local LibSpellHighlight = Wheel:Set("LibSpellHighlight", 8)
if (not LibSpellHighlight) then
	return
end

local LibEvent = Wheel("LibEvent")
assert(LibEvent, "LibSpellHighlight requires LibEvent to be loaded.")

local LibMessage = Wheel("LibMessage")
assert(LibMessage, "LibSpellHighlight requires LibMessage to be loaded.")

local LibClientBuild = Wheel("LibClientBuild")
assert(LibClientBuild, "LibCast requires LibClientBuild to be loaded.")

local LibAura = Wheel("LibAura")
assert(LibAura, "LibSpellHighlight requires LibAura to be loaded.")

local LibModule = Wheel("LibModule")
assert(LibModule, "LibSpellHighlight requires LibModule to be loaded.")

local Debug = function(...)
	LibModule:AddDebugMessageFormatted(...)
end

-- Embed functionality into this
LibEvent:Embed(LibSpellHighlight)
LibMessage:Embed(LibSpellHighlight)
LibAura:Embed(LibSpellHighlight)

-- Lua API
local _G = _G
local assert = assert
local bit_band = bit.band
local debugstack = debugstack
local error = error
local select = select
local string_format = string.format
local string_join = string.join
local string_match = string.match
local table_wipe = table.wipe
local type = type

-- WoW API
local CombatLogGetCurrentEventInfo = CombatLogGetCurrentEventInfo
local GetComboPoints = GetComboPoints
local GetSpellInfo = GetSpellInfo
local IsPlayerSpell = IsPlayerSpell
local IsUsableSpell = IsUsableSpell
local UnitClass = UnitClass
local UnitCreatureType = UnitCreatureType
local UnitExists = UnitExists
local UnitGUID = UnitGUID
local UnitHealth = UnitHealth
local UnitHealthMax = UnitHealthMax
local UnitIsDeadOrGhost = UnitIsDeadOrGhost
local UnitIsFriend = UnitIsFriend
local UnitPower = UnitPower
local UnitPowerMax = UnitPowerMax
local UnitPowerType = UnitPowerType

-- Doing it this way to make the transition to library later on easier
LibSpellHighlight.embeds = LibSpellHighlight.embeds or {} 
LibSpellHighlight.activeHighlights = LibSpellHighlight.activeHighlights or {} -- current active highlights spellIDs and their highlight type
LibSpellHighlight.activeHighlightsByAuraID = LibSpellHighlight.activeHighlightsByAuraID or {}
LibSpellHighlight.highlightSpellsByAuraID = LibSpellHighlight.highlightSpellsByAuraID or {} -- reactive auras and actionbar highlight spells
LibSpellHighlight.highlightTypeByAuraID = LibSpellHighlight.highlightTypeByAuraID or {} -- character auraID to actionbar highlight type
LibSpellHighlight.highlightTypeBySpellID = LibSpellHighlight.highlightTypeBySpellID or {}
LibSpellHighlight.reactiveSpellsBySpellID = LibSpellHighlight.reactiveSpellsBySpellID or {}
LibSpellHighlight.comboFinishersBySpellID = LibSpellHighlight.comboFinishersBySpellID or {}
LibSpellHighlight.spellIDToAuraID = LibSpellHighlight.spellIDToAuraID or {} -- table to convert spellID to triggering auraID
LibSpellHighlight.playerSpellCache = LibSpellHighlight.playerSpellCache or {} -- dynamically updated cache of current available spellIDs
LibSpellHighlight.runningTimers = LibSpellHighlight.runningTimers or {} -- currently running timers

-- Frame tracking timers
LibSpellHighlight.frame = LibSpellHighlight.frame or CreateFrame("Frame") 

