#include <SPI.h>

#include "ws2801.h"

uint8_t message[3 * MAX_NUM_MODULES];

uint32_t ws2801_num_modules;

void ws2801_init(void)
{
	ws2801_num_modules = MAX_NUM_MODULES;

	SPI.begin();
}

void ws2801_set_colour(uint32_t module, uint8_t red, uint8_t green, uint8_t blue)
{
	message[3*module + 0] = red;
	message[3*module + 1] = blue;
	message[3*module + 2] = green;
}

void ws2801_send_update(void)
{
	SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE0));

	for(uint32_t i = 0; i < 3*ws2801_num_modules; i++) {
		SPI.transfer(message[i]);
	}

	SPI.endTransaction();
}

void ws2801_set_num_modules(uint32_t n)
{
	if(n <= MAX_NUM_MODULES) {
		ws2801_num_modules = n;
	}
}