// Copyright 2023 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 lockstats

import (
	"context"
	"fmt"
	"strconv"
	"testing"
	"time"

	"github.com/pingcap/failpoint"
	"github.com/pingcap/tidb/pkg/config"
	"github.com/pingcap/tidb/pkg/domain"
	"github.com/pingcap/tidb/pkg/kv"
	"github.com/pingcap/tidb/pkg/meta/model"
	pmodel "github.com/pingcap/tidb/pkg/parser/model"
	"github.com/pingcap/tidb/pkg/statistics"
	"github.com/pingcap/tidb/pkg/testkit"
	"github.com/stretchr/testify/require"
)

func TestLockAndUnlockTableStats(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithTableT(t)

	handle := dom.StatsHandle()
	tblStats := handle.GetTableStats(tbl)
	tblStats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.True(t, col.IsStatsInitialized())
		return false
	})
	tk.MustExec("lock stats t")

	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 1)

	tk.MustExec("insert into t(a, b) values(1,'a')")
	tk.MustExec("insert into t(a, b) values(2,'b')")

	tk.MustExec("analyze table test.t")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip analyze locked table: test.t",
	))
	tblStats1 := handle.GetTableStats(tbl)
	require.Equal(t, tblStats, tblStats1)

	lockedTables, err := handle.GetTableLockedAndClearForTest()
	require.Nil(t, err)
	require.Equal(t, 1, len(lockedTables))

	// Insert a new row to the table.
	tk.MustExec("insert into t(a, b) values(3,'c')")
	// Enable the failpoint to test the historical stats meta is not recorded.
	err = failpoint.Enable(
		"github.com/pingcap/tidb/pkg/statistics/handle/usage/panic-when-record-historical-stats-meta",
		"1*return(true)",
	)
	require.NoError(t, err)
	// Dump stats delta to KV.
	require.NotPanics(t, func() { handle.DumpStatsDeltaToKV(true) })

	tk.MustExec("unlock stats t")
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 0)

	tk.MustExec("analyze table test.t")
	tblStats2 := handle.GetTableStats(tbl)
	require.Equal(t, int64(3), tblStats2.RealtimeCount)
}

func TestLockAndUnlockPartitionedTableStats(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithPartitionedTableT(t)

	handle := dom.StatsHandle()
	tblStats := handle.GetTableStats(tbl)
	tblStats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.True(t, col.IsStatsInitialized())
		return false
	})

	tk.MustExec("lock stats t")
	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 3)

	rows = tk.MustQuery("show stats_locked").Rows()
	require.Len(t, rows, 3)

	tk.MustExec("analyze table test.t")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip analyze locked tables: test.t partition (p0), test.t partition (p1)",
	))

	tk.MustExec("unlock stats t")
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 0)

	rows = tk.MustQuery("show stats_locked").Rows()
	require.Len(t, rows, 0)
}

func TestLockTableAndUnlockTableStatsRepeatedly(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithTableT(t)

	handle := dom.StatsHandle()
	tblStats := handle.GetTableStats(tbl)
	tblStats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.True(t, col.IsStatsInitialized())
		return false
	})
	tk.MustExec("lock stats t")

	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 1)

	tk.MustExec("insert into t(a, b) values(1,'a')")
	tk.MustExec("insert into t(a, b) values(2,'b')")

	tk.MustExec("analyze table test.t")
	tblStats1 := handle.GetTableStats(tbl)
	require.Equal(t, tblStats, tblStats1)

	// Lock the table again and check the warning.
	lockedTables1, err := handle.GetTableLockedAndClearForTest()
	require.Nil(t, err)
	tk.MustExec("lock stats t")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip locking locked table: test.t",
	))

	lockedTables2, err := handle.GetTableLockedAndClearForTest()
	require.Nil(t, err)
	require.Equal(t, lockedTables1, lockedTables2)

	// Unlock the table.
	tk.MustExec("unlock stats t")
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 0)

	tk.MustExec("analyze table test.t")
	tblStats2 := handle.GetTableStats(tbl)
	require.Equal(t, int64(2), tblStats2.RealtimeCount)