-- Shortcuts
local Frame = LibSpellHighlight.frame
local Timers = LibSpellHighlight.runningTimers
local ActiveHighlights = LibSpellHighlight.activeHighlights
local ActiveHighlightsByAuraID = LibSpellHighlight.activeHighlightsByAuraID
local HighlightSpellsByAuraID = LibSpellHighlight.highlightSpellsByAuraID
local HighlightTypeByAuraID = LibSpellHighlight.highlightTypeByAuraID
local HighlightTypeBySpellID = LibSpellHighlight.highlightTypeBySpellID
local ReactiveSpellsBySpellID = LibSpellHighlight.reactiveSpellsBySpellID
local ComboFinishersBySpellID = LibSpellHighlight.comboFinishersBySpellID
local SpellIDToAuraID = LibSpellHighlight.spellIDToAuraID
local PlayerSpellCache = LibSpellHighlight.playerSpellCache

-- Reset caches in case of library upgrade
table_wipe(ComboFinishersBySpellID)
table_wipe(HighlightSpellsByAuraID)
table_wipe(HighlightTypeByAuraID)
table_wipe(HighlightTypeBySpellID)
table_wipe(ReactiveSpellsBySpellID)

-- Kill off any existing events in case of a library upgrade
LibSpellHighlight:UnregisterAllEvents()
LibSpellHighlight:UnregisterAllMessages()

-- Player Constants
local _,playerClass = UnitClass("player")
local playerGUID = UnitGUID("player")

-- Constants for client version
local IsClassic = LibClientBuild:IsClassic()
local IsRetail = LibClientBuild:IsRetail()

-- Sourced from BlizzardInterfaceResources/Resources/EnumerationTables.lua
local SPELL_POWER_COMBO_POINTS = Enum.PowerType.ComboPoints
local SPELL_POWER_ENERGY = Enum.PowerType.Energy

-- Sourced from FrameXML/TargetFrame.lua
local MAX_COMBO_POINTS = MAX_COMBO_POINTS

-- Sourced from FrameXML/BuffFrame.lua
local BUFF_MAX_DISPLAY = BUFF_MAX_DISPLAY

-- Sourced from FrameXML/Constants.lua
local COMBATLOG_OBJECT_AFFILIATION_MINE = COMBATLOG_OBJECT_AFFILIATION_MINE

-- Localized spell- and creature type names
-- https://wow.gamepedia.com/API_UnitCreatureType
local gameLocale = GetLocale()
local L = {
	Creature_Demon = ({
		enUS = "Demon",
		deDE = "Dämon",
		esES = "Demonio",
		esMX = "Demonio",
		frFR = "Démon",
		itIT = "Demone",
		ptBR = "Demônio",
		ruRU = "Демон",
		koKR = "악마",
		zhCN = "恶魔",
		zhTW = "惡魔"
	})[gameLocale],

	Creature_Undead = ({
		enUS = "Undead",
		deDE = "Untoter",
		esES = "No-muerto",
		esMX = "No-muerto",
		frFR = "Mort-vivant",
		itIT = "Non Morto",
		ptBR = "Renegado",
		ruRU = "Нежить",
		koKR = "언데드",
		zhCN = "亡灵",
		zhTW = "不死族"
	})[gameLocale],

	Spell_Counterattack = GetSpellInfo(19306),
	Spell_Execute = GetSpellInfo(20662),
	Spell_Exorcism = GetSpellInfo(879),
	Spell_HammerOfWrath = GetSpellInfo(24239),
	Spell_MongooseBite = GetSpellInfo(1495),
	Spell_Nightfall = GetSpellInfo(18094),
	Spell_Overpower = GetSpellInfo(7384),
	Spell_Revenge = GetSpellInfo(6572),
	Spell_Riposte = GetSpellInfo(14251),
	Spell_ShadowBolt = GetSpellInfo(686)
}

-- Utility Functions
----------------------------------------------------
-- Syntax check 
local check = function(value, num, ...)
	assert(type(num) == "number", ("Bad argument #%.0f to '%s': %s expected, got %s"):format(2, "Check", "number", type(num)))
	for i = 1,select("#", ...) do
		if type(value) == select(i, ...) then 
			return 
		end
	end
	local types = string_join(", ", ...)
	local name = string_match(debugstack(2, 2, 0), ": in function [`<](.-)['>]")
	error(string_format("Bad argument #%.0f to '%s': %s expected, got %s", num, name, types, type(value)), 3)
end

