package utils

import (
	"errors"
	"fmt"
	"strconv"
)

const TotalRows = 1048576

const MinColumns = 1

const MaxColumns = 16384

// ColumnNumberToName provides a function to convert the integer to Excel
// sheet column title.
//
// Example:
//
//	excelize.ColumnNumberToName(37) // returns "AK", nil
func ColumnNumberToName(num int) (string, error) {
	if num < MinColumns || num > MaxColumns {
		return "", fmt.Errorf("the column number must be greater than or equal to %d and less than or equal to %d", MinColumns, MaxColumns)
	}
	var col string
	for num > 0 {
		col = string(rune((num-1)%26+65)) + col
		num = (num - 1) / 26
	}
	return col, nil
}

// CoordinatesToCellName converts [X, Y] coordinates to alpha-numeric cell
// name or returns an error.
//
// Example:
//
//	excelize.CoordinatesToCellName(1, 1) // returns "A1", nil
//	excelize.CoordinatesToCellName(1, 1, true) // returns "$A$1", nil
func CoordinatesToCellName(col, row int, abs ...bool) (string, error) {
	if col < 1 || row < 1 {
		return "", errors.New("col row < 0")
	}
	if row > TotalRows {
		return "", errors.New("row number exceeds maximum limit")
	}
	colName, err := ColumnNumberToName(col)
	return colName + strconv.Itoa(row), err
}