	// Unlock the table again and check the warning.
	tk.MustExec("unlock stats t")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip unlocking unlocked table: test.t",
	))
}

func TestLockAndUnlockTablesStats(t *testing.T) {
	restore := config.RestoreFunc()
	defer restore()
	config.UpdateGlobal(func(conf *config.Config) {
		conf.Performance.EnableStatsCacheMemQuota = true
	})
	store, dom := testkit.CreateMockStoreAndDomain(t)
	tk := testkit.NewTestKit(t, store)
	tk.MustExec("set @@tidb_analyze_version = 1")
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t1")
	tk.MustExec("drop table if exists t2")
	tk.MustExec("create table t1(a int, b varchar(10), index idx_b (b))")
	tk.MustExec("create table t2(a int, b varchar(10), index idx_b (b))")
	tk.MustExec("analyze table test.t1, test.t2")
	tbl1, err := dom.InfoSchema().TableByName(context.Background(), pmodel.NewCIStr("test"), pmodel.NewCIStr("t1"))
	require.Nil(t, err)
	tbl2, err := dom.InfoSchema().TableByName(context.Background(), pmodel.NewCIStr("test"), pmodel.NewCIStr("t2"))
	require.Nil(t, err)

	handle := domain.GetDomain(tk.Session()).StatsHandle()
	tbl1Stats := handle.GetTableStats(tbl1.Meta())
	tbl1Stats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.Eventually(t, func() bool {
			return col.IsStatsInitialized()
		}, 1*time.Second, 100*time.Millisecond)
		return false
	})
	tbl2Stats := handle.GetTableStats(tbl2.Meta())
	tbl2Stats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.Eventually(t, func() bool {
			return col.IsStatsInitialized()
		}, 1*time.Second, 100*time.Millisecond)
		return false
	})

	tk.MustExec("lock stats t1, t2")
	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 2)

	tk.MustExec("insert into t1(a, b) values(1,'a')")
	tk.MustExec("insert into t1(a, b) values(2,'b')")

	tk.MustExec("insert into t2(a, b) values(1,'a')")
	tk.MustExec("insert into t2(a, b) values(2,'b')")

	tk.MustExec("analyze table test.t1, test.t2")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip analyze locked tables: test.t1, test.t2",
	))
	tbl1Stats1 := handle.GetTableStats(tbl1.Meta())
	require.Equal(t, tbl1Stats, tbl1Stats1)
	tbl2Stats1 := handle.GetTableStats(tbl2.Meta())
	require.Equal(t, tbl2Stats, tbl2Stats1)

	lockedTables, err := handle.GetTableLockedAndClearForTest()
	require.Nil(t, err)
	require.Equal(t, 2, len(lockedTables))

	tk.MustExec("unlock stats test.t1, test.t2")
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, num, 0)

	tk.MustExec("analyze table test.t1, test.t2")
	tbl1Stats2 := handle.GetTableStats(tbl1.Meta())
	require.Equal(t, int64(2), tbl1Stats2.RealtimeCount)
	tbl2Stats2 := handle.GetTableStats(tbl2.Meta())
	require.Equal(t, int64(2), tbl2Stats2.RealtimeCount)
}

func TestDropTableShouldCleanUpLockInfo(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithTableT(t)

	handle := dom.StatsHandle()
	tblStats := handle.GetTableStats(tbl)
	tblStats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.True(t, col.IsStatsInitialized())
		return false
	})
	tk.MustExec("lock stats t")

	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, 1, num)

	// GC stats.
	tk.MustExec("drop table t")
	ddlLease := time.Duration(0)
	require.Nil(t, handle.GCStats(dom.InfoSchema(), ddlLease))

	// Check if the lock info is cleaned up.
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, 0, num)
}

func TestTruncateTableShouldCleanUpLockInfo(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithTableT(t)

	handle := dom.StatsHandle()
	tblStats := handle.GetTableStats(tbl)
	tblStats.ForEachColumnImmutable(func(_ int64, col *statistics.Column) bool {
		require.True(t, col.IsStatsInitialized())
		return false
	})
	tk.MustExec("lock stats t")

	rows := tk.MustQuery(selectTableLockSQL).Rows()
	num, _ := strconv.Atoi(rows[0][0].(string))
	require.Equal(t, 1, num)

	// GC stats.
	tk.MustExec("truncate table t")
	ddlLease := time.Duration(0)
	require.Nil(t, handle.GCStats(dom.InfoSchema(), ddlLease))

