// Copyright (C) Stichting Deltares 2024. All rights reserved.
// 
// This file is part of the Dam Engine.
// 
// The Dam Engine is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// 
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
// 
// All names, logos, and references to "Deltares" are registered trademarks of
// Stichting Deltares and remain full property of Stichting Deltares at all times.
// All rights reserved.

using System;

namespace Deltares.DamEngine.Data.Standard;

/// <summary>
/// Static helper class ComputeDoubles with static helper methods
/// </summary>
public static class ComputeDoubles
{
    private const double cEpsilon = 1.0e-3;

    /// <summary>
    /// Determines whether two values are nearly the same.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    public static bool IsNearEqual(this double aValue1, double aValue2, double aTolerance = cEpsilon)
    {
        if (Math.Abs(aValue1 - aValue2) < aTolerance)
        {
            return true;
        }

        return false;
    }

    /// <summary>
    /// Determines whether the specified value is nearly equal to or is greater than 
    /// another value.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    public static bool IsGreaterThanOrEqualTo(this double aValue1, double aValue2, double tolerance = cEpsilon)
    {
        if (aValue1 - aValue2 > -tolerance)
        {
            return true;
        }

        return false;
    }

    /// <summary>
    /// Determines whether a value is significantly less than another value.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    public static bool IsLessThan(this double aValue1, double aValue2, double tolerance = cEpsilon)
    {
        return !IsGreaterThanOrEqualTo(aValue1, aValue2, tolerance);
    }

    /// <summary>
    /// Determines whether a value is insignificantly greater than, is equal to or is 
    /// less than another value.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    public static bool IsLessThanOrEqualTo(this double aValue1, double aValue2, double tolerance = cEpsilon)
    {
        return !IsGreaterThan(aValue1, aValue2, tolerance);
    }

    /// <summary>
    /// Determines whether the specified value is nearly zero.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    public static bool IsZero(this double aValue1)
    {
        if (Math.Abs(aValue1 - 0.0) < cEpsilon)
        {
            return true;
        }

        return false;
    }

    /// <summary>
    /// Determines whether the specified value is significantly greater than another value.
    /// </summary>
    /// <remarks>Uses a tolerance of 1e-3.</remarks>
    private static bool IsGreaterThan(this double aValue1, double aValue2, double tolerance = cEpsilon)
    {
        if (aValue1 - aValue2 > tolerance)
        {
            return true;
        }

        return false;
    }
}