/*
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
* repeater and gateway builds a routing tables in EEPROM which keeps track of the
* network topology allowing messages to be routed to nodes.
*
* Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
* Copyright (C) 2013-2015 Sensnology AB
* Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
*
* Documentation: http://www.mysensors.org
* Support Forum: http://forum.mysensors.org
*
* This program 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.
*
* Based on maniacbug's RF24 library, copyright (C) 2011 J. Coliz <maniacbug@ymail.com>
* RF24 driver refactored and optimized for speed and size, copyright (C) 2016 Olivier Mauti <olivier@mysensors.org>
*/

#include "RF24.h"

LOCAL uint8_t MY_RF24_BASE_ADDR[MY_RF24_ADDR_WIDTH] = { MY_RF24_BASE_RADIO_ID };
LOCAL uint8_t MY_RF24_NODE_ADDRESS = AUTO;

LOCAL void RF24_csn(bool level) {
	digitalWrite(MY_RF24_CS_PIN, level);		
}

LOCAL void RF24_ce(bool level) {
	digitalWrite(MY_RF24_CE_PIN, level);
}

LOCAL uint8_t RF24_spiMultiByteTransfer(uint8_t cmd, uint8_t* buf, uint8_t len, bool aReadMode) {
	uint8_t* current = buf;
	#if !defined(MY_SOFTSPI)
		_SPI.beginTransaction(SPISettings(MY_RF24_SPI_MAX_SPEED, MY_RF24_SPI_DATA_ORDER, MY_RF24_SPI_DATA_MODE));
	#endif
	RF24_csn(LOW);
	// timing
	delayMicroseconds(10);
	uint8_t status = _SPI.transfer( cmd );
	while ( len-- ) {
		if (aReadMode) {		
			status = _SPI.transfer( NOP );
			if(buf != NULL) *current++ = status;
		} else status = _SPI.transfer(*current++);
	}
	RF24_csn(HIGH);
	#if !defined(MY_SOFTSPI)
		_SPI.endTransaction();
	#endif
	// timing
	delayMicroseconds(10);
	return status;
} 

LOCAL uint8_t RF24_spiByteTransfer(uint8_t cmd) {
	return RF24_spiMultiByteTransfer( cmd, NULL, 0, false);
}

LOCAL uint8_t RF24_RAW_readByteRegister(uint8_t cmd) {
	uint8_t value = RF24_spiMultiByteTransfer( cmd, NULL, 1, true);
	RF24_DEBUG(PSTR("RF24:read register, reg=%d, value=%d\n"), cmd & (R_REGISTER ^ 0xFF), value);
	return value;
}

LOCAL uint8_t RF24_RAW_writeByteRegister(uint8_t cmd, uint8_t value) {
	RF24_DEBUG(PSTR("RF24:write register, reg=%d, value=%d\n"), cmd & (W_REGISTER ^ 0xFF), value);
	return RF24_spiMultiByteTransfer( cmd , &value, 1, false);
}

LOCAL void RF24_flushRX(void) {
	RF24_DEBUG(PSTR("RF24:flushRX\n"));
	RF24_spiByteTransfer( FLUSH_RX );
}

LOCAL void RF24_flushTX(void) {
	RF24_DEBUG(PSTR("RF24:flushTX\n"));
	RF24_spiByteTransfer( FLUSH_TX );
}

LOCAL uint8_t RF24_getStatus(void) {
	return RF24_spiByteTransfer( NOP );
}

LOCAL void RF24_setChannel(uint8_t channel) {
	RF24_writeByteRegister(RF_CH, channel);
}

LOCAL void RF24_setRetries(uint8_t retransmitDelay, uint8_t retransmitCount) {
	RF24_writeByteRegister(SETUP_RETR, retransmitDelay << ARD | retransmitCount << ARC);
}

LOCAL void RF24_setAddressWidth(uint8_t width) {
	RF24_writeByteRegister(SETUP_AW, width - 2);
}

LOCAL void RF24_setRFSetup(uint8_t RFsetup) {
	RF24_writeByteRegister(RF_SETUP, RFsetup);
}

LOCAL void RF24_setFeature(uint8_t feature) {
	RF24_writeByteRegister(FEATURE, feature);
}

LOCAL void RF24_setPipe(uint8_t pipe) {
	RF24_writeByteRegister(EN_RXADDR, pipe);
}

LOCAL void RF24_setAutoACK(uint8_t pipe) {
	RF24_writeByteRegister(EN_AA, pipe);
}

