#include <cstdio>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "evhttp.h"

#include "event.h"

#include "event2/http.h"

#include "event2/event.h"

#include "event2/buffer.h"

#include "event2/bufferevent.h"

#include "event2/bufferevent_compat.h"

#include "event2/http_struct.h"

#include "event2/http_compat.h"

#include "event2/util.h"

#include "event2/listener.h"

int main()

{

    struct evhttp *http_server = NULL;

    short http_port = ;

    char *http_addr = "0.0.0.0";

    //初始化

    event_init();

    //启动http服务端

    http_server = evhttp_start(http_addr, http_port);

    if (http_server == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "http server start failed.");

        return -;

    }

    //设置请求超时时间(s)

    evhttp_set_timeout(http_server, );

    //设置事件处理函数，evhttp_set_cb针对每一个事件(请求)注册一个处理函数，

    //区别于evhttp_set_gencb函数，是对所有请求设置一个统一的处理函数

    evhttp_set_cb(http_server, "/post", http_handler_testpost_msg, NULL);

    evhttp_set_cb(http_server, "/get", http_handler_testget_msg, NULL);

    //循环监听

    event_dispatch();

    //实际上不会释放，代码不会运行到这一步

    evhttp_free(http_server);

    return ;

}

//解析post请求数据

void get_post_message(char *buf, struct evhttp_request *req)

{

    size_t post_size = ;

    post_size = evbuffer_get_length(req->input_buffer);//获取数据长度

    printf("====line:%d,post len:%d\n", __LINE__, post_size);

    if (post_size <= )

    {

        printf("====line:%d,post msg is empty!\n", __LINE__);

        return;

    }

    else

    {

        size_t copy_len = post_size > BUF_MAX ? BUF_MAX : post_size;

        printf("====line:%d,post len:%d, copy_len:%d\n", __LINE__, post_size, copy_len);

        memcpy(buf, evbuffer_pullup(req->input_buffer, -), copy_len);

        buf[post_size] = '\0';

        printf("====line:%d,post msg:%s\n", __LINE__, buf);

    }

}

//处理post请求

void http_handler_testpost_msg(struct evhttp_request *req, void *arg)

{

    if (req == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "input param req is null.\n");

        return;

    }

    char buf[BUF_MAX] = {  };

    get_post_message(buf, req);//获取请求数据，一般是json格式的数据

    if (buf == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "get_post_message return null.\n");

        return;

    }

    else

    {

        //可以使用json库解析需要的数据

        printf("====line:%d,request data:%s", __LINE__, buf);

    }

    //回响应

    struct evbuffer *retbuff = NULL;

    retbuff = evbuffer_new();

    if (retbuff == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "retbuff is null.\n");

        return;

    }

    evbuffer_add_printf(retbuff, "Receive post request,Thamks for the request!\n");

    evhttp_send_reply(req, HTTP_OK, "Client", retbuff);

    evbuffer_free(retbuff);

}

//解析http头，主要用于get请求时解析uri和请求参数

char *find_http_header(struct evhttp_request *req, struct evkeyvalq *params, const char *query_char)

{

    if (req == NULL || params == NULL || query_char == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "input params is null.\n");

        return NULL;

    }

    struct evhttp_uri *decoded = NULL;

    char *query = NULL;

    char *query_result = NULL;

    const char *path;

    const char *uri = evhttp_request_get_uri(req);//获取请求uri

    if (uri == NULL)

    {

        printf("====line:%d,evhttp_request_get_uri return null\n", __LINE__);

        return NULL;

    }

    else

    {

        printf("====line:%d,Got a GET request for <%s>\n", __LINE__, uri);

    }

    /*

    //解码uri

    decoded = evhttp_uri_parse(uri);

    if (!decoded)

    {

        printf("====line:%d,It's not a good URI. Sending BADREQUEST\n", __LINE__);

        evhttp_send_error(req, HTTP_BADREQUEST, 0);

        return;

    }

    //获取uri中的path部分

    path = evhttp_uri_get_path(decoded);

    if (path == NULL)

    {

        path = "/";

    }

    else

    {

        printf("====line:%d,path is:%s\n", __LINE__, path);

    }

    //获取uri中的参数部分

    query = (char*)evhttp_uri_get_query(decoded);

    if (query == NULL)

    {

        printf("====line:%d,evhttp_uri_get_query return null\n", __LINE__);

        return NULL;

    }*/

    //查询指定参数的值

    evhttp_parse_query_str(query, params);

    query_result = (char*)evhttp_find_header(params, query_char);

    return query_result;

}

//处理get请求

void http_handler_testget_msg(struct evhttp_request *req, void *arg)

{

    if (req == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "input param req is null.\n");

        return;

    }

    char *sign = NULL;

    char *data = NULL;

    struct evkeyvalq sign_params = {  };

    sign = find_http_header(req, &sign_params, "sign");//获取get请求uri中的sign参数

    if (sign == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "request uri no param sign.\n");

    }

    else

    {

        printf("====line:%d,get request param: sign=[%s]\n", __LINE__, sign);

    }

    data = find_http_header(req, &sign_params, "data");//获取get请求uri中的data参数

    if (data == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "request uri no param data.\n");

    }

    else

    {

        printf("====line:%d,get request param: data=[%s]\n", __LINE__, data);

    }

    printf("\n");

    //回响应

    struct evbuffer *retbuff = NULL;

    retbuff = evbuffer_new();

    if (retbuff == NULL)

    {

        printf("====line:%d,%s\n", __LINE__, "retbuff is null.");

        return;

    }

    evbuffer_add_printf(retbuff, "Receive get request,Thamks for the request!");

    evhttp_send_reply(req, HTTP_OK, "Client", retbuff);

    evbuffer_free(retbuff);

}