#include "head.h"


// 文件大小少于 100MB 时，使用小文件传输
void transMinFile(int netfd, int fd){
    printf("小文件发送\n");
    train_t train;
    while(1){
        bzero(&train, sizeof(train));
        ssize_t sret = read(fd, train.data, sizeof(train.data));
        if(sret == 0){
            break;
        }
        train.length = sret;
        sret = send(netfd, &train, sizeof(train.length)+train.length, MSG_NOSIGNAL);
    }
    // 发送空车箱
    train.length = 0;
    send(netfd, &train, sizeof(train.length), MSG_NOSIGNAL);
}


// 大文件的发送，mmap方式
void transMaxFile(int netfd, int fd, off_t fileSize){
    printf("大文件发送\n");
    char *p = (char *)mmap(NULL, fileSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
    ERROR_CHECK(p, MAP_FAILED, "mmap");
    send(netfd, p, fileSize, MSG_NOSIGNAL);
    munmap(p, fileSize);
}


// 续传的发送
void transAgain(int netfd, int fd, off_t fileSize, off_t offset){
    printf("续传发送\n");
    // 使用mmap
    char *p = (char *)mmap(NULL, fileSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
    ERROR_CHECK(p, MAP_FAILED, "mmap");
    send(netfd, p+offset, fileSize-offset, MSG_NOSIGNAL);
    munmap(p, fileSize);
}


int getPath(char* path,int currid, MYSQL* mysql){
    LOGRECORD(INFO,"getPath start");
    char sqlCommand[1024];
    bzero(sqlCommand,sizeof(sqlCommand));
    sprintf(sqlCommand,"select  path from vfsystem where id = %d",currid);
    int ret = mysql_query(mysql, sqlCommand);
    if(ret != 0){ 
        LOGRECORD(ERROR,"mysql_query");
        return -1;
    }
    MYSQL_RES *result = mysql_store_result(mysql);
    MYSQL_ROW row = mysql_fetch_row(result);
    if(row == NULL){
        LOGRECORD(ERROR,"mysql_fetch_row");
        return -1;
    }else{
        strcpy(path,row[0]);
    }
    
    return 0;
}



int sendFile(int netfd, const char *fileName, MYSQL* mysql, userProcess_t* usr){
    char sqlCommand[1024];
    bzero(sqlCommand,sizeof(sqlCommand));
    char path[128];
    bzero(path, sizeof(path));
    getPath(path, usr->curid, mysql);
    LOGRECORD(INFO,"getPath finish");
    printf("%s    %d    %s\n",usr->username,usr->curid,fileName);
    sprintf(sqlCommand, "select  MD5 from vfsystem "
            "where user = '%s' and tomb = 0 and name = '%s'",
            usr->username, fileName);
    int ret = mysql_query(mysql, sqlCommand);
    ERROR_CHECK(ret, -1, "mysql_query");
    MYSQL_RES *result = mysql_store_result(mysql);
    MYSQL_ROW row = mysql_fetch_row(result);
    if(row == 0){
        LOGRECORD(ERROR,"MD5 IS NOT EXISTS");
        return -1;
    }
    char realfile[128] = {0};
    strcpy(realfile,row[0]);
    LOGRECORD(INFO,"sendfile start");

    train_t train1, train2, train3, train4;

    // step1：发送文件名的长度和文件名
    bzero(&train1, sizeof(train1));
    train1.length = strlen(fileName);
    memcpy(train1.data, fileName, train1.length);
    send(netfd, &train1, sizeof(train1.length)+train1.length, MSG_NOSIGNAL);

    // step2：发送文件的总大小
    int fd = open(realfile, O_RDWR);
    ERROR_CHECK(fd, -1, "open");
    bzero(&train2, sizeof(train2));
    struct stat statbuf;
    fstat(fd, &statbuf);
    off_t fileSize = statbuf.st_size;
    printf("fileSize = %ld\n", fileSize);
    train2.length = sizeof(statbuf.st_size);
    memcpy(train2.data, &statbuf.st_size, train2.length);
    send(netfd, &train2, sizeof(train2.length)+train2.length, MSG_NOSIGNAL);

    // step3：发送文件的md5码
    LOGRECORD(INFO,"start to send MD5");
    bzero(&train3,sizeof(train3));
    train3.length = strlen(realfile);
    strcpy(train3.data,realfile);
    send(netfd, &train3, sizeof(train3.length)+train3.length, MSG_NOSIGNAL);
    printf("send md5 done!\n");


    // 偏移到文件开头
    lseek(fd, 0, SEEK_SET);

    // step4：接收偏移量(接收放已接收的文件大小)
    bzero(&train4, sizeof(train4));
    off_t offset;
    recvn(netfd, &train4.length, sizeof(train4.length));
    recvn(netfd, train4.data, train4.length);
    if(train4.length == 0){
        recvn(netfd, &train4.length, sizeof(train4.length));
        recvn(netfd, train4.data, train4.length);
    }
    memcpy(&offset, train4.data, sizeof(off_t));
    printf("offset = %ld\n", offset);


    if(offset == fileSize){
        printf("秒传模式\n");
    }
    else{
        if(offset > 0){
            // 续传
            transAgain(netfd, fd, fileSize, offset);
        }
        else if(offset == 0 && fileSize >= 100*1024*1024){
            // 大文件发送
            transMaxFile(netfd, fd, fileSize);
        }
        else if(offset == 0 && fileSize < 100*1024*1024){
            // 小文件发送
            transMinFile(netfd, fd);
        }
    }

    printf("send file done!\n");
    return 0;
}