#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "common.h"
#include "procs.h"

int main(int argc, char *argv[]) {
	int ssocket; /* server socket */
	struct sockaddr_in server; /* server address */
	struct procreg pr; /* procedure registry */
	int running = 1; /* whether or not we continue looping (boolean) */

	initprocreg(&pr); /* initialize the procedure registry */

	/* get the server socket, check for error */
	if((ssocket = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("couldn't create server socket");
		exit(1);
	}

	bzero(&server, sizeof(server)); /* zero the address */
	/* listen on any INET address at port PORT */
	server.sin_family = AF_INET;
	server.sin_addr.s_addr = htonl(INADDR_ANY);
	server.sin_port = htons(PORT);

	/* bind the socket, check for error */
	if(bind(ssocket, (struct sockaddr *)&server, sizeof(server)) == -1) {
		perror("couldn't bind socket");
		close(ssocket); exit(1);
	}

	/* listen on the socket, check for error */
	if(listen(ssocket, 1) == -1) {
		perror("couldn't listen on socket");
		close(ssocket); exit(1);
	}

	while(running) { /* loop forever */
		int csocket, addrlen; /* client socket and length of address */
		struct sockaddr_in client; /* client address */
		char buffer[BLEN]; /* socket buffer */

		fprintf(stderr, "waiting for connection\n");

		/* accept an incoming connection, check for error */
		addrlen = sizeof(client);
		if((csocket = accept(ssocket, (struct sockaddr *)&client, &addrlen))
			== -1) {
			perror("couldn't accept connection");
			close(ssocket); exit(1);
		}

		printf("connected!\n");

		/* receive data into the buffer, check for error */
		if(read(csocket, buffer, BLEN) == -1) {
			perror("couldn't read from socket");
			close(ssocket); exit(1);
		}

		/* see what the client wants */
		if(strncasecmp(buffer, "Q\n", 2) == 0) { /* got a 'quit' */
			printf("received a quit, exiting\n");
			write(csocket, "OK\n", 4); /* acknowledge client */
			running = 0; /* don't loop next time */
		} else if(strncasecmp(buffer, "L\n", 2) == 0) {
			/* got a 'listregistry' */
			/* list the proc registry to the client */
			listregistry(pr, csocket);
		} else if(strncasecmp(buffer, "E", 1) == 0) {
			/* got an 'execute' */
			/* attempt to call the desired procedure, check for error */
			if(!prcall(pr, buffer, csocket)) {
				write(csocket, "bad procedure call\n", 34);
			}
		} else {
			printf("received unknown command\n");
			/* tell the client we don't know what it means */
			write(csocket, "unknown command\n", 17);
		}
		close(csocket); /* close the client socket */
	}
	return 0;
}