/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/

#include "UnitFormatter.hpp"
#include <string>
#include <sstream>
#include <iomanip>

namespace
{
	template<typename T>
	std::string FormatValue(T value, int precision, bool trimTrailingZeros, const std::string& suffix)
	{
		std::ostringstream out;
		out << std::fixed << std::setprecision(precision) << value;
		std::string result = out.str();

		if (trimTrailingZeros && result.find('.') != std::string::npos)
		{
			result.erase(result.find_last_not_of('0') + 1);

			if (result.back() == '.')
			{
				result.pop_back();
			}
		}
		result += suffix;
		return result;
	}
}

namespace OpenVulkano
{
	UnitFormatter::UnitFormatter(bool useMetric, int precisionDigits, bool doTrimTrailingZeros)
	    : metric(useMetric), precision(precisionDigits), trimTrailingZeros(doTrimTrailingZeros)
	{
	}

	std::string UnitFormatter::Format(units::length::meter_t distance) const
	{
		if (metric)
		{
			if (distance > units::length::meter_t(0) && distance < units::length::meter_t(1))
			{
				return FormatValue(units::length::millimeter_t(distance).value(), precision, trimTrailingZeros, " mm");
			}
			else if (distance >= units::length::kilometer_t(1))
			{
				return FormatValue(units::length::kilometer_t(distance).value(), precision, trimTrailingZeros, " km");
			}
			return FormatValue(distance.value(), precision, trimTrailingZeros, " m");
		}
		else
		{
			auto distanceFeet = units::length::foot_t(distance).value();
			auto distanceInches = units::length::inch_t(distance).value();

			if (distanceFeet > 0 && distanceFeet < 1)
			{
				return FormatValue(distanceInches, precision, trimTrailingZeros, " in");
			}
			else if (distanceFeet >= 5280.0)
			{
				return FormatValue(units::length::mile_t(distance).value(), precision, trimTrailingZeros, " mi");
			}
			return FormatValue(distanceFeet, precision, trimTrailingZeros, " ft");
		}
	}

	std::string UnitFormatter::Format(units::area::square_meter_t area) const
	{
		if (metric)
		{
			if (area >= units::area::square_kilometer_t(1))
			{
				return FormatValue(units::area::square_kilometer_t(area).value(), precision, trimTrailingZeros, " km²");
			}
			return FormatValue(area.value(), precision, trimTrailingZeros, " m²");
		}
		else
		{
			auto areaSquareFeet = units::area::square_foot_t(area).value();
			if (areaSquareFeet >= 27878400.0)
			{
				return FormatValue(units::area::square_mile_t(area).value(), precision, trimTrailingZeros, " mi²");
			}
			return FormatValue(areaSquareFeet, precision, trimTrailingZeros, " ft²");
		}
	}
}