/**
 * ============LICENSE_START=======================================================
 * org.onap.aai
 * ================================================================================
 * Copyright © 2017-2018 AT&T Intellectual Property. All rights reserved.
 * ================================================================================
 * Modifications Copyright © 2024 DEUTSCHE TELEKOM AG.
 * ================================================================================
 * 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.
 * ============LICENSE_END=========================================================
 */

package org.onap.aai.query.builder;

import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.ws.rs.core.MultivaluedMap;

import org.apache.tinkerpop.gremlin.process.traversal.Path;
import org.apache.tinkerpop.gremlin.process.traversal.Pop;
import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
import org.apache.tinkerpop.gremlin.process.traversal.step.util.Tree;
import org.apache.tinkerpop.gremlin.structure.Edge;
import org.apache.tinkerpop.gremlin.structure.Vertex;
import org.onap.aai.config.SpringContextAware;
import org.onap.aai.db.props.AAIProperties;
import org.onap.aai.edges.EdgeIngestor;
import org.onap.aai.edges.enums.AAIDirection;
import org.onap.aai.edges.enums.EdgeProperty;
import org.onap.aai.edges.enums.EdgeType;
import org.onap.aai.exceptions.AAIException;
import org.onap.aai.introspection.Introspector;
import org.onap.aai.introspection.Loader;
import org.onap.aai.parsers.query.QueryParser;
import org.onap.aai.parsers.query.QueryParserStrategy;
import org.springframework.context.ApplicationContext;

/**
 * The Class QueryBuilder.
 */
public abstract class QueryBuilder<E> implements Iterator<E> {

    protected final GraphTraversalSource source;
    protected QueryParserStrategy factory = null;
    protected Loader loader = null;
    protected EdgeIngestor edgeRules;
    protected boolean optimize = false;
    protected Vertex start = null;

    protected int parentStepIndex = 0;
    protected int containerStepIndex = 0;
    protected int stepIndex = 0;

    /**
     * Instantiates a new query builder.
     *
     * @param loader the loader
     */
    public QueryBuilder(Loader loader, GraphTraversalSource source) {
        this.loader = loader;
        this.source = source;
        initEdgeIngestor();
    }

    /**
     * Instantiates a new query builder.
     *
     * @param loader the loader
     * @param start the start
     */
    public QueryBuilder(Loader loader, GraphTraversalSource source, Vertex start) {
        this.loader = loader;
        this.start = start;
        this.source = source;
        initEdgeIngestor();
    }

    public void changeLoader(Loader loader) {
        this.loader = loader;
    }

    /**
     * Creates a new {@link QueryBuilder} that contains the traversal up to the provided index.
     * @param index
     * @return
     */
    protected abstract QueryBuilder<E> cloneQueryAtStep(int index);

    /**
     * Gets the vertices by indexed property.
     *
     * @param key the key
     * @param value the value
     * @return the vertices by indexed property
     */
    public QueryBuilder<Vertex> getVerticesByIndexedProperty(String key, Object value) {
        return this.getVerticesByProperty(key, value);
    }

    /**
     * Gets the vertices by property.
     *
     * @param key the key
     * @param value the value
     * @return the vertices by property
     */
    public abstract QueryBuilder<Vertex> getVerticesByProperty(String key, Object value);

    /**
     * Gets the edges by property.
     *
     * @param key the key
     * @param value the value
     * @return the vertices by property
     */
    public QueryBuilder<Edge> getEdgesByProperty(String key, Object value) {
        return this.has(key, value.toString());
    }

    /**
     * filters by all the values for this property
     *
     * @param key
     * @param values
     * @return vertices that match these values
     */
    public QueryBuilder<Vertex> getVerticesByIndexedProperty(String key, List<?> values) {
        return this.getVerticesByProperty(key, values);
    }

    /**
     * filters by all the values for this property
     *
     * @param key
     * @param values
     * @return vertices that match these values
     */
    public abstract QueryBuilder<Vertex> getVerticesByProperty(String key, List<?> values);

    /**
     * filters by all the values for this property
     *
     * @param key
     * @param value in comma delimited string format
     * @return vertices that match these values
     */
    public abstract QueryBuilder<Vertex> getVerticesByCommaSeperatedValue(String key, String value);

    /**
     * Gets the vertices that have this property key.
     *
     * @param key the key
     * @return the vertices by property
     */
    public abstract QueryBuilder<Vertex> getVerticesByProperty(String key);

