/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.atlas.repository.store.graph.v1;


import org.apache.atlas.ApplicationProperties;
import org.apache.atlas.AtlasErrorCode;
import org.apache.atlas.discovery.SearchProcessor;
import org.apache.atlas.exception.AtlasBaseException;
import org.apache.atlas.model.TypeCategory;
import org.apache.atlas.model.instance.AtlasEntity;
import org.apache.atlas.model.typedef.AtlasBaseTypeDef;
import org.apache.atlas.repository.Constants;
import org.apache.atlas.repository.graph.AtlasGraphProvider;
import org.apache.atlas.repository.graph.GraphHelper;
import org.apache.atlas.repository.graphdb.AtlasEdge;
import org.apache.atlas.repository.graphdb.AtlasElement;
import org.apache.atlas.repository.graphdb.AtlasGraphQuery;
import org.apache.atlas.repository.graphdb.AtlasIndexQuery;
import org.apache.atlas.repository.graphdb.AtlasVertex;
import org.apache.atlas.type.AtlasEntityType;
import org.apache.atlas.type.AtlasStructType;
import org.apache.atlas.type.AtlasStructType.AtlasAttribute;
import org.apache.atlas.type.AtlasType;
import org.apache.commons.collections.MapUtils;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * Utility methods for Graph.
 */
public class AtlasGraphUtilsV1 {
    private static final Logger LOG = LoggerFactory.getLogger(AtlasGraphUtilsV1.class);

    public static final String PROPERTY_PREFIX      = Constants.INTERNAL_PROPERTY_KEY_PREFIX + "type.";
    public static final String SUPERTYPE_EDGE_LABEL = PROPERTY_PREFIX + ".supertype";
    public static final String VERTEX_TYPE          = "typeSystem";
    public static final String RELATIONSHIPTYPE_EDGE_LABEL = PROPERTY_PREFIX + ".relationshipType";

    private static boolean USE_INDEX_QUERY_TO_FIND_ENTITY_BY_UNIQUE_ATTRIBUTES = false;

    static {
        try {
            Configuration conf = ApplicationProperties.get();

            USE_INDEX_QUERY_TO_FIND_ENTITY_BY_UNIQUE_ATTRIBUTES = conf.getBoolean("atlas.use.index.query.to.find.entity.by.unique.attributes", USE_INDEX_QUERY_TO_FIND_ENTITY_BY_UNIQUE_ATTRIBUTES);
        } catch (Exception excp) {
            LOG.error("Error reading configuration", excp);
        } finally {
            LOG.info("atlas.use.index.query.to.find.entity.by.unique.attributes=" + USE_INDEX_QUERY_TO_FIND_ENTITY_BY_UNIQUE_ATTRIBUTES);
        }
    }

    public static String getTypeDefPropertyKey(AtlasBaseTypeDef typeDef) {
        return getTypeDefPropertyKey(typeDef.getName());
    }

    public static String getTypeDefPropertyKey(AtlasBaseTypeDef typeDef, String child) {
        return getTypeDefPropertyKey(typeDef.getName(), child);
    }

    public static String getTypeDefPropertyKey(String typeName) {
        return PROPERTY_PREFIX + typeName;
    }

    public static String getTypeDefPropertyKey(String typeName, String child) {
        return PROPERTY_PREFIX + typeName + "." + child;
    }

    public static String getIdFromVertex(AtlasVertex vertex) {
        return vertex.getProperty(Constants.GUID_PROPERTY_KEY, String.class);
    }

    public static String getTypeName(AtlasElement element) {
        return element.getProperty(Constants.ENTITY_TYPE_PROPERTY_KEY, String.class);
    }

    public static String getEdgeLabel(String fromNode, String toNode) {
        return PROPERTY_PREFIX + "edge." + fromNode + "." + toNode;
    }

    public static String getEdgeLabel(String property) {
        return GraphHelper.EDGE_LABEL_PREFIX + property;
    }

    public static String getAttributeEdgeLabel(AtlasStructType fromType, String attributeName) throws AtlasBaseException {
        return getEdgeLabel(getQualifiedAttributePropertyKey(fromType, attributeName));
    }

    public static String getQualifiedAttributePropertyKey(AtlasStructType fromType, String attributeName) throws AtlasBaseException {
        switch (fromType.getTypeCategory()) {
         case ENTITY:
         case STRUCT:
         case CLASSIFICATION:
             return fromType.getQualifiedAttributeName(attributeName);
        default:
            throw new AtlasBaseException(AtlasErrorCode.UNKNOWN_TYPE, fromType.getTypeCategory().name());
        }
    }

