package turing;

public class FireField 
{
	private double Vh;  //火場上火頭蔓延速度
	private double Vf;  //火場風速
	private double S;   //火場面積
	private double L;   //火場周邊長
	private double Vs;  //火場面積增長速度
	private double Vl;  //火場周邊長增長速度
	private double k1;  //火速在不同的可燃物類型中的修正系數
	private double k2;  //火速在不同坡度條件下的修正系數
	private double VHRelation;//橫縱向比例關系
	private double VsAverage;//火場面積平均增長速度
	private double VlAverage;//火場周邊長平均增長速度
	
	public FireField()
	{
		Vf=2;
		k1=1.0;
	}
	
	
	
	public double getVsAverage() {
		return VsAverage;
	}

	public double getVlAverage() {
		return VlAverage;
	}

	public void countVh(int VfDegree,int grade,int fieldVariety,double time )//風力等級，坡度，火場類型，時間
	{
		double temp;
		switch(VfDegree)//根據風力等級判斷火速Vf（m/s）
		{
		case 1:
			Vf=2;
			break;
		case 2:
			Vf=3.6;
			break;
		case 3:
			Vf=5.4;
			break;
		case 4:
			Vf=7.4;
			break;
		case 5:
			Vf=9.8;
			break;	
		case 6:
			Vf=12.3;
			break;
		case 7:
			Vf=14.9;
			break;
		case 8:
			Vf=17.7;
			break;
		case 9:
			Vf=20.8;
			break;
		case 10:
			Vf=24.2;
			break;
		case 11:
			Vf=27.8;
			break;
		case 12:
			Vf=29.838;
			break;
		}
		
		VHRelation=countVHRelation(Vf);
		
		switch(fieldVariety)//根據輸入的可燃物類型，判斷修正系數k1
		{
		case 1:
			k1=1.0;//草甸
			break;
		case 2:
			k1=0.7;//次生林
			break;
		case 3:
			k1=0.4;//針葉林
			break;				
		}
		//根據坡度計算修正系數k2
		k2=countK2(grade);	
		
		//   根據k1（可燃物類型 1草甸 2次生林 3針葉林）
		//和   根據k2 （火速在不同坡度條件下的修正系數 -42°~42°）
		//和   Vf（風在不同風力等級下的風傳播速度）m/s
		//   計算火頭傳播速度（Vh）    m/s
		Vh=k1*k2*14.1895*Math.exp(0.1547*Vf);
		
		temp=Math.sqrt(1/(VHRelation*VHRelation)+4);
		
		S=( (Math.PI/2)*(1/(VHRelation*VHRelation))+(4/3)*(1/VHRelation) )*(Vh*time*time);
		
		L=( (Math.PI/VHRelation)+temp+1/(VHRelation*VHRelation)*Math.log(1/VHRelation)*(2+temp) )*Vh*time;
		
		Vs=(Math.PI/(VHRelation*VHRelation)+(8/3)/VHRelation)*Vh*Vh*time;
		VsAverage=Vs/2;
		
		Vl=(Math.log(1/VHRelation)+temp+1/(VHRelation*VHRelation)*Math.log(1/VHRelation)*(2+temp))*Vh;
		VlAverage=Vl;
		
		
	}
	
	public double getVh() {
		return Vh;
	}

	public double getVf() {
		return Vf;
	}

	public double getS() {
		return S;
	}

	public double getL() {
		return L;
	}

	public double getVs() {
		return Vs;
	}

	public double getVl() {
		return Vl;
	}

	public double getK1() {
		return k1;
	}

	public double getK2() {
		return k2;
	}

	public double getVHRelation() {
		return VHRelation;
	}

	public double countK2(int grade)
	{
		double K2;
		if(grade>=-42&&grade<=-38)
			k2=0.07;
		else if(grade>=-37&&grade<=-33)
			k2=0.13;
		else if(grade>=-32&&grade<=-28)
			k2=0.21;
		else if(grade>=-27&&grade<=-23)
			k2=0.32;
		else if(grade>=-22&&grade<=-18)
			k2=0.46;
		else if(grade>=-17&&grade<=-13)
			k2=0.63;
		else if(grade>=-12&&grade<=-8)
			k2=0.83;
		else if(grade>=-7&&grade<=-3)
			k2=0.90;
		else if(grade>=-2&&grade<=2)
			k2=1.00;
		else if(grade>=3&&grade<=7)
			k2=1.20;
		else if(grade>=8&&grade<=12)
			k2=1.60;
		else if(grade>=13&&grade<=17)
			k2=2.10;
		else if(grade>=18&&grade<=22)
			k2=2.9;
		else if(grade>=23&&grade<=27)
			k2=4.10;
		else if(grade>=28&&grade<=32)
			k2=6.20;
		else if(grade>=33&&grade<=37)
			k2=10.10;
		else if(grade>=38&&grade<=42)
			k2=17.50;	
		K2=k2;
		return K2;
	}
	
	public double countVHRelation(double vf)
	{
		double VH;
		if(vf==0)
			VHRelation=1;
		else if(vf>=0.1&&vf<=2.8)
			VHRelation=1.2;
		else if(vf>=2.9&&vf<=5.6)
			VHRelation=1.5;
		else if(vf>=5.7&&vf<=8.4)
			VHRelation=2.2;
		else if(vf>=8.5&&vf<=11.2)
			VHRelation=3.3;
		else if(vf>=11.3&&vf<=14)
			VHRelation=5;
		else if(vf>=14.1)
			VHRelation=7;
		
		VH=VHRelation;
		return VH;
	}	

}