/*
 * 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 nildummy
 *  @{
 */

/** @file
 *  Dummy network interface layer module implementation.
 *  @see nildummy.h
 */

#include <async.h>
#include <malloc.h>
#include <mem.h>
#include <stdio.h>
#include <string.h>

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

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

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

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

#include "../nil_module.h"

#include "nildummy.h"

/** Default maximum transmission unit.
 */
#define NET_DEFAULT_MTU	1500

/** Network interface layer module global data.
 */
nildummy_globals_t	nildummy_globals;

/** @name Message processing functions
 */
/*@{*/

/** Processes IPC messages from the registered device driver modules in an infinite loop.
 *  @param[in] iid The message identifier.
 *  @param[in,out] icall The message parameters.
 */
void	nildummy_receiver( ipc_callid_t iid, ipc_call_t * icall );

/** Registers new device or updates the MTU of an existing one.
 *  Determines the device local hardware address.
 *  @param[in] device_id The new device identifier.
 *  @param[in] service The device driver service.
 *  @param[in] mtu The device maximum transmission unit.
 *  @returns EOK on success.
 *  @returns EEXIST if the device with the different service exists.
 *  @returns ENOMEM if there is not enough memory left.
 *  @returns Other error codes as defined for the netif_bind_service() function.
 *  @returns Other error codes as defined for the netif_get_addr_req() function.
 */
int	nildummy_device_message( device_id_t device_id, services_t service, size_t mtu );

/** Returns the device packet dimensions for sending.
 *  @param[in] device_id The device identifier.
 *  @param[out] addr_len The minimum reserved address length.
 *  @param[out] prefix The minimum reserved prefix size.
 *  @param[out] content The maximum content size.
 *  @param[out] suffix The minimum reserved suffix size.
 *  @returns EOK on success.
 *  @returns EBADMEM if either one of the parameters is NULL.
 *  @returns ENOENT if there is no such device.
 */
int	nildummy_packet_space_message( device_id_t device_id, size_t * addr_len, size_t * prefix, size_t * content, size_t * suffix );

/** Registers receiving module service.
 *  Passes received packets for this service.
 *  @param[in] service The module service.
 *  @param[in] phone The service phone.
 *  @returns EOK on success.
 *  @returns ENOENT if the service is not known.
 *  @returns ENOMEM if there is not enough memory left.
 */
int	nildummy_register_message( services_t service, int phone );

/** Sends the packet queue.
 *  @param[in] device_id The device identifier.
 *  @param[in] packet The packet queue.
 *  @param[in] sender The sending module service.
 *  @returns EOK on success.
 *  @returns ENOENT if there no such device.
 *  @returns EINVAL if the service parameter is not known.
 */
int	nildummy_send_message( device_id_t device_id, packet_t packet, services_t sender );

/** Returns the device hardware address.
 *  @param[in] device_id The device identifier.
 *  @param[out] address The device hardware address.
 *  @returns EOK on success.
 *  @returns EBADMEM if the address parameter is NULL.
 *  @returns ENOENT if there no such device.
 */
int	nildummy_addr_message( device_id_t device_id, measured_string_ref * address );

/*@}*/

DEVICE_MAP_IMPLEMENT( nildummy_devices, nildummy_device_t )

int	nil_device_state_msg( int nil_phone, device_id_t device_id, int state ){
	fibril_rwlock_read_lock( & nildummy_globals.protos_lock );
	if( nildummy_globals.proto.phone ) il_device_state_msg( nildummy_globals.proto.phone, device_id, state, nildummy_globals.proto.service );
	fibril_rwlock_read_unlock( & nildummy_globals.protos_lock );
	return EOK;
}

int nil_initialize( int net_phone ){
	ERROR_DECLARE;

	fibril_rwlock_initialize( & nildummy_globals.devices_lock );
	fibril_rwlock_initialize( & nildummy_globals.protos_lock );
	fibril_rwlock_write_lock( & nildummy_globals.devices_lock );
	fibril_rwlock_write_lock( & nildummy_globals.protos_lock );
	nildummy_globals.net_phone = net_phone;
	nildummy_globals.proto.phone = 0;
	ERROR_PROPAGATE( nildummy_devices_initialize( & nildummy_globals.devices ));
	fibril_rwlock_write_unlock( & nildummy_globals.protos_lock );
	fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
	return EOK;
}

