//start from the very beginning,and to create greatness

//@author: Chuangwei Lin

//@E-mail：979951191@qq.com

//@brief： 服务器SHTTPD请求方法解析

#include "lcw_shttpd.h"

/******************************************************

函数名： Method_DoGet(struct worker_ctl *wctl)

参数：

功能：GET方法

*******************************************************/

static int Method_DoGet(struct worker_ctl *wctl)

{

    DBGPRINT("LCW==>Method_DoGet\n");

    struct conn_response *res = &wctl->conn.con_res;

    struct conn_request *req = &wctl->conn.con_req;

    char path[URI_MAX];

    memset(path, 0, URI_MAX);

    size_t    n;

    unsigned long r1, r2;

    char *fmt = "%a, %d %b %Y %H:%M:%S GMT";//时间格式

    //需要确定的参数

    size_t status = 200;//状态值,已确定

    char *msg = "OK";    //状态信息,已确定

    char date[64] = "";//时间

    char lm[64] = "";    //请求文件最后修改信息

    char etag[64] = "";//etag信息

    big_int_t cl;        //内容长度

    char range[64] = "";//范围

    struct mine_type *mine = NULL;

    time_t t = time(NULL);//取得当前时间

    //根据fmt指向字符串的命令将localtime(&t)中的时间信息储存在date中

    (void)strftime(date, sizeof(date),fmt,localtime(&t));

    //最后修改时间

    (void) strftime(lm, sizeof(lm), fmt,localtime(&res->fsate.st_mtime));

    //ETAG 将可变个参数(...)按照"%lx.%lx"格式化成字符串，然后将其复制到etag中

    (void) snprintf(etag, sizeof(etag), "%lx.%lx",(unsigned long)res->fsate.st_mtime,(unsigned long)res->fsate.st_size);

    //发送的MIME类型

    mine = Mine_Type(req->uri, strlen(req->uri), wctl);

    //内容长度

    cl = (big_int_t) res->fsate.st_size;

    //范围range

    memset(range, 0, sizeof(range));

    n = -1;

    if (req->ch.range.v_vec.len > 0 )//取出请求范围

    {

        printf("request range:%d\n",req->ch.range.v_vec.len);

        //从ptr里读进数据，依照第二个参数的格式将数据写入到后面的参数里

        n = sscanf(req->ch.range.v_vec.ptr,"bytes=%lu-%lu",&r1, &r2);

    }

    printf("n:%d\n",n);

    if(n > 0)

    {

        status = 206;

        lseek(res->fd, r1, SEEK_SET);

        //n==2取前一个

        cl = n == 2 ? r2 - r1 + 1: cl - r1;

        (void) snprintf(range, sizeof(range),"Content-Range: bytes %lu-%lu/%lu\r\n",r1, r1 + cl - 1, (unsigned long) res->fsate.st_size);

        msg = "Partial Content";

    }

    //构建输出的头部

    memset(res->res.ptr, 0, sizeof(wctl->conn.dres));

    snprintf(res->res.ptr,//缓冲区

        sizeof(wctl->conn.dres),//缓冲区长度

        "HTTP/1.1 %d %s\r\n" //状态和状态信息

        "Date: %s\r\n"//日期

        "Last-Modified: %s\r\n"//最后修改时间

        "Etag: \"%s\"\r\n"//Web资源标记号

        "Content-Type: %.*s\r\n"//内容类型

        "Content-Length: %lu\r\n"//内容长度

        //"Connection:close\r\n"

        "Accept-Ranges: bytes\r\n"//发送范围

        "%s\r\n",//范围起始

        status,msg,date,lm,etag,strlen(mine->mime_type),mine->mime_type,cl,range);

    res->cl = cl;

    res->status = status;

    printf("content length:%d, status:%d\n",res->cl, res->status);

    DBGPRINT("LCW<==Method_DoGet\n");

    return 0;

}

/******************************************************

未实现的方法

*******************************************************/

static int Method_DoPost(struct worker_ctl *wctl)

{

    return 0;

}

static int Method_DoHead(struct worker_ctl *wctl)

{

    Method_DoGet(wctl);

    close(wctl->conn.con_res.fd);

    wctl->conn.con_res.fd = -1;

    return 0;

}

static int Method_DoPut(struct worker_ctl *wctl)

{

    return 0;

}

static int Method_DoDelete(struct worker_ctl *wctl)

{

    return 0;

}

static int Method_DoCGI(struct worker_ctl *wctl)

{

    return 0;

}

static int Method_DoList(struct worker_ctl *wctl)

{

    return 0;

}

/******************************************************

函数名：Method_Do(struct worker_ctl *wctl)

参数：业务和线程状态结构

功能：匹配方法

*******************************************************/

void Method_Do(struct worker_ctl *wctl)

{

    DBGPRINT("LCW==>Method_Do\n");

    if(0)//????什么意思 不执行？

        Method_DoCGI(wctl);

    switch(wctl->conn.con_req.method)//匹配请求类型

    {

        case METHOD_PUT://PUT方法

            Method_DoPut(wctl);

            break;

        case METHOD_DELETE://DELETE方法

            Method_DoDelete(wctl);

            break;

        case METHOD_GET://GET方法(这里只实现GET方法)

            Method_DoGet(wctl);

            break;

        case METHOD_POST://POST方法

            Method_DoPost(wctl);

            break;

        case METHOD_HEAD://HEAD方法

            Method_DoHead(wctl);

            break;

        default:

            Method_DoList(wctl);

    }

    DBGPRINT("LCW<==Method_Do\n");

}