// 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.

//go:build !codes

package testutil

import (
	"math/rand"
	"testing"

	"github.com/pingcap/tidb/kv"
	"github.com/pingcap/tidb/sessionctx/stmtctx"
	"github.com/pingcap/tidb/types"
	"github.com/pingcap/tidb/util/collate"
	"github.com/stretchr/testify/require"
)

// DatumEqual verifies that the actual value is equal to the expected value. For string datum, they are compared by the binary collation.
func DatumEqual(t testing.TB, expected, actual types.Datum, msgAndArgs ...interface{}) {
	sc := new(stmtctx.StatementContext)
	res, err := actual.Compare(sc, &expected, collate.GetBinaryCollator())
	require.NoError(t, err, msgAndArgs)
	require.Zero(t, res, msgAndArgs)
}

// HandleEqual verifies that the actual handle is equal to the expected handle.
func HandleEqual(t testing.TB, expected, actual kv.Handle, msgAndArgs ...interface{}) {
	require.Equal(t, expected.IsInt(), actual.IsInt(), msgAndArgs)
	require.Equal(t, expected.String(), actual.String(), msgAndArgs)
}

// CompareUnorderedStringSlice compare two string slices.
// If a and b is exactly the same except the order, it returns true.
// In otherwise return false.
func CompareUnorderedStringSlice(a []string, b []string) bool {
	if a == nil && b == nil {
		return true
	}
	if a == nil || b == nil {
		return false
	}
	if len(a) != len(b) {
		return false
	}
	m := make(map[string]int, len(a))
	for _, i := range a {
		_, ok := m[i]
		if !ok {
			m[i] = 1
		} else {
			m[i]++
		}
	}

	for _, i := range b {
		_, ok := m[i]
		if !ok {
			return false
		}
		m[i]--
		if m[i] == 0 {
			delete(m, i)
		}
	}
	return len(m) == 0
}

var letterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

// RandStringRunes generate random string of length n.
func RandStringRunes(n int) string {
	b := make([]rune, n)
	for i := range b {
		b[i] = letterRunes[rand.Intn(len(letterRunes))]
	}
	return string(b)
}