-- Public API
----------------------------------------------------
-- Strict boolean return values
LibSpellHighlight.IsSpellOverlayed = function(self, spellID)
	-- Check for active spellIDs
	if (ActiveHighlights[spellID]) then
		return true
	else
		-- Check if an aura connected to the spellID is active
		local auraID = SpellIDToAuraID[spellID]
		if (auraID) and (ActiveHighlightsByAuraID[auraID]) then
			return true
		end
	end
	return false
end

-- Can be used in the same manner as the above,
-- but this one returns the overlay type or nil instead of strictly booleans.
LibSpellHighlight.GetSpellOverlayType = function(self, spellID)
	-- Check for active spellIDs
	if (ActiveHighlights[spellID]) then
		local highlightType = HighlightTypeBySpellID[spellID]
		if (highlightType) then
			return highlightType
		end
	else
		-- Check if an aura connected to the spellID is active
		local auraID = SpellIDToAuraID[spellID]
		if (auraID) and (ActiveHighlightsByAuraID[auraID]) then
			return HighlightTypeByAuraID[auraID]
		end
	end
end

-- Library Timers
----------------------------------------------------
-- Constant to track if updates are running
local TimerRunning 

-- Reset the frame, in case this is a library update
Frame:SetScript("OnUpdate", nil)
Frame.timers = Timers

local OnUpdate = function(self, elapsed)
	local hasTimers
	for spellID, timeLeft in pairs(self.timers) do
		if (timeLeft - elapsed > 0) then
			self.timers[spellID] = timeLeft - elapsed
			hasTimers = true
		else
			Debug(string_format("Disabling SpellHighlight timer for %d",spellID))
			LibSpellHighlight:DeactivateHighlight(spellID)
		end
	end
	if (not hasTimers) then
		Debug(string_format("Disabling SpellHighlight OnUpdate"))
		TimerRunning = nil
		self:SetScript("OnUpdate", nil)
	end
end

LibSpellHighlight.ActivateHighlight = function(self, spellID, duration)
	Timers[spellID] = duration
	ActiveHighlights[spellID] = true

	if (duration) then
		Debug(string_format("Enabling SpellHighlight for %d (%d seconds)",spellID,duration))
	else
		Debug(string_format("Enabling SpellHighlight for %d",spellID))
	end

	self:SendMessage("GP_SPELL_ACTIVATION_OVERLAY_GLOW_SHOW", spellID, HighlightTypeBySpellID[spellID])

	if (duration) and (not TimerRunning) then
		Debug(string_format("Enabling SpellHighlight OnUpdate"))
		TimerRunning = true
		Frame:SetScript("OnUpdate", OnUpdate)
	end
end

LibSpellHighlight.DeactivateHighlight = function(self, spellID)
	Timers[spellID] = nil
	ActiveHighlights[spellID] = nil
	Debug(string_format("Disabling SpellHighlight for %d",spellID))
	self:SendMessage("GP_SPELL_ACTIVATION_OVERLAY_GLOW_HIDE", spellID, HighlightTypeBySpellID[spellID])
end

-- TODO: Create a faster cache on entering world / changing spells!
-- TODO: proxy the events, call class methods from it
LibSpellHighlight.UpdatePlayerSpellCache = function(self)
	-- Clear the old. Faster than wipe.
	for spellName in pairs(PlayerSpellCache) do
		PlayerSpellCache[spellName] = nil
	end
	-- Cache the new.
	for spellName,spellList in pairs(ReactiveSpellsBySpellID) do
		for i = #spellList,1,-1 do
			local spellID = spellList[i]
			if (IsPlayerSpell(spellID)) then
				PlayerSpellCache[spellName] = spellID
				break -- need to break to avoid overwriting it with a lower rank
			end
		end
	end
end

-- Library Updates
----------------------------------------------------
local currentTriggerAuras = {}
local comboPointsAreMaxed

-- Druid, Warlock
LibSpellHighlight.UpdateAuras = function(self, event, ...)
	local unit = ...

