//
//  customDownloadManager.m
//  双子星云手机
//
//  Created by xd h on 2024/7/1.
//

#import "customDownloadManager.h"
#import "customDownloadOperation.h"
#import "customDownloadCacheManager.h"

@interface customDownloadManager ()<NSURLSessionDataDelegate>
//排队等候下载的下载地址数组
@property(nonatomic,strong) NSMutableArray *downloadWaitingUrlArr;
//正在下载的下载地址数组
@property(nonatomic,strong) NSMutableArray *downloadingOperationArr;
@end

@implementation customDownloadManager
+ (instancetype)shareManager {
    static customDownloadManager *_instance;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        _instance = [[self alloc] init];
    });
    return _instance;
}

- (instancetype)init {

    if (self = [super init]) {
        _maxDownLoadCount = 1;
        //[self registeNotification];
    }
    return self;
}

- (NSString*)uid{
    if(!_uid || _uid.length == 0){
        return @"customUserName";
    }
    
    return _uid;
}

/** 添加要下载的 网络连接  */
- (void)addDownloadWithURLs:(NSArray *)urls{
    
    for (NSString *addUrl in urls) {
        BOOL needAddType = YES;
        
        //1. 排查下载中
        for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
            if([operationDoing.url isEqualToString:addUrl]){
                needAddType = NO;
                break;
            }
        }
        
        //1. 排查等待下载
        for (NSString *waitUrl in self.downloadWaitingUrlArr) {
            if([waitUrl isEqualToString:addUrl]){
                needAddType = NO;
                break;
            }
        }
        
        if(needAddType){
            [self.downloadWaitingUrlArr addObject:addUrl];
        }
    }
    
    //启动下载
    [self beginDownload];
}

//在添加下载地址后 启动下载
- (void)beginDownload
{
    @synchronized (self) {
        if(self.downloadingOperationArr.count == _maxDownLoadCount){
            HLog(@"正在下载的数量达到了最大值 %ld",_maxDownLoadCount)
            return;
        }
        
        if(self.downloadWaitingUrlArr.count == 0){
            HLog(@"没有等待中的下载任务")
            return;
        }
        
        NSInteger canAddTaskNumber = _maxDownLoadCount - self.downloadingOperationArr.count;
        
        for (int i=0; i<canAddTaskNumber; i++) {
            
            if(self.downloadWaitingUrlArr.count >= 1){
                //创建下载任务
                NSString *downloadUrl = self.downloadWaitingUrlArr.firstObject;
                
                NSURLSession *session = [self creatNewSessionFun];
                customDownloadOperation * operation = [[customDownloadOperation alloc] initWith:downloadUrl session:session];
                
                //等待下载中的任务
                [self.downloadWaitingUrlArr removeObjectAtIndex:0];
                //添加到下载中数组
                [self.downloadingOperationArr addObject:operation];
                
                [operation.dataTask resume];
            }
            
        }
    
    }
    
}

/** 开始任务（不会自动添加任务，列队中没有就直接返回） 后续改为会自动添加任务 */
- (void)startDownLoadWithUrl:(NSString *)url
{
    
    BOOL needAddType = YES;
    
    //1. 排查下载中
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if([operationDoing.url isEqualToString:url]){
            needAddType = NO;
            break;
        }
    }
    
    //1. 排查等待下载
    for (NSString *waitUrl in self.downloadWaitingUrlArr) {
        if([waitUrl isEqualToString:url]){
            needAddType = NO;
            break;
        }
    }
    
    if(needAddType){
        [self.downloadWaitingUrlArr addObject:url];
    }
    
    //启动下载
    [self beginDownload];
}

/** 删除任务（删除下载url内容的任务） */
- (void)deleteDownloadWithUrl:(NSString *)url
{
    //1.检测等待下载的任务
    for (NSString*waitingUrl in self.downloadWaitingUrlArr) {
        if ([waitingUrl isEqualToString:url]) {
            [self.downloadWaitingUrlArr removeObject:waitingUrl];
            break;
        }
    }
    
