package parameterrules;

import java.io.*;
import main.BetterTokenizer;
import main.GeneralInput;
import main.MoreMath;
import parameters.Parameter;
import parameters.ParameterSet;

/** Implements the rule that the product of all the input parameters has to lie between
	lowerBound <= product <= upperBound.
*/
public class ProductBetweenRule extends ParameterRule {
	/** These store the lower and upper bounds that the product of the parameters have to be between (inclusive of edges) */
	private	float	lowerBound, upperBound;
	
	ProductBetweenRule() {}
	
	
	public float getFuzzyScore(float [] params) {
		float	val = 1f;
		
		for(int i = 0; i < numParams; i++) {
			val *= params[paramNums[i]];
		}
		if(val < lowerBound) return lowerBound - val;
		else if(val > upperBound) return val - upperBound;
		else return 0f;
	}
	
	public boolean changeParameters(float [] params, int mode, ParameterSet set) {
		float	val = 1f;
		
	// First check if its already good. If so, return true
		for(int i = 0; i < numParams; i++) {
			val *= params[paramNums[i]];
		}
		if(val >= lowerBound && val <= upperBound) return true;
		
	// Not already good, so randomly pick one value to change
		int change_param = (int)(MoreMath.random() * numParams);
	// Take out value we'll change
		val /= params[paramNums[change_param]];
		
	// Calculate new range
		float min = lowerBound / val;
		float max = upperBound / val;
		
	// Pick the value
		pickNewParameterValue(params, paramNums[change_param], min, max, mode, set);

		return false;
	}
	
	
	protected void loadParameter(String info, BetterTokenizer tokenizer) throws Exception	{
		if(info.equals("LowerBound")) {
			GeneralInput.nextToken(tokenizer);
			lowerBound = (float)tokenizer.nval;
		}
		else if(info.equals("UpperBound")) {
			GeneralInput.nextToken(tokenizer);
			upperBound = (float)tokenizer.nval;
		}
		else super.loadParameter(info, tokenizer);
	}
}