/* 
 * Copyright 2011 Marian Ohligs, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM. 
 */

#include <metalsvm/stdlib.h>
#include <metalsvm/string.h>
#include <metalsvm/stdio.h>
#include <metalsvm/errno.h>
#include <metalsvm/fs.h>
#include <metalsvm/spinlock.h>
#include <lwip/opt.h>

#if defined(CONFIG_LWIP) && LWIP_SOCKET
#include <lwip/mem.h>
#include <lwip/raw.h>
#include <lwip/icmp.h>
#include <lwip/netif.h>
#include <lwip/sys.h>
#include <lwip/timers.h>
#include <lwip/inet_chksum.h>
#include <lwip/ip.h>
#include <lwip/sockets.h>
#include <lwip/inet.h>
#include <lwip/err.h>
#endif


/* Implementation of a simple netio device */

static ssize_t socket_read(fildes_t* file, uint8_t* buffer, size_t size)
{
	int ret = 0;
#if defined(CONFIG_LWIP) && LWIP_SOCKET
	ret = lwip_read((int)file->offset, buffer, size);

	if (ret < 0)
		ret = -errno;
#endif
	return ret;
}

static ssize_t socket_write(fildes_t* file, uint8_t* buffer, size_t size)
{
	int ret = 0;
#if defined(CONFIG_LWIP) && LWIP_SOCKET
	if (BUILTIN_EXPECT(!size, 0))
		return 0;

#if LWIP_TCPIP_CORE_LOCKING
	ret = lwip_write(file->offset, buffer, size);
#else
	// create a copy and forward this copy to the TCP/IP stack
	uint8_t* tmp = kmalloc(size);
	if (BUILTIN_EXPECT(!tmp, 0))
		return -ENOMEM;
	memcpy(tmp, buffer, size);
	ret = lwip_write(file->offset, tmp, size);
	kfree(tmp);
#endif
	if (ret < 0)
		ret = -errno;
#endif
	return ret;
}

static int socket_open(fildes_t* file, const char* name)
{
	return 0;
}

static int socket_close(fildes_t* file)
{
	int ret = 0;
#if defined(CONFIG_LWIP) && LWIP_SOCKET
	ret = lwip_close(file->offset);
	if (ret < 0)
		ret = -errno;
#endif
	return ret;
}

int socket_init(vfs_node_t* node, const char* name)
{
	uint32_t i, j;
	vfs_node_t* new_node;
	dir_block_t* blockdir;
	dirent_t* dirent;
	block_list_t* blist;

	if (BUILTIN_EXPECT(!node || !name, 0))
		return -EINVAL;

	if (BUILTIN_EXPECT(node->type != FS_DIRECTORY, 0))
		return -EINVAL;

	if (finddir_fs(node, name))
		return -EINVAL;

	new_node = kmalloc(sizeof(vfs_node_t));
	if (BUILTIN_EXPECT(!new_node, 0))
		return -ENOMEM;

	memset(new_node, 0x00, sizeof(vfs_node_t));
	new_node->type = FS_SOCKET;
	new_node->open = &socket_open;
	new_node->close = &socket_close;
	new_node->read = &socket_read;
	new_node->write = &socket_write;
	spinlock_init(&new_node->lock);

	blist= &node->block_list;
	do {
		for(i=0; i<MAX_DATABLOCKS; i++) {
			if (blist->data[i]) {
				blockdir = (dir_block_t*) blist->data[i];
				for(j=0; j<MAX_DIRENTRIES; j++) {
					dirent = &blockdir->entries[j];
					if (!dirent->vfs_node) {
						dirent->vfs_node = new_node;
						strncpy(dirent->name, name, MAX_FNAME);
						return 0;
					}
				}
			}
		}

		if (!blist->next) {
			blist->next = (block_list_t*) kmalloc(sizeof(block_list_t));
			if (blist->next)
				memset(blist->next, 0x00, sizeof(block_list_t));
		}

	} while(blist);

	kfree(new_node);

	return -ENOMEM;
}