// Copyright 2021 PingCAP, Inc.
//
// Licensed 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 executor_test

import (
	"fmt"
	"strings"
	"testing"

	"github.com/pingcap/tidb/testkit"
	"github.com/stretchr/testify/require"
)

func TestAggInDisk(t *testing.T) {
	store, clean := testkit.CreateMockStore(t)
	defer clean()
	tk := testkit.NewTestKit(t, store)
	tk.MustExec("use test")
	tk.MustExec("set tidb_hashagg_final_concurrency = 1;")
	tk.MustExec("set tidb_hashagg_partial_concurrency = 1;")
	tk.MustExec("set tidb_mem_quota_query = 4194304")
	tk.MustExec("drop table if exists t1")
	tk.MustExec("create table t(a int)")
	sql := "insert into t values (0)"
	for i := 1; i <= 200; i++ {
		sql += fmt.Sprintf(",(%v)", i)
	}
	sql += ";"
	tk.MustExec(sql)
	rows := tk.MustQuery("desc analyze select /*+ HASH_AGG() */ avg(t1.a) from t t1 join t t2 group by t1.a, t2.a;").Rows()
	for _, row := range rows {
		length := len(row)
		line := fmt.Sprintf("%v", row)
		disk := fmt.Sprintf("%v", row[length-1])
		if strings.Contains(line, "HashAgg") {
			require.False(t, strings.Contains(disk, "0 Bytes"))
			require.True(t, strings.Contains(disk, "MB") ||
				strings.Contains(disk, "KB") ||
				strings.Contains(disk, "Bytes"))
		}
	}

	// Add code cover
	// Test spill chunk. Add a line to avoid tmp spill chunk is always full.
	tk.MustExec("insert into t values(0)")
	tk.MustQuery("select sum(tt.b) from ( select /*+ HASH_AGG() */ avg(t1.a) as b from t t1 join t t2 group by t1.a, t2.a) as tt").Check(
		testkit.Rows("4040100.0000"))
	// Test no groupby and no data.
	tk.MustExec("drop table t;")
	tk.MustExec("create table t(c int, c1 int);")
	tk.MustQuery("select /*+ HASH_AGG() */ count(c) from t;").Check(testkit.Rows("0"))
	tk.MustQuery("select /*+ HASH_AGG() */ count(c) from t group by c1;").Check(testkit.Rows())
}