/*
 * FreeRTOS V202212.00
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * https://www.FreeRTOS.org
 * https://github.com/FreeRTOS
 *
 */

/* Standard includes. */
#include <stdint.h>
#include <stdio.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"

/* FreeRTOS+CLI includes. */
#include "FreeRTOS_CLI.h"

/* FreeRTOS+UDP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"

/* Demo app includes. */
#include "UDPCommandInterpreter.h"

/* Dimensions the buffer into which input characters are placed. */
#define cmdMAX_INPUT_SIZE	60

/* Dimensions the buffer into which string outputs can be placed. */
#define cmdMAX_OUTPUT_SIZE	1024

/* Dimensions the buffer passed to the recvfrom() call. */
#define cmdSOCKET_INPUT_BUFFER_SIZE 60

/*
 * The task that runs FreeRTOS+CLI.
 */
void vUDPCommandInterpreterTask( void *pvParameters );

/*
 * Open and configure the UDP socket.
 */
static Socket_t prvOpenUDPServerSocket( uint16_t usPort );

/*-----------------------------------------------------------*/

void vStartUDPCommandInterpreterTask( uint16_t usStackSize, uint32_t ulPort, unsigned portBASE_TYPE uxPriority )
{
	xTaskCreate( vUDPCommandInterpreterTask, ( signed char * ) "CLI", usStackSize, ( void * ) ulPort, uxPriority, NULL );
}
/*-----------------------------------------------------------*/

/* 
 * Task that provides the input and output for the FreeRTOS+CLI command
 * interpreter.  In this case a UDP port is used.  See the URL in the comments
 * within main.c for the location of the online documentation.
 */
void vUDPCommandInterpreterTask( void *pvParameters )
{
long lBytes, lByte;
signed char cInChar, cInputIndex = 0;
static signed char cInputString[ cmdMAX_INPUT_SIZE ], cOutputString[ cmdMAX_OUTPUT_SIZE ], cLocalBuffer[ cmdSOCKET_INPUT_BUFFER_SIZE ];
portBASE_TYPE xMoreDataToFollow;
struct freertos_sockaddr xClient;
socklen_t xClientAddressLength = 0; /* This is required as a parameter to maintain the sendto() Berkeley sockets API - but it is not actually used so can take any value. */
Socket_t xSocket;
extern const uint8_t ucIPAddress[ 4 ];
extern const uint8_t ucMACAddress[ 6 ];

	/* Just to prevent compiler warnings. */
	( void ) pvParameters;

	/* Attempt to open the socket.  The port number is passed in the task
	parameter.  The strange casting is to remove compiler warnings on 32-bit
	machines. */
	xSocket = prvOpenUDPServerSocket( ( uint16_t ) ( ( uint32_t ) pvParameters ) & 0xffffUL );

	if( xSocket != FREERTOS_INVALID_SOCKET )
	{
		for( ;; )
		{
			/* Wait for incoming data on the opened socket. */
			lBytes = FreeRTOS_recvfrom( xSocket, ( void * ) cLocalBuffer, sizeof( cLocalBuffer ), 0, &xClient, &xClientAddressLength );

			if( lBytes != FREERTOS_SOCKET_ERROR )
			{
				/* Process each received byte in turn. */
				lByte = 0;
				while( lByte < lBytes )
				{
					/* The next character in the input buffer. */
					cInChar = cLocalBuffer[ lByte ];
					lByte++;

					/* Newline characters are taken as the end of the command
					string. */
					if( cInChar == '\n' )
					{
						/* Process the input string received prior to the 
						newline. */
						do
						{
							/* Pass the string to FreeRTOS+CLI. */
							xMoreDataToFollow = FreeRTOS_CLIProcessCommand( cInputString, cOutputString, cmdMAX_OUTPUT_SIZE );
							
							/* Send the output generated by the command's
							implementation. */
							FreeRTOS_sendto( xSocket, cOutputString,  strlen( ( const char * ) cOutputString ), 0, &xClient, xClientAddressLength );

						} while( xMoreDataToFollow != pdFALSE ); /* Until the command does not generate any more output. */

						/* All the strings generated by the command processing 
						have been sent.  Clear the input string ready to receive 
						the next command. */
						cInputIndex = 0;
						memset( cInputString, 0x00, cmdMAX_INPUT_SIZE );
						
						/* Transmit a spacer, just to make the command console
						easier to read. */
						FreeRTOS_sendto( xSocket, "\r\n",  strlen( "\r\n" ), 0, &xClient, xClientAddressLength );
					}
					else
					{
						if( cInChar == '\r' )
						{
							/* Ignore the character.  Newlines are used to 
							detect the end of the input string. */
						}
						else if( cInChar == '\b' )
						{
							/* Backspace was pressed.  Erase the last character 
							in the string - if any. */
							if( cInputIndex > 0 )
							{
								cInputIndex--;
								cInputString[ cInputIndex ] = '\0';
							}
						}
						else
						{
							/* A character was entered.  Add it to the string
							entered so far.  When a \n is entered the complete
							string will be passed to the command interpreter. */
							if( cInputIndex < cmdMAX_INPUT_SIZE )
							{
								cInputString[ cInputIndex ] = cInChar;
								cInputIndex++;
							}
						}
					}
				}
			}
		} 
	}
	else
	{
		/* The socket could not be opened. */
		vTaskDelete( NULL );
	}
}
/*-----------------------------------------------------------*/

static Socket_t prvOpenUDPServerSocket( uint16_t usPort )
{
struct freertos_sockaddr xServer;
Socket_t xSocket = FREERTOS_INVALID_SOCKET;

	xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );
	if( xSocket != FREERTOS_INVALID_SOCKET)
	{
		/* Zero out the server structure. */
		memset( ( void * ) &xServer, 0x00, sizeof( xServer ) );

		/* Set family and port. */
		xServer.sin_port = FreeRTOS_htons( usPort );
		xServer.sin_family = FREERTOS_AF_INET;

		/* Bind the address to the socket. */
		if( FreeRTOS_bind( xSocket, &xServer, sizeof( xServer ) ) == -1 )
		{			
			FreeRTOS_closesocket( xSocket );
			xSocket = FREERTOS_INVALID_SOCKET;
		}
	}

	return xSocket;
}