	-- This is a local temporary list of highlights,
	-- which we need to reset on every iteration.
	for auraID in pairs(currentTriggerAuras) do
		currentTriggerAuras[auraID] = nil
	end

	-- Iterate for current highlights
	for i = 1, BUFF_MAX_DISPLAY do 

		-- Retrieve buff information
		local name, icon, count, debuffType, duration, expirationTime, unitCaster, isStealable, nameplateShowPersonal, auraID, canApplyAura, isBossDebuff, isCastByPlayer, nameplateShowAll, timeMod, value1, value2, value3 = self:GetUnitBuff("player", i, "HELPFUL PLAYER")

		-- No name means no more buffs matching the filter
		if (not name) then
			break
		end

		local highlightsByAuraID = HighlightSpellsByAuraID[auraID]
		if (highlightsByAuraID) then

			-- Add it to this iteration's highlights.
			currentTriggerAuras[auraID] = true

			if (not ActiveHighlightsByAuraID[auraID]) then
				ActiveHighlightsByAuraID[auraID] = true

				for spellID in pairs(highlightsByAuraID) do -- iterate spell list
					self:ActivateHighlight(spellID)
				end
			end
		end
		
	end

	-- Disable active highlights that no longer match the current iteration.
	for auraID in pairs(ActiveHighlightsByAuraID) do -- iterate the previous aura iteration
		if (not currentTriggerAuras[auraID]) then -- compare to the current iteration

			-- Clear out this entry
			ActiveHighlightsByAuraID[auraID] = nil

			local highlightsByAuraID = HighlightSpellsByAuraID[auraID] -- get spell list
			if (highlightsByAuraID) then
				for spellID in pairs(highlightsByAuraID) do -- iterate spell list
					self:DeactivateHighlight(spellID)
				end
			end
		end
	end
end

-- Druid, Rogue
LibSpellHighlight.UpdateComboPoints = function(self, event, ...)
	local min = UnitPower("player", SPELL_POWER_COMBO_POINTS)
	local max = UnitPowerMax("player", SPELL_POWER_COMBO_POINTS)
	if (min == max) then
		if (not comboPointsAreMaxed) then
			comboPointsAreMaxed = true
			for spellID in pairs(ComboFinishersBySpellID) do
				self:ActivateHighlight(spellID)
			end
		end
	else
		if (comboPointsAreMaxed) then
			comboPointsAreMaxed = nil
			for spellID in pairs(ComboFinishersBySpellID) do
				self:DeactivateHighlight(spellID)
			end
		end
	end
end

-- Hunter
LibSpellHighlight.UpdateCounterAttack = function(self, event, ...)
	local timestamp, eventType, hideCaster,
	sourceGUID, sourceName, sourceFlags, sourceRaidFlags,
	destGUID, destName, destFlags, destRaidFlags,
	swingMissType, spellName, _, spellMissType, swingBlocked = CombatLogGetCurrentEventInfo()

	local isSrcPlayer = bit_band(sourceFlags, COMBATLOG_OBJECT_AFFILIATION_MINE) == COMBATLOG_OBJECT_AFFILIATION_MINE
	local isDstPlayer = destGUID == playerGUID

	if (isDstPlayer) then
		if (eventType == "SWING_MISSED") or (eventType == "SPELL_MISSED") then
			local missedType
			if (eventType == "SWING_MISSED") then
				missedType = swingMissType
			elseif (eventType == "SPELL_MISSED") then
				missedType = spellMissType
			end
			if (missedType == "PARRY") then
				local spellID = PlayerSpellCache[L.Spell_Counterattack]
				self:ActivateHighlight(spellID, 5)
			end
		end
	end
	
	if (isSrcPlayer) and (eventType == "SPELL_CAST_SUCCESS") and (spellName == L.Spell_Counterattack) then
		local spellID = PlayerSpellCache[L.Spell_Counterattack]
		self:DeactivateHighlight(spellID)
	end
end

