#include <glib.h>
#include <sys/time.h>
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>

#include "gm-net.h"
#include "gm-marshal.h"
#include "gm-debug.h"
#include "gm-support.h"

#define GM_NET_GET_PRIVATE(object)(G_TYPE_INSTANCE_GET_PRIVATE((object),	GM_TYPE_NET, GmNetPrivate))

typedef struct _threadinfo {
	gchar *host;
	gchar *port;
	struct addrinfo *addr;
	struct addrinfo *current;
	struct addrinfo *tmp;
	
	pthread_mutex_t *mutex_idle;
	guint idle_id;
	gint ret;
	gchar *message;
	GmNet *net;
} threadinfo;

struct _GmNetPrivate {
	int socket; /**< the connection socket, is -1 if not connected */
	GIOChannel *channel; /**< the channel which is used to 'listen' on the socket via the glib main loop */
	guint source; /**< the id of the socket watch */
	guint connect_timeout_id; /**< the connect timeout id */
	guint connect_check_id; /**< the connect timeout id */
	struct timeval last_connected; /**< contains when the last connect happened */
	int tn_last; /**< used for telnet */
	int tn_subneg; /**< used for telnet */

	pthread_t thread;
	threadinfo *thread_info;
	pthread_mutex_t mutex_idle;
	
	struct addrinfo *addr;
	struct addrinfo *current;

	GmNetState state; /**< state of the connection */
	gchar *current_host;
	gchar *current_port;
};

/* Signals */

enum {
	STATE_CHANGING,
	STATE_CHANGED,
	NET_ERROR,
	BYTES_RECV,
  NUM_SIGNALS
};

static guint net_signals[NUM_SIGNALS] = {0};

G_DEFINE_TYPE(GmNet, gm_net, G_TYPE_OBJECT)

/* These values taken from RFC 854 and RFC 857. */
#define TN_WILL 251
#define TN_WONT 252
#define TN_DO   253
#define TN_DONT 254
#define TN_IAC  255             /* Interpret As Command */
#define TN_SB   250             /* start of subnegotiation */
#define TN_SE   240             /* end of subnegotiaton */

void gm_net_connect_next(GmNet *net);

gboolean on_gm_net_input_recv(GIOChannel * source, GIOCondition condition, 
		GmNet *net);
gboolean on_gm_net_connect_check(GIOChannel * source, GIOCondition condition,
		GmNet *net);
gboolean on_gm_net_connect_timeout(GmNet *net);

static void
gm_net_free_thread_info(GmNet *net) {
	g_free(net->priv->thread_info->message);
	g_free(net->priv->thread_info->host);
	g_free(net->priv->thread_info->port);
	g_free(net->priv->thread_info);
	
	net->priv->thread_info = NULL;
}

static void
gm_net_close_thread(GmNet *net) {
	if (net->priv->thread != 0) {
		pthread_kill(net->priv->thread, SIGKILL);
		
		if (net->priv->thread_info->idle_id) {
			g_source_remove(net->priv->thread_info->idle_id);
		}

		gm_net_free_thread_info(net);
	}
}

static void
gm_net_finalize(GObject *object) {
	GmNet *net = GM_NET(object);
	
	gm_net_close_thread(net);
	
	g_free(net->priv->current_host);
	g_free(net->priv->current_port);

	G_OBJECT_CLASS(gm_net_parent_class)->finalize(object);
}

static void
gm_net_class_init(GmNetClass *klass) {
	GObjectClass *object_class = G_OBJECT_CLASS(klass);
	
	object_class->finalize = gm_net_finalize;
	
	net_signals[STATE_CHANGING] = 
		g_signal_new("state_changing",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmNetClass, state_changing),
			NULL, NULL,
			g_cclosure_marshal_VOID__UINT,
			G_TYPE_NONE,
			1,
			G_TYPE_UINT);

	net_signals[STATE_CHANGED] = 
		g_signal_new("state_changed",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmNetClass, state_changed),
			NULL, NULL,
			g_cclosure_marshal_VOID__UINT,
			G_TYPE_NONE,
			1,
			G_TYPE_UINT);
			
	net_signals[NET_ERROR] =
		g_signal_new("net_error",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmNetClass, net_error),
			NULL, NULL,
			gm_marshal_VOID__STRING_INT,
			G_TYPE_NONE,
			2,
			G_TYPE_STRING,
			G_TYPE_INT);
			
