/*
 *      socket.h - this file is part of Geany, a fast and lightweight IDE
 *
 *      Copyright 2006 Enrico Tröger <enrico.troeger@uvena.de>
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $Id$
 */


#include "geany.h"

#ifdef HAVE_SOCKET

#ifndef G_OS_WIN32
# include <sys/socket.h>
# include <sys/un.h>
# include <netinet/in.h>
#else
# include <winsock2.h>
# include <ws2tcpip.h>
#endif
#include <unistd.h>
#include <fcntl.h>

#include "main.h"
#include "socket.h"
#include "document.h"



#ifdef G_OS_WIN32
#define REMOTE_CMD_PORT		49876
#define SockDesc			SOCKET
#define SOCKET_IS_VALID(s)	((s) != INVALID_SOCKET)
#else
#define SockDesc			gint
#define SOCKET_IS_VALID(s)	((s) >= 0)
#define INVALID_SOCKET		(-1)
#endif


#ifdef G_OS_WIN32
static gint socket_fd_connect_inet	(gushort port);
static gint socket_fd_open_inet		(gushort port);
static void socket_init_win32();
#else
static gint socket_fd_connect_unix	(const gchar *path);
static gint socket_fd_open_unix		(const gchar *path);
#endif

static gint socket_fd_write			(gint sock, const gchar *buf, gint len);
static gint socket_fd_write_all		(gint sock, const gchar *buf, gint len);
static gint socket_fd_gets			(gint sock, gchar *buf, gint len);
static gint socket_fd_check_io		(gint fd, GIOCondition cond);
static gint socket_fd_read			(gint sock, gchar *buf, gint len);
static gint socket_fd_recv			(gint fd, gchar *buf, gint len, gint flags);
static gint socket_fd_close			(gint sock);



/* (Unix domain) socket support to replace the old FIFO code
 * (taken from Sylpheed, thanks) */
gint socket_init(gint argc, gchar **argv)
{
	gint sock;

#ifdef G_OS_WIN32
	HANDLE hmutex;

	socket_init_win32();
	hmutex = CreateMutexA(NULL, FALSE, "Geany");
	if (! hmutex)
	{
		geany_debug("cannot create Mutex\n");
		return -1;
	}
	if (GetLastError() != ERROR_ALREADY_EXISTS)
	{
		sock = socket_fd_open_inet(REMOTE_CMD_PORT);
		if (sock < 0)
			return 0;
		return sock;
	}

	sock = socket_fd_connect_inet(REMOTE_CMD_PORT);
	if (sock < 0)
		return -1;
#else

	if (socket_info.file_name == NULL)
		socket_info.file_name = g_strdup_printf("%s%cgeany_socket", app->configdir, G_DIR_SEPARATOR);

	sock = socket_fd_connect_unix(socket_info.file_name);
	if (sock < 0)
	{
		unlink(socket_info.file_name);
		return socket_fd_open_unix(socket_info.file_name);
	}
#endif

	// remote command mode, here we have another running instance and want to use it
	if (argc > 1)
	{
		gint i;
		gchar *filename;

		geany_debug("using running instance of Geany");

		socket_fd_write_all(sock, "open\n", 5);

		for(i = 1; i < argc && argv[i] != NULL; i++)
		{
			filename = get_argv_filename(argv[i]);

			if (filename != NULL)
			{
				socket_fd_write_all(sock, filename, strlen(filename));
				socket_fd_write_all(sock, "\n", 1);
				g_free(filename);
			}
		}
		socket_fd_write_all(sock, ".\n", 2);
	}

	socket_fd_close(sock);
	return -1;
}


gint socket_finalize(void)
{
	if (socket_info.lock_socket < 0) return -1;

	if (socket_info.lock_socket_tag > 0)
		g_source_remove(socket_info.lock_socket_tag);
	if (socket_info.read_ioc)
	{
		g_io_channel_shutdown(socket_info.read_ioc, FALSE, NULL);
		g_io_channel_unref(socket_info.read_ioc);
		socket_info.read_ioc = NULL;
	}

#ifdef G_OS_WIN32
	WSACleanup();
#else
	unlink(socket_info.file_name);
	g_free(socket_info.file_name);
#endif

	return 0;
}


#ifdef G_OS_UNIX
static gint socket_fd_connect_unix(const gchar *path)
{
	gint sock;
	struct sockaddr_un addr;

	sock = socket(PF_UNIX, SOCK_STREAM, 0);
	if (sock < 0)
	{
		perror("fd_connect_unix(): socket");
		return -1;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);

	if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		socket_fd_close(sock);
		return -1;
	}

	return sock;
}


static gint socket_fd_open_unix(const gchar *path)
{
	gint sock;
	struct sockaddr_un addr;
	gint val;

	sock = socket(PF_UNIX, SOCK_STREAM, 0);

	if (sock < 0)
	{
		perror("sock_open_unix(): socket");
		return -1;
	}

	val = 1;
	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
	{
		perror("setsockopt");
		socket_fd_close(sock);
		return -1;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sun_family = AF_UNIX;
	strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);

	if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		perror("bind");
		socket_fd_close(sock);
		return -1;
	}

	if (listen(sock, 1) < 0)
	{
		perror("listen");
		socket_fd_close(sock);
		return -1;
	}

	return sock;
}
#endif

static gint socket_fd_close(gint fd)
{
#ifdef G_OS_WIN32
	return closesocket(fd);
#else
	return close(fd);
#endif
}


