// currencyUnits converts a types.Currency to a string with human-readable
// units. The unit used will be the largest unit that results in a value
// greater than 1. The value is rounded to 4 significant digits.
func currencyUnits(c types.Currency) string {
pico := types.SiacoinPrecision.Div64(1e12)
if c.Cmp(pico) < 0 {
return c.String() + " H"
}
// iterate until we find a unit greater than c
mag := pico
unit := ""
for _, unit = range []string{"pS", "nS", "uS", "mS", "SC", "KS", "MS", "GS", "TS"} {
if c.Cmp(mag.Mul64(1e3)) < 0 {
break
} else if unit != "TS" {
// don't want to perform this multiply on the last iter; that
// would give us 1.235 TS instead of 1235 TS
mag = mag.Mul64(1e3)
}
}
num := new(big.Rat).SetInt(c.Big())
denom := new(big.Rat).SetInt(mag.Big())
res, _ := new(big.Rat).Mul(num, denom.Inv(denom)).Float64()
return fmt.Sprintf("%.4g %s", res, unit)
}