feat(release): beelloo v0.1

internal/invoice/quantity.go

@@ -0,0 +1,70 @@
+package invoice
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// Quantity stores hundredths (e.g. 0.5 => 50).
+func ParseQuantity(input string) (Quantity, error) {
+	clean := strings.TrimSpace(input)
+	if clean == "" {
+		return 0, errors.New("empty quantity")
+	}
+	clean = strings.ReplaceAll(clean, " ", "")
+	clean = strings.ReplaceAll(clean, ",", ".")
+	if strings.HasPrefix(clean, ".") || strings.HasSuffix(clean, ".") {
+		return 0, fmt.Errorf("invalid quantity: %q", input)
+	}
+	parts := strings.Split(clean, ".")
+	if len(parts) > 2 {
+		return 0, fmt.Errorf("invalid quantity: %q", input)
+	}
+	whole := parts[0]
+	frac := ""
+	if len(parts) == 2 {
+		frac = parts[1]
+	}
+	if whole == "" {
+		whole = "0"
+	}
+	for _, r := range whole {
+		if r < '0' || r > '9' {
+			return 0, fmt.Errorf("invalid quantity: %q", input)
+		}
+	}
+	for _, r := range frac {
+		if r < '0' || r > '9' {
+			return 0, fmt.Errorf("invalid quantity: %q", input)
+		}
+	}
+	if len(frac) > 2 {
+		return 0, fmt.Errorf("invalid quantity: %q", input)
+	}
+	for len(frac) < 2 {
+		frac += "0"
+	}
+	var wholeValue int64
+	for _, r := range whole {
+		wholeValue = wholeValue*10 + int64(r-'0')
+	}
+	var fracValue int64
+	for _, r := range frac {
+		fracValue = fracValue*10 + int64(r-'0')
+	}
+	return Quantity(wholeValue*100 + fracValue), nil
+}
+
+func FormatQuantity(q Quantity) string {
+	value := int64(q)
+	whole := value / 100
+	frac := value % 100
+	if frac == 0 {
+		return fmt.Sprintf("%d", whole)
+	}
+	if frac%10 == 0 {
+		return fmt.Sprintf("%d.%d", whole, frac/10)
+	}
+	return fmt.Sprintf("%d.%02d", whole, frac)
+}