#include <iostream>
#include <string>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <fstream>
#include <unistd.h>
#include <fcntl.h>
#include <queue>

using namespace std;

const int PORT = 4632;
const int number = 5;

queue<pair<char*, int> > list;


struct data{
	
	int socket;
	sockaddr_in server;
	pthread_t start_thread;
};
void* work_to_do(void* info);
void* main_work(void* info);
void error_checking(int i, char* message)
{
	if(i == -1) 
	{
		cout << message << endl;
		exit(0);
	}
}
int main(int argc, char** argv)
{
	int domain = AF_INET;
	int type = SOCK_STREAM;
	int protocol = 0;

	int sfd = socket(domain, type, protocol);
	error_checking(sfd, "invalid socket");

	int optval = 1;
	setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof optval);

	struct sockaddr_in client_address;

	client_address.sin_family = AF_INET;
	client_address.sin_port = htons(PORT);
	client_address.sin_addr.s_addr = INADDR_ANY;
	
	memset (&(client_address.sin_zero), '\0', 8);

	if(bind(sfd,(struct sockaddr*) &client_address, sizeof (struct sockaddr)) == -1)
		cout << "Unsuccessful binding\n";
	else cout << "Binding\n";
	
	
	data main_thread[1];
	
	data & one = main_thread[1];
	one.socket = sfd;
	one.server = client_address;
	
	data threads[number];
	int i = 0;
	while(true)
	{
		data & information = threads[i];
		information.socket = sfd;
		information.server = client_address;
		
		pthread_create(&one.start_thread, NULL, main_work, &one);
		pthread_join(main_thread[1].start_thread, NULL);
		pthread_create(&information.start_thread, NULL, work_to_do, &information);
		i++;
		if(i > 5) i = i % 5;
	}
	for(int i = 0; i < number; ++i)
		pthread_join(threads[i].start_thread, NULL);
	pthread_exit(NULL);
}
void* main_work(void* info)
{
	data information = *(data*)info;
	if(listen(information.socket, 10) == -1)
	{
		cout << "listen() error\n";
		exit(0);
	}
	else cout << "Listening\n";
	
	int sin_size = sizeof(struct sockaddr_in);
	int new_sfd = accept(information.socket, (struct sockaddr *)&information.server, (socklen_t *)&sin_size);
	if(new_sfd == -1) cout << "bad accept\n";
	
	//receive the file from client
	char file[BUFSIZ];
	int receive = read(new_sfd, file, BUFSIZ);
	if(receive == -1) perror("bad reading");
	
	pair<char*, int> temp(file, new_sfd);
	list.push(temp);
	
	//close(new_sfd);
	pthread_exit(NULL);
}
void*work_to_do(void* info)
{
	data information = *(data*)info;
		
	cout << "connection established\n";
	
	pair<char*, int> temp = list.front();
	list.pop();
	
	//write to client
	char buffer[BUFSIZ];
	int writting;
	
	int read_file_decrypter = open(temp.first, O_RDONLY);
	if(read_file_decrypter == -1) perror("bad file decrypter");
	else cout << "Sending " << temp.first << ".." << endl;
	
	while((writting = read(read_file_decrypter,buffer,BUFSIZ)) > 0)
		write(temp.second,buffer, writting);
	if(read_file_decrypter == -1) perror("file not sent");
	else cout << "file sent\n";
	
	close(read_file_decrypter);
	close(temp.second);
		
	pthread_exit(NULL);
}