    //2.检测下载中的任务
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if([operationDoing.url isEqualToString:url]){
            [operationDoing.dataTask cancel];
//            operationDoing.dataTask = nil;
//            operationDoing.session = nil;
//        
//            [operationDoing.handle closeFile];
//            operationDoing.handle = nil;
//            
//            [self.downloadingOperationArr removeObject:operationDoing];
            break;
        }
    }
    
    //3. 删除本地文件
    [customDownloadCacheManager deleteFileWithUrl:url];
    
    //4.进行下一个任务
    //[self beginDownload];
}

/** 暂停任务（暂停下载url内容的任务） */
- (void)supendDownloadWithUrl:(NSString *)url
{
    //1.检测等待下载的任务
    for (NSString*waitingUrl in self.downloadWaitingUrlArr) {
        if ([waitingUrl isEqualToString:url]) {
            [self.downloadWaitingUrlArr removeObject:waitingUrl];
            break;
        }
    }
    
    //2.检测下载中的任务
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if([operationDoing.url isEqualToString:url]){
            operationDoing.isManualCancel = YES;
            
            if(operationDoing.dataTask){
                [operationDoing.dataTask cancel];
            }
//            operationDoing.dataTask = nil;
//            operationDoing.session = nil;
//        
//            [operationDoing.handle closeFile];
//            operationDoing.handle = nil;
//            
//            //删除后 didCompleteWithError 不再处理
//            [self.downloadingOperationArr removeObject:operationDoing];
           
            break;
        }
    }
    
    //进行下一个任务
    //[self beginDownload];
}

/** 暂停当前所有的下载任务 下载任务不会从列队中删除 */
- (void)suspendAllDownloadTask
{
    //1.删除等待下载的任务
    [self.downloadWaitingUrlArr removeAllObjects];
    
    //2.检测下载中的任务
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        operationDoing.isManualCancel = YES;
        if(operationDoing.dataTask){
            [operationDoing.dataTask cancel];
        }
        
//        operationDoing.dataTask = nil;
//        operationDoing.session = nil;
//        [operationDoing.handle closeFile];
//        operationDoing.handle = nil;
    }

    [self.downloadingOperationArr removeAllObjects];
}

#pragma mark 重新启动因为网络失败而停止的任务
- (void)reDownloadNetworkTaskBy:(NSString*)url
{
    @synchronized (self) {
        [self.downloadWaitingUrlArr insertObject:url atIndex:0];
    }
    
    [self beginDownload];
}

#pragma mark - <NSURLSessionDataDelegate>

// ssl 服务 证书信任
- (void)URLSession:(NSURLSession *)session
didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
 completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential * _Nullable credential))completionHandler{
    if(![challenge.protectionSpace.authenticationMethod isEqualToString:@"NSURLAuthenticationMethodServerTrust"]) {
        return;
    }
    
    // 信任该插件
    NSURLCredential *credential = [[NSURLCredential alloc] initWithTrust:challenge.protectionSpace.serverTrust];
    // 第一个参数 告诉系统如何处置
    completionHandler(NSURLSessionAuthChallengeUseCredential,credential);
}

//当请求协议是https的时候回调用该方法
//Challenge 挑战 质询(受保护空间)
//NSURLAuthenticationMethodServerTrust 服务器信任证书
- (void)URLSession:(NSURLSession *)session
              task:(NSURLSessionTask *)task
didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge
 completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential * __nullable credential))completionHandler {
    
    if(![challenge.protectionSpace.authenticationMethod isEqualToString:@"NSURLAuthenticationMethodServerTrust"]) {
        return;
    }
    
    // 信任该插件
    NSURLCredential *credential = [[NSURLCredential alloc] initWithTrust:challenge.protectionSpace.serverTrust];
    // 第一个参数 告诉系统如何处置
    completionHandler(NSURLSessionAuthChallengeUseCredential,credential);
    
}


// 接受到响应调用
- (void)URLSession:(NSURLSession *)session
          dataTask:(NSURLSessionDataTask *)dataTask
didReceiveResponse:(NSURLResponse *)response
 completionHandler:(void (^)(NSURLSessionResponseDisposition disposition))completionHandler {
    
