/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2009 Sun Microsystems, Inc.
 *      Portions copyright 2011 ForgeRock AS
 */

package org.forgerock.opendj.ldap.schema;

import static org.forgerock.opendj.ldap.CoreMessages.*;

import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.forgerock.i18n.LocalizableMessage;

import com.forgerock.opendj.util.Validator;

/**
 * This class defines a DIT content rule, which defines the set of allowed,
 * required, and prohibited attributes for entries with a given structural
 * objectclass, and also indicates which auxiliary classes may be included in
 * the entry.
 */
public final class DITContentRule extends SchemaElement {
    // The structural objectclass for this DIT content rule.
    private final String structuralClassOID;

    // The set of user defined names for this definition.
    private final List<String> names;

    // Indicates whether this definition is declared "obsolete".
    private final boolean isObsolete;

    // The set of auxiliary objectclasses that entries with this content
    // rule may contain, in a mapping between the objectclass and the
    // user-defined name for that class.
    private final Set<String> auxiliaryClassOIDs;

    // The set of optional attribute types for this DIT content rule.
    private final Set<String> optionalAttributeOIDs;

    // The set of prohibited attribute types for this DIT content rule.
    private final Set<String> prohibitedAttributeOIDs;

    // The set of required attribute types for this DIT content rule.
    private final Set<String> requiredAttributeOIDs;

    // The definition string used to create this objectclass.
    private final String definition;

    private ObjectClass structuralClass;
    private Set<ObjectClass> auxiliaryClasses = Collections.emptySet();
    private Set<AttributeType> optionalAttributes = Collections.emptySet();
    private Set<AttributeType> prohibitedAttributes = Collections.emptySet();
    private Set<AttributeType> requiredAttributes = Collections.emptySet();

    DITContentRule(final String structuralClassOID, final List<String> names,
            final String description, final boolean obsolete, final Set<String> auxiliaryClassOIDs,
            final Set<String> optionalAttributeOIDs, final Set<String> prohibitedAttributeOIDs,
            final Set<String> requiredAttributeOIDs,
            final Map<String, List<String>> extraProperties, final String definition) {
        super(description, extraProperties);

        Validator.ensureNotNull(structuralClassOID, names);
        Validator.ensureNotNull(auxiliaryClassOIDs, optionalAttributeOIDs, prohibitedAttributeOIDs,
                requiredAttributeOIDs);
        this.names = names;
        this.isObsolete = obsolete;
        this.structuralClassOID = structuralClassOID;
        this.auxiliaryClassOIDs = auxiliaryClassOIDs;
        this.optionalAttributeOIDs = optionalAttributeOIDs;
        this.prohibitedAttributeOIDs = prohibitedAttributeOIDs;
        this.requiredAttributeOIDs = requiredAttributeOIDs;

        if (definition != null) {
            this.definition = definition;
        } else {
            this.definition = buildDefinition();
        }
    }

    /**
     * Returns {@code true} if the provided object is a DIT content rule having
     * the same structural object class OID as this DIT content rule.
     *
     * @param o
     *            The object to be compared.
     * @return {@code true} if the provided object is a DIT content rule having
     *         the same numeric OID as this DIT content rule.
     */
    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        } else if (o instanceof DITContentRule) {
            final DITContentRule other = (DITContentRule) o;
            return structuralClassOID.equals(other.structuralClassOID);
        } else {
            return false;
        }
    }

    /**
     * Returns an unmodifiable set containing the auxiliary objectclasses that
     * may be used for entries associated with this DIT content rule.
     *
     * @return An unmodifiable set containing the auxiliary objectclasses that
     *         may be used for entries associated with this DIT content rule.
     */
    public Set<ObjectClass> getAuxiliaryClasses() {
        return auxiliaryClasses;
    }

    /**
     * Returns the name or structural class OID for this schema definition. If
     * it has one or more names, then the primary name will be returned. If it
     * does not have any names, then the OID will be returned.
     *
     * @return The name or OID for this schema definition.
     */
    public String getNameOrOID() {
        if (names.isEmpty()) {
            return structuralClassOID;
        }
        return names.get(0);
    }

