#define _GNU_SOURCE

#include "frontend_common.h"
#include "config.h"

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <err.h>

struct backend_conn {
	FILE * socket;

	size_t len;
	char * buf;
};

struct backend_conn * ucart_backendConnect()
{
	int s;
	struct sockaddr_un remote;
	char str[100];

	if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
		perror("socket");
		exit(1);
	}

	struct backend_conn * conn = NULL;

	printf("Trying to connect...\n");

	remote.sun_family = AF_UNIX;
	char * sock_env = getenv(SOCKET_ENV);
	strcpy(remote.sun_path, sock_env ? sock_env : DEFAULT_SOCKET);
	if (connect(s, (struct sockaddr *)&remote, sizeof(remote))  == -1) {
		perror("connect");
		goto fail_final;
	}

	conn = malloc(sizeof(struct backend_conn));
	if (conn == NULL) {
		perror("malloc");
		goto fail_sock;
	}

	conn->len = 0;
	conn->buf = NULL;
	conn->socket = fdopen(s, "r+");
	if (conn->socket == NULL) {
		perror("fdopen");
		goto fail_malloc_conn;
	}
	if (setvbuf(conn->socket, NULL, _IONBF, 0)) {
		warn("setvbuf");
	}

	/* success */
	goto fail_final;

fail_malloc_conn:
	free(conn);
	conn = NULL;
fail_sock:
	close(s);
fail_final:
	return conn;
}

void ucart_backendDisconnect(struct backend_conn * conn)
{
	fclose(conn->socket);
	if (conn->buf) {
		free(conn->buf);
	}
	free(conn);
}

char * ucart_backendGetline(struct backend_conn *conn)
{
	getline(&conn->buf, &conn->len, conn->socket);
	return conn->buf;
}

int ucart_backendWrite(struct backend_conn *conn, const char * line)
{
	return fputs(line, conn->socket);
}