    /**
     * Gets the vertices that do not have this property key.
     *
     * @param key the key
     * @return the vertices by property
     */
    public abstract QueryBuilder<Vertex> getVerticesExcludeByProperty(String key);

    /**
     * filters by elements that start with the value for this property
     *
     * @param key
     * @param value
     * @return vertices that match these values
     */
    public abstract QueryBuilder<Vertex> getVerticesStartsWithProperty(String key, Object value);

    /**
     * Gets the vertices that are excluded by property.
     *
     * @param key the key
     * @param value the value
     * @return the vertices by property
     */
    public abstract QueryBuilder<Vertex> getVerticesExcludeByProperty(String key, Object value);

    /**
     * filters by all the values for this property and excludes the vertices
     *
     * @param key
     * @param values
     * @return vertices that match these values
     */
    public QueryBuilder<Vertex> getVerticesExcludeByIndexedProperty(String key, List<?> values) {
        return this.getVerticesExcludeByProperty(key, values);
    }

    /**
     * filters by all the values for this property and excludes the vertices
     *
     * @param key
     * @param values
     * @return vertices that match these values
     */
    public abstract QueryBuilder<Vertex> getVerticesExcludeByProperty(String key, List<?> values);

    /**
     * filters by all the values greater than for this property
     *
     * @param key
     * @param value
     * @return vertices that match these values
     */
    public abstract QueryBuilder<Vertex> getVerticesGreaterThanProperty(String key, Object value);

    /**
     * filters by all the values less than for this property
     *
     * @param key
     * @param value
     * @return vertices that match these values
     */

    public abstract QueryBuilder<Vertex> getVerticesLessThanProperty(String key, Object value);

    /**
     * Gets the child vertices from parent.
     *
     * @param parentKey the parent key
     * @param parentValue the parent value
     * @param childType the child type
     * @return the child vertices from parent
     */
    public abstract QueryBuilder<Vertex> getChildVerticesFromParent(String parentKey, String parentValue,
            String childType);

    /**
     * Gets the typed vertices by map.
     *
     * @param type the type
     * @param map the map
     * @return the typed vertices by map
     */
    public abstract QueryBuilder<Vertex> getTypedVerticesByMap(String type, Map<String, String> map);

    /**
     * Creates the DB query.
     *
     * @param obj the obj
     * @return the query builder
     */
    public QueryBuilder<Vertex> createDBQuery(Introspector obj) {
        this.createKeyQuery(obj);
        this.createContainerQuery(obj);
        return (QueryBuilder<Vertex>) this;
    }

    /**
     * Creates the key query.
     *
     * @param obj the obj
     * @return the query builder
     */
    public abstract QueryBuilder<Vertex> createKeyQuery(Introspector obj);

    /**
     * Creates the container query.<br>
     * A container query is a query that will return a collection of objects:
     * <pre>
     * /cloud-infrastructure/complexes/complex/key1
     *           ↑              ↑        ↑
     *       namespace      container  object
     *
     * </pre>
     * @param obj the Introspector into the db schema
     * @return the query builder
     */
    public abstract QueryBuilder<Vertex> createContainerQuery(Introspector obj);

    /**
     * Creates the edge traversal.
     *
     * @param parent the parent
     * @param child the child
     * @return the query builder
     */
    public abstract QueryBuilder<Vertex> createEdgeTraversal(EdgeType type, Introspector parent, Introspector child)
            throws AAIException;

    public abstract QueryBuilder<Vertex> getVerticesByBooleanProperty(String key, Object value);

    public QueryBuilder<Vertex> getVerticesByBooleanProperty(String key, MissingOptionalParameter value) {
        return (QueryBuilder<Vertex>) this;
    }

    /**
     * Creates the private edge traversal.
     *
     * @param parent the parent
     * @param child the child
     * @return the query builder
     */
    public abstract QueryBuilder<Vertex> createPrivateEdgeTraversal(EdgeType type, Introspector parent,
            Introspector child) throws AAIException;

    /**
     * Creates the edge traversal.
     *
     * @param parent the parent
     * @param child the child
     * @return the query builder
     */
    public QueryBuilder<Vertex> createEdgeTraversal(EdgeType type, Vertex parent, Introspector child)
            throws AAIException {
        String nodeType = parent.<String>property(AAIProperties.NODE_TYPE).orElse(null);
        this.createEdgeTraversal(type, nodeType, child.getDbName());
        return (QueryBuilder<Vertex>) this;
    }

