ArgumentAcceptingOptionSpec.java

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 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * The MIT License
 *
 * Copyright (c) 2004-2015 Paul R. Holser, Jr.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
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package jdk.internal.joptsimple;

import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

import static java.util.Collections.*;
import static java.util.Objects.*;

import static jdk.internal.joptsimple.internal.Reflection.*;
import static jdk.internal.joptsimple.internal.Strings.*;

/**
 * <p>Specification of an option that accepts an argument.</p>
 *
 * <p>Instances are returned from {@link OptionSpecBuilder} methods to allow the formation of parser directives as
 * sentences in a "fluent interface" language. For example:</p>
 *
 * <pre>
 *   <code>
 *   OptionParser parser = new OptionParser();
 *   parser.accepts( "c" ).withRequiredArg().<strong>ofType( Integer.class )</strong>;
 *   </code>
 * </pre>
 *
 * <p>If no methods are invoked on an instance of this class, then that instance's option will treat its argument as
 * a {@link String}.</p>
 *
 * @param <V> represents the type of the arguments this option accepts
 * @author <a href="mailto:[email protected]">Paul Holser</a>
 */
public abstract class ArgumentAcceptingOptionSpec<V> extends AbstractOptionSpec<V> {
    private static final char NIL_VALUE_SEPARATOR = '\u0000';

    private final boolean argumentRequired;
    private final List<V> defaultValues = new ArrayList<>();

    private boolean optionRequired;
    private ValueConverter<V> converter;
    private String argumentDescription = "";
    private String valueSeparator = String.valueOf( NIL_VALUE_SEPARATOR );

    ArgumentAcceptingOptionSpec( String option, boolean argumentRequired ) {
        super( option );

        this.argumentRequired = argumentRequired;
    }

    ArgumentAcceptingOptionSpec( List<String> options, boolean argumentRequired, String description ) {
        super( options, description );

        this.argumentRequired = argumentRequired;
    }

    /**
     * <p>Specifies a type to which arguments of this spec's option are to be converted.</p>
     *
     * <p>JOpt Simple accepts types that have either:</p>
     *
     * <ol>
     *   <li>a public static method called {@code valueOf} which accepts a single argument of type {@link String}
     *   and whose return type is the same as the class on which the method is declared.  The {@code java.lang}
     *   primitive wrapper classes have such methods.</li>
     *
     *   <li>a public constructor which accepts a single argument of type {@link String}.</li>
     * </ol>
     *
     * <p>This class converts arguments using those methods in that order; that is, {@code valueOf} would be invoked
     * before a one-{@link String}-arg constructor would.</p>
     *
     * <p>Invoking this method will trump any previous calls to this method or to
     * {@link #withValuesConvertedBy(ValueConverter)}.</p>
     *
     * @param <T> represents the runtime class of the desired option argument type
     * @param argumentType desired type of arguments to this spec's option
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws NullPointerException if the type is {@code null}
     * @throws IllegalArgumentException if the type does not have the standard conversion methods
     */
    public final <T> ArgumentAcceptingOptionSpec<T> ofType( Class<T> argumentType ) {
        return withValuesConvertedBy( findConverter( argumentType ) );
    }

    /**
     * <p>Specifies a converter to use to translate arguments of this spec's option into Java objects.  This is useful
     * when converting to types that do not have the requisite factory method or constructor for
     * {@link #ofType(Class)}.</p>
     *
     * <p>Invoking this method will trump any previous calls to this method or to {@link #ofType(Class)}.
     *
     * @param <T> represents the runtime class of the desired option argument type
     * @param aConverter the converter to use
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws NullPointerException if the converter is {@code null}
     */
    @SuppressWarnings( "unchecked" )
    public final <T> ArgumentAcceptingOptionSpec<T> withValuesConvertedBy( ValueConverter<T> aConverter ) {
        if ( aConverter == null )
            throw new NullPointerException( "illegal null converter" );

        converter = (ValueConverter<V>) aConverter;
        return (ArgumentAcceptingOptionSpec<T>) this;
    }

    /**
     * <p>Specifies a description for the argument of the option that this spec represents.  This description is used
     * when generating help information about the parser.</p>
     *
     * @param description describes the nature of the argument of this spec's option
     * @return self, so that the caller can add clauses to the fluent interface sentence
     */
    public final ArgumentAcceptingOptionSpec<V> describedAs( String description ) {
        argumentDescription = description;
        return this;
    }

    /**
     * <p>Specifies a value separator for the argument of the option that this spec represents.  This allows a single
     * option argument to represent multiple values for the option.  For example:</p>
     *
     * <pre>
     *   <code>
     *   parser.accepts( "z" ).withRequiredArg()
     *       .<strong>withValuesSeparatedBy( ',' )</strong>;
     *   OptionSet options = parser.parse( new String[] { "-z", "foo,bar,baz", "-z",
     *       "fizz", "-z", "buzz" } );
     *   </code>
     * </pre>
     *
     * <p>Then <code>options.valuesOf( "z" )</code> would yield the list {@code [foo, bar, baz, fizz, buzz]}.</p>
     *
     * <p>You cannot use Unicode U+0000 as the separator.</p>
     *
     * @param separator a character separator
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws IllegalArgumentException if the separator is Unicode U+0000
     */
    public final ArgumentAcceptingOptionSpec<V> withValuesSeparatedBy( char separator ) {
        if ( separator == NIL_VALUE_SEPARATOR )
            throw new IllegalArgumentException( "cannot use U+0000 as separator" );

