Parse.java

package org.cryptocoinpartners.command;

import java.math.BigDecimal;

import javax.inject.Inject;

import org.antlr.v4.runtime.tree.TerminalNode;
import org.apache.commons.lang.StringUtils;
import org.cryptocoinpartners.enumeration.PositionEffect;
import org.cryptocoinpartners.schema.Currency;
import org.cryptocoinpartners.schema.Listing;
import org.cryptocoinpartners.schema.Market;

/**
 * This helper utility converts Antlr TerminalNodes into Cointrader schema classes
 *
 * @author Tim Olson
 */
public class Parse {
    @Inject
    static Market markets;

    public static BigDecimal amount(TerminalNode node) throws ParseError {
        String text = text(node);
        if (StringUtils.isBlank(text))
            throw new ParseError("Expected an amount");
        try {
            return new BigDecimal(text);
        } catch (NumberFormatException e) {
            throw new ParseError("Expected an amount: " + text);
        }
    }

    public static Currency currency(TerminalNode node) throws ParseError {
        String text = text(node);
        Currency currency = Currency.forSymbol(text);
        if (currency == null)
            throw new ParseError("Unknown currency " + text);
        return currency;
    }

    public static Listing listing(TerminalNode node) throws ParseError {
        String text = text(node);
        Listing listing = Listing.forSymbol(text);
        if (listing == null)
            throw new ParseError("Unknown listing " + text);
        return listing;
    }

    public static PositionEffect positionEffect(TerminalNode node) throws ParseError {
        String text = text(node);
        PositionEffect positionEffect = (text.equals("close") || text.equals("Close") || text.equals("CLOSE")) ? PositionEffect.CLOSE : PositionEffect.OPEN;
        if (positionEffect == null)
            throw new ParseError("Unknown position effect " + text);
        return positionEffect;
    }

    public static Market market(TerminalNode node) throws ParseError {
        String text = text(node);
        Market market = markets.forSymbol(text);
        if (market == null)
            throw new ParseError("Unknown market " + text);
        return market;
    }

    private static String text(TerminalNode node) {
        return node == null ? "" : node.getSymbol().getText();
    }

}