    /**
     *
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversal(EdgeType type, String outNodeType, String inNodeType)
            throws AAIException {
        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);

        return createEdgeTraversal(type, out, in);
    }

    /**
     *
     * @param edgeType
     * @param outNodeType
     * @param inNodeType
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversal(String edgeType, String outNodeType, String inNodeType)
            throws AAIException {
        /*
         * When the optional parameter edgetype is sent it is a string that needs to be converted to Enum
         */
        EdgeType type = EdgeType.valueOf(edgeType);
        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);

        return createEdgeTraversal(type, out, in);
    }

    /**
     *
     * @param edgeType
     * @param outNodeType
     * @param inNodeType
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversal(MissingOptionalParameter edgeType, String outNodeType,
            String inNodeType) throws AAIException {
        /*
         * When no optional parameter edgetype is sent get all edges between the 2 nodetypes
         */
        return this.createEdgeTraversal(outNodeType, inNodeType);
    }

    /**
     *
     * @param edgeType
     * @param outNodeType
     * @param inNodeType
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversalWithLabels(MissingOptionalParameter edgeType, String outNodeType,
            String inNodeType, List<String> labels) throws AAIException {
        /*
         * When no optional parameter edgetype is sent get all edges between the 2 nodetypes
         */
        return this.createEdgeTraversalWithLabels(outNodeType, inNodeType, labels);
    }

    public QueryBuilder<Vertex> createEdgeTraversal(String outNodeType, String inNodeType) throws AAIException {

        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);

        QueryBuilder<Vertex> cousinBuilder = null;
        QueryBuilder<Vertex> treeBuilder = null;
        QueryBuilder<Vertex> queryBuilder = null;

        try {
            cousinBuilder = this.newInstance().createEdgeTraversal(EdgeType.COUSIN, out, in);
        } catch (AAIException e) {
        }

        if (cousinBuilder != null) {
            try {
                treeBuilder = this.newInstance().createEdgeTraversal(EdgeType.TREE, out, in);
            } catch (AAIException e) {
            }
            if (treeBuilder != null) {
                queryBuilder = this.union(new QueryBuilder[] {cousinBuilder, treeBuilder});
            } else {
                queryBuilder = this.union(new QueryBuilder[] {cousinBuilder});
            }
        } else {
            treeBuilder = this.newInstance().createEdgeTraversal(EdgeType.TREE, out, in);
            queryBuilder = this.union(new QueryBuilder[] {treeBuilder});
        }

        return queryBuilder;
    }

    public QueryBuilder<Vertex> createEdgeTraversalWithLabels(String outNodeType, String inNodeType,
            List<String> labels) throws AAIException {

        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);

        QueryBuilder<Vertex> cousinBuilder = null;
        QueryBuilder<Vertex> treeBuilder = null;
        QueryBuilder<Vertex> queryBuilder = null;

        try {
            cousinBuilder = this.newInstance().createEdgeTraversalWithLabels(EdgeType.COUSIN, out, in, labels);
        } catch (AAIException e) {
        }

        if (cousinBuilder != null) {
            try {
                treeBuilder = this.newInstance().createEdgeTraversalWithLabels(EdgeType.TREE, out, in, labels);
            } catch (AAIException e) {
            }
            if (treeBuilder != null) {
                queryBuilder = this.union(new QueryBuilder[] {cousinBuilder, treeBuilder});
            } else {
                queryBuilder = this.union(new QueryBuilder[] {cousinBuilder});
            }
        } else {
            treeBuilder = this.newInstance().createEdgeTraversalWithLabels(EdgeType.TREE, out, in, labels);
            queryBuilder = this.union(new QueryBuilder[] {treeBuilder});
        }

        return queryBuilder;
    }

    public QueryBuilder<Vertex> createPrivateEdgeTraversal(EdgeType type, String outNodeType, String inNodeType)
            throws AAIException {
        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);
        return createPrivateEdgeTraversal(type, out, in);
    }

    /**
     *
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @param labels
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversalWithLabels(EdgeType type, String outNodeType, String inNodeType,
            List<String> labels) throws AAIException {
        Introspector out = loader.introspectorFromName(outNodeType);
        Introspector in = loader.introspectorFromName(inNodeType);

        return createEdgeTraversalWithLabels(type, out, in, labels);
    }

    /**
     *
     * @param type
     * @param out
     * @param in
     * @param labels
     * @return
     */
    public abstract QueryBuilder<Vertex> createEdgeTraversalWithLabels(EdgeType type, Introspector out, Introspector in,
            List<String> labels) throws AAIException;

