#include <psemek/audio/engine.hpp>
#include <psemek/audio/wave/silence.hpp>
#include <psemek/audio/wave/sine.hpp>
#include <psemek/audio/wave/sawtooth.hpp>
#include <psemek/audio/wave/square.hpp>
#include <psemek/audio/wave/triangle.hpp>
#include <psemek/audio/effect/volume.hpp>
#include <psemek/audio/duplicate.hpp>
#include <psemek/audio/stereo.hpp>
#include <psemek/audio/mixer.hpp>
#include <psemek/app/app.hpp>
#include <psemek/app/main.hpp>
#include <psemek/util/clock.hpp>
#include <psemek/geom/constants.hpp>

#include <map>

using namespace psemek;

static std::map<SDL_Keycode, int> const key_to_midi
{
	{SDLK_a, 69},
	{SDLK_s, 70},
	{SDLK_d, 71},
	{SDLK_f, 72},
	{SDLK_g, 73},
	{SDLK_h, 74},
	{SDLK_j, 75},
	{SDLK_k, 76},
	{SDLK_l, 77},
	{SDLK_SEMICOLON, 78},
	{SDLK_QUOTE, 79},
};

struct audio_app
	: app::app
{
	audio_app()
		: app::app("Audio example")
	{
		mixer_ = audio::make_mixer();

		auto [ dup1, dup2 ] = audio::duplicate(mixer_);
		left_volume_ = audio::volume(dup1, 0.f, 0.1f);
		right_volume_ = audio::volume(dup2, 0.f, 0.1f);
		auto result = audio::stereo(left_volume_, right_volume_);
		engine_.output(result);
	}

	void on_key_down(SDL_Keycode key) override
	{
		app::app::on_key_down(key);

		if (key_to_midi.contains(key) && !channels_.contains(key))
		{
			int midi = key_to_midi.at(key);
			auto tone = audio::sine_wave(440.f * std::pow(2.f, (midi - 69) / 12.f));
			channels_[key] = mixer_->add(tone);
		}
	}

	void on_key_up(SDL_Keycode key) override
	{
		app::app::on_key_up(key);

		if (channels_.contains(key))
		{
			channels_[key]->stop();
			channels_.erase(key);
		}
	}

	void update() override
	{
		float const time = clock_.count();

		float volume = std::sin(time);
		left_volume_->gain(0.5f + 0.5f * volume);
		right_volume_->gain(0.5f - 0.5f * volume);
	}

private:
	audio::engine engine_;
	audio::mixer_ptr mixer_;
	std::shared_ptr<audio::volume_control> left_volume_, right_volume_;
	std::map<SDL_Keycode, audio::mixer::channel_ptr> channels_;

	util::clock<> clock_;
};

int main()
{
	return app::main<audio_app>();
}