#include <emscripten/bind.h>
#include <emscripten/val.h>
#include <emscripten.h>

#include <cstdio>
#include <string>
#include <memory>
#include <array>

#include "models/timer.hpp"
#include "models/counter.hpp"
#include "utils/utils.hpp"

using emval = emscripten::val;

thread_local const emval document = emval::global("document");

class TimerView {

	public:

	TimerView()
		: _counters { FreqCounter(_timer), FreqCounter(_timer) }
		, _alarm_sound_triggered(false)
	{ }

	/*
	 * Timer
	 */

	void timer_display_text(std::string const & text) {
		set_inner_text_by_id("time-display", text);
	}

	void timer_record_floor(std::string const & text) {
		set_inner_text_by_id("record-floor", text);
	}

	void timer_start_stop_button_label(std::string const & text) {
		set_inner_text_by_id("start-stop-btn", text);
	}

	void timer_clear_reset_button_label(std::string const & text) {
		set_inner_text_by_id("clear-reset-btn", text);
	}

	void handle_inc_time(uint32_t amount) {
		_timer.increment_preset_ms(amount * 1000);

		_update_start_stop_label();
		_update_clear_reset_btn_label();
		_update_clear_reset_btn();
	}

	void handle_start_stop() {
		_timer.toggleStart();

		_update_start_stop_label();
		_update_clear_reset_btn_label();
		_update_clear_reset_btn();
	}

	void handle_clear_reset() {
		if(_clear_reset_btn_clears()) {
			clear();
		} else {
			reset();
		}

		_update_clear_reset_btn_label();
	}

	/*
	 * Counter
	 */

	void counter_display_text(uint32_t counter_num, std::string const & counter_text, std::string const & rate_text) {
		std::string counter_id = "counter-";
		counter_id.append(std::to_string(counter_num));

		std::string rate_id = "rate-";
		rate_id.append(std::to_string(counter_num));

		set_inner_text_by_id(counter_id, counter_text);
		set_inner_text_by_id(rate_id, rate_text);
	}

	void handle_inc_counter(uint32_t counter_num) {
		_counters[counter_num].inc();

		_update_counter(counter_num);
	}

	void handle_timer_update() {

		std::string value = _timer.counter_display_value();

		timer_display_text(value);

		double record_floor = _timer.record_floor();

		std::string rec_floor_text;
		format_rate(rec_floor_text, record_floor);

		if(_timer.overtime()) {
			std::string rec_floor_overtime;
			format_rate(rec_floor_overtime, _timer.overtime_record_floor());
			rec_floor_text.append(", ");
			rec_floor_text.append(rec_floor_overtime);
		}

		timer_record_floor(rec_floor_text);

		for(size_t i = 0; i < _counters.size(); i++)
			_update_counter(i);

		if(_timer.overtime() && !_alarm_sound_triggered) {
			_play_alarm();
			_alarm_sound_triggered = true;
		}
	}

	private:

	FreqTimer _timer;
	std::array<FreqCounter, 2> _counters;
	bool _alarm_sound_triggered;

	static void set_inner_text_by_id(std::string const & id, std::string const & text) {
		emval timer_display = document.call<emval>("getElementById", emval(id.c_str()));
		timer_display.set("innerText", text.c_str());
	}

	static void set_button_disabled(std::string const & id, bool disabled) {
		emval timer_display = document.call<emval>("getElementById", emval(id.c_str()));
		timer_display.set("disabled", disabled);
	}

	void _update_counter(uint32_t counter_num) {
		FreqCounter & counter = _counters[counter_num];

		std::string text = counter.display_value();
		double rate = counter.rate();

		std::string rate_val;
		format_rate(rate_val, rate);

		if(_timer.overtime()) {
			std::string rate_overtime;
			format_rate(rate_overtime, counter.overtime_rate());
			rate_val.append(", ");
			rate_val.append(rate_overtime);
		}

		counter_display_text(counter_num, text, rate_val);
	}

	static void _play_alarm() {

		EM_ASM({
			const handle = document.getElementById("sound-handle");

			const duration = Math.round(handle.duration * 1000.0);

			handle.currentTime = 0;
			handle.play().then(() => {
				setTimeout(() => {
					handle.pause();
				}, duration);
			});
		});

	}

	void _update_start_stop_label() {
		if(_timer.running()) {
			timer_start_stop_button_label("Stop");
		} else {
			timer_start_stop_button_label("Start");
		}
	}

	bool _clear_reset_btn_clears() const {
		return _timer.has_preset() and !_timer.started();
	}

	void _update_clear_reset_btn_label() {
		if(_clear_reset_btn_clears()) {
			timer_clear_reset_button_label("Clear");
		} else {
			timer_clear_reset_button_label("Reset");
		}
	}

	void _update_clear_reset_btn() {
		set_button_disabled("clear-reset-btn", _timer.running());
	}

	void clear() {
		_timer.clear();

		for(FreqCounter & counter : _counters)
			counter.reset();

		_alarm_sound_triggered = false;
	}

	void reset() {
		_timer.reset();

		for(FreqCounter & counter : _counters)
			counter.reset();

		_alarm_sound_triggered = false;
	}

};


EMSCRIPTEN_BINDINGS(timer_view) {
	emscripten::class_<TimerView>("TimerView")
		.constructor()
		.function("handle_start_stop",
			&TimerView::handle_start_stop
		)
		.function("handle_clear_reset",
			&TimerView::handle_clear_reset
		)
		.function("handle_inc_counter",
			&TimerView::handle_inc_counter
		)
		.function("handle_inc_time",
			&TimerView::handle_inc_time
		)
		.function("handle_timer_update",
			&TimerView::handle_timer_update
		);
}