#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <poll.h>

#include "temperature.h"
#include "rpc.h"

#define BACKLOG 4

static int socketfd;

void runcommand(int command, int clientfd) {
	char buf[32];
	float temp;
	
	switch(command) {
		case CMD_TEMP_SISA:
			temp = get_temperature_sisa();
			memcpy(buf, &temp, sizeof(float));
			send(clientfd, buf, sizeof(float), 0);
			break;
		
		case CMD_TEMP_ULKO:
			temp = get_temperature_ulko();
			memcpy(buf, &temp, sizeof(float));
			send(clientfd, buf, sizeof(float), 0);
			break;

		case CMD_HUM_SISA:
			temp = get_humidity_sisa();
			memcpy(buf, &temp, sizeof(float));
			send(clientfd, buf, sizeof(float), 0);
			break;
	}
}

void server_handle(int clientfd) {
	int command;
	if (recv(clientfd, &command, sizeof(command), MSG_WAITALL) != sizeof(command))
		return;
	
	runcommand(command, clientfd);
}

/* Public functions */

void server_initialize() {
	struct sockaddr_in servaddr;
	socketfd = socket(AF_INET, SOCK_STREAM, 0);
	
	memset(&servaddr, 0, sizeof(servaddr));
	servaddr.sin_family = AF_INET;
	servaddr.sin_addr.s_addr = RPC_ADDR;
	servaddr.sin_port = RPC_PORT;
	
	// Set socket to reuse address, even if old instance has still
	// connections waiting.
	int on = 1;
	setsockopt(socketfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
	
	
	if (bind(socketfd, (struct sockaddr *) &servaddr, sizeof(servaddr)) != 0) {
		perror("bind");
		exit(1);
	}
	
	listen(socketfd, BACKLOG);
	fcntl(socketfd, F_SETFL, O_NONBLOCK);
}

void server_do() {
	int clientfd;
	
	while (1) {
		clientfd = accept(socketfd, NULL, NULL);
		
		if (clientfd == -1 && errno == EAGAIN) { // No connections waiting
			return;
		} else if (clientfd == -1) {
			perror("socket_receive");
			return;
		}
		
		server_handle(clientfd);
		close(clientfd);
	}
}

void server_dolong(int timeout) {
	int endtime = time(NULL) + timeout;
	
	struct pollfd sfd_poll;
	sfd_poll.fd = socketfd;
	sfd_poll.events = POLLIN;
	
	while (time(NULL) < endtime) {
		if (poll(&sfd_poll, 1, (endtime - time(NULL)) * 1000))
			server_do();
	}
}