// Copyright 2022 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 util

import (
	"github.com/pingcap/tidb/expression"
	"github.com/pingcap/tidb/parser/model"
	"github.com/pingcap/tidb/util/ranger"
)

// CloneExprs uses Expression.Clone to clone a slice of Expression.
func CloneExprs(exprs []expression.Expression) []expression.Expression {
	cloned := make([]expression.Expression, 0, len(exprs))
	for _, e := range exprs {
		cloned = append(cloned, e.Clone())
	}
	return cloned
}

// CloneCols uses (*Column).Clone to clone a slice of *Column.
func CloneCols(cols []*expression.Column) []*expression.Column {
	cloned := make([]*expression.Column, 0, len(cols))
	for _, c := range cols {
		if c == nil {
			cloned = append(cloned, nil)
			continue
		}
		cloned = append(cloned, c.Clone().(*expression.Column))
	}
	return cloned
}

// CloneColInfos uses (*ColumnInfo).Clone to clone a slice of *ColumnInfo.
func CloneColInfos(cols []*model.ColumnInfo) []*model.ColumnInfo {
	cloned := make([]*model.ColumnInfo, 0, len(cols))
	for _, c := range cols {
		cloned = append(cloned, c.Clone())
	}
	return cloned
}

// CloneRanges uses (*Range).Clone to clone a slice of *Range.
func CloneRanges(ranges []*ranger.Range) []*ranger.Range {
	cloned := make([]*ranger.Range, 0, len(ranges))
	for _, r := range ranges {
		cloned = append(cloned, r.Clone())
	}
	return cloned
}