content: /*
   * 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.asterix.lang.sqlpp.rewrites.visitor;
  
  import java.util.function.BiFunction;
  
  import org.apache.asterix.common.exceptions.CompilationException;
  import org.apache.asterix.common.functions.FunctionSignature;
  import org.apache.asterix.lang.common.base.Expression;
  import org.apache.asterix.lang.common.base.ILangExpression;
  import org.apache.asterix.lang.common.expression.CallExpr;
  import org.apache.asterix.lang.common.rewrites.LangRewritingContext;
  import org.apache.asterix.lang.common.util.FunctionUtil;
  import org.apache.asterix.lang.sqlpp.expression.WindowExpression;
  import org.apache.asterix.lang.sqlpp.util.FunctionMapUtil;
  import org.apache.asterix.lang.sqlpp.visitor.base.AbstractSqlppSimpleExpressionVisitor;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  
  public class SqlppFunctionCallResolverVisitor extends AbstractSqlppSimpleExpressionVisitor {
  
      private final LangRewritingContext context;
  
      private final boolean allowNonStoredUdfCalls;
  
      private final BiFunction<String, Integer, FunctionSignature> builtinFunctionResolver;
  
      private final BiFunction<String, Integer, FunctionSignature> callExprResolver;
  
      public SqlppFunctionCallResolverVisitor(LangRewritingContext context, boolean allowNonStoredUdfCalls) {
          this.context = context;
          this.allowNonStoredUdfCalls = allowNonStoredUdfCalls;
          this.builtinFunctionResolver = FunctionUtil.createBuiltinFunctionResolver(context.getMetadataProvider());
          this.callExprResolver = this::resolveCallExpr;
      }
  
      @Override
      public Expression visit(CallExpr callExpr, ILangExpression arg) throws CompilationException {
          FunctionSignature fs = FunctionUtil.resolveFunctionCall(callExpr.getFunctionSignature(),
                  callExpr.getSourceLocation(), context.getMetadataProvider(), callExprResolver, true,
                  context.getDeclaredFunctions(), allowNonStoredUdfCalls);
          callExpr.setFunctionSignature(fs);
          return super.visit(callExpr, arg);
      }
  
      @Override
      public Expression visit(WindowExpression winExpr, ILangExpression arg) throws CompilationException {
          FunctionSignature fs = FunctionUtil.resolveFunctionCall(winExpr.getFunctionSignature(),
                  winExpr.getSourceLocation(), context.getMetadataProvider(), callExprResolver, false, null, false);
          winExpr.setFunctionSignature(fs);
          return super.visit(winExpr, arg);
      }
  
      private FunctionSignature resolveCallExpr(String name, int arity) {
          FunctionSignature fs = builtinFunctionResolver.apply(name, arity);
          if (fs != null) {
              return fs;
          }
          fs = FunctionSignature.newAsterix(name, arity);
          return isAggregateFunction(fs) || isWindowFunction(fs) ? fs : null;
      }
  
      private static boolean isAggregateFunction(FunctionSignature fs) {
          return FunctionMapUtil.isSql92AggregateFunction(fs) || FunctionMapUtil.isCoreAggregateFunction(fs);
      }
  
      private static boolean isWindowFunction(FunctionSignature fs) {
          return BuiltinFunctions.getWindowFunction(fs.createFunctionIdentifier()) != null;
      }
  }
  