        valueSeparator = String.valueOf( separator );
        return this;
    }

    /**
     * <p>Specifies a value separator for the argument of the option that this spec represents.  This allows a single
     * option argument to represent multiple values for the option.  For example:</p>
     *
     * <pre>
     *   <code>
     *   parser.accepts( "z" ).withRequiredArg()
     *       .<strong>withValuesSeparatedBy( ":::" )</strong>;
     *   OptionSet options = parser.parse( new String[] { "-z", "foo:::bar:::baz", "-z",
     *       "fizz", "-z", "buzz" } );
     *   </code>
     * </pre>
     *
     * <p>Then <code>options.valuesOf( "z" )</code> would yield the list {@code [foo, bar, baz, fizz, buzz]}.</p>
     *
     * <p>You cannot use Unicode U+0000 in the separator.</p>
     *
     * @param separator a string separator
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws IllegalArgumentException if the separator contains Unicode U+0000
     */
    public final ArgumentAcceptingOptionSpec<V> withValuesSeparatedBy( String separator ) {
        if ( separator.indexOf( NIL_VALUE_SEPARATOR ) != -1 )
            throw new IllegalArgumentException( "cannot use U+0000 in separator" );

        valueSeparator = separator;
        return this;
    }

    /**
     * Specifies a set of default values for the argument of the option that this spec represents.
     *
     * @param value the first in the set of default argument values for this spec's option
     * @param values the (optional) remainder of the set of default argument values for this spec's option
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws NullPointerException if {@code value}, {@code values}, or any elements of {@code values} are
     * {@code null}
     */
    @SafeVarargs
    @SuppressWarnings("varargs")
    public final ArgumentAcceptingOptionSpec<V> defaultsTo( V value, V... values ) {
        addDefaultValue( value );
        defaultsTo( values );

        return this;
    }

    /**
     * Specifies a set of default values for the argument of the option that this spec represents.
     *
     * @param values the set of default argument values for this spec's option
     * @return self, so that the caller can add clauses to the fluent interface sentence
     * @throws NullPointerException if {@code values} or any elements of {@code values} are {@code null}
     */
    public ArgumentAcceptingOptionSpec<V> defaultsTo( V[] values ) {
        for ( V each : values )
            addDefaultValue( each );

        return this;
    }

    /**
     * Marks this option as required. An {@link OptionException} will be thrown when
     * {@link OptionParser#parse(java.lang.String...)} is called, if an option is marked as required and not specified
     * on the command line.
     *
     * @return self, so that the caller can add clauses to the fluent interface sentence
     */
    public ArgumentAcceptingOptionSpec<V> required() {
        optionRequired = true;
        return this;
    }

    public boolean isRequired() {
        return optionRequired;
    }

    private void addDefaultValue( V value ) {
        requireNonNull( value );
        defaultValues.add( value );
    }

    @Override
    final void handleOption( OptionParser parser, ArgumentList arguments, OptionSet detectedOptions,
        String detectedArgument ) {

        if ( detectedArgument == null )
            detectOptionArgument( parser, arguments, detectedOptions );
        else
            addArguments( detectedOptions, detectedArgument );
    }

    protected void addArguments( OptionSet detectedOptions, String detectedArgument ) {
        StringTokenizer lexer = new StringTokenizer( detectedArgument, valueSeparator );
        if ( !lexer.hasMoreTokens() )
            detectedOptions.addWithArgument( this, detectedArgument );
        else {
            while ( lexer.hasMoreTokens() )
                detectedOptions.addWithArgument( this, lexer.nextToken() );
        }
    }

    protected abstract void detectOptionArgument( OptionParser parser, ArgumentList arguments,
        OptionSet detectedOptions );

    @Override
    protected final V convert( String argument ) {
        return convertWith( converter, argument );
    }

    protected boolean canConvertArgument( String argument ) {
        StringTokenizer lexer = new StringTokenizer( argument, valueSeparator );

        try {
            while ( lexer.hasMoreTokens() )
                convert( lexer.nextToken() );
            return true;
        } catch ( OptionException ignored ) {
            return false;
        }
    }

    protected boolean isArgumentOfNumberType() {
        return converter != null && Number.class.isAssignableFrom( converter.valueType() );
    }

    public boolean acceptsArguments() {
        return true;
    }

    public boolean requiresArgument() {
        return argumentRequired;
    }

    public String argumentDescription() {
        return argumentDescription;
    }

    public String argumentTypeIndicator() {
        return argumentTypeIndicatorFrom( converter );
    }

    public List<V> defaultValues() {
        return unmodifiableList( defaultValues );
    }

    @Override
    public boolean equals( Object that ) {
        if ( !super.equals( that ) )
            return false;

        ArgumentAcceptingOptionSpec<?> other = (ArgumentAcceptingOptionSpec<?>) that;
        return requiresArgument() == other.requiresArgument();
    }

    @Override
    public int hashCode() {
        return super.hashCode() ^ ( argumentRequired ? 0 : 1 );
    }
}