// 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 ddltest

import (
	goctx "context"
	"fmt"
	"math"
	"os"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/pingcap/log"
	"github.com/pingcap/tidb/store/gcworker"
	"github.com/pingcap/tidb/table"
	"github.com/stretchr/testify/require"
)

func getIndex(t table.Table, name string) table.Index {
	for _, idx := range t.Indices() {
		if idx.Meta().Name.O == name {
			return idx
		}
	}

	return nil
}

func (s *ddlSuite) checkDropIndex(t *testing.T, tableName string) {
	gcWorker, err := gcworker.NewMockGCWorker(s.store)
	require.NoError(t, err)
	err = gcWorker.DeleteRanges(goctx.Background(), uint64(math.MaxInt32))
	require.NoError(t, err)
	s.mustExec(fmt.Sprintf("admin check table %s", tableName))
}

// TestIndex operations on table test_index (c int, c1 bigint, c2 double, c3 varchar(256), primary key(c)).
func TestIndex(t *testing.T) {
	err := os.Setenv("tidb_manager_ttl", fmt.Sprintf("%d", *lease+5))
	if err != nil {
		log.Fatal("set tidb_manager_ttl failed")
	}

	s := createDDLSuite(t)
	defer s.teardown(t)

	// first add many data
	workerNum := 10
	base := *dataNum / workerNum
	var wg sync.WaitGroup
	wg.Add(workerNum)
	for i := 0; i < workerNum; i++ {
		go func(i int) {
			defer wg.Done()
			for j := 0; j < base; j++ {
				k := base*i + j
				s.execInsert(
					fmt.Sprintf("insert into test_index values (%d, %d, %f, '%s')",
						k, randomInt(), randomFloat(), randomString(10)))
			}
		}(i)
	}
	wg.Wait()

	tbl := []struct {
		Query     string
		IndexName string
		Add       bool
	}{
		{"create index c1_index on test_index (c1)", "c1_index", true},
		{"drop index c1_index on test_index", "c1_index", false},
		{"create index c2_index on test_index (c2)", "c2_index", true},
		{"drop index c2_index on test_index", "c2_index", false},
		{"create index c3_index on test_index (c3)", "c3_index", true},
		{"drop index c3_index on test_index", "c3_index", false},
	}

	insertID := int64(*dataNum)
	for _, col := range tbl {
		done := s.runDDL(col.Query)

		ticker := time.NewTicker(time.Duration(*lease) * time.Second / 2)
		//nolint:all_revive,revive
		defer ticker.Stop()
	LOOP:
		for {
			select {
			case err := <-done:
				require.NoError(t, err)
				break LOOP
			case <-ticker.C:
				// add count new data
				// delete count old data randomly
				// update count old data randomly
				count := 10
				s.execIndexOperations(t, workerNum, count, &insertID)
			}
		}

		tbl := s.getTable(t, "test_index")
		index := getIndex(tbl, col.IndexName)
		if col.Add {
			require.NotNil(t, index)
			s.mustExec("admin check table test_index")
		} else {
			require.Nil(t, index)
			s.checkDropIndex(t, "test_index")
		}
	}
}

func (s *ddlSuite) execIndexOperations(t *testing.T, workerNum, count int, insertID *int64) {
	var wg sync.WaitGroup
	// workerNum = 10
	wg.Add(workerNum)
	for i := 0; i < workerNum; i++ {
		go func() {
			defer wg.Done()
			for j := 0; j < count; j++ {
				id := atomic.AddInt64(insertID, 1)
				sql := fmt.Sprintf("insert into test_index values (%d, %d, %f, '%s')", id, randomInt(), randomFloat(), randomString(10))
				s.execInsert(sql)
				t.Logf("sql %s", sql)
				sql = fmt.Sprintf("delete from test_index where c = %d", randomIntn(int(id)))
				s.mustExec(sql)
				t.Logf("sql %s", sql)
				sql = fmt.Sprintf("update test_index set c1 = %d, c2 = %f, c3 = '%s' where c = %d", randomInt(), randomFloat(), randomString(10), randomIntn(int(id)))
				s.mustExec(sql)
				t.Logf("sql %s", sql)
			}
		}()
	}
	wg.Wait()
}