-- Warrior
LibSpellHighlight.UpdateExecute = function(self, event, ...)
	local enable
	if (UnitExists("target")) and (not UnitIsFriend("player", "target")) then
		local min = UnitHealth("target")
		local max = UnitHealthMax("target")
		if (min > 0) and (max > 0) and ((min/max < .2) or IsUsableSpell(spellID)) then
			enable = true
		end
	end
	local spellID = PlayerSpellCache[L.Spell_Execute]
	if (enable) then
		self:ActivateHighlight(spellID, 10)
	else
		self:DeactivateHighlight(spellID)
	end
end

-- Paladin
LibSpellHighlight.UpdateExorcism = function(self, event, ...)
	-- 5 sec duration
end

-- Paladin
LibSpellHighlight.UpdateHammerOfWrath = function(self, event, ...)
	local spellID = PlayerSpellCache[L.Spell_HammerOfWrath]
	local enable
	if (UnitExists("target")) and (not UnitIsFriend("player", "target")) then
		local min = UnitHealth("target")
		local max = UnitHealthMax("target")
		if (min > 0) and (max > 0) and (min/max < .2) then
			enable = true
		end
	end
	if (enable) then
		self:ActivateHighlight(spellID, 10)
	else
		self:DeactivateHighlight(spellID)
	end
end

-- Hunter
LibSpellHighlight.UpdateMongooseBite = function(self, event, ...)
	local timestamp, eventType, hideCaster,
	sourceGUID, sourceName, sourceFlags, sourceRaidFlags,
	destGUID, destName, destFlags, destRaidFlags,
	swingMissType, spellName, _, spellMissType, swingBlocked = CombatLogGetCurrentEventInfo()

	local isSrcPlayer = bit_band(sourceFlags, COMBATLOG_OBJECT_AFFILIATION_MINE) == COMBATLOG_OBJECT_AFFILIATION_MINE
	local isDstPlayer = destGUID == playerGUID

	if (isDstPlayer) then
		if (eventType == "SWING_MISSED") or (eventType == "SPELL_MISSED") then
			local missedType
			if (eventType == "SWING_MISSED") then
				missedType = swingMissType
			elseif (eventType == "SPELL_MISSED") then
				missedType = spellMissType
			end
			if (missedType == "DODGE") then
				local spellID = PlayerSpellCache[L.Spell_MongooseBite]
				self:ActivateHighlight(spellID, 5)
			end
		end
	end
	
	if (isSrcPlayer) and (eventType == "SPELL_CAST_SUCCESS") and (spellName == L.Spell_MongooseBite) then
		local spellID = PlayerSpellCache[L.Spell_MongooseBite]
		self:DeactivateHighlight(spellID)
	end
end

-- Warrior
LibSpellHighlight.UpdateOverpower = function(self, event, ...)
	local timestamp, eventType, hideCaster,
	sourceGUID, sourceName, sourceFlags, sourceRaidFlags,
	destGUID, destName, destFlags, destRaidFlags,
	swingMissType, spellName, _, spellMissType = CombatLogGetCurrentEventInfo()

	local isSrcPlayer = bit_band(sourceFlags, COMBATLOG_OBJECT_AFFILIATION_MINE) == COMBATLOG_OBJECT_AFFILIATION_MINE

	if (isSrcPlayer) then
		if (eventType == "SWING_MISSED") or (eventType == "SPELL_MISSED") then
			local missedType
			if (eventType == "SWING_MISSED") then
				missedType = swingMissType
			elseif (eventType == "SPELL_MISSED") then
				missedType = spellMissType
			end
			if (missedType == "DODGE") then
				local spellID = PlayerSpellCache[L.Spell_Overpower]
				self:ActivateHighlight(spellID, 5)
			end
		elseif (eventType == "SPELL_CAST_SUCCESS") then
			if (spellName == L.Spell_Overpower) then
				local spellID = PlayerSpellCache[L.Spell_Overpower]
				self:DeactivateHighlight(spellID)
			end
		end
	end
end

