--[[ Element: Power Bar

 Handles updating of `self.Power` based upon the units power.

 Widget

 Power - A StatusBar used to represent mana.

 Sub-Widgets

 .bg - A Texture which functions as a background. It will inherit the color of
       the main StatusBar.

 Notes

 The default StatusBar texture will be applied if the UI widget doesn't have a
 status bar texture or color defined.

 Options

 .displayAltPower   - Use this to let the widget display alternate power if the
                      unit has one. If no alternate power the display will fall
                      back to primary power.

 The following options are listed by priority. The first check that returns
 true decides the color of the bar.

 .colorTapping      - Use `self.colors.tapping` to color the bar if the unit
                      isn't tapped by the player.
 .colorDisconnected - Use `self.colors.disconnected` to color the bar if the
                      unit is offline.
 .altPowerColor     - A table containing the RGB values to use for a fixed
                      color if the alt power bar is being displayed instead
 .colorPower        - Use `self.colors.power[token]` to color the bar based on
                      the unit's power type. This method will fall-back to
                      `:GetAlternativeColor()` if it can't find a color matching
                      the token. If this function isn't defined, then it will
                      attempt to color based upon the alternative power colors
                      returned by [UnitPowerType](http://wowprogramming.com/docs/api/UnitPowerType).
                      Finally, if these aren't defined, then it will attempt to
                      color the bar based upon `self.colors.power[type]`.
 .colorClass        - Use `self.colors.class[class]` to color the bar based on
                      unit class. `class` is defined by the second return of
                      [UnitClass](http://wowprogramming.com/docs/api/UnitClass).
 .colorClassNPC     - Use `self.colors.class[class]` to color the bar if the
                      unit is a NPC.
 .colorClassPet     - Use `self.colors.class[class]` to color the bar if the
                      unit is player controlled, but not a player.
 .colorReaction     - Use `self.colors.reaction[reaction]` to color the bar
                      based on the player's reaction towards the unit.
                      `reaction` is defined by the return value of
                      [UnitReaction](http://wowprogramming.com/docs/api/UnitReaction).
 .colorSmooth       - Use `self.colors.smooth` to color the bar with a smooth
                      gradient based on the player's current health percentage.

 Sub-Widget Options

 .multiplier - Defines a multiplier, which is used to tint the background based
               on the main widgets R, G and B values. Defaults to 1 if not
               present.

 Examples

   -- Position and size
   local Power = CreateFrame("StatusBar", nil, self)
   Power:SetHeight(20)
   Power:SetPoint('BOTTOM')
   Power:SetPoint('LEFT')
   Power:SetPoint('RIGHT')
   
   -- Add a background
   local Background = Power:CreateTexture(nil, 'BACKGROUND')
   Background:SetAllPoints(Power)
   Background:SetTexture(1, 1, 1, .5)
   
   -- Options
   Power.frequentUpdates = true
   Power.colorTapping = true
   Power.colorDisconnected = true
   Power.colorPower = true
   Power.colorClass = true
   Power.colorReaction = true
   
   -- Make the background darker.
   Background.multiplier = .5
   
   -- Register it with oUF
   self.Power = Power
   self.Power.bg = Background

 Hooks

 Override(self) - Used to completely override the internal update function.
                  Removing the table key entry will make the element fall-back
                  to its internal function again.
]]

local parent, ns = ...
local oUF = ns.oUF

oUF.colors.power = {}
for power, color in next, PowerBarColor do
	if (type(power) == "string") then
		oUF.colors.power[power] = {color.r, color.g, color.b}
	end
end

oUF.colors.power[0] = oUF.colors.power["MANA"]
oUF.colors.power[1] = oUF.colors.power["RAGE"]
oUF.colors.power[2] = oUF.colors.power["FOCUS"]
oUF.colors.power[3] = oUF.colors.power["ENERGY"]
oUF.colors.power[4] = oUF.colors.power["CHI"]
oUF.colors.power[5] = oUF.colors.power["RUNES"]
oUF.colors.power[6] = oUF.colors.power["RUNIC_POWER"]
oUF.colors.power[7] = oUF.colors.power["SOUL_SHARDS"]
oUF.colors.power[8] = oUF.colors.power["ECLIPSE"]
oUF.colors.power[9] = oUF.colors.power["HOLY_POWER"]

local GetDisplayPower = function(unit)
	local _, min, _, _, _, _, showOnRaid = UnitAlternatePowerInfo(unit)
	if(showOnRaid) then
		return ALTERNATE_POWER_INDEX, min
	end
end

