Initial add backend stuff

finance/helpers.go

@@ -0,0 +1,234 @@
+package finance
+
+import (
+	. "kjol/basic"
+	"fmt"
+	"math"
+	"strconv"
+	"strings"
+)
+
+// takes a number such as 123456, and outputs (1234, 56) as strings
+func SplitInt64(n int64) (string, string) {
+	// Calculate the first part as string
+	firstPart := fmt.Sprintf("%d", n/100)
+	// Calculate the second part as string with leading zero if necessary
+	secondPart := fmt.Sprintf("%02d", n%100)
+	return firstPart, secondPart
+}
+
+func Int64ToMoney(value int64) string {
+	decimalValue := float64(value) / 100.0
+	moneyString := fmt.Sprintf("%.2f", decimalValue)
+	return moneyString
+}
+
+func Int64ToMoneyWithCommas(value int64) string {
+	decimalValue := float64(value) / 100.0
+	moneyString := fmt.Sprintf("%.2f", decimalValue)
+
+	parts := strings.Split(moneyString, ".")
+	dollars := parts[0]
+	cents := parts[1]
+
+	negative := false
+	if strings.HasPrefix(dollars, "-") {
+		negative = true
+		dollars = dollars[1:]
+	}
+
+	result := ""
+	for i, char := range dollars {
+		if i > 0 && (len(dollars)-i)%3 == 0 {
+			result += ","
+		}
+		result += string(char)
+	}
+
+	if negative {
+		result = "-" + result
+	}
+
+	return result + "." + cents
+}
+
+func MoneyToInt64(input string) int64 {
+	if !strings.Contains(input, ".") {
+		input += ".00"
+	} else if strings.Count(input, ".") == 1 {
+		digits := strings.Split(input, ".")
+		if len(digits[1]) == 1 {
+			input += "0"
+		}
+	}
+	processedString := strings.ReplaceAll(input, ".", "")
+	processedString = strings.ReplaceAll(processedString, ",", "")
+	processedString = strings.ReplaceAll(processedString, " ", "")
+	result, _ := strconv.Atoi(processedString)
+	return int64(result)
+}
+
+func Int64ToRate(rate int64) string {
+	decimalValue := float64(rate) / 1000.0
+	rateString := fmt.Sprintf("%.3f", decimalValue)
+	return rateString
+}
+
+func RoundUpToCeiling(input int64) int64 {
+	remainder := input % 100
+	if remainder == 0 {
+		return input
+	}
+	return input + 100 - remainder
+}
+
+func RoundDownToFloor(input int64) int64 {
+	remainder := input % 100
+	if remainder == 0 {
+		return input
+	}
+	return input - remainder
+}
+
+func MultiplyByPercentageS64(amount int64, percentage float64) int64 {
+	amount_float64 := float64(amount) / 100
+	out_float64 := (amount_float64 * (percentage / 100))
+
+	out_int64 := int64(math.Round(out_float64 * 100))
+
+	return out_int64
+}
+
+func MultiplyByPercentageF64(amount int64, percentage float64) float64 {
+	amount_float64 := float64(amount) / 100
+
+	return amount_float64 * percentage
+}
+
+func ProcessDiscount(discount string) float64 {
+	discount_f64, _ := strconv.ParseFloat(discount, 64)
+
+	if discount_f64 < 0 {
+		return 0
+	} else if discount_f64 > 100 {
+		return 100
+	}
+
+	return discount_f64
+}
+
+// DaysToRateTerm Takes days as an input and outputs the string representation of the number of
+// days, months, or years in the term based on which unit is the best fit for the amount of days
+// along with the corresponding unit string.
+func DaysToRateTerm(days int32) (string, string) {
+	years := days / 365
+	months := (days - years*365) / 30
+	dayRemainder := days - years*365 - months*30
+
+	if days == 0 { // Return empty string for value
+		return "", "days"
+	} else if days <= 270 || dayRemainder > 0 {
+		return ToString(days), "days"
+	} else if months > 0 {
+		return ToString(months + years*12), "months"
+	} else {
+		return ToString(years), "years"
+	}
+}
+
+func RateTermToDays(value string, unit string) int32 {
+	valueInt := StringToInt32(value)
+	switch unit {
+	case "months":
+		years := valueInt / 12
+		months := valueInt % 12
+		return years*365 + months*30
+	case "years":
+		return valueInt * 365
+	default: // case "days":
+		return valueInt
+	}
+}
+
+func RateToString(rateValue float64) string {
+	str, err := NumberToString(rateValue, 3, "%", true)
+	if err != nil {
+		fmt.Println(err)
+		return fmt.Sprint(rateValue)
+	}
+	return str
+}
+
+func RatePlainToString(rateValue float64) string {
+	str, err := NumberToString(rateValue, 3, "", false)
+	if err != nil {
+		fmt.Println(err)
+		return fmt.Sprint(rateValue)
+	}
+	return str
+}
+
+func DollarAmountToString(amount float64) string {
+	str, err := NumberToString(amount, 2, "", false)
+	if err != nil {
+		fmt.Println(err)
+		return fmt.Sprint(amount)
+	}
+	return str
+}
+
+func DollarAmountPlainToString(amount float64) string {
+	str, err := NumberToString(amount, 2, "$", false)
+	if err != nil {
+		fmt.Println(err)
+		return fmt.Sprint(amount)
+	}
+	return str
+}
+
+func NumberToString(i any, precision int, symbol string, symbolLast bool) (string, error) {
+	var numberFloat float64 = 0.0
+	err := fmt.Errorf("error: could not convert %s to a decimal value", i)
+	switch i.(type) {
+	case int32, int64, int, uint64, uint32, uint, float32, float64:
+		if val, ok := i.(float64); ok {
+			numberFloat = val
+		} else {
+			return "", err
+		}
+	default:
+		return "", fmt.Errorf("error: could not convert %s to a decimal value", i)
+	}
+
+	s := fmt.Sprintf("%.[2]*[1]f", numberFloat, precision)
+
+	parts := strings.Split(s, ".")
+	if len(parts) == 0 {
+		return "", fmt.Errorf("error: could not convert '%s' to a decimal value", s)
+	}
+
+	numberLeftSide := parts[0][len(parts[0])-1:]
+
+	for i := len(parts[0]) - 2; i >= 0; i-- {
+
+		if len(strings.Replace(numberLeftSide, ",", "", -1))%3 == 0 {
+			numberLeftSide = "," + numberLeftSide
+		}
+		numberLeftSide = string(parts[0][i]) + numberLeftSide
+
+	}
+	numberToReturn := numberLeftSide
+	if len(parts) > 1 {
+		numberToReturn = numberToReturn + "." + parts[1]
+	}
+
+	if symbol != "" {
+		if symbolLast {
+			numberToReturn = numberToReturn + symbol
+		} else {
+			numberToReturn = symbol + numberToReturn
+		}
+	}
+
+	return numberToReturn, nil
+}