options.go

package rail_fence_cipher

// ------------------------------------------------ ---------------------------------------------------------------------

// EdgeDirection 用于表示栅栏的起点和方向，对标准的栅栏加密进行的一些扩展，使其能够更灵活精细的控制加密过程从而组合打造独属于自己的栅栏加密算法
type EdgeDirection int

const (

	// EdgeDirectionLeftTop2Right 从左上往右
	EdgeDirectionLeftTop2Right EdgeDirection = iota

	// EdgeDirectionLeftTop2Bottom 从左上往下
	EdgeDirectionLeftTop2Bottom

	// EdgeDirectionLeftBottom2Top 从左下往上
	EdgeDirectionLeftBottom2Top

	// EdgeDirectionLeftBottom2Right 从左下往右
	EdgeDirectionLeftBottom2Right

	// EdgeDirectionRightTop2Left 从右上往左
	EdgeDirectionRightTop2Left

	// EdgeDirectionRightTop2Bottom 从右上往下
	EdgeDirectionRightTop2Bottom

	// EdgeDirectionRightBottom2Top 从右下往上
	EdgeDirectionRightBottom2Top

	// EdgeDirectionRightBottom2Left 从右下往左
	EdgeDirectionRightBottom2Left
)

// ------------------------------------------------ ---------------------------------------------------------------------

// Options 加密或者解密时通用的一些选项
type Options struct {

	// 往栅栏中放入字符的时候的方向，不能与TakeEdgeDirection相同
	PutEdgeDirection EdgeDirection

	// 从栅栏中拿字符的时候的方向，不能与TakeEdgeDirection相同
	TakeEdgeDirection EdgeDirection

	// 栅栏是几列
	Columns int
	// 栅栏是几行
	Rows int

	// 长度不够的时候拿什么字符来填充对齐
	FillCharacter rune
}

// NewOptions 创建一个选项，使用默认的参数配置
func NewOptions() *Options {
	return &Options{
		PutEdgeDirection:  EdgeDirectionLeftTop2Right,
		TakeEdgeDirection: EdgeDirectionLeftTop2Bottom,
		Columns:           2,
		Rows:              3,
		FillCharacter:     'x',
	}
}

func (x *Options) WithPutEdgeDirection(putEdgeDirection EdgeDirection) *Options {
	x.PutEdgeDirection = putEdgeDirection
	return x
}

func (x *Options) WithTakeEdgeDirection(takeEdgeDirection EdgeDirection) *Options {
	x.TakeEdgeDirection = takeEdgeDirection
	return x
}

func (x *Options) WithColumns(columns int) *Options {
	x.Columns = columns
	return x
}

func (x *Options) WithRows(rows int) *Options {
	x.Rows = rows
	return x
}

func (x *Options) WithFillCharacter(fillCharacter rune) *Options {
	x.FillCharacter = fillCharacter
	return x
}

// ------------------------------------------------ ---------------------------------------------------------------------