/**
 * 2d box with no scalar fields of a fixed (at construction time)
 * width and height
 * @author     Michael Schuresko
 * @version    %I%, %G%
 * @since      1.0
 */

public class SimpleScalarEnvironment implements IEnvironment 
{
    BoxBoundary m_boundary;
    double[] m_arrLfMin;
    double[] m_arrLfMax;
    IScalarField m_field;

    public SimpleScalarEnvironment()
    {
    	initializeVars(100.0,100.0, false);
    }

    public SimpleScalarEnvironment(double lfWidth, double lfHeight, boolean bAddDefault)
    {
    	initializeVars(lfWidth, lfHeight, bAddDefault);
    }

    public SimpleScalarEnvironment(double [] arrLfMin, double [] arrLfMax, boolean bAddDflt)
    {
    	initializeVars(arrLfMin, arrLfMax, bAddDflt);
    }

    
    public SimpleScalarEnvironment(SimpleScalarEnvironment src) {
    	m_field = src.m_field.makeCopy();
    	m_arrLfMax = MathUtils.arrDblCpy(src.m_arrLfMax, 
    			src.m_arrLfMax.length);
    	m_arrLfMin = MathUtils.arrDblCpy(src.m_arrLfMin, 
    			src.m_arrLfMin.length);
    	m_boundary = new BoxBoundary(m_arrLfMin, m_arrLfMax);
    }

    public void initializeVars(double lfWidth, double lfHeight, boolean bAddDefault) 
    {
    	m_arrLfMin = new double[2];
    	m_arrLfMax = new double[2];
    	m_arrLfMin[0] = 0.0; m_arrLfMin[1] = 0.0;
    	m_arrLfMax[0] = lfWidth; m_arrLfMax[1] = lfHeight;

    	Jama.Matrix matSigInv = Jama.Matrix.identity(2, 2);
    	
    	if(!bAddDefault) {
    		matSigInv.timesEquals(0.0);
    	}
    	
    	Jama.Matrix matCenter = new Jama.Matrix(2,1);
    	
    	matCenter.set(1, 0, 0.5*lfHeight);
    	matCenter.set(0, 0, 0.25*lfWidth);
    	
    	ScalarFieldSumGauss field = new ScalarFieldSumGauss(2);	
    		try {
    			field.addGaussian(1.0, matCenter, matSigInv);
    			matCenter.set(0, 0, 0.75*lfWidth);
    			field.addGaussian(1.0, matCenter, matSigInv);        	
    		} catch(Exception e) {
    			System.out.println("Mike, you'd better debug this");
    		}
    	m_field = field;
    	
    	m_boundary = new BoxBoundary(m_arrLfMin, m_arrLfMax);
    }

    public void initializeVars(double [] arrLfMin, double [] arrLfMax, boolean bAddDflt) 
    {
    	m_arrLfMax = MathUtils.arrDblCpy(arrLfMax, 
    			arrLfMax.length);
    	m_arrLfMin = MathUtils.arrDblCpy(arrLfMin, 
    			arrLfMin.length);

    	Jama.Matrix matSigInv = Jama.Matrix.identity(2, 2);
    	
    	matSigInv.timesEquals(10.0);
    	
    	if(!bAddDflt) {
    		matSigInv.timesEquals(0.0);
    	}
    	
    	Jama.Matrix matCenter = new Jama.Matrix(2,1);
    	
    	matCenter.set(0, 0, 0.6*m_arrLfMin[0]+0.4*m_arrLfMax[0]);
    	matCenter.set(1, 0, 0.15*m_arrLfMin[1] + 0.85*m_arrLfMax[1]);
    	
    	ScalarFieldSumGauss field = new ScalarFieldSumGauss(2);	
    	try {
    		field.addGaussian(1.0, matCenter, matSigInv);
    		matCenter.set(0, 0, 0.4*m_arrLfMin[0]+0.6*m_arrLfMax[0]);
    		matCenter.set(1, 0, 0.85*m_arrLfMin[1] + 0.15*m_arrLfMax[1]);
    		field.addGaussian(1.0, matCenter, matSigInv);        	
    	} catch(Exception e) {
    		System.out.println("Mike, you'd better debug this");
    	}
    	m_field = field;
    	
    	m_boundary = new BoxBoundary(m_arrLfMin, m_arrLfMax);
    }

    /**
     * Gradient at a particular location for a given field
     * @param nWhichField field to take gradient of
     * @param arrLoc place at which to take gradient
     * @return gradient (of proper dimensionality) as a double []
     */
    public double [] getGradient(int nWhichField, double arrLoc[])
    {
    	if(nWhichField == 0 && m_field != null) {
    		return this.m_field.getGradient(arrLoc);
    	}
    	
    	return new double[m_arrLfMin.length];
    }
    
    /**
     * Gradient at a particular location for a given field
     * @param nWhichField field to take gradient of
     * @param arrLoc place at which to take gradient
     * @param arrRslt gradient (of proper dimensionality) as a double []
     */
    public void getGradient(int nWhichField, double arrLoc[], double arrRslt[])
    {
    	if(nWhichField == 0 && m_field != null) {
    		m_field.getGradient(arrLoc, arrRslt);
    	} else {
    		for(int i = 0; i < arrRslt.length; ++i) {
    			arrRslt[i] = 0.0;
    		}
    	}
    	
    	
    }
    
    
    /**
     * dimensionality of space in which environment is embedded
     */
    public int getDimensionality() { return 2; }

    /**
     * number of scalar fields over environment
     */
    public int getNumScalars() { return 1; }

    /**
     * Gets a particular field value at a particular location
     * Invalid for this class
     * Figure out how to declare exceptions in interface definitions
     */
    public double getFieldVal(int nWhichField, double arrLoc[])
    {
    	if(nWhichField == 0) {
    		return this.m_field.getVal(arrLoc);
    	}
	return 0.0;
    }

    /**
     * Gets all field values for a particular location as a vector
     * Invalid for this class
     * Figure out how to declare exceptions in interface definitions
     * @param arrLoc invalid for this class
     * @return null --  invalid for this class
     */
    public double [] getFieldVals(double arrLoc[])
    {
    	double [] arrLfResult = new double[1];
    	arrLfResult[0] = getFieldVal(0, arrLoc);
    	return arrLfResult;
    }

    public IEnvironment makeCopy() {
    	return new SimpleScalarEnvironment(this);
    }
    
    /**
     * Gets boundary interface
     */
    public IBoundary getBoundary()
    {
	return m_boundary;
    }
}