]) {
        return NO;
    }
    
    NSString *savedPath = [downloadDir stringByAppendingPathComponent:[NSString stringWithFormat:@"media_%ld", mediaContent.remoteUrl.hash]];
    
    if ([mediaContent isKindOfClass:[WFCCSoundMessageContent class]]) {
        savedPath = [NSString stringWithFormat:@"%@.wav", savedPath];
    } else if([mediaContent isKindOfClass:[WFCCVideoMessageContent class]]) {
        savedPath = [NSString stringWithFormat:@"%@.mp4", savedPath];
    } else if([mediaContent isKindOfClass:[WFCCImageMessageContent class]]) {
        savedPath = [NSString stringWithFormat:@"%@.jpg", savedPath];
    } else if([mediaContent isKindOfClass:[WFCCFileMessageContent class]]) {
        WFCCFileMessageContent *content = (WFCCFileMessageContent *)mediaContent;
        savedPath = [downloadDir stringByAppendingPathComponent:[NSString stringWithFormat:@"%ld-%@", mediaContent.remoteUrl.hash, content.name]];
    }
    
    if ([fileManager fileExistsAtPath:savedPath]) {
        mediaContent.localPath = savedPath;
        [[WFCCIMService sharedWFCIMService] updateMessage:messageUid content:mediaContent];
        
        successBlock(msg.messageUid, savedPath);
        
        [[NSNotificationCenter defaultCenter] postNotificationName:kMediaMessageDownloadFinished object:@(messageUid) userInfo:@{@"result":@(YES), @"localPath":savedPath}];
        
        return YES;
    }
    
    [self.downloadingMessages setObject:@(messageUid) forKey:mediaContent.remoteUrl];
    
    [self downloadFileWithURL:mediaContent.remoteUrl parameters:nil savedPath:savedPath downloadSuccess:^(NSURLResponse *response, NSURL *filePath) {
        NSLog(@"download message content of %lld success", messageUid);
        dispatch_async(dispatch_get_main_queue(), ^{
            [[WFCUMediaMessageDownloader sharedDownloader].downloadingMessages removeObjectForKey:mediaContent.remoteUrl];
            WFCCMessage *newMsg = msg;
            if (msg.conversation.type != Chatroom_Type) {
                newMsg = [[WFCCIMService sharedWFCIMService] getMessageByUid:messageUid];
            }
            
            if (!newMsg) {
                NSLog(@"Error, message %lld not exist", messageUid);
                errorBlock(msg.messageUid, -1);
                return;
            }
            
            if (![newMsg.content isKindOfClass:[WFCCMediaMessageContent class]]) {
                NSLog(@"Error, message %lld not media message", messageUid);
                errorBlock(msg.messageUid, -1);
                return;
            }
            
            WFCCMediaMessageContent *newContent = (WFCCMediaMessageContent *)newMsg.content;
            newContent.localPath = filePath.absoluteString;
            [[WFCCIMService sharedWFCIMService] updateMessage:newMsg.messageId content:newContent];
            
            mediaContent.localPath = filePath.absoluteString;
            successBlock(newMsg.messageUid, filePath.absoluteString);
            
            [[NSNotificationCenter defaultCenter] postNotificationName:kMediaMessageDownloadFinished object:@(messageUid) userInfo:@{@"result":@(YES), @"localPath":filePath.absoluteString}];
        });
    } downloadFailure:^(NSError *error) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [[WFCUMediaMessageDownloader sharedDownloader].downloadingMessages removeObjectForKey:mediaContent.remoteUrl];
            
            errorBlock(msg.messageUid, -1);
            
            [[NSNotificationCenter defaultCenter] postNotificationName:kMediaMessageDownloadFinished object:@(messageUid) userInfo:@{@"result":@(NO)}];
        });
        NSLog(@"download message content of %lld failure with error %@", messageUid, error);
    } downloadProgress:^(NSProgress *downloadProgress) {
        NSLog(@"总大小：%lld,当前大小:%lld",downloadProgress.totalUnitCount,downloadProgress.completedUnitCount);
    }];
    return YES;
}

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}
@end