    /**
     * Returns an unmodifiable list containing the user-defined names that may
     * be used to reference this schema definition.
     *
     * @return Returns an unmodifiable list containing the user-defined names
     *         that may be used to reference this schema definition.
     */
    public List<String> getNames() {
        return names;
    }

    /**
     * Returns an unmodifiable set containing the optional attributes for this
     * DIT content rule.
     *
     * @return An unmodifiable set containing the optional attributes for this
     *         DIT content rule.
     */
    public Set<AttributeType> getOptionalAttributes() {
        return optionalAttributes;
    }

    /**
     * Returns an unmodifiable set containing the prohibited attributes for this
     * DIT content rule.
     *
     * @return An unmodifiable set containing the prohibited attributes for this
     *         DIT content rule.
     */
    public Set<AttributeType> getProhibitedAttributes() {
        return prohibitedAttributes;
    }

    /**
     * Returns an unmodifiable set containing the required attributes for this
     * DIT content rule.
     *
     * @return An unmodifiable set containing the required attributes for this
     *         DIT content rule.
     */
    public Set<AttributeType> getRequiredAttributes() {
        return requiredAttributes;
    }

    /**
     * Returns the structural objectclass for this DIT content rule.
     *
     * @return The structural objectclass for this DIT content rule.
     */
    public ObjectClass getStructuralClass() {
        return structuralClass;
    }

    /**
     * Returns the structural class OID for this schema definition.
     *
     * @return The structural class OID for this schema definition.
     */
    public String getStructuralClassOID() {
        return structuralClassOID;
    }

    /**
     * Returns the hash code for this DIT content rule. It will be calculated as
     * the hash code of the structural object class OID.
     *
     * @return The hash code for this DIT content rule.
     */
    @Override
    public int hashCode() {
        return structuralClassOID.hashCode();
    }

    /**
     * Indicates whether this schema definition has the specified name.
     *
     * @param name
     *            The name for which to make the determination.
     * @return <code>true</code> if the specified name is assigned to this
     *         schema definition, or <code>false</code> if not.
     */
    public boolean hasName(final String name) {
        for (final String n : names) {
            if (n.equalsIgnoreCase(name)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Indicates whether this schema definition has the specified name or
     * structural class OID.
     *
     * @param value
     *            The value for which to make the determination.
     * @return <code>true</code> if the provided value matches the OID or one of
     *         the names assigned to this schema definition, or
     *         <code>false</code> if not.
     */
    public boolean hasNameOrOID(final String value) {
        return hasName(value) || structuralClassOID.equals(value);
    }

    /**
     * Indicates whether this schema definition is declared "obsolete".
     *
     * @return <code>true</code> if this schema definition is declared
     *         "obsolete", or <code>false</code> if not.
     */
    public boolean isObsolete() {
        return isObsolete;
    }

    /**
     * Indicates whether the provided attribute type is included in the optional
     * attribute list for this DIT content rule.
     *
     * @param attributeType
     *            The attribute type for which to make the determination.
     * @return <code>true</code> if the provided attribute type is optional for
     *         this DIT content rule, or <code>false</code> if not.
     */
    public boolean isOptional(final AttributeType attributeType) {
        return optionalAttributes.contains(attributeType);
    }

    /**
     * Indicates whether the provided attribute type is included in the required
     * attribute list for this DIT content rule.
     *
     * @param attributeType
     *            The attribute type for which to make the determination.
     * @return <code>true</code> if the provided attribute type is required by
     *         this DIT content rule, or <code>false</code> if not.
     */
    public boolean isRequired(final AttributeType attributeType) {
        return requiredAttributes.contains(attributeType);
    }

    /**
     * Indicates whether the provided attribute type is in the list of required
     * or optional attributes for this DIT content rule.
     *
     * @param attributeType
     *            The attribute type for which to make the determination.
     * @return <code>true</code> if the provided attribute type is required or
     *         allowed for this DIT content rule, or <code>false</code> if it is
     *         not.
     */
    public boolean isRequiredOrOptional(final AttributeType attributeType) {
        return isRequired(attributeType) || isOptional(attributeType);
    }