    /**
     * This method and it's overloaded counterpart are conditional statements.
     * This method creates an edge traversal step if an optional property is present
     * This is necessary in cases such as "if the Optional Property 1 is sent,
     * find all Nodes of type A with edges to Nodes of type B with property 1,
     * otherwise, simply find all nodes of type A".
     * 
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @param value
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversalIfParameterIsPresent(EdgeType type, String outNodeType,
            String inNodeType, Object value) throws AAIException {
        return this.createEdgeTraversal(type, outNodeType, inNodeType);
    }

    /**
     * This method and it's overloaded counterpart are conditional statements.
     * This method skips an edge traversal step if there is an optional property missing.
     * This is necessary in cases such as "if the Optional Property 1 is sent,
     * find all Nodes of type A with edges to Nodes of type B with property 1,
     * otherwise, simply find all nodes of type A".
     * 
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @param value
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Vertex> createEdgeTraversalIfParameterIsPresent(EdgeType type, String outNodeType,
            String inNodeType, MissingOptionalParameter value) throws AAIException {
        return (QueryBuilder<Vertex>) this;
    }

    /**
     *
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @return
     * @throws AAIException
     */
    public QueryBuilder<Edge> getEdgesBetween(EdgeType type, String outNodeType, String inNodeType)
            throws AAIException {
        this.getEdgesBetweenWithLabels(type, outNodeType, inNodeType, null);

        return (QueryBuilder<Edge>) this;

    }

    /**
     *
     * @param type
     * @param outNodeType
     * @param inNodeType
     * @param labels
     * @return
     * @throws AAIException
     */
    public abstract QueryBuilder<Edge> getEdgesBetweenWithLabels(EdgeType type, String outNodeType, String inNodeType,
            List<String> labels) throws AAIException;

    /**
     * Creates the query from URI.
     *
     * @param uri the uri
     * @return the query parser
     * @throws UnsupportedEncodingException the unsupported encoding exception
     * @throws AAIException the AAI exception
     */
    public abstract QueryParser createQueryFromURI(URI uri) throws UnsupportedEncodingException, AAIException;

    /**
     * Creates the query from URI.
     *
     * @param uri the uri
     * @param queryParams the query params
     * @return the query parser
     * @throws UnsupportedEncodingException the unsupported encoding exception
     * @throws AAIException the AAI exception
     */
    public abstract QueryParser createQueryFromURI(URI uri, MultivaluedMap<String, String> queryParams)
            throws UnsupportedEncodingException, AAIException;

    /**
     * Creates a queryparser from a given object name.
     *
     * @param objName - name of the object type as it appears in the database
     * @return
     */
    public abstract QueryParser createQueryFromObjectName(String objName);

    /**
     * Creates the query from relationship.
     *
     * @param relationship the relationship
     * @return the query parser
     * @throws UnsupportedEncodingException the unsupported encoding exception
     * @throws AAIException the AAI exception
     */
    public abstract QueryParser createQueryFromRelationship(Introspector relationship)
            throws UnsupportedEncodingException, AAIException;

    /**
     * Gets the parent query.
     *
     * @return the parent query
     */
    public abstract QueryBuilder<E> getParentQuery();

    /**
     * Gets the query.
     *
     * @return the query
     */
    public abstract <E2> E2 getQuery();

    /**
     * Form boundary.
     */
    public abstract void markParentBoundary();

    public abstract QueryBuilder<E> limit(long amount);

    /**
     * New instance.
     *
     * @param start the start
     * @return the query builder
     */
    public abstract QueryBuilder<E> newInstance(Vertex start);

    /**
     * New instance.
     *
     * @return the query builder
     */
    public abstract QueryBuilder<E> newInstance();

    /**
     * Gets the start.
     *
     * @return the start
     */
    public abstract Vertex getStart();

    protected Object correctObjectType(Object obj) {

        if (obj != null && obj.getClass().equals(Long.class)) {
            return Integer.valueOf(obj.toString());
        }

        return obj;
    }

    /**
     * uses all fields in the introspector to create a query
     *
     * @param obj
     * @return
     */
    public abstract QueryBuilder<Vertex> exactMatchQuery(Introspector obj);

