/*
 * 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.jena.arq.querybuilder;

import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.apache.jena.arq.querybuilder.clauses.DatasetClause;
import org.apache.jena.arq.querybuilder.clauses.SelectClause;
import org.apache.jena.arq.querybuilder.clauses.SolutionModifierClause;
import org.apache.jena.arq.querybuilder.clauses.WhereClause;
import org.apache.jena.arq.querybuilder.handlers.DatasetHandler;
import org.apache.jena.arq.querybuilder.handlers.HandlerBlock;
import org.apache.jena.arq.querybuilder.handlers.SelectHandler;
import org.apache.jena.arq.querybuilder.handlers.SolutionModifierHandler;
import org.apache.jena.graph.FrontsNode;
import org.apache.jena.graph.FrontsTriple;
import org.apache.jena.graph.Node;
import org.apache.jena.graph.Triple;
import org.apache.jena.query.SortCondition;
import org.apache.jena.sparql.core.TriplePath;
import org.apache.jena.sparql.core.Var;
import org.apache.jena.sparql.expr.Expr;

/**
 * Builder for SPARQL Select Queries.
 * <p>
 * The SelectBuilder provides chainable methods to programmatically generate
 * SPARQL Select Queries. The application order of the methods is not relevant
 * for the resulting query. An {@link ExprFactory} is intended for use along
 * with the SelectBuilder to generate needed {@link Expr} parameter values. An
 * {@link ExprFactory} that works with the same prefixes can be obtained with
 * {@link SelectBuilder#getExprFactory()}.
 * <p>
 * The SelectBuilder can be used as <b>prepared query</b>. Values for variables
 * in the created query can be set with
 * {@link SelectBuilder#setVar(Object, Object)} and
 * {@link SelectBuilder#setVar(Var, Node)}. The method
 * {@link SelectBuilder#clearWhereValues()} allows to clear the set values.
 *
 * @see AskBuilder
 * @see ConstructBuilder
 * @see DescribeBuilder
 * @see UpdateBuilder
 */
public class SelectBuilder extends AbstractQueryBuilder<SelectBuilder> implements DatasetClause<SelectBuilder>,
        WhereClause<SelectBuilder>, SolutionModifierClause<SelectBuilder>, SelectClause<SelectBuilder> {

    private final HandlerBlock handlerBlock;

    public SelectBuilder() {
        super();
        query.setQuerySelectType();
        handlerBlock = new HandlerBlock(query);
    }

    @Override
    public DatasetHandler getDatasetHandler() {
        return handlerBlock.getDatasetHandler();
    }

    @Override
    public HandlerBlock getHandlerBlock() {
        return handlerBlock;
    }

    @Override
    public SelectBuilder clone() {
        SelectBuilder qb = new SelectBuilder();
        qb.handlerBlock.addAll(handlerBlock);
        return qb;
    }

    /**
     * Sets the distinct flag.
     *
     * Setting the select distinct will unset reduced if it was set.
     *
     * @param state if true results will be distinct.
     * @return This builder for chaining.
     */
    public SelectBuilder setDistinct(boolean state) {
        getSelectHandler().setDistinct(state);
        return this;
    }

    /**
     * Sets the reduced flag.
     *
     * Setting the select reduced will unset distinct if it was set.
     *
     * @param state if true results will be reduced.
     * @return This builder for chaining.
     */
    public SelectBuilder setReduced(boolean state) {
        getSelectHandler().setReduced(state);
        return this;
    }

    @Override
    public SelectBuilder addVar(Object var) {
        getSelectHandler().addVar(Converters.makeVar(var));
        return this;
    }

    @Override
    public SelectBuilder addVar(String expression, Object var) {
        getSelectHandler().addVar(expression, Converters.makeVar(var));
        return this;
    }

    @Override
    public SelectBuilder addVar(Expr expr, Object var) {
        getSelectHandler().addVar(expr, Converters.makeVar(var));
        return this;
    }

    @Override
    public List<Var> getVars() {
        return getSelectHandler().getVars();
    }

    @Override
    public SelectBuilder fromNamed(String graphName) {
        getDatasetHandler().fromNamed(graphName);
        return this;
    }

    @Override
    public SelectBuilder fromNamed(Collection<String> graphNames) {
        getDatasetHandler().fromNamed(graphNames);
        return this;
    }

    @Override
    public SelectBuilder from(String graphName) {
        getDatasetHandler().from(graphName);
        return this;
    }

    @Override
    public SelectBuilder from(Collection<String> graphName) {
        getDatasetHandler().from(graphName);
        return this;
    }