int nildummy_device_message( device_id_t device_id, services_t service, size_t mtu ){
	ERROR_DECLARE;

	nildummy_device_ref	device;
	int					index;

	fibril_rwlock_write_lock( & nildummy_globals.devices_lock );
	// an existing device?
	device = nildummy_devices_find( & nildummy_globals.devices, device_id );
	if( device ){
		if( device->service != service ){
			printf( "Device %d already exists\n", device->device_id );
			fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
			return EEXIST;
		}else{
			// update mtu
			if( mtu > 0 ){
				device->mtu = mtu;
			}else{
				device->mtu = NET_DEFAULT_MTU;
			}
			printf( "Device %d already exists:\tMTU\t= %d\n", device->device_id, device->mtu );
			fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
			// notify the upper layer module
			fibril_rwlock_read_lock( & nildummy_globals.protos_lock );
			if( nildummy_globals.proto.phone ){
				il_mtu_changed_msg( nildummy_globals.proto.phone, device->device_id, device->mtu, nildummy_globals.proto.service );
			}
			fibril_rwlock_read_unlock( & nildummy_globals.protos_lock );
			return EOK;
		}
	}else{
		// create a new device
		device = ( nildummy_device_ref ) malloc( sizeof( nildummy_device_t ));
		if( ! device ) return ENOMEM;
		device->device_id = device_id;
		device->service = service;
		if( mtu > 0 ){
			device->mtu = mtu;
		}else{
			device->mtu = NET_DEFAULT_MTU;
		}
		// bind the device driver
		device->phone = netif_bind_service( device->service, device->device_id, SERVICE_ETHERNET, nildummy_receiver );
		if( device->phone < 0 ){
			fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
			free( device );
			return device->phone;
		}
		// get hardware address
		if( ERROR_OCCURRED( netif_get_addr_req( device->phone, device->device_id, & device->addr, & device->addr_data ))){
			fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
			free( device );
			return ERROR_CODE;
		}
		// add to the cache
		index = nildummy_devices_add( & nildummy_globals.devices, device->device_id, device );
		if( index < 0 ){
			fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
			free( device->addr );
			free( device->addr_data );
			free( device );
			return index;
		}
		printf( "New device registered:\n\tid\t= %d\n\tservice\t= %d\n\tMTU\t= %d\n", device->device_id, device->service, device->mtu );
	}
	fibril_rwlock_write_unlock( & nildummy_globals.devices_lock );
	return EOK;
}

int nildummy_addr_message( device_id_t device_id, measured_string_ref * address ){
	nildummy_device_ref	device;

	if( ! address ) return EBADMEM;
	fibril_rwlock_read_lock( & nildummy_globals.devices_lock );
	device = nildummy_devices_find( & nildummy_globals.devices, device_id );
	if( ! device ){
		fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
		return ENOENT;
	}
	* address = device->addr;
	fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
	return ( * address ) ? EOK : ENOENT;
}

int nildummy_packet_space_message( device_id_t device_id, size_t * addr_len, size_t * prefix, size_t * content, size_t * suffix ){
	nildummy_device_ref	device;

	if( !( addr_len && prefix && content && suffix )) return EBADMEM;
	fibril_rwlock_read_lock( & nildummy_globals.devices_lock );
	device = nildummy_devices_find( & nildummy_globals.devices, device_id );
	if( ! device ){
		fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
		return ENOENT;
	}
	* content = device->mtu;
	fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
	* addr_len = 0;
	* prefix = 0;
	* suffix = 0;
	return EOK;
}

int nil_received_msg( int nil_phone, device_id_t device_id, packet_t packet, services_t target ){
	packet_t		next;

	fibril_rwlock_read_lock( & nildummy_globals.protos_lock );
	if( nildummy_globals.proto.phone ){
		do{
			next = pq_detach( packet );
			il_received_msg( nildummy_globals.proto.phone, device_id, packet, nildummy_globals.proto.service );
			packet = next;
		}while( packet );
	}
	fibril_rwlock_read_unlock( & nildummy_globals.protos_lock );
	return EOK;
}

