/*
 * Copyright 2019-2025 Andrey Pokidov <andrey.pokidov@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System;

/*
 * Author: Andrey Pokidov
 * Date: 1 Feb 2019
 */

namespace Geometry
{
    public static class DPAngle
    {
        public const double PI = 3.14159265358979324;
        public const double TWO_PI = 6.28318530717958648;
        public const double HALF_OF_PI = 1.57079632679489662;
        public const double THIRD_OF_PI = 1.04719755119659775;
        public const double FOURTH_OF_PI = 0.78539816339744831;
        public const double SIXTH_OF_PI = 0.523598775598298873;

        public const double DEGREES_IN_RADIAN = 57.2957795130823209;
        public const double TURNS_IN_RADIAN = 0.159154943091895336;
        public const double RADIANS_IN_DEGREE = 1.74532925199432958E-2;
        public const double TURNS_IN_DEGREE = 2.77777777777777778E-3;

        public static double RadiansToDegrees(double radians)
        {
            return radians * DEGREES_IN_RADIAN;
        }

        public static double RadiansToTurns(double radians)
        {
            return radians * TURNS_IN_RADIAN;
        }

        public static double DegreesToRadians(double degrees)
        {
            return degrees * RADIANS_IN_DEGREE;
        }

        public static double DegreesToTurns(double degrees)
        {
            return degrees * TURNS_IN_DEGREE;
        }

        public static double TurnsToRadians(double turns)
        {
            return turns * TWO_PI;
        }

        public static double TurnsToDegrees(double turns)
        {
            return turns * 360.0;
        }

        public static double ConvertFromRadians(double radians, AngleUnit toUnit)
        {
            if (toUnit == AngleUnit.DEGREES)
            {
                return radians * DEGREES_IN_RADIAN;
            }

            if (toUnit == AngleUnit.TURNS)
            {
                return radians * TURNS_IN_RADIAN;
            }

            return radians;
        }

        public static double ConvertFromDegrees(double degrees, AngleUnit toUnit)
        {
            if (toUnit == AngleUnit.RADIANS)
            {
                return degrees * RADIANS_IN_DEGREE;
            }

            if (toUnit == AngleUnit.TURNS)
            {
                return degrees * TURNS_IN_DEGREE;
            }

            return degrees;
        }

        public static double ConvertFromTurns(double turns, AngleUnit toUnit)
        {
            if (toUnit == AngleUnit.RADIANS)
            {
                return turns * TWO_PI;
            }

            if (toUnit == AngleUnit.DEGREES)
            {
                return turns * 360.0;
            }

            return turns;
        }
        public static double ConvertToRadians(double angle, AngleUnit unit)
        {
            if (unit == AngleUnit.DEGREES)
            {
                return angle * RADIANS_IN_DEGREE;
            }

            if (unit == AngleUnit.TURNS)
            {
                return angle * TWO_PI;
            }

            return angle;
        }

        public static double ConvertToDegrees(double angle, AngleUnit unit)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return angle * DEGREES_IN_RADIAN;
            }

            if (unit == AngleUnit.TURNS)
            {
                return angle * 360.0;
            }

            return angle;
        }

        public static double ConvertToTurns(double angle, AngleUnit unit)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return angle * TURNS_IN_RADIAN;
            }

            if (unit == AngleUnit.DEGREES)
            {
                return angle * TURNS_IN_DEGREE;
            }

            return angle;
        }

        public static double GetFullCircle(AngleUnit unit)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return TWO_PI;
            }
        
            if (unit == AngleUnit.DEGREES)
            {
                return 360.0;
            }
        
            return 1.0;
        }
    
        public static double GetHalfCircle(AngleUnit unit)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return PI;
            }
        
            if (unit == AngleUnit.DEGREES)
            {
                return 180.0;
            }
        
            return 0.5;
        }
    
        public static double GetQuarterCircle(AngleUnit unit)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return HALF_OF_PI;
            }
        
            if (unit == AngleUnit.DEGREES)
            {
                return 90.0;
            }
        
            return 0.25;
        }

        public static double NormalizeRadians(double radians, AngleRange range)
        {
            if (range == AngleRange.UNSIGNED_RANGE)
            {
                if (0.0 <= radians && radians < TWO_PI)
                {
                    return radians;
                }

            }
            else
            {
                if (-PI < radians && radians <= PI)
                {
                    return radians;
                }
            }

            double turns = radians * TURNS_IN_RADIAN;

            turns -= Math.Floor(turns);

            if (range == AngleRange.SIGNED_RANGE && turns > 0.5)
            {
                turns -= 1.0;
            }

            return turns * TWO_PI;
        }

        public static double NormalizeDegrees(double degrees, AngleRange range)
        {
            if (range == AngleRange.UNSIGNED_RANGE)
            {
                if (0.0 <= degrees && degrees < 360.0)
                {
                    return degrees;
                }
            }
            else
            {
                if (-180.0 < degrees && degrees <= 180.0)
                {
                    return degrees;
                }
            }

            double turns = degrees * TURNS_IN_DEGREE;

            turns -= Math.Floor(turns);

            if (range == AngleRange.SIGNED_RANGE && turns > 0.5)
            {
                turns -= 1.0;
            }

            return turns * 360.0;
        }

        public static double NormalizeTurns(double turns, AngleRange range)
        {
            if (range == AngleRange.UNSIGNED_RANGE)
            {
                if (0.0 <= turns && turns < 1.0)
                {
                    return turns;
                }
            }
            else
            {
                if (-0.5 < turns && turns <= 0.5)
                {
                    return turns;
                }
            }

            double rest = turns - Math.Floor(turns);

            if (range == AngleRange.SIGNED_RANGE && rest > 0.5)
            {
                rest -= 1.0;
            }

            return rest;
        }

        public static double Normalize(double angle, AngleUnit unit, AngleRange range)
        {
            if (unit == AngleUnit.RADIANS)
            {
                return NormalizeRadians(angle, range);
            }

            if (unit == AngleUnit.DEGREES)
            {
                return NormalizeDegrees(angle, range);
            }

            return NormalizeTurns(angle, range);
        }
    }
}