/*
 * 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 <stdio.h>
#include <str.h>

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

#include "../../err.h"
#include "../../messages.h"
#include "../../modules.h"

#include "../../structures/measured_strings.h"
#include "../../structures/packet/packet_client.h"

#include "../../include/device.h"
#include "../../include/nil_interface.h"

#include "../../nil/nil_messages.h"

#include "../netif.h"
#include "../netif_module.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 - loopback interface"

/** 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(device_ref 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, device_ref * device);

/** Prints the module name.
 *  @see NAME
 */
void module_print_name(void);

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;

	device_ref 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(device_ref device, device_state_t state){
	if(device->state != state){
		device->state = state;
		printf("State changed to %s\n", (state == NETIF_ACTIVE) ? "ACTIVE" : "STOPPED");
		return state;
	}
	return EOK;
}

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

	if(device_map_count(&netif_globals.device_map) > 0){
		return EXDEV;
	}else{
		*device = (device_ref) malloc(sizeof(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 = 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);
}

void module_print_name(void){
	printf("%s", NAME);
}

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

	device_ref device;

	// create a new device
	ERROR_PROPAGATE(create(device_id, &device));
	// print the settings
	printf("New device created:\n\tid\t= %d\n", device->device_id);
	return EOK;
}

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

	device_ref 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(device_ref device){
	return change_state_message(device, NETIF_ACTIVE);
}

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

/** @}
 */