/*
    FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception.

    ***************************************************************************
    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
    ***************************************************************************

    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
     *                                                                       *
     *    Help yourself get started quickly while simultaneously helping     *
     *    to support the FreeRTOS project by purchasing a FreeRTOS           *
     *    tutorial book, reference manual, or both:                          *
     *    http://www.FreeRTOS.org/Documentation                              *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
    the FAQ page "My application does not run, what could be wrong?".  Have you
    defined configASSERT()?

    http://www.FreeRTOS.org/support - In return for receiving this top quality
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    http://www.FreeRTOS.org/training - Investing in training allows your team to
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    FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
    Ltd, and the world's leading authority on the world's leading RTOS.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/

/* Standard includes. */
#include "string.h"
#include "stdio.h"

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

/* Driver includes. */
#include "drivers/mss_uart/mss_uart.h"

/* Example includes. */
#include "FreeRTOS_CLI.h"
#include "UARTCommandConsole.h"

/* Dimensions the buffer into which input characters are placed. */
#define cmdMAX_INPUT_SIZE		50

/* The maximum time in ticks to wait for the UART access mutex. */
#define cmdMAX_MUTEX_WAIT		( 200 / portTICK_PERIOD_MS )

/* Characters are only ever received slowly on the CLI so it is ok to pass
received characters from the UART interrupt to the task on a queue.  This sets
the length of the queue used for that purpose. */
#define cmdRXED_CHARS_QUEUE_LENGTH			( 10 )

/*-----------------------------------------------------------*/

/*
 * The task that implements the command console processing.
 */
static void prvUARTCommandConsoleTask( void *pvParameters );

/*
 * Ensure a previous interrupt driven Tx has completed before sending the next
 * data block to the UART.
 */
static void prvSendBuffer( const char * pcBuffer, size_t xBufferLength );

/*
 * A UART is used for printf() output and CLI input and output.  Configure the
 * UART and register prvUARTRxNotificationHandler() to handle UART Rx events.
 */
static void prvConfigureUART( void );
static void prvUARTRxNotificationHandler( mss_uart_instance_t * this_uart );

/*-----------------------------------------------------------*/

/* Const messages output by the command console. */
static const char * const pcWelcomeMessage = "\r\n\r\nFreeRTOS command server.\r\nType Help to view a list of registered commands.\r\n\r\n>";
static const char * const pcEndOfOutputMessage = "\r\n[Press ENTER to execute the previous command again]\r\n>";
static const char * const pcNewLine = "\r\n";

/* The UART used by the CLI. */
#if configBUILD_FOR_DEVELOPMENT_KIT == 1
	static const mss_uart_instance_t * const pxUART = &g_mss_uart1;
	static const IRQn_Type xUART_IRQ = UART1_IRQn;
#else
	static const mss_uart_instance_t * const pxUART = &g_mss_uart0;
	static const IRQn_Type xUART_IRQ = UART0_IRQn;
#endif

/* Because characters are received slowly (at the speed somebody can type) then
it is ok to pass received characters from the Rx interrupt to the task on a
queue.  This is the queue used for that purpose. */
static QueueHandle_t xRxedChars = NULL;

/*-----------------------------------------------------------*/

void vUARTCommandConsoleStart( uint16_t usStackSize, unsigned portBASE_TYPE uxPriority )
{
	/* A UART is used for printf() output and CLI input and output.  Note there
	is no mutual exclusion on the UART, but the demo as it stands does not
	require mutual exclusion. */
	prvConfigureUART();

	/* Create that task that handles the console itself. */
	xTaskCreate( 	prvUARTCommandConsoleTask,	/* The task that implements the command console. */
					"CLI",						/* Text name assigned to the task.  This is just to assist debugging.  The kernel does not use this name itself. */
					usStackSize,				/* The size of the stack allocated to the task. */
					NULL,						/* The parameter is not used, so NULL is passed. */
					uxPriority,					/* The priority allocated to the task. */
					NULL );						/* A handle is not required, so just pass NULL. */
}
/*-----------------------------------------------------------*/

static void prvUARTCommandConsoleTask( void *pvParameters )
{
char cRxedChar, *pcOutputString;
unsigned char cInputIndex = 0;
static char cInputString[ cmdMAX_INPUT_SIZE ], cLastInputString[ cmdMAX_INPUT_SIZE ];
portBASE_TYPE xReturned;

	( void ) pvParameters;

	/* Obtain the address of the output buffer.  Note there is no mutual
	exclusion on this buffer as it is assumed only one command console
	interface will be used at any one time. */
	pcOutputString = FreeRTOS_CLIGetOutputBuffer();

	/* Send the welcome message. */
	prvSendBuffer( pcWelcomeMessage, strlen( pcWelcomeMessage ) );

	for( ;; )
	{
		/* Wait for the next character to arrive. */
		if( xQueueReceive( xRxedChars, &cRxedChar, portMAX_DELAY ) == pdPASS )
		{
			/* Echo the character back. */
			prvSendBuffer( &cRxedChar, sizeof( cRxedChar ) );

