/*
 * Copyright (c) 2009 Lukas Mejdrech
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup lo
 *  @{
 */

/** @file
 *  Loopback network interface implementation.
 */

#include <async.h>
#include <errno.h>
#include <err.h>
#include <stdio.h>
#include <str.h>

#include <ipc/ipc.h>
#include <ipc/services.h>

#include <net_messages.h>
#include <net_modules.h>
#include <adt/measured_strings.h>
#include <packet/packet_client.h>
#include <net_device.h>
#include <nil_interface.h>
#include <nil_messages.h>
#include <netif_interface.h>
#include <netif_local.h>

/** Default hardware address.
 */
#define DEFAULT_ADDR		"\0\0\0\0\0\0"

/** Default address length.
 */
#define DEFAULT_ADDR_LEN	(sizeof(DEFAULT_ADDR) / sizeof(char))

/** Loopback module name.
 */
#define NAME  "lo"

/** Network interface global data.
 */
netif_globals_t	netif_globals;

/** Changes the loopback state.
 *  @param[in] device The device structure.
 *  @param[in] state The new device state.
 *  @returns The new state if changed.
 *  @returns EOK otherwise.
 */
int change_state_message(netif_device_t * device, device_state_t state);

/** Creates and returns the loopback network interface structure.
 *  @param[in] device_id The new devce identifier.
 *  @param[out] device The device structure.
 *  @returns EOK on success.
 *  @returns EXDEV if one loopback network interface already exists.
 *  @returns ENOMEM if there is not enough memory left.
 */
int create(device_id_t device_id, netif_device_t * * device);

int netif_specific_message(ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count){
	return ENOTSUP;
}

int netif_get_addr_message(device_id_t device_id, measured_string_ref address){
	if(! address){
		return EBADMEM;
	}
	address->value = str_dup(DEFAULT_ADDR);
	address->length = DEFAULT_ADDR_LEN;
	return EOK;
}

int netif_get_device_stats(device_id_t device_id, device_stats_ref stats){
	ERROR_DECLARE;

	netif_device_t * device;

	if(! stats){
		return EBADMEM;
	}
	ERROR_PROPAGATE(find_device(device_id, &device));
	memcpy(stats, (device_stats_ref) device->specific, sizeof(device_stats_t));
	return EOK;
}

int change_state_message(netif_device_t * device, device_state_t state)
{
	if (device->state != state) {
		device->state = state;
		
		printf("%s: State changed to %s\n", NAME,
		    (state == NETIF_ACTIVE) ? "active" : "stopped");
		
		return state;
	}
	
	return EOK;
}

int create(device_id_t device_id, netif_device_t * * device){
	int index;

	if(netif_device_map_count(&netif_globals.device_map) > 0){
		return EXDEV;
	}else{
		*device = (netif_device_t *) malloc(sizeof(netif_device_t));
		if(!(*device)){
			return ENOMEM;
		}
		(** device).specific = malloc(sizeof(device_stats_t));
		if(! (** device).specific){
			free(*device);
			return ENOMEM;
		}
		null_device_stats((device_stats_ref)(** device).specific);
		(** device).device_id = device_id;
		(** device).nil_phone = -1;
		(** device).state = NETIF_STOPPED;
		index = netif_device_map_add(&netif_globals.device_map, (** device).device_id, * device);
		if(index < 0){
			free(*device);
			free((** device).specific);
			*device = NULL;
			return index;
		}
	}
	return EOK;
}

int netif_initialize(void){
	ipcarg_t phonehash;

	return REGISTER_ME(SERVICE_LO, &phonehash);
}

int netif_probe_message(device_id_t device_id, int irq, uintptr_t io){
	ERROR_DECLARE;

	netif_device_t * device;

	// create a new device
	ERROR_PROPAGATE(create(device_id, &device));
	// print the settings
	printf("%s: Device created (id: %d)\n", NAME, device->device_id);
	return EOK;
}

int netif_send_message(device_id_t device_id, packet_t packet, services_t sender){
	ERROR_DECLARE;

	netif_device_t * device;
	size_t length;
	packet_t next;
	int phone;

	ERROR_PROPAGATE(find_device(device_id, &device));
	if(device->state != NETIF_ACTIVE){
		netif_pq_release(packet_get_id(packet));
		return EFORWARD;
	}
	next = packet;
	do{
		++ ((device_stats_ref) device->specific)->send_packets;
		++ ((device_stats_ref) device->specific)->receive_packets;
		length = packet_get_data_length(next);
		((device_stats_ref) device->specific)->send_bytes += length;
		((device_stats_ref) device->specific)->receive_bytes += length;
		next = pq_next(next);
	}while(next);
	phone = device->nil_phone;
	fibril_rwlock_write_unlock(&netif_globals.lock);
	nil_received_msg(phone, device_id, packet, sender);
	fibril_rwlock_write_lock(&netif_globals.lock);
	return EOK;
}

int netif_start_message(netif_device_t * device){
	return change_state_message(device, NETIF_ACTIVE);
}

int netif_stop_message(netif_device_t * device){
	return change_state_message(device, NETIF_STOPPED);
}

/** Default thread for new connections.
 *
 * @param[in] iid The initial message identifier.
 * @param[in] icall The initial message call structure.
 *
 */
static void netif_client_connection(ipc_callid_t iid, ipc_call_t *icall)
{
	/*
	 * Accept the connection
	 *  - Answer the first IPC_M_CONNECT_ME_TO call.
	 */
	ipc_answer_0(iid, EOK);
	
	while(true) {
		ipc_call_t answer;
		int answer_count;
		
		/* Clear the answer structure */
		refresh_answer(&answer, &answer_count);
		
		/* Fetch the next message */
		ipc_call_t call;
		ipc_callid_t callid = async_get_call(&call);
		
		/* Process the message */
		int res = netif_module_message(NAME, callid, &call, &answer,
		    &answer_count);
		
		/* End if said to either by the message or the processing result */
		if ((IPC_GET_METHOD(call) == IPC_M_PHONE_HUNGUP) || (res == EHANGUP))
			return;
		
		/* Answer the message */
		answer_call(callid, res, &answer, answer_count);
	}
}

int main(int argc, char *argv[])
{
	ERROR_DECLARE;
	
	/* Start the module */
	if (ERROR_OCCURRED(netif_module_start(netif_client_connection)))
		return ERROR_CODE;
	
	return EOK;
}

/** @}
 */