#include "DACSound16S.hh"

#include "DeviceConfig.hh"
#include "DynamicClock.hh"
#include "MSXMotherBoard.hh"
#include "serialize.hh"

#include "narrow.hh"

namespace openmsx {

static constexpr unsigned DUMMY_INPUT_RATE = 44100; // actual rate depends on frequency setting

DACSound16S::DACSound16S(std::string_view name_, static_string_view desc,
                         const DeviceConfig& config)
	: SoundDevice(config.getMotherBoard().getMSXMixer(), name_, desc, 1, DUMMY_INPUT_RATE, false)
{
	registerSound(config);
}

DACSound16S::~DACSound16S()
{
	unregisterSound();
}

void DACSound16S::setOutputRate(unsigned hostSampleRate, double /*speed*/)
{
	setInputRate(hostSampleRate);
}

void DACSound16S::reset(EmuTime time)
{
	writeDAC(0, time);
}

void DACSound16S::writeDAC(int16_t value, EmuTime time)
{
	int delta = value - lastWrittenValue;
	if (delta == 0) return;
	lastWrittenValue = value;

	BlipBuffer::TimeIndex t;
	getHostSampleClock().getTicksTill(time, t);
	blip.addDelta(t, narrow<float>(delta));
}

void DACSound16S::generateChannels(std::span<float*> bufs, unsigned num)
{
	// Note: readSamples() replaces the values in the buffer (it doesn't
	// add the new values to the existing values in the buffer). That's OK
	// because this is a single-channel SoundDevice.
	assert(bufs.size() == 1);
	if (!blip.readSamples<1>(bufs[0], num)) {
		bufs[0] = nullptr;
	}
}

bool DACSound16S::updateBuffer(size_t length, float* buffer,
                               EmuTime /*time*/)
{
	return mixChannels(buffer, length);
}

template<typename Archive>
void DACSound16S::serialize(Archive& ar, unsigned /*version*/)
{
	// Note: It's ok to NOT serialize a DAC object if you call the
	//       writeDAC() method in some other way during de-serialization.
	//       This is for example done in MSXPPI/KeyClick.
	int16_t lastValue = lastWrittenValue;
	ar.serialize("lastValue", lastValue);
	if constexpr (Archive::IS_LOADER) {
		writeDAC(lastValue, getHostSampleClock().getTime());
	}
}
INSTANTIATE_SERIALIZE_METHODS(DACSound16S);

} // namespace openmsx