#ifdef G_OS_WIN32
static gint socket_fd_open_inet(gushort port)
{
	SockDesc sock;
	struct sockaddr_in addr;
	gchar val;

	sock = socket(AF_INET, SOCK_STREAM, 0);
	if (! SOCKET_IS_VALID(sock))
	{
		geany_debug("fd_open_inet(): socket() failed: %ld\n", WSAGetLastError());
		return -1;
	}

	val = 1;
	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val)) < 0)
	{
		perror("setsockopt");
		socket_fd_close(sock);
		return -1;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

	if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		perror("bind");
		socket_fd_close(sock);
		return -1;
	}

	if (listen(sock, 1) < 0)
	{
		perror("listen");
		socket_fd_close(sock);
		return -1;
	}

	return sock;
}


static gint socket_fd_connect_inet(gushort port)
{
	SockDesc sock;
	struct sockaddr_in addr;

	sock = socket(AF_INET, SOCK_STREAM, 0);
	if (! SOCKET_IS_VALID(sock))
	{
		geany_debug("fd_connect_inet(): socket() failed: %ld\n", WSAGetLastError());
		return -1;
	}

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);

	if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
		socket_fd_close(sock);
		return -1;
	}

	return sock;
}


static void socket_init_win32()
{
	WSADATA wsadata;

	if (WSAStartup(MAKEWORD(2, 2), &wsadata) != NO_ERROR)
		geany_debug("WSAStartup() failed\n");

	return;
}
#endif


gboolean socket_lock_input_cb(GIOChannel *source, GIOCondition condition, gpointer data)
{
	gint fd, sock;
	gchar buf[4096];
	struct sockaddr_in caddr;
	guint caddr_len;

	caddr_len = sizeof(caddr);

	fd = g_io_channel_unix_get_fd(source);
	sock = accept(fd, (struct sockaddr *)&caddr, &caddr_len);

	// first get the command
	if (socket_fd_gets(sock, buf, sizeof(buf)) != -1 && strncmp(buf, "open", 4) == 0)
	{
		geany_debug("remote command: open");
		while (socket_fd_gets(sock, buf, sizeof(buf)) != -1 && *buf != '.')
		{
			g_strstrip(buf); // remove \n char

			if (g_file_test(buf, G_FILE_TEST_IS_REGULAR | G_FILE_TEST_IS_SYMLINK))
				document_open_file(-1, buf, 0, FALSE, NULL, NULL);
			else
				geany_debug("got data from socket, but it does not look like a filename");
		}
		gtk_window_deiconify(GTK_WINDOW(app->window));
#ifdef G_OS_WIN32
		gtk_window_present(GTK_WINDOW(app->window));
#endif
	}

	socket_fd_close(sock);

	return TRUE;
}


static gint socket_fd_gets(gint fd, gchar *buf, gint len)
{
	gchar *newline, *bp = buf;
	gint n;

	if (--len < 1)
		return -1;
	do
	{
		if ((n = socket_fd_recv(fd, bp, len, MSG_PEEK)) <= 0)
			return -1;
		if ((newline = memchr(bp, '\n', n)) != NULL)
			n = newline - bp + 1;
		if ((n = socket_fd_read(fd, bp, n)) < 0)
			return -1;
		bp += n;
		len -= n;
	} while (! newline && len);

	*bp = '\0';
	return bp - buf;
}


static gint socket_fd_recv(gint fd, gchar *buf, gint len, gint flags)
{
	if (socket_fd_check_io(fd, G_IO_IN) < 0)
		return -1;

	return recv(fd, buf, len, flags);
}


static gint socket_fd_read(gint fd, gchar *buf, gint len)
{
	if (socket_fd_check_io(fd, G_IO_IN) < 0)
		return -1;

#ifdef G_OS_WIN32
	return recv(fd, buf, len, 0);
#else
	return read(fd, buf, len);
#endif
}


static gint socket_fd_check_io(gint fd, GIOCondition cond)
{
	struct timeval timeout;
	fd_set fds;
#ifdef G_OS_UNIX
	gint flags;
#endif

	timeout.tv_sec  = 60;
	timeout.tv_usec = 0;

#ifdef G_OS_UNIX
	// checking for non-blocking mode

	flags = fcntl(fd, F_GETFL, 0);
	if (flags < 0)
	{
		perror("fcntl");
		return 0;
	}

	if ((flags & O_NONBLOCK) != 0)
		return 0;
#endif

	FD_ZERO(&fds);
	FD_SET(fd, &fds);

	if (cond == G_IO_IN)
	{
		select(fd + 1, &fds, NULL, NULL, &timeout);
	}
	else
	{
		select(fd + 1, NULL, &fds, NULL, &timeout);
	}

	if (FD_ISSET(fd, &fds))
	{
		return 0;
	}
	else
	{
		geany_debug("Socket IO timeout\n");
		return -1;
	}
}


static gint socket_fd_write_all(gint fd, const gchar *buf, gint len)
{
	gint n, wrlen = 0;

	while (len)
	{
		n = socket_fd_write(fd, buf, len);
		if (n <= 0)
			return -1;
		len -= n;
		wrlen += n;
		buf += n;
	}

	return wrlen;
}


gint socket_fd_write(gint fd, const gchar *buf, gint len)
{
	if (socket_fd_check_io(fd, G_IO_OUT) < 0)
		return -1;

#ifdef G_OS_WIN32
	return send(fd, buf, len, 0);
#else
	return write(fd, buf, len);
#endif
}


#endif