#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/effect/fade_in.hpp>
#include <psemek/audio/effect/fade_out.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_z, 59},
	{SDLK_x, 60},
	{SDLK_c, 61},
	{SDLK_v, 62},
	{SDLK_b, 63},
	{SDLK_n, 64},
	{SDLK_m, 65},
	{SDLK_COMMA, 66},
	{SDLK_PERIOD, 67},
	{SDLK_SLASH, 68},
	{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},
	{SDLK_q, 80},
	{SDLK_w, 81},
	{SDLK_e, 82},
	{SDLK_r, 83},
	{SDLK_t, 84},
	{SDLK_y, 85},
	{SDLK_u, 86},
	{SDLK_i, 87},
	{SDLK_o, 88},
	{SDLK_p, 89},
	{SDLK_LEFTBRACKET, 90},
	{SDLK_RIGHTBRACKET, 91},
};

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, 0.5f, 0.1f);
		right_volume_ = audio::volume(dup2, 0.5f, 0.1f);
		auto result = audio::stereo(left_volume_, right_volume_);
		engine_.output()->stream(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(audio::fade_in(tone, 0.01f));
		}
	}

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

		if (channels_.contains(key))
		{
			auto & ch = channels_[key];
			if (auto s = ch->stream())
				ch->stream(audio::fade_out(s, 0.01f));
			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::channel_ptr> channels_;

	util::clock<> clock_;
};

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