invoice

type Bill struct {
	ClientName    string
	ClientAddress CompanyAddress
	InvoiceNumber string
	DateOfIssue   string
	// nothing fancy here and complicated, we will just prepend the currency with the price
	Currency string
	Units    []Unit
}

type CompanyAddress struct {
	Number  int
	Street  string
	ZipCode string
	Country string
}

type CompanyDetails struct {
	Email  string
	Phone  string
	Domain string
}

type Generator struct {
	CompanyDetails
	CompanyAddress
	Bill
}

type Unit struct {
	UnitName       string
	PricePerUnit   int // in cent
	UnitsPurchased int
}