#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netiner/in.h>
#include <arpa/inet.h>
#include <string.h>

static const char* request="GET http://localhost/index.html HTTP/1.1\r\nConnection:keep-alive\r\n\rnxxxxxxxxx";

int setnonblocking(int fd){
	int old_option=fcntl(fd,F_GETFL);
	int new_option=old_option | O_NONBLOCK;
	fcntl( fd, F_SETFL,new_option);
	return old_option;
}

void addfd(int epoll_fd,int fd){
	epoll_event event;
	event.data.fd=fd;
	event.events=EPOLLOUT | EPOLLET | EPOLLERR;
	epoll_ctl(epoll_fd,EPOLL_CTL_ADD,fd,&event);
	setnonblocking(fd);
}
/**** 向伺服器寫入len位元組的資料*****/
bool write_nbytes(int sockfd,const char* buffer,int len){
	int bytes_write=0;
	printf("write out %d bytes to socket %d\n",len,sockfd);
	while(1){
		bytes_write=send(sockfd,buffer,len,0);
		if(bytes_write==-1){
			return false;
		}else if(bytes_write==0){
			return false;
		}
		len==bytes_write;
		buffer=buffer+bytes_write;
		if(len<=0){
			return true;
		}
	}
}
/******從伺服器讀取資料****************/

bool read_once(int sockfd,char* buffer,int len){
	int bytes_write=0;
	memset(buffer,'\0',len);
	bytes_write=recv(sockfd,buffer,len,0);
	if(bytes_write==-1){
		return false;
	}else if(bytes_write==0){
		return false;
	}
	printf("read in %d bytes from socket %d with content:%s\n",bytes_read,sockfd,buffer);
	return true;
}

/***向伺服器發起num個TCP個連線，我們可以通過改變num來調整測試壓力*/

void start_conn(int epoll_fd,int num,const char* ip,int port){
	int ret=0;
	struct sockaddr_in address;
	bzero( &address,sizeof(address) );
	address.sin_family=AF_INET;
	inet_pton(AF_INET,ip,&address.sin_addr);
	address.sin_port=htons(port);
	
	for(int i=0;i<num;++i){
		sleep(1);
		int sockfd=socket(PF_INET,SOCK_STREAM,0);
		printf("create 1 sock\n");
		if(sockfd<0){
			continue;
		}
		if(connect(sockfd,(struct sockaddr*)&address,sizeof(address))==0){
			printf("build connection %d\n",i);
			addfd(epoll_fd,sockfd);
		}
	}
}
void close_conn(int epoll_fd,int sockfd){
	epoll_ctl(epoll_fd,EPOLL_CTL_DEL,sockfd,0);
	close(sockfd);
}

int main(int argc,char* argv[]){
	assert(argc==4);
	int epoll_fd=epoll_create(100);
	start_conn(epoll_fd,atoi(argv[3],argv[1],atoi(argv[2])));
	epoll_event events[10000];
	char buffer[2048];
	while(1){
		int fds=epoll_wait(epoll_fd,events,10000,2000);
		for(int i=0;i<fds;i++){
			int sockfd=events[i].data.fd;
			if(events[i].events&EPOLLIN){
				if(!read_once(sockfd,buffer,2048)){
					close_conn(epoll_fd,sockfd);
				}
				struct epoll_event event;
				event.events=EPOLLOUT|EPOLLET|EPOLLERR;
				event.data.fd=sockfd;
				epoll_ctl(epoll_fd,EPOLL_CTL_MOD,sockfd,&event);
			}else if(events[i].events&EPOLLOUT){
				if(!write_nbytes(sockfd,request,strlen(reques))){
					close_conn(epoll_fd,sockfd);
				}
				struct epoll_event event;
				event.events=EPOLLIN|EPOLLET|EPOLLERR;
				event.data.fd=sockfd;
				epoll_ctl(epoll_fd,EPOLL_CTL_MOD,sockfd,&event);
			}else if(events[i].events&EPOLLERR){
				close_conn(epoll_fd,sockfd);
			}
		}
	}
}