    /**
     * lets you join any number of QueryBuilders
     * <b>be careful about starting with a union it will not use indexes</b>
     *
     * @param builder
     * @return
     */
    public abstract QueryBuilder<E> union(QueryBuilder<E>... builder);

    public abstract QueryBuilder<E> where(QueryBuilder<E>... builder);

    public abstract QueryBuilder<E> or(QueryBuilder<E>... builder);

    public abstract QueryBuilder<E> store(String name);

    public abstract QueryBuilder<E> cap(String name);

    public abstract QueryBuilder<E> unfold();

    public abstract QueryBuilder<E> fold();

    public abstract QueryBuilder<E> id();

    public abstract QueryBuilder<E> dedup();

    public abstract QueryBuilder<E> emit();

    public abstract QueryBuilder<E> repeat(QueryBuilder<E> builder);

    public abstract QueryBuilder<Edge> outE();

    public abstract QueryBuilder<Edge> inE();

    public abstract QueryBuilder<Vertex> inV();

    public abstract QueryBuilder<Vertex> outV();

    public abstract QueryBuilder<E> not(QueryBuilder<E> builder);

    public abstract QueryBuilder<E> as(String name);

    public abstract QueryBuilder<E> select(String name);

    public abstract QueryBuilder<E> select(Pop pop, String name);

    public abstract QueryBuilder<E> select(String... names);

    public abstract QueryBuilder<E> until(QueryBuilder<E> builder);

    public abstract QueryBuilder<E> groupCount();

    public abstract QueryBuilder<E> by(String name);

    public abstract QueryBuilder<E> valueMap();

    public abstract QueryBuilder<E> valueMap(String... names);

    public abstract QueryBuilder<E> both();

    public abstract QueryBuilder<Tree> tree();

    /**
     * Used to prevent the traversal from repeating its path through the graph.
     * See http://tinkerpop.apache.org/docs/3.0.1-incubating/#simplepath-step for more info.
     *
     * @return a QueryBuilder with the simplePath step appended to its traversal
     */
    public abstract QueryBuilder<E> simplePath();

    /**
     *
     * @return QueryBuilder with the path step appended to its traversal
     */
    public abstract QueryBuilder<Path> path();

    public abstract void markContainer();

    public abstract QueryBuilder<E> getContainerQuery();

    public abstract List<E> toList();

    /**
     * Used to skip step if there is an optional property missing.
     *
     * @param key
     * @param value
     * @return
     */
    public QueryBuilder<Vertex> getVerticesByProperty(String key, MissingOptionalParameter value) {
        return (QueryBuilder<Vertex>) this;
    }

    /**
     * TODO the edge direction is hardcoded here, make it more generic
     * Returns the parent edge of the vertex
     *
     * @return
     */
    public QueryBuilder<Edge> getParentEdge() {
        this.outE().has(EdgeProperty.CONTAINS.toString(), AAIDirection.IN.toString());
        return (QueryBuilder<Edge>) this;
    }

    /**
     * TODO the edge direction is hardcoded here, make it more generic
     * Returns the parent vertex of the vertex
     *
     * @return
     */
    public QueryBuilder<Vertex> getParentVertex() {
        this.getParentEdge().inV();
        return (QueryBuilder<Vertex>) this;
    }

    protected abstract QueryBuilder<Edge> has(String key, String value);

    protected void initEdgeIngestor() {
        // TODO proper spring wiring, but that requires a lot of refactoring so for now we have this
        ApplicationContext ctx = SpringContextAware.getApplicationContext();
        EdgeIngestor ei = ctx.getBean(EdgeIngestor.class);
        setEdgeIngestor(ei);
    }

    protected void setEdgeIngestor(EdgeIngestor ei) {
        this.edgeRules = ei;
    }

    public QueryBuilder<Vertex> getVerticesByNumberProperty(String key, Object value) {
        return getVerticesByProperty(key, value);
    }

    public QueryBuilder<Vertex> getVerticesByNumberProperty(String key) {
        return getVerticesByProperty(key);
    }

    public QueryBuilder<Vertex> getVerticesByNumberProperty(String key, MissingOptionalParameter value) {
        return getVerticesByProperty(key, value);
    }

    protected abstract void vertexHas(String key, Object value);

    protected abstract void vertexHasNot(String key);

    protected abstract void vertexHas(String key);

    // TODO: This probably is not required but need to test
    // protected abstract void vertexHas(final String key, final P<?> predicate);
}