    @Override
    public SelectBuilder addOrderBy(Expr orderBy) {
        getSolutionModifierHandler().addOrderBy(orderBy);
        return this;
    }

    @Override
    public SelectBuilder addOrderBy(Object orderBy) {
        getSolutionModifierHandler().addOrderBy(Converters.makeVar(orderBy));
        return this;
    }

    @Override
    public SelectBuilder addOrderBy(SortCondition orderBy) {
        getSolutionModifierHandler().addOrderBy(orderBy);
        return this;
    }

    @Override
    public SelectBuilder addOrderBy(Expr orderBy, Order order) {
        getSolutionModifierHandler().addOrderBy(orderBy, order);
        return this;
    }

    @Override
    public SelectBuilder addOrderBy(Object orderBy, Order order) {
        getSolutionModifierHandler().addOrderBy(Converters.makeVar(orderBy), order);
        return this;
    }

    @Override
    public SelectBuilder addGroupBy(Object groupBy) {
        getSolutionModifierHandler().addGroupBy(Converters.makeVar(groupBy));
        return this;
    }

    @Override
    public SelectBuilder addGroupBy(Expr groupBy) {
        getSolutionModifierHandler().addGroupBy(groupBy);
        return this;
    }

    @Override
    public SelectBuilder addGroupBy(Object var, Expr expr) {
        getSolutionModifierHandler().addGroupBy(Converters.makeVar(var), expr);
        return this;
    }

    @Override
    public SelectBuilder addGroupBy(Object var, String expr) {
        getSolutionModifierHandler().addGroupBy(Converters.makeVar(var), makeExpr(expr));
        return this;
    }

    @Override
    public SolutionModifierHandler getSolutionModifierHandler() {
        return handlerBlock.getModifierHandler();
    }

    @Override
    public SelectBuilder addHaving(String having) {
        getSolutionModifierHandler().addHaving(having);
        return this;
    }

    @Override
    public SelectBuilder addHaving(Expr expression) {
        getSolutionModifierHandler().addHaving(expression);
        return this;
    }

    @Override
    public SelectBuilder addHaving(Object var) {
        getSolutionModifierHandler().addHaving(Converters.makeVar(var));
        return this;
    }

    @Override
    public SelectBuilder setLimit(int limit) {
        getSolutionModifierHandler().setLimit(limit);
        return this;
    }

    @Override
    public SelectBuilder setOffset(int offset) {
        getSolutionModifierHandler().setOffset(offset);
        return this;
    }

    /**
     * Converts a node to a string. If the node is a literal return the literal
     * value. If the node is a URI return the URI enclosed with &lt; and &gt; If the
     * node is a variable return the name preceded by '?'
     *
     * @param node The node to convert.
     * @return A string representation of the node.
     */
    private static String toString(Node node) {
        if (node.isBlank()) {
            return node.getBlankNodeLabel();
        }
        if (node.isLiteral()) {
            return node.toString();
        }
        if (node.isURI()) {
            return String.format("<%s>", node.getURI());
        }
        if (node.isVariable()) {
            return String.format("?%s", node.getName());
        }
        return node.toString();
    }

    /**
     * Converts the object to a string. If the object is a node or fronts a node
     * then
     * <ul>
     * <li>If the node is a literal return the literal value.</li>
     * <li>If the node is a URI return the URI enclosed with &lt; and &gt;</li>
     * <li>If the node is a variable return the name preceded by '?'</li>
     * </ul>
     * otherwise return the toString() method of the object.
     *
     * @param o the Object to convert.
     * @return The string representation of the object.
     */
    public static String makeString(Object o) {
        if (o instanceof FrontsNode) {
            return toString(((FrontsNode) o).asNode());
        }
        if (o instanceof Node) {
            return toString((Node) o);
        }
        return o.toString();
    }

    @Override
    public SelectBuilder addWhere(TriplePath t) {
        getWhereHandler().addWhere(t);
        return this;
    }

    @Override
    public SelectBuilder addWhere(Triple t) {
        getWhereHandler().addWhere(new TriplePath(t));
        return this;
    }

    @Override
    public SelectBuilder addWhere(FrontsTriple t) {
        getWhereHandler().addWhere(new TriplePath(t.asTriple()));
        return this;
    }

    @Override
    public SelectBuilder addWhere(Object s, Object p, Object o) {
        getWhereHandler().addWhere(makeTriplePath(s, p, o));
        return this;
    }