    // 将响应交给列队处理
    BOOL canDownload =  [self handleOperateby:dataTask WithResponse:response];
    
    if(canDownload){
        // 允许下载
        completionHandler(NSURLSessionResponseAllow);
    }
    else{
        // 不允许下载
        completionHandler(NSURLSessionResponseCancel);
    }
    
}

// 接受到数据碎片 的时候调用，调用多次
- (void)URLSession:(NSURLSession *)session
          dataTask:(NSURLSessionDataTask *)dataTask
    didReceiveData:(NSData *)data {
    // 接收到session 下载碎片交个列队管理
    [self dataTask:dataTask didReceiveData:data];
}

// <NSURLSessionDataDelegate> 完成下载
- (void)URLSession:(NSURLSession *)session
              task:(NSURLSessionTask *)task
didCompleteWithError:(nullable NSError *)error {
    [self task:task didCompleteWithError:error];
}

- (void)URLSession:(NSURLSession *)session
              task:(NSURLSessionTask *)task
 needNewBodyStream:(void (^)(NSInputStream * _Nullable bodyStream))completionHandler {
    
}

- (void)URLSession:(NSURLSession *)session
              task:(NSURLSessionTask *)task
   didSendBodyData:(int64_t)bytesSent
    totalBytesSent:(int64_t)totalBytesSent
totalBytesExpectedToSend:(int64_t)totalBytesExpectedToSend {
    
}

#pragma mark 处理接收到的数据

// 接收到相应时
- (BOOL)handleOperateby:(NSURLSessionTask*)dataTask WithResponse:(NSURLResponse *)response {
    
    customDownloadOperation *operation = nil;
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if(operationDoing.dataTask == dataTask){
            operation = operationDoing;
            break;
        }
    }
    
    if (!operation) {
        HLog(@"没找到当前下载任务");
        operation.downloadState = customDownloadStateFailed;
        [dataTask cancel];
        return NO;
    }
    
    // 检查response是否是NSHTTPURLResponse的实例
    if ([response isKindOfClass:[NSHTTPURLResponse class]]) {
        NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
        NSInteger statusCode = httpResponse.statusCode;
        HLog(@"HTTP Status Code: %ld", (long)statusCode);
          
        if(statusCode == 404){
            operation.downloadState = customDownloadStateFailed;
            operation.isFile404Cancel = YES;
            return NO;
        }
        
    }
    
    // 总的size
    if (operation.currentSize + response.expectedContentLength == 0) {
        HLog(@"下载数据回调异常");
        operation.downloadState = customDownloadStateFailed;
        return NO;
    }
    operation.totalSize = operation.currentSize + response.expectedContentLength;
    
    // 创建空的文件夹
    if (operation.currentSize == 0) {
        // 创建空的文件
        [[NSFileManager defaultManager]  createFileAtPath:operation.fullPath contents:nil attributes:nil];
    }
    
    // 创建文件句柄
    operation.handle = [NSFileHandle fileHandleForWritingAtPath:operation.fullPath];
    
    // 文件句柄移动到文件末尾 位置 // 返回值是 unsign long long
    [operation.handle seekToEndOfFile];
    
    // 开始下载记录文件下载信息
    operation.downloadState = customDownloadStateDoing;
    
    return YES;
}

- (void)dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    customDownloadOperation *operation = nil;
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if(operationDoing.dataTask == dataTask){
            operation = operationDoing;
            break;
        }
    }
    
    if (!operation) {
        HLog(@"没找到当前下载任务");
        [dataTask cancel];
        return;
    }
    
    //手动取消任务
    if (operation.isManualCancel) {
        return;
    }
    
    // 获得已经下载的文件大小
    operation.currentSize += data.length;
    HLog(@"currentSize:%lld---progress:%.2f", operation.currentSize, 1.00*operation.currentSize/operation.totalSize);

    // 写入文件
    if(operation.handle){
        [operation.handle writeData:data];
    }

