// Copyright 2015 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 ddl

import (
	"context"
	"testing"
	"time"

	"github.com/pingcap/failpoint"
	"github.com/pingcap/tidb/infoschema"
	"github.com/pingcap/tidb/kv"
	"github.com/pingcap/tidb/meta"
	"github.com/pingcap/tidb/parser"
	"github.com/pingcap/tidb/parser/ast"
	"github.com/pingcap/tidb/parser/charset"
	"github.com/pingcap/tidb/parser/model"
	"github.com/pingcap/tidb/parser/mysql"
	"github.com/pingcap/tidb/parser/terror"
	"github.com/pingcap/tidb/sessionctx"
	"github.com/pingcap/tidb/store/mockstore"
	"github.com/pingcap/tidb/table"
	"github.com/pingcap/tidb/types"
	"github.com/pingcap/tidb/util/dbterror"
	"github.com/pingcap/tidb/util/mock"
	"github.com/stretchr/testify/require"
)

const testLease = 5 * time.Millisecond

type DDLForTest interface {
	// SetInterceptor sets the interceptor.
	SetInterceptor(h Interceptor)
}

// SetInterceptor implements DDL.SetInterceptor interface.
func (d *ddl) SetInterceptor(i Interceptor) {
	d.mu.Lock()
	defer d.mu.Unlock()

	d.mu.interceptor = i
}

// JobNeedGCForTest is only used for test.
var JobNeedGCForTest = jobNeedGC

// GetMaxRowID is used for test.
func GetMaxRowID(store kv.Storage, priority int, t table.Table, startHandle, endHandle kv.Key) (kv.Key, error) {
	return getRangeEndKey(NewJobContext(), store, priority, t.RecordPrefix(), startHandle, endHandle)
}

func testNewDDLAndStart(ctx context.Context, options ...Option) (*ddl, error) {
	// init infoCache and a stub infoSchema
	ic := infoschema.NewCache(2)
	ic.Insert(infoschema.MockInfoSchemaWithSchemaVer(nil, 0), 0)
	options = append(options, WithInfoCache(ic))
	d := newDDL(ctx, options...)
	err := d.Start(nil)
	return d, err
}

func createMockStore(t *testing.T) kv.Storage {
	store, err := mockstore.NewMockStore()
	require.NoError(t, err)
	return store
}

func TestGetIntervalFromPolicy(t *testing.T) {
	policy := []time.Duration{
		1 * time.Second,
		2 * time.Second,
	}
	var (
		val     time.Duration
		changed bool
	)

	val, changed = getIntervalFromPolicy(policy, 0)
	require.Equal(t, val, 1*time.Second)
	require.True(t, changed)

	val, changed = getIntervalFromPolicy(policy, 1)
	require.Equal(t, val, 2*time.Second)
	require.True(t, changed)

	val, changed = getIntervalFromPolicy(policy, 2)
	require.Equal(t, val, 2*time.Second)
	require.False(t, changed)

	val, changed = getIntervalFromPolicy(policy, 3)
	require.Equal(t, val, 2*time.Second)
	require.False(t, changed)
}

func colDefStrToFieldType(t *testing.T, str string, ctx sessionctx.Context) *types.FieldType {
	sqlA := "alter table t modify column a " + str
	stmt, err := parser.New().ParseOneStmt(sqlA, "", "")
	require.NoError(t, err)
	colDef := stmt.(*ast.AlterTableStmt).Specs[0].NewColumns[0]
	chs, coll := charset.GetDefaultCharsetAndCollate()
	col, _, err := buildColumnAndConstraint(ctx, 0, colDef, nil, chs, coll)
	require.NoError(t, err)
	return &col.FieldType
}

