#pragma once

#include <cstdint>
#include <string_view>

#include <libavr/libavr.hpp>

#include "board.hpp"
#include "bootloader.hpp"
#include "controller.hpp"
#include "curve.hpp"
#include "statistics.hpp"

// The serial console: line-buffered commands over the hardware UART.
// `help` lists everything; `monitor` streams until any key.
namespace app {

class terminal {
	static constexpr std::uint8_t line_max = 24;
	static inline char line[line_max]{};
	static inline std::uint8_t at = 0;
	static inline bool monitoring = false;
	static inline std::uint64_t last_monitor = 0;

	static void prompt()
	{
		serial << "> "_P;
	}

	static void show()
	{
		serial << "temperature "_P << controller::temperature_quarters() / 4 << '.'
		       << (controller::temperature_quarters() % 4) * 25 << " C, adc "_P << controller::last_adc() << ", fan "_P
		       << controller::fan_percent() << " %, "_P;
		if (controller::automatic())
			serial << "auto"_P;
		else
			serial << "manual"_P;
		serial << "\r\n"_P;
	}

	static void print_curve()
	{
		for (std::int8_t t = 15; t <= 60; t += 5)
			serial << t << " C -> "_P << curve::duty(t) << " %\r\n"_P;
	}

	static void print_uptime()
	{
		auto seconds = static_cast<std::uint32_t>(uptime::millis() / 1000);
		serial << seconds / 86400 << "d "_P << (seconds / 3600) % 24 << "h "_P << (seconds / 60) % 60 << "m "_P
		       << seconds % 60 << "s\r\n"_P;
	}

	static void print_statistics()
	{
		serial << "min "_P << statistics::min_temperature() << " C, max "_P << statistics::max_temperature()
		       << " C, samples "_P << static_cast<std::uint32_t>(statistics::total_samples()) << "\r\n"_P;
	}

	static void print_histogram()
	{
		auto highest = statistics::highest_bucket();
		if (highest == 0) {
			serial << "empty\r\n"_P;
			return;
		}
		for (std::uint8_t t = statistics::min_temperature(); t <= statistics::max_temperature(); ++t) {
			serial << t << " C |"_P;
			auto width = static_cast<std::uint8_t>((statistics::bucket(t) * 40) / highest);
			for (std::uint8_t i = 0; i < width; ++i)
				serial << '#';
			serial << ' ' << statistics::bucket(t) << "\r\n"_P;
		}
	}

	static void help()
	{
		serial << "help show curve monitor uptime statistics histogram reset set <0-100> auto version bootloader\r\n"_P;
	}

	static void dispatch(std::string_view cmd)
	{
		if (cmd.empty()) {
		} else if (cmd == "help") {
			help();
		} else if (cmd == "show") {
			show();
		} else if (cmd == "curve") {
			print_curve();
		} else if (cmd == "monitor") {
			monitoring = true;
		} else if (cmd == "uptime") {
			print_uptime();
		} else if (cmd == "statistics") {
			print_statistics();
		} else if (cmd == "histogram") {
			print_histogram();
		} else if (cmd == "reset") {
			statistics::reset();
			serial << "statistics cleared\r\n"_P;
		} else if (cmd == "auto") {
			controller::set_automatic();
			serial << "auto\r\n"_P;
		} else if (cmd == "version") {
			serial << "fantemp on libavr\r\n"_P;
		} else if (cmd == "bootloader") {
			serial << "entering bootloader\r\n"_P;
			statistics::save();
			bootloader::enter();
		} else if (cmd.starts_with("set ")) {
			std::uint8_t percent = 0;
			bool valid = cmd.size() > 4;
			for (std::size_t i = 4; i < cmd.size(); ++i) {
				if (cmd[i] < '0' || cmd[i] > '9') {
					valid = false;
					break;
				}
				percent = static_cast<std::uint8_t>(percent * 10 + (cmd[i] - '0'));
			}
			if (valid && percent <= 100) {
				controller::set_manual(percent);
				serial << "fan "_P << percent << " %\r\n"_P;
			} else {
				serial << "set 0..100\r\n"_P;
			}
		} else {
			serial << "? (help)\r\n"_P;
		}
	}

  public:
	static void init()
	{
		serial << "\r\nfantemp on libavr — help for commands\r\n"_P;
		prompt();
	}

	static void poll()
	{
		if (monitoring) {
			if (uptime::millis() >= last_monitor + 1000) {
				show();
				last_monitor = uptime::millis();
			}
			if (serial_t::read()) { // any key stops
				monitoring = false;
				prompt();
			}
			return;
		}
		while (auto in = serial_t::read()) {
			char c = static_cast<char>(*in);
			if (c == '\r' || c == '\n') {
				serial << "\r\n"_P;
				dispatch(std::string_view{line, at});
				at = 0;
				if (!monitoring)
					prompt();
			} else if (c == 0x7f || c == 0x08) {
				if (at) {
					--at;
					serial << "\b \b"_P;
				}
			} else if (at < line_max && c >= ' ') {
				line[at++] = c;
				serial << c; // echo
			}
		}
	}
};

} // namespace app