import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.math.RoundingMode;
import java.util.ArrayList;

public class Variables {
	private double m, CD, CL, S, A, TimeInterval, r, alpha, omega, l, gamma;
    private double g, rho, b, RD, vVerticle, vTerminal, vAirflow, vTrue, t, mu, W, theta,RN, Temp,Temp_0;
	public Variables(double[] InitConditions){
	    /*v_v-vertical velocity, V- true velocity,t_v terminal velocity*/
		m = InitConditions[0];
		CD = InitConditions[1];
		CL = InitConditions[2];
		S = InitConditions[3];
		A = InitConditions[4];
		TimeInterval = InitConditions[5];
		r = InitConditions[6];
		alpha = InitConditions[7];
		l = InitConditions[8];
		gamma = InitConditions[9];
		Temp_0 = 15;
		Temp = Temperature();
		t = 0; 
		g = gravity(); 
		rho = airDensity();
		W = Weight();
		b = b();
		vTerminal = terminalVelocity();
		vTrue = trueVelocity();
		RD = RD();
		/*estimate vertical velocity to seed calculation*/
		vVerticle = (.5 * g *1);
		omega = 1;/*?rotation rate?*/
		theta = PitchAttitudeAngle();
		mu = mu();
		vAirflow = Airflow();		
		RN = RN();	
	}
	/*updates conditions*/
	public Variables(Variables v){
		m = v.m;
		CD = v.CD;
		CL = v.CL;
		S = v.S;
		Temp_0 = v.Temp_0;
		TimeInterval = v.TimeInterval;
		if(v.t==0){
			t=1;
			A = v.A - v.vVerticle;
		}else{
			t = v.t + TimeInterval;
			BigDecimal bigA = new BigDecimal(Double.toString(v.A));
			BigDecimal bigg = new BigDecimal(Double.toString(v.g));
			BigDecimal bigb = new BigDecimal(Double.toString(v.b));
			BigDecimal bigt = new BigDecimal(Double.toString(t));
			A = bigA.multiply(bigb).subtract(log10(cosh(sqrt(bigg.multiply(bigb))).multiply(bigt))).divide(bigb,1).doubleValue();
			//A = (v.A*v.b-Math.log10(Math.cosh(Math.sqrt(v.g*v.b)*t)))/v.b;
		}
		Temp = Temperature();
		r = v.r;
		alpha = v.alpha;
		l = v.l;
		gamma = v.gamma;
		g = gravity(); 
		rho = airDensity();
		W = Weight();
		b = b();
		vTerminal = terminalVelocity();
		vTrue = trueVelocity();
		RD = RD();
		/*estimate vertical velocity to seed calculation*/
		vVerticle = -(Math.sqrt(v.g)*Math.tanh(Math.sqrt(v.g)*Math.sqrt(this.b)*this.t)/Math.sqrt(this.b));
		omega = 1;/*?rotation rate?*/
		theta = PitchAttitudeAngle();
		mu = mu();
		vAirflow = Airflow();		
		RN = RN();	
	}
	public double mu(){
		return (0.000001458 * Math.sqrt(Temp))/(1+(110.4/Temp));
	}
	public double Temperature(){
		if(A < 11){
			return Temp_0 + (-6.5)*(A - 0);
		}else if(11 <= A && A < 20.1){
			return Temp_0 + (0)*(A - 11);
		}else if(20.1 <= A && A < 32.2){
			return Temp_0 + (1)*(A - 20.1);
		}else if(32.2 <= A && A < 47.3){
			return Temp_0 + (2.8)*(A - 32.2);
		}else if(47.3 <= A && A < 52.4){
			return Temp_0 + (0)*(A - 47.3);
		}else if(52.4 <= A && A < 61.6){
			return Temp_0 + (-2)*(A - 52.4);
		}else if(61.6 <= A && A < 80){
			return Temp_0 + (-4)*(A - 61.6);
		}else{
			return Temp_0 + (0)*(A - 80);
		}
	}
	public double Airflow(){
		return omega* r;
	}
	public double RN(){
		return (vAirflow*rho*l)/mu;
	}
	public double PitchAttitudeAngle(){
		return Math.atan(RD/(omega*r))-alpha;
	}
	public double Weight(){
		return m*g;
	}
	public double trueVelocity(){
		return Math.sqrt((2*W)/(rho*CL*S));
	}
	public double terminalVelocity(){
		return Math.sqrt((2*W)/(rho*CD*S));
	}
	public double RD(){
		return ((vTrue*CD)/CL);
	}
	public double b(){
		return (.5*rho*CD*S);
	}
	public double gravity(){
		return ((-0.000003)*A)+ 9.8064;
	}
	public double airDensity(){
		return 1.4213*Math.exp((-0.0001)*A);
	}
	public double getAltitude(){
		return A;
	}
	public String Headers(){
		return "Altitude,Time,Terminal Velocity,Vertical Velocity,True Velocity,Pitch Attitude Angle,RN";
	}
	public String toString(){
		return A+","+t+","+vTerminal+","+vVerticle+","+vTrue+","+theta+","+RN;
	}
	//hyperbolic cos
	/*from: http://www.shodor.org/~jmorrell/interactivate/org/shodor/math11/FormulaMath.java*/
	public static BigDecimal cosh(BigDecimal x) {
		return (exp(x).add(x.negate())).divide(new BigDecimal("2"), x.scale(),
				BigDecimal.ROUND_HALF_EVEN);
	}
	public static BigDecimal exp(BigDecimal bd) {
		double d = bd.doubleValue();
		BigDecimal ret = new BigDecimal(Math.exp(d));
		return ret.setScale(bd.scale(), BigDecimal.ROUND_HALF_EVEN);
	}
	public static BigDecimal sqrt(BigDecimal bd) {
		double d = bd.doubleValue();
		BigDecimal ret = new BigDecimal(Math.sqrt(d));
		return ret.setScale(bd.scale(), BigDecimal.ROUND_HALF_EVEN);
	}
	/**
	 * COMMON log.  (Log base 10)
	 * @param bd
	 * @return Common log of bd
	 */
	public static BigDecimal log10(BigDecimal x) {
		BigDecimal ret = log(x);
		BigDecimal denom = log(new BigDecimal("10"));
		BigDecimal result = ret.divide(denom, x.scale(),
				BigDecimal.ROUND_HALF_EVEN);
		return result;
	}
	/**
	 * NATURAL log.  (Log base e)
	 * @param bd
	 * @return Natural log of bd
	 */
	public static BigDecimal log(BigDecimal bd) {
		double d = bd.doubleValue();
		double result = 0.0;
		result = Math.log(d);
		if(Double.isNaN(result) || Double.isInfinite(result))
			return new BigDecimal("0");
		BigDecimal ret = new BigDecimal(Math.log(d));
		return ret.setScale(bd.scale(), BigDecimal.ROUND_HALF_EVEN);
	}

}