    /**
     * Returns the string representation of this schema definition in the form
     * specified in RFC 2252.
     *
     * @return The string representation of this schema definition in the form
     *         specified in RFC 2252.
     */
    @Override
    public String toString() {
        return definition;
    }

    DITContentRule duplicate() {
        return new DITContentRule(structuralClassOID, names, description, isObsolete,
                auxiliaryClassOIDs, optionalAttributeOIDs, prohibitedAttributeOIDs,
                requiredAttributeOIDs, extraProperties, definition);
    }

    @Override
    void toStringContent(final StringBuilder buffer) {
        buffer.append(structuralClassOID);

        if (!names.isEmpty()) {
            final Iterator<String> iterator = names.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" NAME ( '");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append("' '");
                    buffer.append(iterator.next());
                }

                buffer.append("' )");
            } else {
                buffer.append(" NAME '");
                buffer.append(firstName);
                buffer.append("'");
            }
        }

        if (description != null && description.length() > 0) {
            buffer.append(" DESC '");
            buffer.append(description);
            buffer.append("'");
        }

        if (isObsolete) {
            buffer.append(" OBSOLETE");
        }

        if (!auxiliaryClassOIDs.isEmpty()) {
            final Iterator<String> iterator = auxiliaryClassOIDs.iterator();

            final String firstClass = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" AUX (");
                buffer.append(firstClass);

                while (iterator.hasNext()) {
                    buffer.append(" $ ");
                    buffer.append(iterator.next());
                }

                buffer.append(" )");
            } else {
                buffer.append(" AUX ");
                buffer.append(firstClass);
            }
        }

        if (!requiredAttributeOIDs.isEmpty()) {
            final Iterator<String> iterator = requiredAttributeOIDs.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" MUST ( ");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append(" $ ");
                    buffer.append(iterator.next());
                }

                buffer.append(" )");
            } else {
                buffer.append(" MUST ");
                buffer.append(firstName);
            }
        }

        if (!optionalAttributeOIDs.isEmpty()) {
            final Iterator<String> iterator = optionalAttributeOIDs.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" MAY ( ");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append(" $ ");
                    buffer.append(iterator.next());
                }

                buffer.append(" )");
            } else {
                buffer.append(" MAY ");
                buffer.append(firstName);
            }
        }

        if (!prohibitedAttributeOIDs.isEmpty()) {
            final Iterator<String> iterator = prohibitedAttributeOIDs.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" NOT ( ");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append(" $ ");
                    buffer.append(iterator.next());
                }

                buffer.append(" )");
            } else {
                buffer.append(" NOT ");
                buffer.append(firstName);
            }
        }
    }

    void validate(final Schema schema, final List<LocalizableMessage> warnings)
            throws SchemaException {
        // Get the objectclass with the specified OID. If it does not exist
        // or is not structural, then fail.
        if (structuralClassOID != null) {
            try {
                structuralClass = schema.getObjectClass(structuralClassOID);
            } catch (final UnknownSchemaElementException e) {
                final LocalizableMessage message =
                        ERR_ATTR_SYNTAX_DCR_UNKNOWN_STRUCTURAL_CLASS1.get(getNameOrOID(),
                                structuralClassOID);
                throw new SchemaException(message, e);
            }
            if (structuralClass.getObjectClassType() != ObjectClassType.STRUCTURAL) {
                final LocalizableMessage message =
                        ERR_ATTR_SYNTAX_DCR_STRUCTURAL_CLASS_NOT_STRUCTURAL1.get(getNameOrOID(),
                                structuralClass.getNameOrOID(), structuralClass
                                        .getObjectClassType().toString());
                warnings.add(message);
            }
        }