	net_signals[BYTES_RECV] =
		g_signal_new("bytes_recv",
			G_OBJECT_CLASS_TYPE(object_class),
			G_SIGNAL_RUN_LAST,
			G_STRUCT_OFFSET(GmNetClass, bytes_recv),
			NULL, NULL,
			gm_marshal_VOID__STRING_UINT,
			G_TYPE_NONE,
			2,
			G_TYPE_STRING,
			G_TYPE_UINT);
						
	g_type_class_add_private(object_class, sizeof(GmNetPrivate));
}

static void
gm_net_init(GmNet *net) {
	net->priv = GM_NET_GET_PRIVATE(net);
	net->priv->state = GM_NET_STATE_DISCONNECTED;
	net->priv->addr = NULL;
	net->priv->current = NULL;
	net->priv->channel = NULL;
	
	net->priv->source = 0;
	net->priv->connect_timeout_id = 0;
	net->priv->connect_check_id = 0;
	
	pthread_mutex_init(&(net->priv->mutex_idle), NULL);
}

static void
gm_net_set_host(GmNet *net, gchar const *host) {
	g_free(net->priv->current_host);
	net->priv->current_host = g_strdup(host);
}

static void
gm_net_set_port(GmNet *net, gchar const *port) {
	g_free(net->priv->current_port);
	net->priv->current_port = g_strdup(port);
}

void
gm_net_set_state(GmNet *net, GmNetState state) {
	g_signal_emit(net, net_signals[STATE_CHANGING], 0, state);
	net->priv->state = state;
	g_signal_emit(net, net_signals[STATE_CHANGED], 0, state);
}

void
gm_net_clean_disconnection(GmNet *net) {
	GError *err = NULL;

	if (!net->priv->channel) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.CleanDisconnection: NOT clean for %d",
				net->priv->socket);
		return;
	}

	gm_debug_msg(DEBUG_DEFAULT, "GmNet.CleanDisconnection: clean disconnect for %d",
			net->priv->socket);

	// Shutdown the channel
	g_io_channel_shutdown(net->priv->channel, TRUE, &err);

	if (err) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.CleanDisconnection: error on channel shutdown: "
				"%s", err->message);
		g_error_free(err);
		err = NULL;
	}

	g_io_channel_unref(net->priv->channel);
	
	if (net->priv->source) {
		g_source_remove(net->priv->source);
		net->priv->source = 0;
	}

	net->priv->channel = NULL;
	net->priv->socket = -1;

	net->priv->tn_last = 0;
	net->priv->tn_subneg = 0;

	gm_net_set_state(net, GM_NET_STATE_DISCONNECTED);
}

void
gm_net_dirty_disconnection(GmNet *net, int err) {
	gchar *msg;
  
	// Pff, stupid, we print a message and pass it on to clean_disconnection
	gm_debug_msg(DEBUG_DEFAULT, "GmNet.DirtyDisconnection: dirty disconnect %d",
			net->priv->socket);

	msg = g_strdup_printf(_("Connection lost... (%s)"), strerror(err));
	g_signal_emit(net, net_signals[NET_ERROR], 0, msg, 
			GM_NET_ERROR_DISCONNECTED);
	g_free(msg);
  
	gm_net_clean_disconnection(net);
}

void
gm_net_connect_succeed(GmNet *net) {
	freeaddrinfo(net->priv->addr);
	net->priv->addr = NULL;
	net->priv->current = NULL;
  
	net->priv->source =	g_io_add_watch(net->priv->channel, 
			G_IO_IN | G_IO_HUP, (GIOFunc)on_gm_net_input_recv, net);

	if (net->priv->connect_timeout_id != 0) { 
		g_source_remove(net->priv->connect_timeout_id);
		net->priv->connect_timeout_id = 0;
	}
  
	if (net->priv->connect_check_id != 0) {
		g_source_remove(net->priv->connect_check_id);
		net->priv->connect_check_id = 0;
	}
  
	gettimeofday(&(net->priv->last_connected), NULL);
	gm_net_set_state(net, GM_NET_STATE_CONNECTED);
}

void
gm_net_connect_failed(GmNet *net, gchar *err, gint code) {
	if (net->priv->channel) {
		g_io_channel_shutdown(net->priv->channel, TRUE, NULL);
		g_io_channel_unref(net->priv->channel);
		net->priv->channel = NULL;
	}

	g_signal_emit(net, net_signals[NET_ERROR], 0, err, GM_NET_ERROR_CONNECTING);

