/**
 ******************************************************************************
 *
 * @file       apiconfig_config.h
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      RF Module hardware layer
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <string.h>

#include "stm32f10x.h"
#include "gpio_in.h"
#include "api_config.h"
#include "rfm22b.h"
#include "packet_handler.h"
#include "saved_settings.h"
#include "crc.h"
#include "main.h"

#if defined(PIOS_COM_DEBUG)
	#define APICONFIG_DEBUG
#endif

// *****************************************************************************
// modem configuration packets

#define pipx_header_marker			0x76b38a52

#define pipx_packet_type_req_config	1
#define pipx_packet_type_config		2

typedef struct
{
    uint32_t    marker;
    uint32_t    serial_number;
    uint8_t     type;
    uint8_t     spare;
    uint16_t    data_size;
	uint32_t    header_crc;
	uint32_t    data_crc;
//	uint8_t     data[0];
} __attribute__((__packed__)) t_pipx_config_header;

typedef struct
{
    uint8_t     mode;
    uint8_t     state;
} __attribute__((__packed__)) t_pipx_config_data_mode_state;

typedef struct
{
    uint32_t    serial_baudrate;    // serial uart baudrate

    uint32_t    destination_id;

    uint32_t    min_frequency_Hz;
    uint32_t    max_frequency_Hz;
    float	    frequency_Hz;

    uint32_t    max_rf_bandwidth;

    uint8_t     max_tx_power;

    uint8_t     frequency_band;

    uint8_t     rf_xtal_cap;

    bool        aes_enable;
    uint8_t     aes_key[16];

    float	    frequency_step_size;
} __attribute__((__packed__)) t_pipx_config_data_settings;

typedef struct
{
    float	    start_frequency;
    float	    frequency_step_size;
    uint16_t    magnitudes;
//    int8_t      magnitude[0];
} __attribute__((__packed__)) t_pipx_config_data_spectrum;

// *****************************************************************************
// local variables

int8_t				apiconfig_previous_com_port = -1;

volatile uint16_t	apiconfig_rx_timer = 0;
volatile uint16_t	apiconfig_tx_timer = 0;

uint8_t				apiconfig_rx_buffer[256] __attribute__ ((aligned(4)));
uint16_t			apiconfig_rx_buffer_wr;

uint8_t				apiconfig_tx_buffer[256] __attribute__ ((aligned(4)));
uint16_t			apiconfig_tx_buffer_wr;

uint8_t				apiconfig_tx_config_buffer[128] __attribute__ ((aligned(4)));
uint16_t			apiconfig_tx_config_buffer_wr;

// *****************************************************************************

int apiconfig_sendConfigPacket()
{
	if (sizeof(apiconfig_tx_config_buffer) - apiconfig_tx_config_buffer_wr < sizeof(t_pipx_config_header) + sizeof(t_pipx_config_data_settings))
		return -1;	// not enough room in the tx buffer for the packet we were going to send

	t_pipx_config_header *header = (t_pipx_config_header *)(apiconfig_tx_config_buffer + apiconfig_tx_config_buffer_wr);
	t_pipx_config_data_settings *settings = (t_pipx_config_data_settings *)((uint8_t *)header + sizeof(t_pipx_config_header));

	header->marker = pipx_header_marker;
	header->serial_number = serial_number_crc32;
	header->type = pipx_packet_type_config;
	header->spare = 0;
	header->data_size = sizeof(t_pipx_config_data_settings);

	settings->serial_baudrate = saved_settings.serial_baudrate;
	settings->destination_id = saved_settings.destination_id;
	settings->min_frequency_Hz = saved_settings.min_frequency_Hz;
	settings->max_frequency_Hz = saved_settings.max_frequency_Hz;
	settings->frequency_Hz = saved_settings.frequency_Hz;
	settings->max_rf_bandwidth = saved_settings.max_rf_bandwidth;
	settings->max_tx_power = saved_settings.max_tx_power;
	settings->frequency_band = saved_settings.frequency_band;
	settings->rf_xtal_cap = saved_settings.rf_xtal_cap;
	settings->aes_enable = saved_settings.aes_enable;
	memcpy((char *)settings->aes_key, (char *)saved_settings.aes_key, sizeof(settings->aes_key));
	settings->frequency_step_size = rfm22_getFrequencyStepSize();

	header->data_crc = updateCRC32Data(0xffffffff, settings, header->data_size);
	header->header_crc = 0;
	header->header_crc = updateCRC32Data(0xffffffff, header, sizeof(t_pipx_config_header));

	int total_packet_size = sizeof(t_pipx_config_header) + header->data_size;

	apiconfig_tx_config_buffer_wr += total_packet_size;