    public static boolean isEntityVertex(AtlasVertex vertex) {
        return StringUtils.isNotEmpty(getIdFromVertex(vertex)) && StringUtils.isNotEmpty(getTypeName(vertex));
    }

    public static boolean isReference(AtlasType type) {
        return isReference(type.getTypeCategory());
    }

    public static boolean isReference(TypeCategory typeCategory) {
        return typeCategory == TypeCategory.STRUCT ||
            typeCategory == TypeCategory.ENTITY ||
            typeCategory == TypeCategory.CLASSIFICATION ||
            typeCategory == TypeCategory.OBJECT_ID_TYPE;
    }

    public static String encodePropertyKey(String key) {
        String ret = AtlasStructType.AtlasAttribute.encodePropertyKey(key);

        return ret;
    }

    public static String decodePropertyKey(String key) {
        String ret = AtlasStructType.AtlasAttribute.decodePropertyKey(key);

        return ret;
    }

    /**
     * Adds an additional value to a multi-property.
     *
     * @param propertyName
     * @param value
     */
    public static AtlasVertex addProperty(AtlasVertex vertex, String propertyName, Object value) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("==> addProperty({}, {}, {})", toString(vertex), propertyName, value);
        }
        propertyName = encodePropertyKey(propertyName);
        vertex.addProperty(propertyName, value);
        return vertex;
    }

    public static <T extends AtlasElement> void setProperty(T element, String propertyName, Object value) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("==> setProperty({}, {}, {})", toString(element), propertyName, value);
        }

        propertyName = encodePropertyKey(propertyName);

        Object existingValue = element.getProperty(propertyName, Object.class);

        if (value == null || (value instanceof Collection && ((Collection)value).isEmpty())) {
            if (existingValue != null) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug("Removing property {} from {}", propertyName, toString(element));
                }

                element.removeProperty(propertyName);
            }
        } else {
            if (!value.equals(existingValue)) {
                if (LOG.isDebugEnabled()) {
                    LOG.debug("Setting property {} in {}", propertyName, toString(element));
                }

                if ( value instanceof Date) {
                    Long encodedValue = ((Date) value).getTime();
                    element.setProperty(propertyName, encodedValue);
                } else {
                    element.setProperty(propertyName, value);
                }
            }
        }
    }

    public static <T extends AtlasElement, O> O getProperty(T element, String propertyName, Class<O> returnType) {
        Object property = element.getProperty(encodePropertyKey(propertyName), returnType);

        if (LOG.isDebugEnabled()) {
            LOG.debug("getProperty({}, {}) ==> {}", toString(element), propertyName, returnType.cast(property));
        }

        return returnType.cast(property);
    }

    public static AtlasVertex getVertexByUniqueAttributes(AtlasEntityType entityType, Map<String, Object> attrValues) throws AtlasBaseException {
        AtlasVertex vertex = findByUniqueAttributes(entityType, attrValues);

        if (vertex == null) {
            throw new AtlasBaseException(AtlasErrorCode.INSTANCE_BY_UNIQUE_ATTRIBUTE_NOT_FOUND, entityType.getTypeName(),
                                         attrValues.toString());
        }

        return vertex;
    }

    public static String getGuidByUniqueAttributes(AtlasEntityType entityType, Map<String, Object> attrValues) throws AtlasBaseException {
        AtlasVertex vertexByUniqueAttributes = getVertexByUniqueAttributes(entityType, attrValues);
        return getIdFromVertex(vertexByUniqueAttributes);
    }

    public static AtlasVertex findByUniqueAttributes(AtlasEntityType entityType, Map<String, Object> attrValues) {
        AtlasVertex vertex = null;

        final Map<String, AtlasAttribute> uniqueAttributes = entityType.getUniqAttributes();

        if (MapUtils.isNotEmpty(uniqueAttributes) && MapUtils.isNotEmpty(attrValues)) {
            for (AtlasAttribute attribute : uniqueAttributes.values()) {
                Object attrValue = attrValues.get(attribute.getName());

