#include "Fader.h"

Fader::Fader(std::size_t nstrips, std::size_t nmodules_per_strip, uint8_t fadestep, uint32_t flip_strips_mask)
	: m_strips(nstrips),
	  m_modulesPerStrip(nmodules_per_strip),
	  m_fadestep(fadestep),
	  m_flipStripsMask(flip_strips_mask),
	  m_curColor(nstrips * nmodules_per_strip),
	  m_targetColor(nstrips * nmodules_per_strip)
{}

void Fader::set_color(uint32_t strip, uint32_t module, const Fader::Color &color)
{
	uint32_t idx = make_module_idx(strip, module);

	m_targetColor[idx] = m_curColor[idx] = color;

	m_somethingChanged = true;
}

void Fader::add_color(uint32_t strip, uint32_t module, const Fader::Color &color)
{
	uint32_t idx = make_module_idx(strip, module);

	m_curColor[idx] += color;
	m_curColor[idx].normalize();
	m_targetColor[idx] += color;
	m_targetColor[idx].normalize();

	m_somethingChanged = true;
}

void Fader::fade_color(uint32_t strip, uint32_t module, const Fader::Color &color)
{
	uint32_t idx = make_module_idx(strip, module);

	m_targetColor[idx] = color;

	m_somethingChanged = true;
}

void Fader::set_color(const Fader::Color &color)
{
	for(std::size_t module = 0; module < m_curColor.size(); module++) {
		m_targetColor[module] = m_curColor[module] = color;
	}

	m_somethingChanged = true;
}

void Fader::add_color(const Fader::Color &color)
{
	for (std::size_t module = 0; module < m_curColor.size(); module++) {
		m_curColor[module] += color;
		m_curColor[module].normalize();
		m_targetColor[module] += color;
		m_targetColor[module].normalize();
	}

	m_somethingChanged = true;
}

void Fader::fade_color(const Fader::Color &color)
{
	for (std::size_t module = 0; module < m_curColor.size(); module++) {
		m_targetColor[module] = color;
	}
}

void Fader::set_fadestep(uint8_t newFadestep)
{
	m_fadestep = newFadestep;
}

/* internal function */
bool Fader::update_fade(int16_t *cur, const int16_t *target)
{
	int16_t diff;
	if(*cur > *target) {
		diff = *cur - *target;
		if(diff < m_fadestep) {
			*cur = *target;
		} else {
			*cur -= m_fadestep;
		}

		return true;
	} else if(*cur < *target) {
		diff = *target - *cur;
		if(diff < m_fadestep) {
			*cur = *target;
		} else {
			*cur += m_fadestep;
		}

		return true;
	}

	return false;
}

void Fader::update(void)
{
	for(std::size_t i = 0; i < m_curColor.size(); i++) {
		m_somethingChanged =  update_fade(&(m_curColor[i].r), &(m_targetColor[i].r)) || m_somethingChanged;
		m_somethingChanged =  update_fade(&(m_curColor[i].g), &(m_targetColor[i].g)) || m_somethingChanged;
		m_somethingChanged =  update_fade(&(m_curColor[i].b), &(m_targetColor[i].b)) || m_somethingChanged;
		m_somethingChanged =  update_fade(&(m_curColor[i].w), &(m_targetColor[i].w)) || m_somethingChanged;
	}
}

uint32_t Fader::make_module_idx(uint32_t strip, uint32_t module)
{
	strip = (strip + STRIP_OFFSET) % m_strips;

	bool flip = m_flipStripsMask & (1 << strip);
	if(flip) {
		module = m_modulesPerStrip - module - 1;
	}
	return strip * m_modulesPerStrip + module;
}