	#if defined(APICONFIG_DEBUG)
		DEBUG_PRINTF("TX api config: config\r\n");
	#endif

	return total_packet_size;
}

void apiconfig_processInputPacket(void *buf, uint16_t len)
{
	if (len <= 0)
		return;

	t_pipx_config_header *header = (t_pipx_config_header *)buf;
	uint8_t *data = (uint8_t *)header + sizeof(t_pipx_config_header);

	switch (header->type)
	{
		case pipx_packet_type_req_config:	// they are requesting our configuration

			#if defined(APICONFIG_DEBUG)
				DEBUG_PRINTF("RX api config: req_config\r\n");
			#endif

			if (header->serial_number == 0 || header->serial_number == 0xffffffff || header->serial_number == serial_number_crc32)
				apiconfig_sendConfigPacket();
			break;

		case pipx_packet_type_config:	// they have sent us new configuration settings
			#if defined(APICONFIG_DEBUG)
				DEBUG_PRINTF("RX api config: config\r\n");
			#endif

			if (header->serial_number == serial_number_crc32)
			{	// the packet is meant for us

				t_pipx_config_data_settings *settings = (t_pipx_config_data_settings *)data;

				saved_settings.destination_id = settings->destination_id;

				saved_settings.frequency_Hz = settings->frequency_Hz;

				saved_settings.max_tx_power = settings->max_tx_power;

				saved_settings.max_rf_bandwidth = settings->max_rf_bandwidth;

				saved_settings.rf_xtal_cap = settings->rf_xtal_cap;

				saved_settings.serial_baudrate = settings->serial_baudrate;

				saved_settings.aes_enable = settings->aes_enable;
				memcpy((char *)saved_settings.aes_key, (char *)settings->aes_key, sizeof(saved_settings.aes_key));

			    saved_settings_save();	// save the new settings

			    ph_set_remote_serial_number(0, 0);
			    PIOS_COM_ChangeBaud(PIOS_COM_SERIAL, saved_settings.serial_baudrate);
			    rfm22_setFreqCalibration(saved_settings.rf_xtal_cap);
			    ph_setNominalCarrierFrequency(saved_settings.frequency_Hz);
			    ph_setDatarate(saved_settings.max_rf_bandwidth);
			    ph_setTxPower(saved_settings.max_tx_power);
			    ph_set_remote_serial_number(0, saved_settings.destination_id);
			    ph_set_remote_encryption(0, saved_settings.aes_enable, (const void *)saved_settings.aes_key);
			}
			break;

		default:
			#if defined(APICONFIG_DEBUG)
				DEBUG_PRINTF("RX api config: unknown type [%u]\r\n", header->type);
			#endif
			break;
	}
}

uint16_t apiconfig_scanForConfigPacket(void *buf, uint16_t *len, bool rf_packet)
{
	uint16_t length = *len;
	uint16_t i = 0;

	while (TRUE)
	{
		uint32_t crc1, crc2;

		t_pipx_config_header *header = (t_pipx_config_header *)buf + i;
		uint8_t *data = (uint8_t *)header + sizeof(t_pipx_config_header);

		if (i + sizeof(t_pipx_config_header) > length)
		{	// not enough data for a packet
			if (i >= sizeof(header->marker))
				i -= sizeof(header->marker);
			else
				i = 0;
			break;
		}

		if (header->marker != pipx_header_marker)
		{	// no packet marker found
			i++;
			continue;
		}

		// check the header is error free
		crc1 = header->header_crc;
		header->header_crc = 0;
		crc2 = updateCRC32Data(0xffffffff, header, sizeof(t_pipx_config_header));
		header->header_crc = crc1;
		if (crc2 != crc1)
		{	// faulty header or not really a header
			i++;
			continue;
		}

		// valid header found!

		#if defined(APICONFIG_DEBUG)
			DEBUG_PRINTF("RX api config: header found\r\n");
		#endif

		if (!rf_packet)
			apiconfig_rx_timer = 0;					// reset the timer

		int total_packet_size = sizeof(t_pipx_config_header) + header->data_size;

		if (i + total_packet_size > length)
		{	// not yet got a full packet
			break;
		}

		if (header->data_size > 0)
		{	// check the data is error free
			crc1 = header->data_crc;
			crc2 = updateCRC32Data(0xffffffff, data, header->data_size);
			if (crc2 != crc1)
			{	// faulty data .. remove the entire packet
				length -= total_packet_size;
				if (length - i > 0)
					memmove(buf + i, buf + i + total_packet_size, length - i);
				continue;
			}
		}

		if (!rf_packet)
			apiconfig_processInputPacket(buf + i, length - i);

