/*
 * 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
 *
 *   https://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.
 *
 *   SPDX-License-Identifier: Apache-2.0
 */

package org.apache.jena.sparql.expr;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.fail;

import org.junit.jupiter.api.Test;

import org.apache.jena.sparql.algebra.Algebra;
import org.apache.jena.sparql.algebra.Op;
import org.apache.jena.sparql.algebra.walker.Walker;
import org.apache.jena.sparql.core.Var;
import org.apache.jena.sparql.graph.NodeTransform;
import org.apache.jena.sparql.graph.NodeTransformLib;
import org.apache.jena.sparql.syntax.Element;
import org.apache.jena.sparql.util.ExprUtils;

public class TestExprFunctionOp_NodeTransform {
    private NodeTransform nt = node -> node instanceof Var v
        ? Var.alloc(v.getVarName().toUpperCase())
        : node;

    @Test public void nt_exists_tp_01()        { test(    "exists { ?s ?p ?o }",    "exists { ?S ?P ?O }", nt); }
    @Test public void nt_notExists_tp_01()     { test("not exists { ?s ?p ?o }", "notexists { ?S ?P ?O }", nt); }

    @Test public void nt_exists_filter_01()    { test(    "exists { FILTER(?x = ?y) }",     "exists { FILTER(?X = ?Y) }", nt); }
    @Test public void nt_notExists_filter_01() { test("not exists { FILTER(?x = ?y) }", "not exists { FILTER(?X = ?Y) }", nt); }

    @Test public void nt_exists_bind_01()      { test(    "exists { BIND(?x AS ?y) }",     "exists { BIND(?X AS ?Y) }", nt ); }
    @Test public void nt_notExists_bind_01()   { test("not exists { BIND(?x AS ?y) }", "not exists { BIND(?X AS ?Y) }", nt ); }

    @Test public void nt_exists_nested_filter_01()     { test(    "exists { {} FILTER     exists { {} FILTER(?x = ?y) } }",     "exists { {} FILTER     exists { {} FILTER(?X = ?Y) } }", nt); }
    @Test public void nt_notExists_nested_filter_01()  { test("not exists { {} FILTER not exists { {} FILTER(?x = ?y) } }", "not exists { {} FILTER not exists { {} FILTER(?X = ?Y) } }", nt); }

    private void test(String string, String string2, NodeTransform nt)
    {
        Expr e1 = ExprUtils.parse(string);
        Expr e2 = ExprUtils.parse(string2);

        Expr e3 = NodeTransformLib.transform(nt, e1);

        // Check whether syntax and algebra are consistent
        ExprVisitor opVisitor = new ExprFunctionOpValidator();
        Walker.walk(e2, opVisitor);
        Walker.walk(e3, opVisitor);

        assertEquals(e2, e3);
        if (!e2.equalsBySyntax(e3)) {
            fail("Objects differ by syntax: " + e2 + " != " + e3);
        }
    }

    /** This class asserts that Op and Element of an ExprFunctionOp are consistent. */
    static class ExprFunctionOpValidator
        extends ExprVisitorBase
    {
        @Override
        public void visit(ExprFunctionOp op) {
            Element elt = op.getElement();
            Op actual = op.getGraphPattern();
            Op expected = Algebra.compile(elt);
            assertEquals(expected, actual);
        }
    }
}