                if (attrValue == null) {
                    continue;
                }

                if (canUseIndexQuery(entityType, attribute.getName())) {
                    vertex = AtlasGraphUtilsV1.getAtlasVertexFromIndexQuery(entityType, attribute, attrValue);
                } else {
                    vertex = AtlasGraphUtilsV1.findByTypeAndPropertyName(entityType.getTypeName(), attribute.getVertexPropertyName(), attrValue);

                    if (vertex == null) {
                        vertex = AtlasGraphUtilsV1.findBySuperTypeAndPropertyName(entityType.getTypeName(), attribute.getVertexPropertyName(), attrValue);
                    }
                }

                if (vertex != null) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("findByUniqueAttributes(type={}, attrName={}, attrValue={}: found vertex {}",
                                  entityType.getTypeName(), attribute.getName(), attrValue, vertex);
                    }

                    break;
                }
            }
        }

        return vertex;
    }

    public static AtlasVertex findByGuid(String guid) {
        AtlasGraphQuery query = AtlasGraphProvider.getGraphInstance().query()
                                                  .has(Constants.GUID_PROPERTY_KEY, guid);

        Iterator<AtlasVertex> results = query.vertices().iterator();

        AtlasVertex vertex = results.hasNext() ? results.next() : null;

        return vertex;
    }

    public static String getTypeNameFromGuid(String guid) {
        String ret = null;

        if (StringUtils.isNotEmpty(guid)) {
            AtlasVertex vertex = AtlasGraphUtilsV1.findByGuid(guid);

            ret = (vertex != null) ? AtlasGraphUtilsV1.getTypeName(vertex) : null;
        }

        return ret;
    }

    public static boolean typeHasInstanceVertex(String typeName) throws AtlasBaseException {
        AtlasGraphQuery query = AtlasGraphProvider.getGraphInstance()
                .query()
                .has(Constants.TYPE_NAME_PROPERTY_KEY, AtlasGraphQuery.ComparisionOperator.EQUAL, typeName);

        Iterator<AtlasVertex> results = query.vertices().iterator();

        boolean hasInstanceVertex = results != null && results.hasNext();

        if (LOG.isDebugEnabled()) {
            LOG.debug("typeName {} has instance vertex {}", typeName, hasInstanceVertex);
        }

        return hasInstanceVertex;
    }

    public static AtlasVertex findByTypeAndPropertyName(String typeName, String propertyName, Object attrVal) {
        AtlasGraphQuery query = AtlasGraphProvider.getGraphInstance().query()
                                                    .has(Constants.ENTITY_TYPE_PROPERTY_KEY, typeName)
                                                    .has(Constants.STATE_PROPERTY_KEY, AtlasEntity.Status.ACTIVE.name())
                                                    .has(propertyName, attrVal);

        Iterator<AtlasVertex> results = query.vertices().iterator();

        AtlasVertex vertex = results.hasNext() ? results.next() : null;

        return vertex;
    }

    public static AtlasVertex findBySuperTypeAndPropertyName(String typeName, String propertyName, Object attrVal) {
        AtlasGraphQuery query = AtlasGraphProvider.getGraphInstance().query()
                                                    .has(Constants.SUPER_TYPES_PROPERTY_KEY, typeName)
                                                    .has(Constants.STATE_PROPERTY_KEY, AtlasEntity.Status.ACTIVE.name())
                                                    .has(propertyName, attrVal);

        Iterator<AtlasVertex> results = query.vertices().iterator();

        AtlasVertex vertex = results.hasNext() ? results.next() : null;

        return vertex;
    }

    public static boolean relationshipTypeHasInstanceEdges(String typeName) throws AtlasBaseException {
        AtlasGraphQuery query = AtlasGraphProvider.getGraphInstance()
                .query()
                .has(Constants.TYPE_NAME_PROPERTY_KEY, AtlasGraphQuery.ComparisionOperator.EQUAL, typeName);