	if (net->priv->addr && net->priv->current->ai_next) {
		net->priv->current = net->priv->current->ai_next;
		gm_net_connect_next(net);
	} else {
		net->priv->socket = -1;

		if (net->priv->addr) {
			freeaddrinfo(net->priv->addr);
			net->priv->addr = NULL;
			net->priv->current = NULL;    
		}

		g_signal_emit(net, net_signals[NET_ERROR], 0, 
				_("Could not make connection..."), GM_NET_ERROR_CONNECTING);

		gm_net_set_state(net, GM_NET_STATE_DISCONNECTED);
	}
}

void
gm_net_handle_telnet(GmNet *net, unsigned char *buf, int *len) {
	int i, j;
	unsigned char c;

	j = 0;
	
	for (i = 0; i < *len; ++i) {
		c = buf[i];

		if (net->priv->tn_last) {
			switch (net->priv->tn_last) {
				case TN_WILL: case TN_WONT: case TN_DO: case TN_DONT:
					net->priv->tn_last = 0;
				break;
				case TN_IAC:
					switch (c) {
						case TN_WILL: case TN_WONT: case TN_DO: case TN_DONT:
							net->priv->tn_last = c;
						break;
						case TN_SB:
							net->priv->tn_subneg = 1;
							net->priv->tn_last = 0;
						break;
						case TN_SE:
							net->priv->tn_subneg = 0;
							net->priv->tn_last = 0;
						break;
						case TN_IAC:
							if (!net->priv->tn_subneg) {
								buf[j] = c;
								++j;
							}
							net->priv->tn_last = 0;
						break;
						default:
							net->priv->tn_last = 0;
						break;
					}
			}
		} else if (c == TN_IAC) {
			net->priv->tn_last = TN_IAC;
		} else if (net->priv->tn_subneg) {
			continue;
		} else {
			buf[j] = c;
			++j;
		}
	}

	*len = j; //Since j-- is the last written char
}

static gboolean
idle_proceed_connect_next(gpointer user_data) {
	threadinfo *info = (threadinfo *)user_data;
	GmNet *net = info->net;
	struct addrinfo *tmp;
	gint ret = info->ret;
	gint result;

	info->idle_id = 0;
	pthread_join(net->priv->thread, NULL);
	net->priv->thread = 0;
	
	if (info->ret != 0) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.ConnectNext: getnameinfo error: %s",
				gai_strerror(info->ret));
		gm_net_free_thread_info(net);
		gm_net_connect_failed(net, (gchar *)gai_strerror(ret), ret);
		return FALSE;
	}

	gm_net_set_host(net, info->host);
	gm_net_set_port(net, info->port);
	gm_net_set_state(net, GM_NET_STATE_TRY_ADDRESS);
	
	tmp = info->tmp;
	gm_net_free_thread_info(net);

	net->priv->socket = socket(tmp->ai_family, tmp->ai_socktype, 
			tmp->ai_protocol);   

	if (net->priv->socket < 0) {
		gm_net_connect_failed(net, strerror(errno), errno);
	} else {
		fcntl(net->priv->socket, F_SETFL, 
				fcntl(net->priv->socket, F_GETFL) | O_NONBLOCK);

		if ((result = connect(net->priv->socket, tmp->ai_addr, 
				net->priv->addr->ai_addrlen)) == -1 && errno != EINPROGRESS) {          
			gm_net_connect_failed(net, strerror(errno), errno);
		} else {
			net->priv->channel = g_io_channel_unix_new(net->priv->socket);
			g_io_channel_set_close_on_unref(net->priv->channel, TRUE);

			if (result == 0) {
				gm_net_connect_succeed(net);
			} else {
				net->priv->connect_check_id = g_io_add_watch(net->priv->channel,
						G_IO_OUT|G_IO_ERR, (GIOFunc)on_gm_net_connect_check, net);
				net->priv->connect_timeout_id = g_timeout_add(5000, 
						(GSourceFunc)on_gm_net_connect_timeout, net);
			}
		} 
	}
	
	return FALSE;
}

void
mutex_unlock(void *ptr) {
	pthread_mutex_unlock((pthread_mutex_t *)ptr);
}

void *
nameinfo_thread(void *ptr) {
	threadinfo *info = (threadinfo *)ptr;
	char host[NI_MAXHOST], port[NI_MAXSERV];
	info->tmp = info->current;

