-- just bail out on classic
if WOW_PROJECT_ID ~= WOW_PROJECT_MAINLINE then return end

local oUF = ElvUF or oUF

-- based on oUF_GCD by Exactly.

--[[
	Spell IDs to check if they are available as GCD refs. The
	original oUF_GCD used spell names and did'nt play well
	with other locales. We use the spell id to lookup the
	spell name and look that up in the spell book ...

	Not all these spells are available at level 1 (most
	are learned at level 4). If you have a better suggestion(s),
	post a comment at:

	http://www.wowinterface.com/downloads/info14769-oUF_GCD-HungtarsoUFGlobalCooldownBar.html
--]]

local pairs = pairs
local print = print

local GetSpellTabInfo = GetSpellTabInfo
local GetSpellBookItemName = GetSpellBookItemName
local GetSpellInfo = GetSpellInfo

local referenceSpells = {
	49998,			-- Death Strike (Death Knight)
	193455,			-- Cobra Shoot (Hunter)
	585,			-- Smite (Priest)
	35395,			-- Crusader Strike (Paladin)
	172,			-- Corruption (Warlock)
	133,			-- Fireball (Mage)
	116,			-- Frostbolt (Mage)
	1464,			-- Slam (Warrior)
	188196,			-- Lightning Bold (Shaman)
	1752,			-- Sinister Strike (Rogue)
	53,				-- Backstab (Rogue)
	5176,			-- Wrath (Druid)
	100780,			-- Tiger Palm (Monk)
	162243,			-- Demon's Bite (Demon Hunter)
	203555,			-- Demon Blades (Demon Hunter)
}

local GetTime = GetTime
local BOOKTYPE_SPELL = BOOKTYPE_SPELL
local GetSpellCooldown = GetSpellCooldown

local spellid = nil

--
-- find a spell to use.
--
local Init = function()
	local FindInSpellbook = function(spell)
		for tab = 1, 4 do
			local _, _, offset, numSpells = GetSpellTabInfo(tab)
			for i = (1+offset), (offset + numSpells) do
				local bspell = GetSpellBookItemName(i, BOOKTYPE_SPELL)
				if (bspell == spell) then
					return i
				end
			end
		end
		return nil
	end

	for _, lspell in pairs(referenceSpells) do
		local na = GetSpellInfo (lspell)
		local x = FindInSpellbook(na)
		if x ~= nil then
			spellid = lspell
			break
		end
	end

	if spellid == nil then
		-- XXX: print some error ..
		print("oUF_GCD: Missing Spell Data")
	end

	return spellid
end

local OnUpdateGCD = function(self)
	local perc = (GetTime() - self.starttime) / self.duration
	if perc > 1 then
		self:Hide()
	else
		if self.Text then
			self.Text:SetFormattedText("%.1f", self.duration - GetTime() + self.starttime)
		end
		self:SetValue(perc)
	end
end

local OnHideGCD = function(self)
	self:SetScript('OnUpdate', nil)
end

local OnShowGCD = function(self)
	self:SetScript('OnUpdate', OnUpdateGCD)
end

local Update = function(self, event, unit)
	if self.GCD then
		if spellid == nil then
			if Init() == nil then
				return
			end
		end

		local start, dur = GetSpellCooldown(spellid)

		if (not start) then return end
		if (not dur) then dur = 0 end

		if (dur == 0) then
			self.GCD:Hide()
		else
			self.GCD.starttime = start
			self.GCD.duration = dur
			self.GCD:Show()
		end
	end
end

local Enable = function(self)
	if (self.GCD) then
		self.GCD:Hide()
		self.GCD.starttime = 0
		self.GCD.duration = 0
		self.GCD:SetMinMaxValues(0, 1)

		self:RegisterEvent('ACTIONBAR_UPDATE_COOLDOWN', Update, true)
		self.GCD:SetScript('OnHide', OnHideGCD)
		self.GCD:SetScript('OnShow', OnShowGCD)
	end
end

local Disable = function(self)
	if (self.GCD) then
		self:UnregisterEvent('ACTIONBAR_UPDATE_COOLDOWN')
		self.GCD:Hide()
	end
end

oUF:AddElement('GCD', Update, Enable, Disable)