LOCAL void RF24_setDynamicPayload(uint8_t pipe) {
	RF24_writeByteRegister(DYNPD, pipe);
}

LOCAL void RF24_setRFConfiguration(uint8_t configuration) {
	RF24_writeByteRegister(NRF_CONFIG, configuration);
}

LOCAL void RF24_setPipeAddress(uint8_t pipe, uint8_t* address, uint8_t width) {
	RF24_writeMultiByteRegister(pipe, address, width);
}

LOCAL void RF24_setPipeLSB(uint8_t pipe, uint8_t LSB) {
	RF24_writeByteRegister(pipe, LSB);
}

LOCAL void RF24_setStatus(uint8_t status) {
	RF24_writeByteRegister(RF24_STATUS, status);
}
LOCAL void RF24_enableFeatures(void) {
	RF24_writeByteRegister(ACTIVATE, 0x73);
}

LOCAL void RF24_openWritingPipe(uint8_t recipient) {	
	RF24_DEBUG(PSTR("RF24:open writing pipe, recipient=%d\n"), recipient);	
	// only write LSB of RX0 and TX pipe
	RF24_setPipeLSB(RX_ADDR_P0, recipient);
	RF24_setPipeLSB(TX_ADDR, recipient);
}

LOCAL void RF24_startListening(void) {
	RF24_DEBUG(PSTR("RF24:start listening\n"));
	// toggle PRX		
	RF24_setRFConfiguration(MY_RF24_CONFIGURATION | _BV(PWR_UP) | _BV(PRIM_RX) );
	// all RX pipe addresses must be unique, therefore skip if node ID is 0xFF
	if(MY_RF24_NODE_ADDRESS!=AUTO) RF24_setPipeLSB(RX_ADDR_P0, MY_RF24_NODE_ADDRESS);
	// start listening
	RF24_ce(HIGH);
}

LOCAL void RF24_stopListening(void) {
	RF24_DEBUG(PSTR("RF24:stop listening\n"));
	RF24_ce(LOW);
	// timing
	delayMicroseconds(130);
	RF24_setRFConfiguration(MY_RF24_CONFIGURATION | _BV(PWR_UP) );
	// timing
	delayMicroseconds(100);
}

LOCAL void RF24_powerDown(void) {
	RF24_ce(LOW);
	RF24_setRFConfiguration(MY_RF24_CONFIGURATION);
	RF24_DEBUG(PSTR("RF24:power down\n"));
}

LOCAL bool RF24_sendMessage( uint8_t recipient, const void* buf, uint8_t len ) {
	uint8_t status;

	RF24_stopListening();
	RF24_openWritingPipe( recipient );		
	RF24_DEBUG(PSTR("RF24:send message to %d, len=%d\n"),recipient,len);
	// flush TX FIFO
	RF24_flushTX();
	// this command is affected in clones (e.g. Si24R1):  flipped NoACK bit when using W_TX_PAYLOAD_NO_ACK / W_TX_PAYLOAD
	// RF24_spiMultiByteTransfer( recipient==BROADCAST_ADDRESS ? W_TX_PAYLOAD_NO_ACK : W_TX_PAYLOAD, (uint8_t*)buf, len, false );
	// we are safe by disabling AutoACK on the broadcasting pipe
	RF24_spiMultiByteTransfer( W_TX_PAYLOAD, (uint8_t*)buf, len, false );
	// go, TX starts after ~10us
	RF24_ce(HIGH);
	// timeout counter to detect HW issues
	uint16_t timeout = 0xFFFF;
	do {
		status = RF24_getStatus();
	} while  (!(status & ( _BV(MAX_RT) | _BV(TX_DS) )) && timeout--);
	// timeout value after successful TX on 16Mhz AVR ~ 65500, i.e. msg is transmitted after ~36 loop cycles
	RF24_ce(LOW);
	// reset interrupts
	RF24_setStatus(_BV(TX_DS) | _BV(MAX_RT) );
	// Max retries exceeded
	if( status & _BV(MAX_RT)){
		// flush packet
		RF24_DEBUG(PSTR("RF24:MAX_RT\n"));
		RF24_flushTX();
	}
		
	RF24_startListening();
	// true if message sent and not timeout
	return (status & _BV(TX_DS) && timeout);
}

