package org.unix4j.unix.echo;

import java.util.Arrays;
import java.util.Collections;
import java.util.EnumSet;
import java.util.Iterator;
import org.unix4j.option.Option;

import org.unix4j.unix.Echo;

/**
 * Option sets for the {@link Echo echo} command with 
 * the following options: {@link #n n}.
 * <p>
 * Application code does normally not directly refer to this class;
 * {@link Echo#Options} should be used instead to specify command 
 * options. See also {@link org.unix4j.unix.echo.EchoOptions} for more information.
 */
public enum EchoOptionSet_n implements EchoOptions {
        /** Option set with the following active options: {@link #noNewline n}.*/
        Active_n(
                /*n:*/null /*already set*/, /*noNewline:*/null /*already set*/, 
                true, 
                /*active:*/EchoOption.noNewline
        ),
        /** Option set with the following active options: {@link #noNewline n}.*/
        Active_n_long(
                /*n:*/null /*already set*/, /*noNewline:*/null /*already set*/, 
                false, 
                /*active:*/EchoOption.noNewline
        );
        private EchoOptionSet_n(
                EchoOptionSet_n n, EchoOptionSet_n noNewline, 
                boolean useAcronym,
                EchoOption... activeOptions
        ) {
                this.n = n == null ? this : n;
                this.noNewline = noNewline == null ? this : noNewline;
                this.useAcronym = useAcronym;
                this.options = activeOptions.length == 0 ? EnumSet.noneOf(EchoOption.class) : EnumSet.copyOf(Arrays.asList(activeOptions));
        }
        private final boolean useAcronym;
        /**
         * Option {@code "-n"}: Do not print the trailing newline character(s).
         * <p>
         * The option {@code "-n"} is equivalent to the {@code "--}{@link #noNewline noNewline}{@code "} option.
         * <p>
         * Technically speaking, this field points to a set with the options of the 
         * current set plus the option {@code "-n"}. If the option {@code "-n"}
         * is already set, the field {@code n} points to the enum constant itself
         * as it already represents the current set of options.
         */
        public final EchoOptionSet_n n;
        /**
         * Option {@code "--noNewline"}: Do not print the trailing newline character(s).
         * <p>
         * The option {@code "--noNewline"} is equivalent to the {@code "-}{@link #n n}{@code "} option.
         * <p>
         * Technically speaking, this field points to a set with the options of the 
         * current set plus the option {@code "--noNewline"}. If the option {@code "--noNewline"}
         * is already set, the field {@code noNewline} points to the enum constant itself
         * as it already represents the current set of options.
         */
        public final EchoOptionSet_n noNewline;
        private final EnumSet<EchoOption> options;
        
        //inherit javadoc
        @Override
        public Class<EchoOption> optionType() {
                return EchoOption.class;
        }
        //inherit javadoc
        @Override
        public boolean isSet(EchoOption option) {
                return options.contains(option);
        }
        //inherit javadoc
        @Override
        public int size() {
                return options.size();
        }
        /**
         * Returns the set with the active options. The returned set a new defensive
         * copy instance created when this method is called, modifications of this
         * set will therefore not alter {@code this} option set.
         * 
         * @return a copy of the set with the active options.
         */
        @Override
        public EnumSet<EchoOption> asSet() {
                return EnumSet.copyOf(options);
        }
        /**
         * Returns an immutable iterator with the active options of this option set.
         * 
         * @return an immutable iterator for over the active options
         */
        @Override
        public Iterator<EchoOption> iterator() {
                return Collections.unmodifiableSet(options).iterator();
        }
        /**
         * Returns true if the {@link Option#acronym() acronym} should be used in
         * for the specified {@code option} string representations. 
         * <p>
         * In particular and independent from the {@code option} argument, this 
         * option set returns true if the last option added to this set was an 
         * acronym, and false if it was a long option name. 
         * <p>
         * For instance, the set defined as
         * <pre>
         *    EchoOptionSet_n.n;
         * </pre>
         * uses acronyms, that is, this method always returns true for the above 
         * set. 
         * <p>
         * On the other hand, long option names are used and this method always 
         * returns false for the set
         * <pre>
         *    EchoOptionSet_n.noNewline;
         * </pre>
         * <p>
         * Note that a repeated option is <i>not</i> treated as the last set option.
         * For instance, the first and last option of the following set are 
         * equivalent and acronyms are used:
         * <pre>
         *    EchoOptionSet_n.n.noNewline;
         * </pre>
         * <p>
         * This method always returns true for the empty set with no active options.
         *  
         * @param option
         *            the option of interest, has no impact on the result returned
         *            by this method
         * @return true if option acronyms should be used for string representations
         *         of any option of this option set
         */
        @Override
        public boolean useAcronymFor(EchoOption option) {
                return useAcronym;
        }
}