local MAX_MINUTES = 60 * 12

local Time = {}
Time.__index = Time

local function newTimeRaw(rawMinutes)
  local t = {
    rawminutes = rawMinutes % MAX_MINUTES
  }
  return setmetatable(t, Time)
end

function Time:new(hour, minute)
  return newTimeRaw((hour or 12) % 12 * 60 + (minute or 0))
end

function Time:get()
  local h = math.floor(self.rawminutes / 60 % 12)
  if h == 0 then h = 12 end
  local m = self.rawminutes % 60
  return h, m
end

function Time:getHoursSinceTwelve()
  local h = self.rawminutes / 60
  if h < 1 then h = h + 12 end
  return h
end

function Time:addMinutes(minutes)
  return newTimeRaw(self.rawminutes + minutes)
end

function Time:__tostring()
  local h, m = self:get()
  return string.format("%2d:%02d", h, m)
end

return Time