LOCAL uint8_t RF24_getDynamicPayloadSize(void) {
	uint8_t result = RF24_spiMultiByteTransfer(R_RX_PL_WID, NULL, 1, true);
	// check if payload size invalid
	if(result > 32) { 
		RF24_DEBUG(PSTR("RF24:invalid payload length = %d\n"),result);
		RF24_flushRX(); 
		result = 0; 
	}
	return result;
}


LOCAL bool RF24_isDataAvailable() {
	uint8_t status = RF24_getStatus();
	return (((status >> RX_P_NO) & 0b0111) <= 5);
}


LOCAL uint8_t RF24_readMessage( void* buf) {
	uint8_t len = RF24_getDynamicPayloadSize();
	RF24_DEBUG(PSTR("RF24:read message, len=%d\n"), len);
	RF24_spiMultiByteTransfer( R_RX_PAYLOAD , (uint8_t*)buf, len, true ); 
	// clear RX interrupt
	RF24_setStatus(_BV(RX_DR) );
	return len;
}

LOCAL void RF24_setNodeAddress(uint8_t address) {
	if(address!=AUTO){
		MY_RF24_NODE_ADDRESS = address;
		// enable node pipe
		RF24_setPipe(_BV(ERX_P0 + BROADCAST_PIPE) | _BV(ERX_P0) );
		// enable autoACK on pipe 0
		RF24_setAutoACK(_BV(ENAA_P0) );
	}
}

LOCAL uint8_t RF24_getNodeID(void) {
	return MY_RF24_NODE_ADDRESS;
}

LOCAL bool RF24_sanityCheck(void) {
	// detect HW defect ot interrupted SPI line, CE disconnect cannot be detected
	bool status = RF24_readByteRegister(RF_SETUP) == MY_RF24_RF_SETUP;
	status &= RF24_readByteRegister(RF_CH) == MY_RF24_CHANNEL;
	return status;
}

LOCAL bool RF24_initialize(void) {
	// Initialize pins
	pinMode(MY_RF24_CE_PIN,OUTPUT);
	pinMode(MY_RF24_CS_PIN,OUTPUT);
	// Initialize SPI
	_SPI.begin();
	RF24_ce(LOW);
	RF24_csn(HIGH);
	// CRC and power up
	RF24_setRFConfiguration(MY_RF24_CONFIGURATION | _BV(PWR_UP) ) ;
	// settle >2ms
	delay(5);
	// set address width
	RF24_setAddressWidth(MY_RF24_ADDR_WIDTH);
	// auto retransmit delay 1500us, auto retransmit count 15
	RF24_setRetries(RF24_ARD, RF24_ARC);
	// set channel
	RF24_setChannel(MY_RF24_CHANNEL);
	// set data rate and pa level
	RF24_setRFSetup(MY_RF24_RF_SETUP);
	// sanity check
	#if defined(MY_RF24_SANITY_CHECK)
	if (!RF24_sanityCheck()) {
		RF24_DEBUG(PSTR("RF24:Sanity check failed: configuration mismatch! Check wiring, replace module or non-P version\n"));
		return false;
	}
	#endif
	// toggle features (necessary on some clones)
	RF24_enableFeatures();
	// enable ACK payload and dynamic payload
	RF24_setFeature(MY_RF24_FEATURE);
    // enable broadcasting pipe
	RF24_setPipe(_BV(ERX_P0 + BROADCAST_PIPE));
	// disable AA on all pipes, activate when node pipe set
	RF24_setAutoACK(0x00);
	// enable dynamic payloads on used pipes
	RF24_setDynamicPayload(_BV(DPL_P0 + BROADCAST_PIPE) | _BV(DPL_P0));
	// listen to broadcast pipe
	MY_RF24_BASE_ADDR[0] = BROADCAST_ADDRESS;
	RF24_setPipeAddress(RX_ADDR_P0 + BROADCAST_PIPE, (uint8_t*)&MY_RF24_BASE_ADDR, BROADCAST_PIPE > 1 ? 1 : MY_RF24_ADDR_WIDTH);
	// pipe 0, set full address, later only LSB is updated
	RF24_setPipeAddress(RX_ADDR_P0, (uint8_t*)&MY_RF24_BASE_ADDR, MY_RF24_ADDR_WIDTH);
	RF24_setPipeAddress(TX_ADDR, (uint8_t*)&MY_RF24_BASE_ADDR, MY_RF24_ADDR_WIDTH);
	// reset FIFO
	RF24_flushRX();
	RF24_flushTX();
	// reset interrupts
	RF24_setStatus(_BV(TX_DS) | _BV(MAX_RT) | _BV(RX_DR));
	return true;
}