-- Warrior
LibSpellHighlight.UpdateRevenge = function(self, event, ...)
	local timestamp, eventType, hideCaster,
	sourceGUID, sourceName, sourceFlags, sourceRaidFlags,
	destGUID, destName, destFlags, destRaidFlags,
	swingMissType, spellName, _, spellMissType, swingBlocked = CombatLogGetCurrentEventInfo()

	local isSrcPlayer = bit_band(sourceFlags, COMBATLOG_OBJECT_AFFILIATION_MINE) == COMBATLOG_OBJECT_AFFILIATION_MINE
	local isDstPlayer = destGUID == playerGUID

	if (isDstPlayer) then
		if (eventType == "SWING_MISSED") or (eventType == "SPELL_MISSED") then
			local missedType
			if (eventType == "SWING_MISSED") then
				missedType = swingMissType
			elseif (eventType == "SPELL_MISSED") then
				missedType = spellMissType
			end
			if (missedType == "BLOCK") or (missedType == "DODGE") or (missedType == "PARRY") then
				local spellID = PlayerSpellCache[L.Spell_Revenge]
				self:ActivateHighlight(spellID, 5)
			end
		elseif (eventType == "SWING_DAMAGE") and (swingBlocked) then
			local spellID = PlayerSpellCache[L.Spell_Revenge]
			self:ActivateHighlight(spellID, 5)
		end
	end

	if (isSrcPlayer) and (eventType == "SPELL_CAST_SUCCESS") and (spellName == L.Spell_Revenge) then
		local spellID = PlayerSpellCache[L.Spell_Revenge]
		self:DeactivateHighlight(spellID)
	end
end

-- Rogue
LibSpellHighlight.UpdateRiposte = function(self, event, ...)
	local timestamp, eventType, hideCaster,
	sourceGUID, sourceName, sourceFlags, sourceRaidFlags,
	destGUID, destName, destFlags, destRaidFlags,
	swingMissType, spellName, _, spellMissType, swingBlocked = CombatLogGetCurrentEventInfo()

	local isSrcPlayer = bit_band(sourceFlags, COMBATLOG_OBJECT_AFFILIATION_MINE) == COMBATLOG_OBJECT_AFFILIATION_MINE
	local isDstPlayer = destGUID == playerGUID

	if (isDstPlayer) and ((eventType == "SWING_MISSED") or (eventType == "SPELL_MISSED")) then
		local missedType
		if (eventType == "SWING_MISSED") then
			missedType = swingMissType
		elseif (eventType == "SPELL_MISSED") then
			missedType = spellMissType
		end
		if (missedType == "PARRY") then
			local spellID = PlayerSpellCache[L.Spell_Riposte]
			self:ActivateHighlight(spellID, 5)
		end
	end

	if (isSrcPlayer) and (eventType == "SPELL_CAST_SUCCESS") and (spellName == L.Spell_Riposte) then
		local spellID = PlayerSpellCache[L.Spell_Riposte]
		self:DeactivateHighlight(spellID)
	end
end

LibSpellHighlight.UpdateOverpowerAndRevenge = function(self, event, ...)
	self:UpdateOverpower(event, ...)
	self:UpdateRevenge(event, ...)
end

LibSpellHighlight.UpdateCounterAttackAndMongooseBite = function(self, event, ...)
	self:UpdateCounterAttack(event, ...)
	self:UpdateMongooseBite(event, ...)
end

LibSpellHighlight.ClearAllHighlights = function(self)
	for spellID in pairs(ActivateHighlights) do
		self:DeactivateHighlight(spellID)
	end
	for auraID,spellList in pairs(HighlightSpellsByAuraID) do
		for spellID in pairs(spellList) do
			self:DeactivateHighlight(spellID)
		end
	end
end

