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 com.aliyun.odps.lot.common;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import apsara.odps.lot.ExpressionProtos;
  
  public class WindowFunction {
  
    public static class WindowingClause {
  
      private int preceding;
      private int following;
  
      public int getPreceding() {
        return preceding;
      }
  
      public int getFollowing() {
        return following;
      }
  
      public WindowingClause(int preceding, int following) {
  
        this.preceding = preceding;
        this.following = following;
      }
  
      public ExpressionProtos.WindowFunction.WindowingClause toProtoBuf() {
        ExpressionProtos.WindowFunction.WindowingClause.Builder builder =
            ExpressionProtos.WindowFunction.WindowingClause.newBuilder();
        builder.setBegin(preceding);
        builder.setEnd(following);
        return builder.build();
      }
    }
  
    public static class Order {
  
      private ScalarExpression expression;
      private boolean asc = true;
  
      public void setAsc(boolean asc) {
        this.asc = asc;
      }
  
      public ScalarExpression getExpression() {
        return expression;
      }
  
      public boolean isAsc() {
        return asc;
      }
  
      public Order(ScalarExpression expression, boolean asc) {
        if (expression == null) {
          throw new ArgumentNullException("expression");
        }
  
        this.expression = expression;
        this.asc = asc;
      }
  
      public Order(ScalarExpression expression) {
        if (expression == null) {
          throw new ArgumentNullException("expression");
        }
  
        this.expression = expression;
      }
  
      public ExpressionProtos.WindowFunction.OrderBy toProtoBuf() {
        ExpressionProtos.WindowFunction.OrderBy.Builder builder =
            ExpressionProtos.WindowFunction.OrderBy.newBuilder();
        builder.setExpression(expression.toProtoBuf());
        builder.setIsAsc(asc);
  
        return builder.build();
      }
    }
  
    private String project;
    private String name;
    private List<ScalarExpression> parameters;
    private List<ScalarExpression> partitionBy;
    private List<Order> sortBy;
    private WindowingClause windowing;
    private boolean distinct;
  
    public WindowFunction(String project, String name, List<ScalarExpression> parameters,
                          List<ScalarExpression> partitionBy, boolean isDistinct) {
      if (project == null) {
        throw new ArgumentNullException("project");
      }
  
      if (name == null) {
        throw new ArgumentNullException("name");
      }
  
      if (partitionBy == null) {
        throw new ArgumentNullException("partitionBy");
      }
      if (partitionBy.size() == 0) {
        throw new IllegalArgumentException(
            "You have to specify one item at least in 'partitionBy' parameter.");
      }
  
      if (parameters == null) {
        this.parameters = new ArrayList<ScalarExpression>();
      } else {
        this.parameters = parameters;
      }
      this.project = project;
      this.name = name;
      this.partitionBy = partitionBy;
      this.distinct = isDistinct;
    }
  
    public String getProject() {
      return project;
    }
  
    public String getName() {
      return name;
    }
  
    public List<ScalarExpression> getParameters() {
      return parameters;
    }
  
    public List<ScalarExpression> getPartitionBy() {
      return partitionBy;
    }
  
    public List<Order> getSortBy() {
      return sortBy;
    }
  
    public WindowingClause getWindowing() {
      return windowing;
    }
  
    public boolean isDistinct() {
      return distinct;
    }
  
    public void setSortBy(List<Order> sortBy) {
      if (sortBy == null) {
        throw new ArgumentNullException("sortBy");
      }
  
      this.sortBy = sortBy;
    }
  
    public void setWindowing(WindowingClause windowing) {
      if (windowing == null) {
        throw new ArgumentNullException("windowing");
      }
  
      this.windowing = windowing;
    }
  
    public ExpressionProtos.WindowFunction toProtoBuf() {
      ExpressionProtos.WindowFunction.Builder builder = ExpressionProtos.WindowFunction.newBuilder();
      builder.setProject(project);
      builder.setName(name);
      builder.setIsDistinct(distinct);
  
      for (ScalarExpression param : parameters) {
        builder.addParameters(param.toProtoBuf());
      }
  
      for (ScalarExpression pb : partitionBy) {
        builder.addPartitionBy(pb.toProtoBuf());
      }
  
      if (sortBy != null && sortBy.size() > 0) {
        for (Order order : sortBy) {
          builder.addOrderBy(order.toProtoBuf());
        }
      }
  
      if (windowing != null) {
        builder.setWindowingClause(windowing.toProtoBuf());
      }
  
      return builder.build();
    }
  }
  