/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2008 Sun Microsystems, Inc.
 * Portions Copyright 2015-2016 ForgeRock AS.
 */
package org.forgerock.opendj.config;

import static com.forgerock.opendj.util.StaticUtils.*;

import org.forgerock.opendj.ldap.DN;
import org.forgerock.opendj.ldap.RDN;

/**
 * A reference to another managed object.
 *
 * @param <C>
 *            The type of client managed object configuration that this
 *            reference refers to.
 * @param <S>
 *            The type of server managed object configuration that this
 *            reference refers to.
 */
public final class Reference<C extends ConfigurationClient, S extends Configuration> {

    /**
     * Parses a DN string value as a reference using the provided managed object
     * path and relation definition.
     *
     * @param <C>
     *            The type of client managed object configuration that this
     *            reference refers to.
     * @param <S>
     *            The type of server managed object configuration that this
     *            reference refers to.
     * @param path
     *            The path of the referenced managed object's parent.
     * @param relationDef
     *            The instantiable relation in the parent which contains the
     *            referenced managed object.
     * @param dnAsString
     *            The DN string value.
     * @return Returns the new reference based on the provided DN string value.
     * @throws IllegalArgumentException
     *             If the DN string value could not be decoded as a DN or if the
     *             provided DN did not correspond to the provided path and
     *             relation.
     */
    public static <C extends ConfigurationClient, S extends Configuration> Reference<C, S> parseDN(
        ManagedObjectPath<?, ?> path, InstantiableRelationDefinition<C, S> relationDef, String dnAsString) {
        AbstractManagedObjectDefinition<?, ?> definition = path.getManagedObjectDefinition();
        RelationDefinition<?, ?> tmp = definition.getRelationDefinition(relationDef.getName());
        if (tmp != relationDef) {
            // TODO : i18n ?
            throw new IllegalArgumentException("The relation \"" + relationDef.getName()
                + "\" is not associated with the definition \"" + definition.getName() + "\"");
        }

        DN dn = DN.valueOf(dnAsString);
        RDN rdn = dn.rdn();
        if (rdn == null) {
            // TODO : i18n ?
            throw new IllegalArgumentException("Unabled to decode the DN string: \"" + dnAsString + "\"");
        }

        // Check that the DN was valid.
        String name = rdn.getFirstAVA().getAttributeValue().toString();
        DN expected = path.child(relationDef, name).toDN();
        if (!dn.equals(expected)) {
            // TODO : i18n ?
            throw new IllegalArgumentException("Unabled to decode the DN string: \"" + dnAsString + "\"");
        }

        return new Reference<>(path, relationDef, name);
    }

    /**
     * Parses a name as a reference using the provided managed object path and
     * relation definition.
     *
     * @param <C>
     *            The type of client managed object configuration that this
     *            reference refers to.
     * @param <S>
     *            The type of server managed object configuration that this
     *            reference refers to.
     * @param p
     *            The path of the referenced managed object's parent.
     * @param rd
     *            The instantiable relation in the parent which contains the
     *            referenced managed object.
     * @param s
     *            The name of the referenced managed object.
     * @return Returns the new reference based on the provided name.
     * @throws IllegalArgumentException
     *             If the relation is not associated with the provided parent's
     *             definition, or if the provided name is empty.
     */
    public static <C extends ConfigurationClient, S extends Configuration> Reference<C, S> parseName(
        ManagedObjectPath<?, ?> p, InstantiableRelationDefinition<C, S> rd, String s) {
        // Sanity checks.
        AbstractManagedObjectDefinition<?, ?> d = p.getManagedObjectDefinition();
        RelationDefinition<?, ?> tmp = d.getRelationDefinition(rd.getName());
        if (tmp != rd) {
            throw new IllegalArgumentException("The relation \"" + rd.getName()
                + "\" is not associated with the definition \"" + d.getName() + "\"");
        }

        if (s.trim().length() == 0) {
            throw new IllegalArgumentException("Empty names are not allowed");
        }

        return new Reference<>(p, rd, s);
    }

    /** The name of the referenced managed object. */
    private final String name;

    /** The path of the referenced managed object. */
    private final ManagedObjectPath<C, S> path;

    /** The instantiable relation in the parent which contains the referenced managed object. */
    private final InstantiableRelationDefinition<C, S> relation;

    /** Private constructor. */
    private Reference(ManagedObjectPath<?, ?> parent, InstantiableRelationDefinition<C, S> relation, String name) {
        this.relation = relation;
        this.name = name;
        this.path = parent.child(relation, name);
    }

    /**
     * Gets the name of the referenced managed object.
     *
     * @return Returns the name of the referenced managed object.
     */
    public String getName() {
        return name;
    }

    /**
     * Gets the normalized name of the referenced managed object.
     *
     * @return Returns the normalized name of the referenced managed object.
     */
    public String getNormalizedName() {
        PropertyDefinition<?> pd = relation.getNamingPropertyDefinition();
        return normalizeName(pd);
    }

    /**
     * Gets the DN of the referenced managed object.
     *
     * @return Returns the DN of the referenced managed object.
     */
    public DN toDN() {
        return path.toDN();
    }

    @Override
    public String toString() {
        return name;
    }

    /** Normalize a value using the specified naming property definition if defined. */
    private <T> String normalizeName(PropertyDefinition<T> pd) {
        if (pd != null) {
            try {
                // TODO : is it correct to have no validation ?
                T tvalue = pd.decodeValue(name);
                return pd.normalizeValue(tvalue);
            } catch (PropertyException e) {
                // Fall through to default normalization.
            }
        }

        // FIXME: should really use directory string normalizer.
        String s = name.trim().replaceAll(" +", " ");
        return toLowerCase(s);
    }
}