        if (!auxiliaryClassOIDs.isEmpty()) {
            auxiliaryClasses = new HashSet<ObjectClass>(auxiliaryClassOIDs.size());
            ObjectClass objectClass;
            for (final String oid : auxiliaryClassOIDs) {
                try {
                    objectClass = schema.getObjectClass(oid);
                } catch (final UnknownSchemaElementException e) {
                    // This isn't good because it is an unknown auxiliary class.
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_UNKNOWN_AUXILIARY_CLASS1.get(getNameOrOID(), oid);
                    throw new SchemaException(message, e);
                }
                if (objectClass.getObjectClassType() != ObjectClassType.AUXILIARY) {
                    // This isn't good because it isn't an auxiliary class.
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_AUXILIARY_CLASS_NOT_AUXILIARY1.get(getNameOrOID(),
                                    structuralClass.getOID(), structuralClass.getObjectClassType()
                                            .toString());
                    throw new SchemaException(message);
                }
                auxiliaryClasses.add(objectClass);
            }
        }

        if (!requiredAttributeOIDs.isEmpty()) {
            requiredAttributes = new HashSet<AttributeType>(requiredAttributeOIDs.size());
            AttributeType attributeType;
            for (final String oid : requiredAttributeOIDs) {
                try {
                    attributeType = schema.getAttributeType(oid);
                } catch (final UnknownSchemaElementException e) {
                    // This isn't good because it means that the DIT content
                    // rule
                    // requires an attribute type that we don't know anything
                    // about.
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_UNKNOWN_REQUIRED_ATTR1.get(getNameOrOID(), oid);
                    throw new SchemaException(message, e);
                }
                requiredAttributes.add(attributeType);
            }
        }

        if (!optionalAttributeOIDs.isEmpty()) {
            optionalAttributes = new HashSet<AttributeType>(optionalAttributeOIDs.size());
            AttributeType attributeType;
            for (final String oid : optionalAttributeOIDs) {
                try {
                    attributeType = schema.getAttributeType(oid);
                } catch (final UnknownSchemaElementException e) {
                    // This isn't good because it means that the DIT content
                    // rule
                    // requires an attribute type that we don't know anything
                    // about.
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_UNKNOWN_OPTIONAL_ATTR1.get(getNameOrOID(), oid);
                    throw new SchemaException(message, e);
                }
                optionalAttributes.add(attributeType);
            }
        }

        if (!prohibitedAttributeOIDs.isEmpty()) {
            prohibitedAttributes = new HashSet<AttributeType>(prohibitedAttributeOIDs.size());
            AttributeType attributeType;
            for (final String oid : prohibitedAttributeOIDs) {
                try {
                    attributeType = schema.getAttributeType(oid);
                } catch (final UnknownSchemaElementException e) {
                    // This isn't good because it means that the DIT content
                    // rule
                    // requires an attribute type that we don't know anything
                    // about.
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_UNKNOWN_PROHIBITED_ATTR1.get(getNameOrOID(), oid);
                    throw new SchemaException(message, e);
                }
                prohibitedAttributes.add(attributeType);
            }
        }

        // Make sure that none of the prohibited attributes is required by
        // the structural or any of the auxiliary classes.
        for (final AttributeType t : prohibitedAttributes) {
            if (structuralClass.isRequired(t)) {
                final LocalizableMessage message =
                        ERR_ATTR_SYNTAX_DCR_PROHIBITED_REQUIRED_BY_STRUCTURAL.get(getNameOrOID(), t
                                .getNameOrOID(), structuralClass.getNameOrOID());
                throw new SchemaException(message);
            }

            for (final ObjectClass oc : auxiliaryClasses) {
                if (oc.isRequired(t)) {
                    final LocalizableMessage message =
                            ERR_ATTR_SYNTAX_DCR_PROHIBITED_REQUIRED_BY_AUXILIARY.get(
                                    getNameOrOID(), t.getNameOrOID(), oc.getNameOrOID());
                    throw new SchemaException(message);
                }
            }
        }

        auxiliaryClasses = Collections.unmodifiableSet(auxiliaryClasses);
        optionalAttributes = Collections.unmodifiableSet(optionalAttributes);
        prohibitedAttributes = Collections.unmodifiableSet(prohibitedAttributes);
        requiredAttributes = Collections.unmodifiableSet(requiredAttributes);
    }
}