func TestModifyColumn(t *testing.T) {
	ctx := mock.NewContext()
	tests := []struct {
		origin string
		to     string
		err    error
	}{
		{"int", "bigint", nil},
		{"int", "int unsigned", nil},
		{"varchar(10)", "text", nil},
		{"varbinary(10)", "blob", nil},
		{"text", "blob", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from utf8mb4 to binary")},
		{"varchar(10)", "varchar(8)", nil},
		{"varchar(10)", "varchar(11)", nil},
		{"varchar(10) character set utf8 collate utf8_bin", "varchar(10) character set utf8", nil},
		{"decimal(2,1)", "decimal(3,2)", nil},
		{"decimal(2,1)", "decimal(2,2)", nil},
		{"decimal(2,1)", "decimal(2,1)", nil},
		{"decimal(2,1)", "int", nil},
		{"decimal", "int", nil},
		{"decimal(2,1)", "bigint", nil},
		{"int", "varchar(10) character set gbk", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from binary to gbk")},
		{"varchar(10) character set gbk", "int", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from gbk to binary")},
		{"varchar(10) character set gbk", "varchar(10) character set utf8", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from gbk to utf8")},
		{"varchar(10) character set gbk", "char(10) character set utf8", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from gbk to utf8")},
		{"varchar(10) character set utf8", "char(10) character set gbk", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from utf8 to gbk")},
		{"varchar(10) character set utf8", "varchar(10) character set gbk", dbterror.ErrUnsupportedModifyCharset.GenWithStackByArgs("charset from utf8 to gbk")},
		{"varchar(10) character set gbk", "varchar(255) character set gbk", nil},
	}
	for _, tt := range tests {
		ftA := colDefStrToFieldType(t, tt.origin, ctx)
		ftB := colDefStrToFieldType(t, tt.to, ctx)
		err := checkModifyTypes(ctx, ftA, ftB, false)
		if err == nil {
			require.NoErrorf(t, tt.err, "origin:%v, to:%v", tt.origin, tt.to)
		} else {
			require.EqualError(t, err, tt.err.Error())
		}
	}
}

func TestFieldCase(t *testing.T) {
	var fields = []string{"field", "Field"}
	colObjects := make([]*model.ColumnInfo, len(fields))
	for i, name := range fields {
		colObjects[i] = &model.ColumnInfo{
			Name: model.NewCIStr(name),
		}
	}
	err := checkDuplicateColumn(colObjects)
	require.EqualError(t, err, infoschema.ErrColumnExists.GenWithStackByArgs("Field").Error())
}

func TestIgnorableSpec(t *testing.T) {
	specs := []ast.AlterTableType{
		ast.AlterTableOption,
		ast.AlterTableAddColumns,
		ast.AlterTableAddConstraint,
		ast.AlterTableDropColumn,
		ast.AlterTableDropPrimaryKey,
		ast.AlterTableDropIndex,
		ast.AlterTableDropForeignKey,
		ast.AlterTableModifyColumn,
		ast.AlterTableChangeColumn,
		ast.AlterTableRenameTable,
		ast.AlterTableAlterColumn,
	}
	for _, spec := range specs {
		require.False(t, isIgnorableSpec(spec))
	}

	ignorableSpecs := []ast.AlterTableType{
		ast.AlterTableLock,
		ast.AlterTableAlgorithm,
	}
	for _, spec := range ignorableSpecs {
		require.True(t, isIgnorableSpec(spec))
	}
}

func TestBuildJobDependence(t *testing.T) {
	store := createMockStore(t)
	defer func() {
		require.NoError(t, store.Close())
	}()
	ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnDDL)
	// Add some non-add-index jobs.
	job1 := &model.Job{ID: 1, TableID: 1, Type: model.ActionAddColumn}
	job2 := &model.Job{ID: 2, TableID: 1, Type: model.ActionCreateTable}
	job3 := &model.Job{ID: 3, TableID: 2, Type: model.ActionDropColumn}
	job6 := &model.Job{ID: 6, TableID: 1, Type: model.ActionDropTable}
	job7 := &model.Job{ID: 7, TableID: 2, Type: model.ActionModifyColumn}
	job9 := &model.Job{ID: 9, SchemaID: 111, Type: model.ActionDropSchema}
	job11 := &model.Job{ID: 11, TableID: 2, Type: model.ActionRenameTable, Args: []interface{}{int64(111), "old db name"}}
	err := kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		require.NoError(t, m.EnQueueDDLJob(job1))
		require.NoError(t, m.EnQueueDDLJob(job2))
		require.NoError(t, m.EnQueueDDLJob(job3))
		require.NoError(t, m.EnQueueDDLJob(job6))
		require.NoError(t, m.EnQueueDDLJob(job7))
		require.NoError(t, m.EnQueueDDLJob(job9))
		require.NoError(t, m.EnQueueDDLJob(job11))
		return nil
	})
	require.NoError(t, err)
	job4 := &model.Job{ID: 4, TableID: 1, Type: model.ActionAddIndex}
	err = kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		err := buildJobDependence(m, job4)
		require.NoError(t, err)
		require.Equal(t, job4.DependencyID, int64(2))
		return nil
	})
	require.NoError(t, err)
	job5 := &model.Job{ID: 5, TableID: 2, Type: model.ActionAddIndex}
	err = kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		err := buildJobDependence(m, job5)
		require.NoError(t, err)
		require.Equal(t, job5.DependencyID, int64(3))
		return nil
	})
	require.NoError(t, err)
	job8 := &model.Job{ID: 8, TableID: 3, Type: model.ActionAddIndex}
	err = kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		err := buildJobDependence(m, job8)
		require.NoError(t, err)
		require.Equal(t, job8.DependencyID, int64(0))
		return nil
	})
	require.NoError(t, err)
	job10 := &model.Job{ID: 10, SchemaID: 111, TableID: 3, Type: model.ActionAddIndex}
	err = kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		err := buildJobDependence(m, job10)
		require.NoError(t, err)
		require.Equal(t, job10.DependencyID, int64(9))
		return nil
	})
	require.NoError(t, err)
	job12 := &model.Job{ID: 12, SchemaID: 112, TableID: 2, Type: model.ActionAddIndex}
	err = kv.RunInNewTxn(ctx, store, false, func(ctx context.Context, txn kv.Transaction) error {
		m := meta.NewMeta(txn)
		err := buildJobDependence(m, job12)
		require.NoError(t, err)
		require.Equal(t, job12.DependencyID, int64(11))
		return nil
	})
	require.NoError(t, err)
}