    // 下载中通知
    [self operationDoningWithOperation:operation];
}

- (void)task:(NSURLSessionTask *)dataTask didCompleteWithError:(NSError *)error
{
    customDownloadOperation *operation = nil;
    for (customDownloadOperation *operationDoing in self.downloadingOperationArr) {
        if(operationDoing.dataTask == dataTask){
            operation = operationDoing;
            [self.downloadingOperationArr removeObject:operationDoing];
            break;
        }
    }
    
    if (!operation) {
        HLog(@"没找到当前下载任务");
        //[dataTask suspend];
        return;
    }
    
    if(operation.dataTask){
        //[operation.dataTask cancel];
        operation.dataTask = nil;
        operation.session = nil;
        
        if(operation.handle){
            // 关闭文件句柄
            [operation.handle closeFile];
            // 释放文件句柄
            operation.handle = nil;
        }
    }
    
    if(error && (error.code == -1005 || error.code == -1009) && !operation.isFile404Cancel){//网络中断
        HLog(@"reDownloadNetworkTaskBy");
        //延时几秒再次启动这个任务
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self reDownloadNetworkTaskBy:operation.url];
        });
        return;
    }
    
    if(operation.isManualCancel){
        [self beginDownload];
        return;
    }
    
    // 完成下载 通知 block
    if (error ||operation.downloadState == customDownloadStateFailed) {
        [self operationFailedWithOperation:operation];
    } else {
        operation.isFinished = YES;
        operation.timeStamp = [iTools getNowTimeStamp];
        [self operationSuccessWithOperation:operation];
    }
    
    [self beginDownload];
}


#pragma mark 发送通知

// 失败某一个operation 保存本地 通知外界
- (void)operationFailedWithOperation:(customDownloadOperation *)operation {
    HLog(@"DownloadTaskExeError \n %@",operation.url);
    operation.downloadState = customDownloadStateFailed;
    [[NSNotificationCenter defaultCenter] postNotificationName:customDownloadTaskExeError object:nil userInfo:@{@"operation" : operation}];
}

// 重启某一个operation 保存本地 通知外界
- (void)operationDoningWithOperation:(customDownloadOperation *)operation {
    HLog(@"DownloadTaskExeing");
    
    NSTimeInterval curTime = [[NSDate date] timeIntervalSince1970];
    NSTimeInterval timeDiff = curTime - operation.preNotTimeInterval;
    
    HLog(@"控制刷新时间为1秒：%f",timeDiff);
    CGFloat RefreshTimer = 0.8;
    if(operation.totalSize <= 5*1024*1024){//小于5M 
        RefreshTimer = 0.2;
    }
    
    if (operation.preNotTimeInterval <= 0
        || timeDiff > RefreshTimer ) {
        
        operation.preNotTimeInterval = curTime;
        [[NSNotificationCenter defaultCenter] postNotificationName:customDownloadTaskExeing object:nil userInfo:@{@"operation" : operation}];
    }
}

// 等待某一个operation 保存本地 通知外界
- (void)operationSuccessWithOperation:(customDownloadOperation *)operation {
    HLog(@"DownloadTaskExeEnd \n %@",operation.url);
    operation.downloadState = customDownloadStateCompleted;
    [[NSNotificationCenter defaultCenter] postNotificationName:customDownloadTaskExeEnd object:nil userInfo:@{@"operation" : operation}];
}

-(NSURLSession*)creatNewSessionFun
{
    NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
    // 设置请求超时
    config.timeoutIntervalForRequest = -1;
//        config.networkServiceType = NSURLNetworkServiceTypeVideo;
    config.timeoutIntervalForResource = -1;
//        config.TLSMaximumSupportedProtocol = kSSLProtocolAll;
    
    //_session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:[NSOperationQueue currentQueue]];
    NSURLSession *session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];
    
    return session;
}

#pragma mark - lazy load
- (NSMutableArray *)downloadWaitingUrlArr {
    
    if (!_downloadWaitingUrlArr) {
        _downloadWaitingUrlArr = [NSMutableArray array];
    }
    return _downloadWaitingUrlArr;
}

- (NSMutableArray *)downloadingOperationArr {
    
    if (!_downloadingOperationArr) {
        _downloadingOperationArr = [NSMutableArray array];
    }
    return _downloadingOperationArr;
}

- (BOOL)isDownLoadIngType
{
    if(self.downloadingOperationArr.count >= 1){
        return YES;
    }
    
    return NO;
}
@end