        Iterator<AtlasEdge> results = query.edges().iterator();

        boolean hasInstanceEdges = results != null && results.hasNext();

        if (LOG.isDebugEnabled()) {
            LOG.debug("relationshipType {} has instance edges {}", typeName, hasInstanceEdges);
        }

        return hasInstanceEdges;
    }

    private static String toString(AtlasElement element) {
        if (element instanceof AtlasVertex) {
            return toString((AtlasVertex) element);
        } else if (element instanceof AtlasEdge) {
            return toString((AtlasEdge)element);
        }

        return element.toString();
    }

    public static String toString(AtlasVertex vertex) {
        if(vertex == null) {
            return "vertex[null]";
        } else {
            if (LOG.isDebugEnabled()) {
                return getVertexDetails(vertex);
            } else {
                return String.format("vertex[id=%s]", vertex.getId().toString());
            }
        }
    }


    public static String toString(AtlasEdge edge) {
        if(edge == null) {
            return "edge[null]";
        } else {
            if (LOG.isDebugEnabled()) {
                return getEdgeDetails(edge);
            } else {
                return String.format("edge[id=%s]", edge.getId().toString());
            }
        }
    }

    public static String getVertexDetails(AtlasVertex vertex) {
        return String.format("vertex[id=%s type=%s guid=%s]",
                vertex.getId().toString(), getTypeName(vertex), getIdFromVertex(vertex));
    }

    public static String getEdgeDetails(AtlasEdge edge) {
        return String.format("edge[id=%s label=%s from %s -> to %s]", edge.getId(), edge.getLabel(),
                toString(edge.getOutVertex()), toString(edge.getInVertex()));
    }

    public static AtlasEntity.Status getState(AtlasElement element) {
        String state = getStateAsString(element);
        return state == null ? null : AtlasEntity.Status.valueOf(state);
    }

    public static String getStateAsString(AtlasElement element) {
        return element.getProperty(Constants.STATE_PROPERTY_KEY, String.class);
    }

    private static boolean canUseIndexQuery(AtlasEntityType entityType, String attributeName) {
        boolean ret = false;

        if (USE_INDEX_QUERY_TO_FIND_ENTITY_BY_UNIQUE_ATTRIBUTES) {
            final String typeAndSubTypesQryStr = entityType.getTypeAndAllSubTypesQryStr();

            ret = typeAndSubTypesQryStr.length() <= SearchProcessor.MAX_QUERY_STR_LENGTH_TYPES;

            if (ret) {
                Set<String> indexSet = AtlasGraphProvider.getGraphInstance().getVertexIndexKeys();
                try {
                    ret = indexSet.contains(entityType.getQualifiedAttributeName(attributeName));
                }
                catch (AtlasBaseException ex) {
                    ret = false;
                }
            }
        }

        return ret;
    }

    private static AtlasVertex getAtlasVertexFromIndexQuery(AtlasEntityType entityType, AtlasAttribute attribute, Object attrVal) {
        String          propertyName = attribute.getVertexPropertyName();
        AtlasIndexQuery query        = getIndexQuery(entityType, propertyName, attrVal.toString());

        for (Iterator<AtlasIndexQuery.Result> iter = query.vertices(); iter.hasNext(); ) {
            AtlasIndexQuery.Result result = iter.next();
            AtlasVertex            vertex = result.getVertex();

            // skip non-entity vertices, if any got returned
            if (vertex == null || !vertex.getPropertyKeys().contains(Constants.GUID_PROPERTY_KEY)) {
                continue;
            }

            // verify the typeName
            String typeNameInVertex = getTypeName(vertex);

            if (!entityType.getTypeAndAllSubTypes().contains(typeNameInVertex)) {
                LOG.warn("incorrect vertex type from index-query: expected='{}'; found='{}'", entityType.getTypeName(), typeNameInVertex);

                continue;
            }

            if (attrVal.getClass() == String.class) {
                String s         = (String) attrVal;
                String vertexVal = vertex.getProperty(propertyName, String.class);

                if (!s.equalsIgnoreCase(vertexVal)) {
                    LOG.warn("incorrect match from index-query for property {}: expected='{}'; found='{}'", propertyName, s, vertexVal);

                    continue;
                }
            }

            return vertex;
        }

        return null;
    }

    private static AtlasIndexQuery getIndexQuery(AtlasEntityType entityType, String propertyName, String value) {
        StringBuilder sb = new StringBuilder();

        sb.append("v.\"").append(Constants.TYPE_NAME_PROPERTY_KEY).append("\":").append(entityType.getTypeAndAllSubTypesQryStr())
                .append(" AND ")
                .append("v.\"").append(propertyName).append("\":").append(AtlasAttribute.escapeIndexQueryValue(value))
                .append(" AND ")
                .append("v.\"").append(Constants.STATE_PROPERTY_KEY).append("\":ACTIVE");

        return AtlasGraphProvider.getGraphInstance().indexQuery(Constants.VERTEX_INDEX, sb.toString());
    }
}