	info->ret = getnameinfo(info->tmp->ai_addr, info->tmp->ai_addrlen, host, 
			NI_MAXHOST,	port, NI_MAXSERV, NI_NUMERICHOST | NI_NUMERICSERV);

	if (info->ret == 0) {
		info->host = g_strdup(host);
		info->port = g_strdup(port);
	}
	
	pthread_mutex_lock(info->mutex_idle);
	pthread_cleanup_push(mutex_unlock, info->mutex_idle);
	info->idle_id = g_idle_add(idle_proceed_connect_next, info);
	pthread_cleanup_pop(1);
	
	return NULL;
}

void
gm_net_connect_next(GmNet *net) {
	threadinfo *info;
	
	if (net->priv->current == NULL) {
		return;
	} else {
		info = g_new0(threadinfo, 1);
		info->net = net;
		info->current = net->priv->current;
		info->mutex_idle = &(net->priv->mutex_idle);
		
		net->priv->thread_info = info;
		pthread_create(&(net->priv->thread), NULL, nameinfo_thread, (void *)info);
	}
}

static gboolean
idle_proceed_addrinfo(gpointer user_data) {
	threadinfo *info = (threadinfo *)user_data;
	GmNet *net = info->net;
	
	info->idle_id = 0;
	pthread_join(net->priv->thread, NULL);
	net->priv->thread = 0;
	
	if (info->ret != 0) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.Connect: getaddrinfo failed: %s", 
				gai_strerror(info->ret));
		gm_net_connect_failed(net, (gchar *)gai_strerror(info->ret), 
				info->ret);
		gm_net_free_thread_info(net);
		return FALSE;
	}

	net->priv->addr = info->addr;

	if (info->addr != NULL) {
		net->priv->current = info->addr;
		gm_net_free_thread_info(net);
		gm_net_connect_next(net);
	} else {
		gm_net_free_thread_info(net);
		gm_net_connect_failed(net, _("No addresses available"), 0);
	}
	
	return FALSE;
}

static void *
addrinfo_thread(void *ptr) {
	threadinfo *info = (threadinfo *)ptr;
	struct addrinfo hint;
	
	memset(&hint, 0, sizeof(hint));
	hint.ai_flags = 0;
	hint.ai_family = AF_UNSPEC;
	hint.ai_socktype = SOCK_STREAM;
	hint.ai_protocol = IPPROTO_TCP;

	gm_debug_msg(DEBUG_DEFAULT, "GmNet.Connect: getaddrinfo: %s : %s", 
			info->host, info->port);
	
	info->ret = getaddrinfo(info->host, info->port, &hint, &(info->addr));
	
	pthread_mutex_lock(info->mutex_idle);
	pthread_cleanup_push(mutex_unlock, info->mutex_idle);	
	info->idle_id = g_idle_add(idle_proceed_addrinfo, info);
	pthread_cleanup_pop(1);
	
	return NULL;
}

/* Public */
GmNet *
gm_net_new() {
	GmNet *net = GM_NET(g_object_new(GM_TYPE_NET, NULL));
	
	return net;
}

GmNetState
gm_net_state(GmNet *net) {
	return net->priv->state;
}

void
gm_net_connect(GmNet *net, const gchar *host, const gchar *port) {
	char shost[NI_MAXHOST], sport[NI_MAXSERV];
	threadinfo *info;
	
	if (net->priv->state != GM_NET_STATE_DISCONNECTED) {
		return;
	}

	snprintf(shost, NI_MAXHOST - 1, "%s", host);
	snprintf(sport, NI_MAXSERV - 1, "%s", port);

	gm_net_set_host(net, shost);
	gm_net_set_port(net, sport);

	gm_net_set_state(net, GM_NET_STATE_CONNECTING);

	info = g_new0(threadinfo, 1);
	info->host = g_strdup(shost);
	info->port = g_strdup(sport);
	info->net = net;
	info->mutex_idle = &(net->priv->mutex_idle);
	
	net->priv->thread_info = info;
	pthread_create(&(net->priv->thread), NULL, addrinfo_thread, (void *)info);
}

void
gm_net_disconnect(GmNet *net) {
	// thread running
	if (net->priv->state != GM_NET_STATE_DISCONNECTED) {
		gm_net_close_thread(net);
		gm_net_set_state(net, GM_NET_STATE_DISCONNECTING);

		if (net->priv->connect_timeout_id != 0) { 
			g_source_remove(net->priv->connect_timeout_id);
			net->priv->connect_timeout_id = 0;
		}
	  
