/*
 * Redberry: symbolic tensor computations.
 *
 * Copyright (c) 2010-2015:
 *   Stanislav Poslavsky   
 *   Bolotin Dmitriy       
 *
 * This file is part of Redberry.
 *
 * Redberry is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Redberry 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Redberry. If not, see .
 */
package cc.redberry.core.number.parser;

import cc.redberry.core.number.Complex;
import cc.redberry.core.number.Rational;
import cc.redberry.core.number.Real;

/**
 * @author Stanislav Poslavsky
 */
public class NumberParser> {

    @SuppressWarnings("unchecked")
    private static final TokenParser[] ComplexTokens = new TokenParser[]{
            BracketToken.INSTANCE,
            new OperatorToken('+', '-') {

                @Override
                protected Complex neutral() {
                    return Complex.ZERO;
                }

                @Override
                protected Complex operation(Complex c1, Complex c2, boolean mode) {
                    if (mode)
                        return c1.subtract(c2);
                    return c1.add(c2);
                }
            },
            new OperatorToken('*', '/') {

                @Override
                protected Complex neutral() {
                    return Complex.ONE;
                }

                @Override
                protected Complex operation(Complex c1, Complex c2, boolean mode) {
                    if (mode)
                        return c1.divide(c2);
                    return c1.multiply(c2);
                }
            },
            ComplexToken.INSTANCE
    };
    @SuppressWarnings("unchecked")
    private static final TokenParser[] RealTokens = new TokenParser[]{
            BracketToken.INSTANCE,
            new OperatorToken('+', '-') {

                @Override
                protected Real neutral() {
                    return Rational.ZERO;
                }

                @Override
                protected Real operation(Real c1, Real c2, boolean mode) {
                    if (mode)
                        return c1.subtract(c2);
                    return c1.add(c2);
                }
            },
            new OperatorToken('*', '/') {

                @Override
                protected Real neutral() {
                    return Rational.ONE;
                }

                @Override
                protected Real operation(Real c1, Real c2, boolean mode) {
                    if (mode)
                        return c1.divide(c2);
                    return c1.multiply(c2);
                }
            },
            RealToken.INSTANCE
    };
    public static final NumberParser REAL_PARSER = new NumberParser<>(RealTokens);
    public static final NumberParser COMPLEX_PARSER = new NumberParser<>(ComplexTokens);
    private final TokenParser[] parsers;

    private NumberParser(TokenParser[] parsers) {
        this.parsers = parsers;
    }

    public T parse(String expression) {
        expression = expression.trim();
        for (TokenParser parser : parsers) {
            @SuppressWarnings("unchecked") T element = (T) parser.parse(expression, this);
            if (element == null)
                continue;
            return element;
        }
        throw new NumberFormatException();
    }
}