//FILE: client/app_stress_client.c
//
//Description: this is the stress test client application code. The client first starts the overlay by creating a direct TCP link between the client and the server. Then it initializes the SRT client by calling srt_client_init(). It creates a socket and connects to the server  by calling srt_client_sock() and srt_client_connect(). Then it reads text data from file send_this_text.txt, and sends the length of the file and file data to the server. After some time, the client disconnects from the server by calling srt_client_disconnect(). Finally the client closes the socket by calling srt_client_close(). Overlay is stopped by calling overlay_end().

//Date: April 26,2008

//Input: None

//Output: SRT client states

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "../common/constants.h"
#include "srt_client.h"

//One connection is created using client port CLIENTPORT1 and server port SVRPORT1. 
#define CLIENTPORT1 87
#define SVRPORT1 88
//after the file is sent, the client waits for WAITTIME seconds, and then closes the connection
#define WAITTIME 5

//this function starts the overlay by creating a direct TCP connection between the client and the server. The TCP socket descriptor is returned. If the TCP connection fails, return -1. The TCP socket desciptor returned will be used by SRT to send segments.
int overlay_start() {

  // Your code here

}

//this function stops the overlay by closing the TCP connection between the server and the client
void overlay_stop(int overlay_conn) {

  // Your code here

}

int main() {
	//random seed for loss rate
	srand(time(NULL));

	//start overlay and get the overlay TCP socket descriptor	
	int overlay_conn = overlay_start();
	if(overlay_conn<0) {
		printf("fail to start overlay\n");
		exit(1);
	}

	//initialize srt client
	srt_client_init(overlay_conn);

	//create a srt client sock on port CLIENTPORT1 and connect to srt server port SVRPORT1
	int sockfd = srt_client_sock(CLIENTPORT1);
	if(sockfd<0) {
		printf("fail to create srt client sock");
		exit(1);
	}
	if(srt_client_connect(sockfd,SVRPORT1)<0) {
		printf("fail to connect to srt server\n");
		exit(1);
	}
	printf("client connected to server, client port:%d, server port %d\n",CLIENTPORT1,SVRPORT1);
	
	//get sampletext.txt file length,
	//create a buffer and read the file data in
	FILE *f;
	f = fopen("send_this_text.txt","r");
	assert(f!=NULL);
	fseek(f,0,SEEK_END);
	int fileLen = ftell(f);
	fseek(f,0,SEEK_SET);
	char *buffer = (char*)malloc(fileLen);
	fread(buffer,fileLen,1,f);
	fclose(f);

	//send file length first, then send the whole file
	srt_client_send(sockfd,&fileLen,sizeof(int));
      	srt_client_send(sockfd, buffer, fileLen);
	free(buffer);

	//wait for a while and close the connections
	sleep(WAITTIME);

	if(srt_client_disconnect(sockfd)<0) {
		printf("fail to disconnect from srt server\n");
		exit(1);
	}
	if(srt_client_close(sockfd)<0) {
		printf("fail to close srt client\n");
		exit(1);
	}
	
	//stop the overlay
	overlay_stop(overlay_conn);
}