// 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

// 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.cloud.utils.db;

import java.util.ArrayList;

import java.util.List;

import com.cloud.utils.Pair;

import com.cloud.utils.db.SearchCriteria.Func;

import com.cloud.utils.db.SearchCriteria.Op;

public class GroupBy<J extends SearchBase<?, T, R>, T, R> {

J _builder;

List<Pair<Func, Attribute>> _groupBys;

Having _having;

public GroupBy(J builder) {

_builder = builder;

_groupBys = new ArrayList<Pair<Func, Attribute>>();

_having = null;

for (Attribute attr : _builder.getSpecifiedAttributes()) {

_groupBys.add(new Pair<Func, Attribute>(null, attr));

}

_builder.getSpecifiedAttributes().clear();

}

public GroupBy<J, T, R> group(Object useless) {

_groupBys.add(new Pair<Func, Attribute>(null, _builder.getSpecifiedAttributes().get(0)));

_builder.getSpecifiedAttributes().clear();

return this;

}

public GroupBy<J, T, R> group(Func func, Object useless) {

_groupBys.add(new Pair<Func, Attribute>(func, _builder.getSpecifiedAttributes().get(0)));

_builder.getSpecifiedAttributes().clear();

return this;

}

public J having(Func func, Object obj, Op op, Object value) {

assert (_having == null) : "You can only specify one having in a group by";

List<Attribute> attrs = _builder.getSpecifiedAttributes();

assert attrs.size() == 1 : "You didn't specified an attribute";

_having = new Having(func, attrs.get(0), op, value);

_builder.getSpecifiedAttributes().clear();

return _builder;

}

public void toSql(StringBuilder builder) {

builder.append(" GROUP BY ");

for (Pair<Func, Attribute> groupBy : _groupBys) {

if (groupBy.first() != null) {

String func = groupBy.first().toString();

func.replaceFirst("@", groupBy.second().table + "." + groupBy.second().columnName);

builder.append(func);

} else {

builder.append(groupBy.second().table + "." + groupBy.second().columnName);

}

builder.append(", ");

}

builder.delete(builder.length() - 2, builder.length());

if (_having != null) {

_having.toSql(builder);

}

}

protected class Having {

public Func func;

public Attribute attr;

public Op op;

public Object value;

public Having(Func func, Attribute attr, Op op, Object value) {

this.func = func;

this.attr = attr;

this.op = op;

this.value = value;

}

public void toSql(StringBuilder builder) {

if (func != null) {

String f = func.toString();

f.replaceFirst("@", attr.toString());

builder.append(func);

} else {

builder.append(attr.toString());

}

builder.append(op.toString());

}

}

}