int nildummy_register_message( services_t service, int phone ){
	fibril_rwlock_write_lock( & nildummy_globals.protos_lock );
	nildummy_globals.proto.service = service;
	nildummy_globals.proto.phone = phone;
	printf( "New protocol registered:\n\tservice\t= %d\n\tphone\t= %d\n", nildummy_globals.proto.service, nildummy_globals.proto.phone );
	fibril_rwlock_write_unlock( & nildummy_globals.protos_lock );
	return EOK;
}

int nildummy_send_message( device_id_t device_id, packet_t packet, services_t sender ){
	nildummy_device_ref		device;

	fibril_rwlock_read_lock( & nildummy_globals.devices_lock );
	device = nildummy_devices_find( & nildummy_globals.devices, device_id );
	if( ! device ){
		fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
		return ENOENT;
	}
	// send packet queue
	if( packet ){
		netif_send_msg( device->phone, device_id, packet, SERVICE_NILDUMMY );
	}
	fibril_rwlock_read_unlock( & nildummy_globals.devices_lock );
	return EOK;
}

int nil_message( ipc_callid_t callid, ipc_call_t * call, ipc_call_t * answer, int * answer_count ){
	ERROR_DECLARE;

	measured_string_ref	address;
	packet_t			packet;

//	printf( "message %d - %d\n", IPC_GET_METHOD( * call ), NET_NIL_FIRST );
	* answer_count = 0;
	switch( IPC_GET_METHOD( * call )){
		case IPC_M_PHONE_HUNGUP:
			return EOK;
		case NET_NIL_DEVICE:
			return nildummy_device_message( IPC_GET_DEVICE( call ), IPC_GET_SERVICE( call ), IPC_GET_MTU( call ));
		case NET_NIL_SEND:
			ERROR_PROPAGATE( packet_translate( nildummy_globals.net_phone, & packet, IPC_GET_PACKET( call )));
			return nildummy_send_message( IPC_GET_DEVICE( call ), packet, IPC_GET_SERVICE( call ));
		case NET_NIL_PACKET_SPACE:
			ERROR_PROPAGATE( nildummy_packet_space_message( IPC_GET_DEVICE( call ), IPC_SET_ADDR( answer ), IPC_SET_PREFIX( answer ), IPC_SET_CONTENT( answer ), IPC_SET_SUFFIX( answer )));
			* answer_count = 4;
			return EOK;
		case NET_NIL_ADDR:
			ERROR_PROPAGATE( nildummy_addr_message( IPC_GET_DEVICE( call ), & address ));
			return measured_strings_reply( address, 1 );
		case IPC_M_CONNECT_TO_ME:
			return nildummy_register_message( NIL_GET_PROTO( call ), IPC_GET_PHONE( call ));
	}
	return ENOTSUP;
}

void nildummy_receiver( ipc_callid_t iid, ipc_call_t * icall ){
	ERROR_DECLARE;

	packet_t		packet;

	while( true ){
//		printf( "message %d - %d\n", IPC_GET_METHOD( * icall ), NET_NIL_FIRST );
		switch( IPC_GET_METHOD( * icall )){
			case NET_NIL_DEVICE_STATE:
				ERROR_CODE = nil_device_state_msg( 0, IPC_GET_DEVICE( icall ), IPC_GET_STATE( icall ));
				ipc_answer_0( iid, ( ipcarg_t ) ERROR_CODE );
				break;
			case NET_NIL_RECEIVED:
				if( ! ERROR_OCCURRED( packet_translate( nildummy_globals.net_phone, & packet, IPC_GET_PACKET( icall )))){
					ERROR_CODE = nil_received_msg( 0, IPC_GET_DEVICE( icall ), packet, 0 );
				}
				ipc_answer_0( iid, ( ipcarg_t ) ERROR_CODE );
				break;
			default:
				ipc_answer_0( iid, ( ipcarg_t ) ENOTSUP );
		}
		iid = async_get_call( icall );
	}
}

/** @}
 */