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

	if(power.PreUpdate) then power:PreUpdate(unit) end

	local displayType, min
	if power.displayAltPower then
		displayType, min = GetDisplayPower(unit)
	end
	local cur, max = UnitPower(unit, displayType), UnitPowerMax(unit, displayType)
	local disconnected = not UnitIsConnected(unit)
	power:SetMinMaxValues(min or 0, max)

	if(disconnected) then
		power:SetValue(max)
	else
		power:SetValue(cur)
	end

	power.disconnected = disconnected

	local r, g, b, t
	if(power.colorTapping and not UnitPlayerControlled(unit) and
		UnitIsTapped(unit) and not UnitIsTappedByPlayer(unit) and not
		UnitIsTappedByAllThreatList(unit)) then
		t = self.colors.tapped
	elseif(power.colorDisconnected and disconnected) then
		t = self.colors.disconnected
	elseif(displayType == ALTERNATE_POWER_INDEX and power.altPowerColor) then
		t = power.altPowerColor
	elseif(power.colorPower) then
		local ptype, ptoken, altR, altG, altB = UnitPowerType(unit)

		t = self.colors.power[ptoken]
		if(not t) then
			if(power.GetAlternativeColor) then
				r, g, b = power:GetAlternativeColor(unit, ptype, ptoken, altR, altG, altB)
			elseif(altR) then
				r, g, b = altR, altG, altB
			else
				t = self.colors.power[ptype]
			end
		end
	elseif(power.colorClass and UnitIsPlayer(unit)) or
		(power.colorClassNPC and not UnitIsPlayer(unit)) or
		(power.colorClassPet and UnitPlayerControlled(unit) and not UnitIsPlayer(unit)) then
		local _, class = UnitClass(unit)
		t = self.colors.class[class]
	elseif(power.colorReaction and UnitReaction(unit, 'player')) then
		t = self.colors.reaction[UnitReaction(unit, "player")]
	elseif(power.colorSmooth) then
        local adjust = 0 - (min or 0)
		r, g, b = self.ColorGradient(cur + adjust, max + adjust, unpack(power.smoothGradient or self.colors.smooth))
	end

	if(t) then
		r, g, b = t[1], t[2], t[3]
	end

	if(b) then
		power:SetStatusBarColor(r, g, b)

		local bg = power.bg
		if(bg) then
			local mu = bg.multiplier or 1
			bg:SetVertexColor(r * mu, g * mu, b * mu)
		end
	end

	if(power.PostUpdate) then
		return power:PostUpdate(unit, cur, max, min)
	end
end

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

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

local Enable = function(self, unit)
	local power = self.Power
	if(power) then
		power.__owner = self
		power.ForceUpdate = ForceUpdate

		if(power.frequentUpdates and (unit == 'player' or unit == 'pet')) then
			self:RegisterEvent('UNIT_POWER_FREQUENT', Path)
		else
			self:RegisterEvent('UNIT_POWER', Path)
		end

		self:RegisterEvent('UNIT_POWER_BAR_SHOW', Path)
		self:RegisterEvent('UNIT_POWER_BAR_HIDE', Path)
		self:RegisterEvent('UNIT_DISPLAYPOWER', Path)
		self:RegisterEvent('UNIT_CONNECTION', Path)
		self:RegisterEvent('UNIT_MAXPOWER', Path)

		-- For tapping.
		self:RegisterEvent('UNIT_FACTION', Path)

		if(power:IsObjectType'StatusBar' and not power:GetStatusBarTexture()) then
			power:SetStatusBarTexture[[Interface\TargetingFrame\UI-StatusBar]]
		end

		return true
	end
end

local Disable = function(self)
	local power = self.Power
	if(power) then
		self:UnregisterEvent('UNIT_POWER_FREQUENT', Path)
		self:UnregisterEvent('UNIT_POWER', Path)
		self:UnregisterEvent('UNIT_POWER_BAR_SHOW', Path)
		self:UnregisterEvent('UNIT_POWER_BAR_HIDE', Path)
		self:UnregisterEvent('UNIT_DISPLAYPOWER', Path)
		self:UnregisterEvent('UNIT_CONNECTION', Path)
		self:UnregisterEvent('UNIT_MAXPOWER', Path)
		self:UnregisterEvent('UNIT_FACTION', Path)
	end
end

oUF:AddElement('Power', Path, Enable, Disable)