    @Override
    public SelectBuilder addWhereValueVar(Object var) {
        getWhereHandler().addValueVar(getPrologHandler().getPrefixes(), var);
        return this;
    }

    @Override
    public SelectBuilder addWhereValueVar(Object var, Object... values) {
        getWhereHandler().addValueVar(getPrologHandler().getPrefixes(), var, values);
        return this;
    }

    @Override
    public <K extends Collection<?>> SelectBuilder addWhereValueVars(Map<?, K> dataTable) {
        getWhereHandler().addValueVars(getPrologHandler().getPrefixes(), dataTable);
        return this;
    }

    @Override
    public SelectBuilder addWhereValueRow(Object... values) {
        getWhereHandler().addValueRow(getPrologHandler().getPrefixes(), values);
        return this;
    }

    @Override
    public SelectBuilder addWhereValueRow(Collection<?> values) {
        getWhereHandler().addValueRow(getPrologHandler().getPrefixes(), values);
        return this;
    }

    @Override
    public List<Var> getWhereValuesVars() {
        return getWhereHandler().getValuesVars();
    }

    @Override
    public Map<Var, List<Node>> getWhereValuesMap() {
        return getWhereHandler().getValuesMap();
    }

    @Override
    public SelectBuilder clearWhereValues() {
        getWhereHandler().clearValues();
        return this;
    }

    @Override
    public SelectBuilder addOptional(TriplePath t) {
        getWhereHandler().addOptional(t);
        return this;
    }

    @Override
    public SelectBuilder addOptional(Triple t) {
        getWhereHandler().addOptional(new TriplePath(t));
        return this;
    }

    @Override
    public SelectBuilder addOptional(FrontsTriple t) {
        getWhereHandler().addOptional(new TriplePath(t.asTriple()));
        return this;
    }

    @Override
    public SelectBuilder addOptional(Object s, Object p, Object o) {
        getWhereHandler().addOptional(makeTriplePath(s, p, o));
        return this;
    }

    @Override
    public SelectBuilder addOptional(AbstractQueryBuilder<?> t) {
        getWhereHandler().addOptional(t.getWhereHandler());
        return this;
    }

    @Override
    public SelectBuilder addFilter(Expr expr) {
        getWhereHandler().addFilter(expr);
        return this;
    }

    @Override
    public SelectBuilder addFilter(String s) {
        getWhereHandler().addFilter(s);
        return this;
    }

    @Override
    public SelectBuilder addSubQuery(AbstractQueryBuilder<?> subQuery) {
        getWhereHandler().addSubQuery(subQuery);
        return this;
    }

    @Override
    public SelectBuilder addUnion(AbstractQueryBuilder<?> subQuery) {
        getWhereHandler().addUnion(subQuery);
        return this;
    }

    @Override
    public SelectBuilder addGraph(Object graph, AbstractQueryBuilder<?> subQuery) {
        getPrologHandler().addAll(subQuery.getPrologHandler());
        getWhereHandler().addGraph(makeNode(graph), subQuery.getWhereHandler());
        return this;
    }

    @Override
    public SelectBuilder addGraph(Object graph, FrontsTriple triple) {
        getWhereHandler().addGraph(makeNode(graph), new TriplePath(triple.asTriple()));
        return this;
    }

    @Override
    public SelectBuilder addGraph(Object graph, Object subject, Object predicate, Object object) {
        getWhereHandler().addGraph(makeNode(graph), makeTriplePath(subject, predicate, object));
        return this;
    }

    @Override
    public SelectBuilder addGraph(Object graph, Triple triple) {
        getWhereHandler().addGraph(makeNode(graph), new TriplePath(triple));
        return this;
    }

    @Override
    public SelectBuilder addGraph(Object graph, TriplePath triplePath) {
        getWhereHandler().addGraph(makeNode(graph), triplePath);
        return this;
    }

    @Override
    public SelectBuilder addBind(Expr expression, Object var) {
        getWhereHandler().addBind(expression, Converters.makeVar(var));
        return this;
    }

    @Override
    public SelectBuilder addBind(String expression, Object var) {
        getWhereHandler().addBind(expression, Converters.makeVar(var));
        return this;
    }

    @Override
    public SelectHandler getSelectHandler() {
        return handlerBlock.getSelectHandler();
    }

    @Override
    public Node list(Object... objs) {
        return getWhereHandler().list(objs);
    }

    @Override
    public SelectBuilder addMinus(AbstractQueryBuilder<?> t) {
        getWhereHandler().addMinus(t);
        return this;
    }

}