		// remove the packet from the buffer
		length -= total_packet_size;
		if (length - i > 0)
			memmove(buf + i, buf + i + total_packet_size, length - i);

		break;
	}

	*len = length;

	return i;
}

// *****************************************************************************
// can be called from an interrupt if you wish

void apiconfig_1ms_tick(void)
{	// call this once every 1ms

	if (apiconfig_rx_timer < 0xffff) apiconfig_rx_timer++;
	if (apiconfig_tx_timer < 0xffff) apiconfig_tx_timer++;
}

// *****************************************************************************
// call this as often as possible - not from an interrupt

void apiconfig_process(void)
{	// copy data from comm-port RX buffer to RF packet handler TX buffer, and from RF packet handler RX buffer to comm-port TX buffer

	// ********************
	// decide which comm-port we are using (usart or usb)

	bool usb_comms = false;						// TRUE if we are using the usb port for comms.
	uint8_t comm_port = PIOS_COM_SERIAL;		// default to using the usart comm-port

	#if defined(PIOS_INCLUDE_USB_HID)
		if (PIOS_USB_HID_CheckAvailable(0))
		{	// USB comms is up, use the USB comm-port instead of the USART comm-port
			usb_comms = true;
			comm_port = PIOS_COM_TELEM_USB;
		}
	#endif

	// ********************
	// check to see if the local communication port has changed (usart/usb)

	if (apiconfig_previous_com_port < 0 && apiconfig_previous_com_port != comm_port)
	{	// the local communications port has changed .. remove any data in the buffers
		apiconfig_rx_buffer_wr = 0;
		apiconfig_tx_buffer_wr = 0;
	}
	else
	if (usb_comms)
	{	// we're using the USB for comms - keep the USART rx buffer empty
		int32_t bytes = PIOS_COM_ReceiveBufferUsed(PIOS_COM_SERIAL);
		while (bytes > 0)
		{
			PIOS_COM_ReceiveBuffer(PIOS_COM_SERIAL);
			bytes--;
		}
	}

	apiconfig_previous_com_port = comm_port;			// remember the current comm-port we are using

	// ********************

	uint16_t connection_index = 0;					// the RF connection we are using

	// ********************
	// send the data received from the local comm-port to the RF packet handler TX buffer

	while (TRUE)
	{
		// free space size in the RF packet handler tx buffer
		uint16_t ph_num = ph_putData_free(connection_index);

		// get the number of data bytes received down the comm-port
		int32_t com_num = PIOS_COM_ReceiveBufferUsed(comm_port);

		// set the USART RTS handshaking line
		if (!usb_comms && ph_connected(connection_index))
		{
			if (ph_num < 32)
				SERIAL_RTS_CLEAR;						// lower the USART RTS line - we don't have space in the buffer for anymore bytes
			else
				SERIAL_RTS_SET;							// release the USART RTS line - we have space in the buffer for now bytes
		}
		else
			SERIAL_RTS_SET;								// release the USART RTS line

		// limit number of bytes we will get to how much space we have in our RX buffer
		if (com_num > sizeof(apiconfig_rx_buffer) - apiconfig_rx_buffer_wr)
			com_num = sizeof(apiconfig_rx_buffer) - apiconfig_rx_buffer_wr;

		while (com_num > 0)
		{	// fetch a byte from the comm-port RX buffer and save it into our RX buffer
			apiconfig_rx_buffer[apiconfig_rx_buffer_wr++] = PIOS_COM_ReceiveBuffer(comm_port);
			com_num--;
		}

		uint16_t data_size = apiconfig_scanForConfigPacket(apiconfig_rx_buffer, &apiconfig_rx_buffer_wr, false);

		if (data_size == 0 && apiconfig_rx_timer >= 10)
		{	// no config packet found in the buffer within the timeout period, treat any data in the buffer as data to be sent over the air
			data_size = apiconfig_rx_buffer_wr;
		}

		if (data_size == 0)
			break;	// no data to send over the air

		#if defined(APICONFIG_DEBUG)
			DEBUG_PRINTF("RX api config: data size %u\r\n", data_size);
		#endif

		if (ph_connected(connection_index))
		{	// we have an RF link to a remote modem

			if (ph_num < data_size)
				break;	// not enough room in the RF packet handler TX buffer for the data

			// copy the data into the RF packet handler TX buffer for sending over the RF link
			data_size = ph_putData(connection_index, apiconfig_rx_buffer, data_size);
		}

		// remove the data from our RX buffer
		apiconfig_rx_buffer_wr -= data_size;
		if (apiconfig_rx_buffer_wr > 0)
			memmove(apiconfig_rx_buffer, apiconfig_rx_buffer + data_size, apiconfig_rx_buffer_wr);
	}

