/**
 * Copyright 2015 DuraSpace, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.fcrepo.kernel.modeshape.utils;

import java.util.Arrays;
import java.util.Optional;
import java.util.function.Predicate;

import org.fcrepo.kernel.api.FedoraJcrTypes;
import org.fcrepo.kernel.api.models.FedoraResource;
import org.fcrepo.kernel.api.services.functions.AnyTypesPredicate;
import org.modeshape.jcr.JcrRepository;
import org.modeshape.jcr.cache.NodeKey;
import org.slf4j.Logger;

import javax.jcr.Node;
import javax.jcr.Property;
import javax.jcr.RepositoryException;
import javax.jcr.Session;
import javax.jcr.nodetype.NodeType;
import javax.jcr.nodetype.PropertyDefinition;

import static java.util.Arrays.stream;
import static javax.jcr.PropertyType.REFERENCE;
import static javax.jcr.PropertyType.WEAKREFERENCE;
import static org.fcrepo.kernel.api.services.functions.JcrPropertyFunctions.isBinaryContentProperty;
import static org.fcrepo.kernel.api.utils.UncheckedPredicate.uncheck;
import static org.slf4j.LoggerFactory.getLogger;

/**
 * Convenience class with static methods for manipulating Fedora types in the
 * JCR.
 *
 * @author ajs6f
 * @since Feb 14, 2013
 */
public abstract class FedoraTypesUtils implements FedoraJcrTypes {

    public static final String REFERENCE_PROPERTY_SUFFIX = "_ref";

    private static final Logger LOGGER = getLogger(FedoraTypesUtils.class);

    /**
     * Predicate for determining whether this {@link Node} is a {@link org.fcrepo.kernel.api.models.Container}.
     */
    public static Predicate<Node> isContainer = new AnyTypesPredicate(FEDORA_CONTAINER);

    /**
     * Predicate for determining whether this {@link Node} is a
     * {@link org.fcrepo.kernel.api.models.NonRdfSourceDescription}.
     */
    public static Predicate<Node> isNonRdfSourceDescription = new AnyTypesPredicate(FEDORA_NON_RDF_SOURCE_DESCRIPTION);


    /**
     * Predicate for determining whether this {@link Node} is a Fedora
     * binary.
     */
    public static Predicate<Node> isFedoraBinary = new AnyTypesPredicate(FEDORA_BINARY);

    /**
     * Predicate for determining whether this {@link FedoraResource} has a frozen node
     */
    public static Predicate<FedoraResource> isFrozenNode = f -> f.hasType(FROZEN_NODE) ||
            f.getPath().contains(JCR_FROZEN_NODE);

    /**
     * Predicate for determining whether this {@link Node} is a Fedora Skolem node.
     */
    public static Predicate<Node> isSkolemNode = new AnyTypesPredicate(FEDORA_SKOLEM);

    /**
     * Check if a property is a reference property.
     */
    public static Predicate<Property> isInternalReferenceProperty = uncheck(p -> (p.getType() == REFERENCE ||
            p.getType() == WEAKREFERENCE) &&
            p.getName().endsWith(REFERENCE_PROPERTY_SUFFIX));

    /**
     * Check whether a property is protected (ie, cannot be modified directly) but
     * is not one we've explicitly chosen to include.
     */
    public static Predicate<Property> isProtectedAndShouldBeHidden = uncheck(p -> {
        if (!p.getDefinition().isProtected()) {
            return false;
        } else if (p.getParent().isNodeType(FROZEN_NODE)) {
            // everything on a frozen node is protected
            // but we wish to display it anyway and there's
            // another mechanism in place to make clear that
            // things cannot be edited.
            return false;
        } else {
            return !EXPOSED_PROTECTED_JCR_TYPES.stream().anyMatch(p.getName()::equals);
        }
    });

    /**
     * Check if a property is intentionally suppressed.
     */
    private static Predicate<Property> isSuppressedProperty = uncheck(p -> p.getName().equals("jcr:mimeType"));

    /**
    * Check whether a property is an internal property that should be suppressed
    * from external output.
    */
    public static Predicate<Property> isInternalProperty = p -> isBinaryContentProperty.test(p) ||
            isProtectedAndShouldBeHidden.test(p) || isSuppressedProperty.test(p);


    /**
     * Check if a node is "internal" and should not be exposed e.g. via the REST
     * API
     */
    public static Predicate<Node> isInternalNode = uncheck(n -> n.isNodeType("mode:system"));