			/* Was it the end of the line? */
			if( cRxedChar == '\n' || cRxedChar == '\r' )
			{
				/* Just to space the output from the input. */
				prvSendBuffer( pcNewLine, strlen( pcNewLine ) );

				/* See if the command is empty, indicating that the last command is
				to be executed again. */
				if( cInputIndex == 0 )
				{
					/* Copy the last command back into the input string. */
					strcpy( cInputString, cLastInputString );
				}

				/* Pass the received command to the command interpreter.  The
				command interpreter is called repeatedly until it returns pdFALSE
				(indicating there is no more output) as it might generate more than
				one string. */
				do
				{
					/* Get the next output string from the command interpreter. */
					xReturned = FreeRTOS_CLIProcessCommand( cInputString, pcOutputString, configCOMMAND_INT_MAX_OUTPUT_SIZE );

					/* Write the generated string to the UART. */
					prvSendBuffer( pcOutputString, strlen( pcOutputString ) );

				} while( xReturned != pdFALSE );

				/* All the strings generated by the input command have been sent.
				Clear the input	string ready to receive the next command.  Remember
				the command that was just processed first in case it is to be
				processed again. */
				strcpy( cLastInputString, cInputString );
				cInputIndex = 0;
				memset( cInputString, 0x00, cmdMAX_INPUT_SIZE );

				prvSendBuffer( pcEndOfOutputMessage, strlen( pcEndOfOutputMessage ) );
			}
			else
			{
				if( cRxedChar == '\r' )
				{
					/* Ignore the character. */
				}
				else if( cRxedChar == '\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( ( cRxedChar >= ' ' ) && ( cRxedChar <= '~' ) )
					{
						if( cInputIndex < cmdMAX_INPUT_SIZE )
						{
							cInputString[ cInputIndex ] = cRxedChar;
							cInputIndex++;
						}
					}
				}
			}
		}
	}
}
/*-----------------------------------------------------------*/

static void prvSendBuffer( const char * pcBuffer, size_t xBufferLength )
{
const TickType_t xVeryShortDelay = 2UL;

	if( xBufferLength > 0 )
	{
		MSS_UART_irq_tx( ( mss_uart_instance_t * ) pxUART, ( uint8_t * ) pcBuffer, xBufferLength );

		/* Ensure any previous transmissions have completed.  The default UART
		interrupt does not provide an event based method of	signally the end of a Tx
		- this is therefore a crude poll of the Tx end status.  Replacing the
		default UART handler with one that 'gives' a semaphore when the Tx is
		complete would allow this poll loop to be replaced by a simple semaphore
		block. */
		while( MSS_UART_tx_complete( ( mss_uart_instance_t * ) pxUART ) == pdFALSE )
		{
			vTaskDelay( xVeryShortDelay );
		}
	}
}
/*-----------------------------------------------------------*/

static void prvConfigureUART( void )
{
	/* Initialise the UART which is used for printf() and CLI IO. */
	MSS_UART_init( ( mss_uart_instance_t * ) pxUART, MSS_UART_115200_BAUD, MSS_UART_DATA_8_BITS | MSS_UART_NO_PARITY | MSS_UART_ONE_STOP_BIT );

	/* Characters are only ever received slowly on the CLI so it is ok to pass
	received characters from the UART interrupt to the task on a queue.  Create
	the queue used for that purpose. */
	xRxedChars = xQueueCreate( cmdRXED_CHARS_QUEUE_LENGTH, sizeof( char ) );

	/* The interrupt handler makes use of FreeRTOS API functions, so its
	priority must be at or below the configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY
	setting (the higher the numeric priority, the lower the logical priority). */
	NVIC_SetPriority( xUART_IRQ, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );

	/* Set the UART Rx notification function. */
	MSS_UART_set_rx_handler( ( mss_uart_instance_t * ) pxUART, prvUARTRxNotificationHandler, MSS_UART_FIFO_SINGLE_BYTE );
}
/*-----------------------------------------------------------*/

static void prvUARTRxNotificationHandler( mss_uart_instance_t * pxUART )
{
char cRxed;
portBASE_TYPE xHigherPriorityTaskWoken;

	/* The command console receives data very slowly (at the speed of somebody
	typing), therefore it is ok to just handle one character at a time and use
	a queue to send the characters to the task. */
	if( MSS_UART_get_rx( pxUART, ( uint8_t * ) &cRxed, sizeof( cRxed ) ) == sizeof( cRxed ) )
	{
		xHigherPriorityTaskWoken = pdFALSE;
		xQueueSendFromISR( xRxedChars, &cRxed, &xHigherPriorityTaskWoken );

		/* portEND_SWITCHING_ISR() or portYIELD_FROM_ISR() can be used here. */
		portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
	}
}