	// Check if the lock info is cleaned up.
	rows = tk.MustQuery(selectTableLockSQL).Rows()
	num, _ = strconv.Atoi(rows[0][0].(string))
	require.Equal(t, 0, num)
}

func TestUnlockPartitionedTableWouldUpdateGlobalCountCorrectly(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithPartitionedTableT(t)

	h := dom.StatsHandle()
	tk.MustExec("lock stats t")
	tk.MustExec("insert into t(a, b) values(1,'a')")
	tk.MustExec("insert into t(a, b) values(2,'b')")
	tk.MustExec("analyze table test.t")
	tblStats := h.GetTableStats(tbl)
	require.Equal(t, int64(0), tblStats.RealtimeCount)

	// Dump stats delta to KV.
	require.Nil(t, h.DumpStatsDeltaToKV(true))
	// Check the mysql.stats_table_locked is updated correctly.
	rows := tk.MustQuery("select count, modify_count, table_id from mysql.stats_table_locked order by table_id").Rows()
	require.Len(t, rows, 3)
	require.Equal(t, "0", rows[0][0])
	require.Equal(t, "0", rows[0][1])
	require.Equal(t, "2", rows[1][0])
	require.Equal(t, "2", rows[1][1])
	require.Equal(t, "0", rows[2][0])
	require.Equal(t, "0", rows[2][1])
	// Unlock partition p0 and p1 failed.
	tk.MustExec("unlock stats t partition p0, p1")
	tk.MustQuery("show warnings").Check(testkit.Rows(
		"Warning 1105 skip unlocking partitions of locked table: test.t",
	))

	// Unlock the table.
	tk.MustExec("unlock stats t")
	// Check the global count is updated correctly.
	rows = tk.MustQuery(fmt.Sprint("select count, modify_count from mysql.stats_meta where table_id = ", tbl.ID)).Rows()
	require.Len(t, rows, 1)
	require.Equal(t, "2", rows[0][0])
	require.Equal(t, "2", rows[0][1])
}

func TestDeltaInLockInfoCanBeNegative(t *testing.T) {
	_, dom, tk, tbl := setupTestEnvironmentWithPartitionedTableT(t)

	h := dom.StatsHandle()
	tk.MustExec("insert into t(a, b) values(1,'a')")
	tk.MustExec("insert into t(a, b) values(2,'b')")
	// Dump stats delta to KV.
	require.Nil(t, h.DumpStatsDeltaToKV(true))
	rows := tk.MustQuery(fmt.Sprint("select count, modify_count from mysql.stats_meta where table_id = ", tbl.ID)).Rows()
	require.Len(t, rows, 1)
	require.Equal(t, "2", rows[0][0])
	require.Equal(t, "2", rows[0][1])

	tk.MustExec("lock stats t")
	// Delete some rows.
	tk.MustExec("delete from t where a = 1")
	tk.MustExec("delete from t where a = 2")

	// Dump stats delta to KV.
	require.Nil(t, h.DumpStatsDeltaToKV(true))
	// Check the mysql.stats_table_locked is updated correctly.
	rows = tk.MustQuery("select count, modify_count, table_id from mysql.stats_table_locked order by table_id").Rows()
	require.Len(t, rows, 3)
	require.Equal(t, "0", rows[0][0])
	require.Equal(t, "0", rows[0][1])
	require.Equal(t, "-2", rows[1][0])
	require.Equal(t, "2", rows[1][1])
	require.Equal(t, "0", rows[2][0])
	require.Equal(t, "0", rows[2][1])

	// Unlock the table.
	tk.MustExec("unlock stats t")
	// Check the global count is updated correctly.
	rows = tk.MustQuery(fmt.Sprint("select count, modify_count from mysql.stats_meta where table_id = ", tbl.ID)).Rows()
	require.Len(t, rows, 1)
	require.Equal(t, "0", rows[0][0])
	require.Equal(t, "4", rows[0][1])
}

func setupTestEnvironmentWithTableT(t *testing.T) (kv.Storage, *domain.Domain, *testkit.TestKit, *model.TableInfo) {
	store, dom := testkit.CreateMockStoreAndDomain(t)
	tk := testkit.NewTestKit(t, store)
	tk.MustExec("set @@tidb_analyze_version = 1")
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t(a int, b varchar(10), index idx_b (b))")
	tk.MustExec("analyze table test.t")
	tbl, err := dom.InfoSchema().TableByName(context.Background(), pmodel.NewCIStr("test"), pmodel.NewCIStr("t"))
	require.Nil(t, err)

	return store, dom, tk, tbl.Meta()
}