    /**
     * Check if a node is externally managed.
     *
     * Note: modeshape uses a source-workspace-identifier scheme
     * to identify whether a node is externally-managed.
     * Ordinary (non-external) nodes will have simple UUIDs
     * as an identifier. These are never external nodes.
     *
     * External nodes will have a 7-character hex code
     * identifying the "source", followed by another
     * 7-character hex code identifying the "workspace", followed
     * by a "/" and then the rest of the "identifier".
     *
     * Following that scheme, if a node's "source" key does not
     * match the repository's configured store name, then it is an
     * external node.
     */
    public static Predicate<Node> isExternalNode = uncheck(n ->  {
        if (NodeKey.isValidRandomIdentifier(n.getIdentifier())) {
            return false;
        } else if (n.getPrimaryNodeType().getName().equals(ROOT)) {
            return false;
        } else {
            final NodeKey key = new NodeKey(n.getIdentifier());
            final String source = NodeKey.keyForSourceName(
                    ((JcrRepository)n.getSession().getRepository()).getConfiguration().getStoreName());
            return !key.getSourceKey().equals(source);
        }
    });

    /**
     * Get the JCR property type ID for a given property name. If unsure, mark
     * it as UNDEFINED.
     *
     * @param node the JCR node to add the property on
     * @param propertyName the property name
     * @return a PropertyType value
     * @throws RepositoryException if repository exception occurred
     */
    public static Optional<Integer> getPropertyType(final Node node, final String propertyName)
            throws RepositoryException {
        LOGGER.debug("Getting type of property: {} from node: {}", propertyName, node);
        return getDefinitionForPropertyName(node, propertyName).map(PropertyDefinition::getRequiredType);
    }

    /**
     * Determine if a given JCR property name is single- or multi- valued.
     * If unsure, choose the least restrictive option (multivalued = true)
     *
     * @param node the JCR node to check
     * @param propertyName the property name (which may or may not already exist)
     * @return true if the property is multivalued
     * @throws RepositoryException if repository exception occurred
     */
    public static boolean isMultivaluedProperty(final Node node, final String propertyName)
            throws RepositoryException {
        return getDefinitionForPropertyName(node, propertyName).map(PropertyDefinition::isMultiple).orElse(true);
    }

    /**
     * Get the property definition information (containing type and multi-value
     * information)
     *
     * @param node the node to use for inferring the property definition
     * @param propertyName the property name to retrieve a definition for
     * @return a JCR PropertyDefinition, if available
     * @throws javax.jcr.RepositoryException if repository exception occurred
     */
    public static Optional<PropertyDefinition> getDefinitionForPropertyName(final Node node, final String propertyName)
            throws RepositoryException {
        LOGGER.debug("Looking for property name: {}", propertyName);
        final Predicate<PropertyDefinition> sameName = p -> propertyName.equals(p.getName());

        final PropertyDefinition[] propDefs = node.getPrimaryNodeType().getPropertyDefinitions();
        final Optional<PropertyDefinition> primaryCandidate = stream(propDefs).filter(sameName).findFirst();
        return primaryCandidate.isPresent() ? primaryCandidate :
                stream(node.getMixinNodeTypes()).map(NodeType::getPropertyDefinitions).flatMap(Arrays::stream)
                        .filter(sameName).findFirst();
    }

    /**
     * When we add certain URI properties, we also want to leave a reference node
     * @param propertyName the property name
     * @return property name as a reference
     */
    public static String getReferencePropertyName(final String propertyName) {
        return propertyName + REFERENCE_PROPERTY_SUFFIX;
    }

    /**
     * Given an internal reference node property, get the original name
     * @param refPropertyName the reference node property name
     * @return original property name of the reference property
     */
    public static String getReferencePropertyOriginalName(final String refPropertyName) {
        final int i = refPropertyName.lastIndexOf(REFERENCE_PROPERTY_SUFFIX);
        return i < 0 ? refPropertyName : refPropertyName.substring(0, i);
    }

    /**
     * Check if a property definition is a reference property
     * @param node the given node
     * @param propertyName the property name
     * @return whether a property definition is a reference property
     * @throws RepositoryException if repository exception occurred
     */
    public static boolean isReferenceProperty(final Node node, final String propertyName) throws RepositoryException {
        final Optional<PropertyDefinition> propertyDefinition = getDefinitionForPropertyName(node, propertyName);

        return propertyDefinition.isPresent() &&
                (propertyDefinition.get().getRequiredType() == REFERENCE
                        || propertyDefinition.get().getRequiredType() == WEAKREFERENCE);
    }


    /**
     * Get the closest ancestor that current exists
     *
     * @param session the given session
     * @param path the given path
     * @return the closest ancestor that current exists
     * @throws RepositoryException if repository exception occurred
     */
    public static Node getClosestExistingAncestor(final Session session, final String path)
            throws RepositoryException {

        String potentialPath = path.startsWith("/") ? path : "/" + path;
        while (!potentialPath.isEmpty()) {
            if (session.nodeExists(potentialPath)) {
                return session.getNode(potentialPath);
            }
            potentialPath = potentialPath.substring(0, potentialPath.lastIndexOf('/'));
        }
        return session.getRootNode();
    }

}