func TestNotifyDDLJob(t *testing.T) {
	store := createMockStore(t)
	defer func() {
		require.NoError(t, store.Close())
	}()

	require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/ddl/NoDDLDispatchLoop", `return(true)`))
	defer require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/ddl/NoDDLDispatchLoop"))

	getFirstNotificationAfterStartDDL := func(d *ddl) {
		select {
		case <-d.workers[addIdxWorker].ddlJobCh:
		default:
			// The notification may be received by the worker.
		}
		select {
		case <-d.workers[generalWorker].ddlJobCh:
		default:
			// The notification may be received by the worker.
		}

		select {
		case <-d.ddlJobCh:
		default:
		}
	}

	d, err := testNewDDLAndStart(
		context.Background(),
		WithStore(store),
		WithLease(testLease),
	)
	require.NoError(t, err)
	defer func() {
		require.NoError(t, d.Stop())
	}()
	getFirstNotificationAfterStartDDL(d)
	// Ensure that the notification is not handled in workers `start` function.
	d.cancel()
	for _, worker := range d.workers {
		worker.Close()
	}

	job := &model.Job{
		SchemaID:   1,
		TableID:    2,
		Type:       model.ActionCreateTable,
		BinlogInfo: &model.HistoryInfo{},
		Args:       []interface{}{},
	}
	// Test the notification mechanism of the owner and the server receiving the DDL request on the same TiDB.
	// This DDL request is a general DDL job.
	d.asyncNotifyWorker(job)
	select {
	case <-d.workers[generalWorker].ddlJobCh:
	case <-d.ddlJobCh:
	default:
		require.FailNow(t, "do not get the general job notification")
	}
	// Test the notification mechanism of the owner and the server receiving the DDL request on the same TiDB.
	// This DDL request is a add index DDL job.
	job.Type = model.ActionAddIndex
	d.asyncNotifyWorker(job)
	select {
	case <-d.workers[addIdxWorker].ddlJobCh:
	case <-d.ddlJobCh:
	default:
		require.FailNow(t, "do not get the add index job notification")
	}

	// Test the notification mechanism that the owner and the server receiving the DDL request are not on the same TiDB.
	// And the etcd client is nil.
	d1, err := testNewDDLAndStart(
		context.Background(),
		WithStore(store),
		WithLease(testLease),
	)
	require.NoError(t, err)
	defer func() {
		require.NoError(t, d1.Stop())
	}()
	getFirstNotificationAfterStartDDL(d1)
	// Ensure that the notification is not handled by worker's "start".
	d1.cancel()
	for _, worker := range d1.workers {
		worker.Close()
	}
	d1.ownerManager.RetireOwner()
	d1.asyncNotifyWorker(job)
	job.Type = model.ActionCreateTable
	d1.asyncNotifyWorker(job)
	require.False(t, d1.OwnerManager().IsOwner())
	select {
	case <-d1.workers[addIdxWorker].ddlJobCh:
		require.FailNow(t, "should not get the add index job notification")
	case <-d1.workers[generalWorker].ddlJobCh:
		require.FailNow(t, "should not get the general job notification")
	case <-d1.ddlJobCh:
		require.FailNow(t, "should not get the job notification")
	default:
	}
}

func TestError(t *testing.T) {
	kvErrs := []*terror.Error{
		dbterror.ErrDDLJobNotFound,
		dbterror.ErrCancelFinishedDDLJob,
		dbterror.ErrCannotCancelDDLJob,
	}
	for _, err := range kvErrs {
		code := terror.ToSQLError(err).Code
		require.NotEqual(t, mysql.ErrUnknown, code)
		require.Equal(t, uint16(err.Code()), code)
	}
}