		if (net->priv->connect_check_id != 0) {
			g_source_remove(net->priv->connect_check_id);
			net->priv->connect_check_id = 0;
		}

		gm_net_clean_disconnection(net);
	}
}

void
gm_net_send_line(GmNet *net, gchar *line) {
	gchar *send_line;

	send_line = (gchar *)(g_strconcat(line, "\r\n", NULL));
	gm_net_send(net, send_line);	
    g_free(send_line);
}

void
gm_net_send(GmNet *net, gchar *text) {
	int result;
	fd_set connect_set;

	if (net->priv->state == GM_NET_STATE_CONNECTED) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.Send: %s", text);

		if ((result = send(net->priv->socket, text, strlen(text), 0)) == -1
				&& (errno == EAGAIN || errno == EWOULDBLOCK)) {
			FD_ZERO(&connect_set);
			FD_SET(net->priv->socket, &connect_set);

			// Wait for sending to be done
			select(net->priv->socket + 1, NULL, &connect_set, NULL, NULL);
		} else if (result == -1) {
			gm_debug_msg(DEBUG_DEFAULT, "GmNet.Send: error on sending line: %s", strerror(errno));
			gm_net_dirty_disconnection(net, errno);
		}
	} else {
		g_signal_emit(net, net_signals[NET_ERROR], 0, _("Not connected"), 
				GM_NET_ERROR);
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.Send: not connected!");
	}
}

const gchar *
gm_net_current_host(GmNet *net) {
	return net->priv->current_host;
}

const gchar *
gm_net_current_port(GmNet *net) {
	return net->priv->current_port;
}

/* Callbacks */

#define MAX_RECV_BUF 1024

gboolean
on_gm_net_input_recv(GIOChannel * source, GIOCondition condition, GmNet *net) {
	unsigned char lbuf[MAX_RECV_BUF];
	int len;

	if (condition == G_IO_HUP) {
		gm_net_set_state(net, GM_NET_STATE_DISCONNECTING);
		gm_net_clean_disconnection(net);
		return FALSE;
	}

	if (net->priv->state != GM_NET_STATE_CONNECTED) {
		gm_debug_msg(DEBUG_DEFAULT, "GmNet.OnInputRecv: not connected!");
		return FALSE;
	}
  
	// Break the received line by newline (skip \r)
	len = recv(net->priv->socket, lbuf, MAX_RECV_BUF - 2, 0);

	gm_debug_msg(DEBUG_DEFAULT, "GmNet.OnInputRecv: received %d bytes", len);

	if (len < 1) {
		// Disconnected, either clean or dirty 
		// (shouldn't this be caught by G_IO_HUP?)
		if (len < 0) {
			if (errno == EAGAIN || errno == EWOULDBLOCK) {
				return TRUE;
			}
			
			gm_net_set_state(net, GM_NET_STATE_DISCONNECTING);
			gm_net_dirty_disconnection(net, errno);
		} else {
			gm_net_set_state(net, GM_NET_STATE_DISCONNECTING);
			gm_net_clean_disconnection(net);
		}

		return FALSE;
	} else {
		// It's fine, we have text!
		gm_net_handle_telnet(net, lbuf, &len);
		g_signal_emit(net, net_signals[BYTES_RECV], 0, lbuf, len);
	}

	return TRUE;
}

gboolean
on_gm_net_connect_check(GIOChannel * source, GIOCondition condition,
		GmNet *net) {
	int option = 0;
	socklen_t optionsize = sizeof(option);

	if (net->priv->connect_timeout_id != 0) {
		g_source_remove(net->priv->connect_timeout_id);
		net->priv->connect_timeout_id = 0;
	}
  
	if (condition == G_IO_ERR) {
		getsockopt(net->priv->socket, SOL_SOCKET, SO_ERROR, &option, &optionsize);
		gm_net_connect_failed(net, strerror(option), option);
	} else {
		gm_net_connect_succeed(net);
	}
  
	return FALSE;
}

gboolean
on_gm_net_connect_timeout(GmNet *net) {
	net->priv->connect_timeout_id = 0;
  
	if (net->priv->connect_check_id != 0) {
		g_source_remove(net->priv->connect_check_id);
		net->priv->connect_check_id = 0;
	}
  
	gm_net_connect_failed(net, _("Connect timeout (5)"), 0);
	return FALSE;
}