/**
 * pcgen.core.term.PCEqTypeTermEvaluator.java
 * Copyright (c) 2008 Andrew Wilson <nuance@users.sourceforge.net>.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Created 09-Aug-2008 11:44:20
 *
 * Current Ver: $Revision:$
 *
 */

package pcgen.core.term;

import java.util.regex.Pattern;

import pcgen.core.PlayerCharacter;
import pcgen.core.spell.Spell;
import pcgen.io.exporttoken.EqTypeToken;
import pcgen.io.exporttoken.Token;

public class PCEqTypeTermEvaluator
		extends BasePCTermEvaluator implements TermEvaluator
{
	private static final String Digits    = "(\\p{Digit}+)";
	private static final String HexDigits = "(\\p{XDigit}+)";
	// an exponent is 'e' or 'E' followed by an optionally
	// signed decimal integer.
	private static final String Exp       = "[eE][+-]?"+Digits;
	private static final String fpRegex   =
		("[\\x00-\\x20]*"+  // Optional leading "whitespace"
		 "[+-]?(" +         // Optional sign character
		 "NaN|" +           // "NaN" string
		 "Infinity|" +      // "Infinity" string

		// A decimal floating-point string representing a finite positive
		// number without a leading sign has at most five basic pieces:
		// Digits . Digits ExponentPart FloatTypeSuffix
		//
		// Since this method allows integer-only strings as input
		// in addition to strings of floating-point literals, the
		// two sub-patterns below are simplifications of the grammar
		// productions from the Java Language Specification, 2nd
		// edition, section 3.10.2.

		// Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt
		"((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+

		// . Digits ExponentPart_opt FloatTypeSuffix_opt
		"(\\.("+Digits+")("+Exp+")?)|"+

		// Hexadecimal strings
		"((" +
		// 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt
		"(0[xX]" + HexDigits + "(\\.)?)|" +

		// 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt
		"(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +

		")[pP][+-]?" + Digits + "))" +
		"[fFdD]?))" +
		"[\\x00-\\x20]*");// Optional trailing "whitespace"

	
	public PCEqTypeTermEvaluator(String originalText)
	{
		this.originalText = originalText;
	}

	@Override
	public Float resolve(PlayerCharacter pc)
	{
		final String sTok = evaluate(pc);

		if (Pattern.matches(fpRegex, sTok))
		{
			return convertToFloat(originalText, sTok);
		}

		return 0.0f;
	}

	@Override
	public String evaluate (PlayerCharacter pc)
	{
		final Token token = new EqTypeToken();
		return token.getToken(originalText, pc, null);
	}

	@Override
	public String evaluate (PlayerCharacter pc, Spell aSpell)
	{
		return evaluate(pc);
	}
	
	@Override
	public boolean isSourceDependant()
	{
		return false;
	}

	public boolean isStatic()
	{
		return false;
	}
}