mchess-server/types/coordinate.go

package types

// coordinates starting at 1:1 and end at 8:8
type Coordinate struct {
	Col int `json:"col"`
	Row int `json:"row"`
}

const (
	RangeLastValid  = 8
	RangeFirstValid = 1

	RangeUpperInvalid = 9
	RangeLowerInvalid = 0
)

func (c Coordinate) Up(number int) *Coordinate {
	check := c.Row + number
	if check <= RangeLastValid {
		return &Coordinate{Row: check, Col: c.Col}
	}
	return nil
}
func (c Coordinate) Down(number int) *Coordinate {
	check := c.Row - number
	if check >= RangeFirstValid {
		return &Coordinate{Row: check, Col: c.Col}
	}
	return nil
}

// Right and left is seen from a board where row 1 is on the bottom
func (c Coordinate) Right(number int) *Coordinate {
	check := c.Col + number
	if check <= RangeLastValid {
		return &Coordinate{Row: c.Row, Col: check}
	}
	return nil
}
func (c Coordinate) Left(number int) *Coordinate {
	check := c.Col - number
	if check >= RangeFirstValid {
		return &Coordinate{Row: c.Row, Col: check}
	}
	return nil
}

func (c Coordinate) GetAllSquaresLeft() []Coordinate {
	squares := []Coordinate{}
	i := 1
	for {
		if square := c.Left(i); square != nil {
			squares = append(squares, *square)
			i += 1
		} else {
			return squares
		}
	}
}

func (c Coordinate) GetAllSquaresRight() []Coordinate {
	squares := []Coordinate{}
	i := 1
	for {
		if square := c.Right(i); square != nil {
			squares = append(squares, *square)
			i += 1
		} else {
			return squares
		}
	}
}

func (c Coordinate) GetAllSquaresAbove() []Coordinate {
	squares := []Coordinate{}
	i := 1
	for {
		if square := c.Up(i); square != nil {
			squares = append(squares, *square)
			i += 1
		} else {
			return squares
		}
	}
}

func (c Coordinate) GetAllSquaresBelow() []Coordinate {
	squares := []Coordinate{}
	i := 1
	for {
		if square := c.Down(i); square != nil {
			squares = append(squares, *square)
			i += 1
		} else {
			return squares
		}
	}
}
func (c Coordinate) GetSquaresOnRow() []Coordinate {
	rowToReturn := []Coordinate{}
	leftMostSquareOnRow := Coordinate{Col: RangeFirstValid, Row: c.Row}
	index := 0
	for {
		squareToAppend := leftMostSquareOnRow.Right(index)
		if squareToAppend == nil {
			break
		}
		rowToReturn = append(rowToReturn, *squareToAppend)
		index = index + 1
	}
	return rowToReturn
}

func (c Coordinate) GetSquaresOnColumn() []Coordinate {
	columnToReturn := []Coordinate{}
	bottomSquareOnColumn := Coordinate{Col: c.Col, Row: RangeFirstValid}
	index := 0
	for {
		squareToAppend := bottomSquareOnColumn.Up(index)
		if squareToAppend == nil {
			break
		}
		columnToReturn = append(columnToReturn, *squareToAppend)
		index = index + 1
	}
	return columnToReturn
}