using System.Collections;
using System.Collections.Generic;
using UnityEngine;

//This class contains utilities for heavenly body calculations
public class HeavenlyUtil {

    private const double stefanBoltzmanConstant = 0.000000560373d;
    private const double PI = 3.14159265359d;
    private const double GM = 0.00000000006740831d;
    private const double sunTemp = 5778;
    private const double sunMag = 4.83;


    public static Star buildStar(Star star)
    {
        //assuming magnitude and temperature are already defined.
        star.solarLuminosity = getSolarLuminosity(star.absoluteMagnitude);
        star.solarRadius = getSolarRadius(star.absoluteMagnitude, star.surfaceTemperature);
        star.solarMass = getSolarMass(star.solarLuminosity);
        star.surfaceGravity = getSurfaceGravity(star.solarRadius, star.solarMass);
        star.escapeVelocity = getEscapeVelocity(star.solarRadius, star.solarMass);
        star.circumfrence = getCircumfrence(star.solarRadius);
        star.volume = getSolarVolume(star.solarRadius);
        star.averageDensity = getDensity(star.solarMass, star.volume);
        star.criticalRotationalVelocity = getCriticalVelocityOfRotation(star.solarMass, star.solarRadius);
        star.rotationalVelocity = generateRotation(star.criticalRotationalVelocity);
        bool giant = false;
        if (star.yerkesClass != "" && star.yerkesClass != "V" && star.yerkesClass != "sd")
        {
            giant = true;
        }
        star.lifespan = getLifespan(giant, star.solarMass);
        star.age = generateAge(star.lifespan);
        return star;
    }

    public static void printStarInfo(Star star)
    {
        Debug.Log(star.fullClassification + " TEMP:  " + star.surfaceTemperature + " AM: " + star.absoluteMagnitude + " L: " + star.solarLuminosity + " Radius: " + star.solarRadius + " Mass: " + star.solarMass + " surfaceGrav: " + star.surfaceGravity + " escapeVelocity: " + star.escapeVelocity + " rot: " + star.rotationalVelocity + " critrot: " + star.criticalRotationalVelocity + " density: " + star.averageDensity + " vol: " + star.volume + " lifespan: " + star.lifespan + " age: " + star.age);
    }

    public static void csvStarInfo(Star star)
    {
        DebugDataWriter.AppendString(star.fullClassification + "," + star.surfaceTemperature + "," + star.absoluteMagnitude + "," + star.solarLuminosity + "," + star.solarRadius + "," + star.solarMass + "," + star.surfaceGravity + "," + star.escapeVelocity + "," + star.rotationalVelocity + "," + star.criticalRotationalVelocity + "," + star.averageDensity + "," + star.volume + "," + star.lifespan + "," + star.age + ",");
    }

    public static void csvStarTitle()
    {
        DebugDataWriter.AppendString("classification,surfaceTemperature,absoluteMagnitude,solarLuminosity,solarRadius,solarMass,surfaceGravity,escapeVelocity,rotation,criticalRotation,averageDensity,volume,lifespan,age,");
    }

    public static double getSolarLuminosity(double absoluteMagnitude)
    {
        return System.Math.Pow(2.51188643, (sunMag - absoluteMagnitude));
    }

    public static double getSolarRadius(double magnitude, double temperature)
    {
        return System.Math.Pow(sunTemp / temperature, 2) * (System.Math.Pow(2.512, 0.5 * (sunMag - magnitude)));

    }

    public static double getSolarMass(double luminosity)
    {
        return (System.Math.Pow(luminosity/1,1/3.5)*1);
    }

    public static double getSurfaceGravity(double solarRadius, double solarMass)
    {
        return solarMass / System.Math.Pow(solarRadius, 2);
    }

    public static double convertSolarMassToKG(double solarMass)
    {
        return solarMass * 1988920001144600000000000000000d;
    }

    public static double convertSolarRadiusToMeter(double solarRadius)
    {
        return solarRadius * 696000000d;
    }

    public static double getEscapeVelocity(double solarRadius, double solarMass)
    {
        return System.Math.Sqrt((2 * GM * convertSolarMassToKG(solarMass)) / convertSolarRadiusToMeter(solarRadius));
    }

    public static double getCircumfrence(double solarRadius)
    {
        return 2 * PI * convertSolarRadiusToMeter(solarRadius);
    }

    public static double getSolarVolume(double solarRadius)
    {
        return (4 / 3) * PI * System.Math.Pow(solarRadius, 3);
    }

    public static double getDensity(double mass, double volume)
    {
        return mass / volume;
    }

    public static double getCriticalVelocityOfRotation(double solarMass, double solarRadius)
    {
        return System.Math.Sqrt(GM * convertSolarMassToKG(solarMass) / (convertSolarRadiusToMeter(solarRadius) / 1000));
    }

    public static float generateRotation(double criticalVelocityOfRotation)
    {
        return Random.Range(0, (float)criticalVelocityOfRotation);
    }

    public static double getLifespan(bool giant, double solarMass)
    {
        double lifetime = System.Math.Pow(10, 10) * System.Math.Pow((1 / solarMass), 2.5);

        if (giant)
        {
            return lifetime * .1;
        }
        else
        {
            return lifetime * .9;
        }
    }

    public static float generateAge(double lifespan)
    {
        return Random.Range((float)lifespan * .1f, (float)lifespan);
    }
}