	// ********************
	// send data down the local comm port

	if (apiconfig_tx_config_buffer_wr > 0)
	{	// send any config packets in the config buffer

		while (TRUE)
		{
			uint16_t data_size = apiconfig_tx_config_buffer_wr;

			if (data_size > 32)
				data_size = 32;

			if (!usb_comms && !GPIO_IN(SERIAL_CTS_PIN))
				break;	// we can't yet send data down the comm-port

			// send the data out the comm-port
			int32_t res;
//			if (usb_comms)
//				res = PIOS_COM_SendBuffer(comm_port, apiconfig_tx_config_buffer, data_size);
//			else
				res = PIOS_COM_SendBufferNonBlocking(comm_port, apiconfig_tx_config_buffer, data_size);
			if (res < 0)
			{	// failed to send the data out the comm-port

				#if defined(APICONFIG_DEBUG)
					DEBUG_PRINTF("PIOS_COM_SendBuffer %d %d\r\n", data_size, res);
				#endif

				if (apiconfig_tx_timer >= 5000)
				{	// seems we can't send our data for at least the last 5 seconds - delete it
					apiconfig_tx_config_buffer_wr = 0;
				}

				break;
			}

			// data was sent out the comm-port OK .. remove the sent data from our buffer

			#if defined(APICONFIG_DEBUG)
				DEBUG_PRINTF("TX api config: data [%u]\r\n", data_size);
			#endif

			apiconfig_tx_config_buffer_wr -= data_size;
			if (apiconfig_tx_config_buffer_wr > 0)
				memmove(apiconfig_tx_config_buffer, apiconfig_tx_config_buffer + data_size, apiconfig_tx_config_buffer_wr);

			apiconfig_tx_timer = 0;

			break;
		}
	}
	else
	{	// send the data received via the RF link out the comm-port

		while (TRUE)
		{
			// get number of data bytes received via the RF link
			uint16_t ph_num = ph_getData_used(connection_index);

			// limit to how much space we have in the temp TX buffer
			if (ph_num > sizeof(apiconfig_tx_buffer) - apiconfig_tx_buffer_wr)
				ph_num = sizeof(apiconfig_tx_buffer) - apiconfig_tx_buffer_wr;

			if (ph_num > 0)
			{	// fetch the data bytes received via the RF link and save into our temp buffer
				ph_num = ph_getData(connection_index, apiconfig_tx_buffer + apiconfig_tx_buffer_wr, ph_num);
				apiconfig_tx_buffer_wr += ph_num;
			}

			uint16_t data_size = apiconfig_tx_buffer_wr;
			if (data_size == 0)
				break;	// no data to send

//			uint16_t data_size = apiconfig_scanForConfigPacket(apiconfig_tx_buffer, &apiconfig_tx_buffer_wr, true);
//			if (data_size == 0)
//				break;	// no data to send

			// we have data to send down the comm-port
/*
			#if (defined(PIOS_COM_DEBUG) && (PIOS_COM_DEBUG == PIOS_COM_SERIAL))
				if (!usb_comms)
					{	// the serial-port is being used for debugging - don't send data down it
						apiconfig_tx_buffer_wr = 0;
						apiconfig_tx_timer = 0;
						continue;
					}
				#endif
*/
			if (!usb_comms && !GPIO_IN(SERIAL_CTS_PIN))
				break;	// we can't yet send data down the comm-port

			// send the data out the comm-port
			int32_t res;
//			if (usb_comms)
//				res = PIOS_COM_SendBuffer(comm_port, apiconfig_tx_buffer, data_size);
//			else
				res = PIOS_COM_SendBufferNonBlocking(comm_port, apiconfig_tx_buffer, data_size);
			if (res < 0)
			{	// failed to send the data out the comm-port

				#if defined(APICONFIG_DEBUG)
					DEBUG_PRINTF("PIOS_COM_SendBuffer %d %d\r\n", data_size, res);
				#endif

				if (apiconfig_tx_timer >= 5000)
				{	// seems we can't send our data for at least the last 5 seconds - delete it
					apiconfig_tx_buffer_wr = 0;
				}

				break;
			}

			// data was sent out the comm-port OK .. remove the sent data from our buffer

			apiconfig_tx_buffer_wr -= data_size;
			if (apiconfig_tx_buffer_wr > 0)
				memmove(apiconfig_tx_buffer, apiconfig_tx_buffer + data_size, apiconfig_tx_buffer_wr);

			apiconfig_tx_timer = 0;
		}
	}

	// ********************
}

// *****************************************************************************

void apiconfig_init(void)
{
	apiconfig_previous_com_port = -1;

	apiconfig_rx_buffer_wr = 0;

	apiconfig_tx_buffer_wr = 0;

	apiconfig_tx_config_buffer_wr = 0;

	apiconfig_rx_timer = 0;
	apiconfig_tx_timer = 0;
}

// *****************************************************************************