DD.WellWorkover.Cloud/AsbCloudInfrastructure/Services/Subsystems/DepthInterpolation.cs

using System;
using System.Collections.Generic;

namespace AsbCloudInfrastructure.Services.Subsystems.Utils;


internal class DepthInterpolation
{
    private readonly TimeSpan maxDeltaDate = TimeSpan.FromHours(12);
    private readonly IEnumerator<(DateTimeOffset x, float y)> enumerator;
    private (DateTimeOffset x, float y) p0;
    private bool canMoveNext;

    public DepthInterpolation(IEnumerable<(DateTimeOffset x, float y)> collection)
    {
        enumerator = collection.GetEnumerator();
        canMoveNext = enumerator.MoveNext();
        p0 = enumerator.Current;
    }

    ~DepthInterpolation()
    {
        enumerator.Dispose();
    }

    public float GetDepth(DateTimeOffset date)
    {
        // ошибка в телеметрии см. прим.: idTelemetry = 93 && date between '2021-11-16 17:18:40.000 +0500' and '2021-11-16 17:19:37.000 +0500'
        while (canMoveNext && enumerator.Current.x < date)
        {
            p0 = enumerator.Current;
            canMoveNext = enumerator.MoveNext();
        }
        return CalcValue(date);
    }
    
    private float CalcValue(DateTimeOffset date)
    {
        var p1 = enumerator.Current;
        if (canMoveNext || p1 == default || p0.y == p1.y || p0.x > date)
            return p0.y;

        if (p1.x < date)
            return p1.y;

        if (p1.x - p0.x > maxDeltaDate && Math.Abs(p1.y - p0.y) > 0.2d)
        {
            if (date - p0.x < p1.x - date)
                return p0.y;
            else
                return p1.y;
        }

        var a = (p1.y - p0.y) / (p1.x - p0.x).TotalSeconds;
        var b = p0.y;
        var x = (date - p0.x).TotalSeconds;
        var y = a * x + b;
        return (float)y;
    }
}