local _, ns = ...
local oUF = ns.oUF

local UnitPower = UnitPower
local UnitPowerMax = UnitPowerMax
local UnitPowerType = UnitPowerType

local OnUpdate = function(self, elapsed)
    self.elapsed = self.elapsed + elapsed

    self:SetValue(self.elapsed)

    if (self.elapsed >= 5) then
        self:Hide()
    end
end

local Update = function(self, event, unit)
    if (unit ~= self.unit) then
        return
    end

    local element = self.ManaTimer

    if element then
        local Type = UnitPowerType(self.unit)

        if (Type ~= 0) or (UnitPower(unit) == UnitPowerMax(unit)) then
            return
        end

        element.elapsed = 0

        element:Show()
        element:SetScript("OnUpdate", OnUpdate)
    end
end

local Path = function(self, ...)
    return (self.ManaTimer.Override or Update)(self, ...)
end

local ForceUpdate = function(element)
    return Path(element.__owner, "ForceUpdate", element.__owner.unit)
end

local Enable = function(self)
    local element = self.ManaTimer

    if element then
        element.__owner = self
        element.ForceUpdate = ForceUpdate

        element:Hide()
        element:SetMinMaxValues(0, 5)
        self:RegisterEvent("UNIT_SPELLCAST_SUCCEEDED", Update)
    end
end

local Disable = function(self)
    local element = self.ManaTimer

    if element then
        element:Hide()
        element:UnregisterEvent("UNIT_SPELLCAST_SUCCEEDED", Update)
    end
end

oUF:AddElement("ManaRegen", Path, Enable, Disable)