LibSpellHighlight.UpdateDead = function(self, event, ...)
	if (UnitIsDeadOrGhost("player")) then
		self:ClearAllHighlights()
	end
end

LibSpellHighlight.UpdateClassicEvents = function(self, event, ...)
	self:UnregisterAllEvents()
	self:UnregisterAllMessages()
	self:UpdatePlayerSpellCache()

	-- Allow it to run on the first occurence
	-- of this event after any sort of UI reset.
	-- Not needed after teleports or instance zoning.
	if (event == "PLAYER_ENTERING_WORLD") then
		local isLogin, isReload = ...
		if not(isLogin or isReload) then
			return
		end
	end

	self:RegisterMessage("UNIT_HEALTH_FREQUENT", "UpdateDead")

	if (playerClass == "DRUID") then
		-- Track clear casting aura for expensive spell highlight.
		self:RegisterUnitEvent("UNIT_AURA", "UpdateAuras", "player")

		-- Track combo points for finisher highlight.
		self:RegisterEvent("PLAYER_TARGET_CHANGED", "UpdateComboPoints")
		self:RegisterUnitEvent("UNIT_MAXPOWER", "UpdateComboPoints", "player")
		self:RegisterUnitEvent("UNIT_POWER_FREQUENT", "UpdateComboPoints", "player")

		-- Initial update of highlights.
		self:UpdateAuras()
		self:UpdateComboPoints()
	
	elseif (playerClass == "HUNTER") then
		-- Register combat log parsing if abilities exist.
		if (PlayerSpellCache[L.Spell_Counterattack]) and (PlayerSpellCache[L.Spell_MongooseBite]) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateCounterAttackAndMongooseBite")

		elseif ((PlayerSpellCache[L.Spell_Counterattack])) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateCounterAttack")

		elseif ((PlayerSpellCache[L.Spell_MongooseBite])) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateMongooseBite")
		end
	
	elseif (playerClass == "ROGUE") then
		-- Track combo points for finisher highlight.
		self:RegisterEvent("PLAYER_TARGET_CHANGED", "UpdateComboPoints")
		self:RegisterUnitEvent("UNIT_MAXPOWER", "UpdateComboPoints", "player")
		self:RegisterUnitEvent("UNIT_POWER_FREQUENT", "UpdateComboPoints", "player")

		-- Register combat log parsing if abilities exist.
		if (PlayerSpellCache[L.Spell_Riposte]) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateRiposte")
		end

		-- Initial update of highlights.
		self:UpdateComboPoints()

	elseif (playerClass == "PALADIN") then
		if (PlayerSpellCache[L.Spell_HammerOfWrath]) then
			-- Track target health for activations.
			self:RegisterUnitEvent("UNIT_HEALTH_FREQUENT", "UpdateHammerOfWrath", "target")
			self:RegisterEvent("PLAYER_TARGET_CHANGED", "UpdateHammerOfWrath")

			-- Initial update of highlights.
			self:UpdateHammerOfWrath()
		end

		-- Register combat log parsing if abilities exist.
		if (PlayerSpellCache[L.Spell_Exorcism]) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateExorcism")
		end

	elseif (playerClass == "WARLOCK") then
		if (PlayerSpellCache[L.Spell_Nightfall]) then
			-- Track Shadow Trance for Shadow Bolt highlighting.
			self:RegisterUnitEvent("UNIT_AURA", "UpdateAuras", "player")

			-- Initial update of highlights.
			self:UpdateAuras()
		end

	elseif (playerClass == "WARRIOR") then
		if (PlayerSpellCache[L.Spell_Execute]) then
			-- Track target health for activations.
			self:RegisterUnitEvent("UNIT_HEALTH_FREQUENT", "UpdateExecute", "target")
			self:RegisterEvent("PLAYER_TARGET_CHANGED", "UpdateExecute")

			-- Initial update of highlights.
			self:UpdateExecute()
		end

		-- Register combat log parsing if abilities exist.
		if (PlayerSpellCache[L.Spell_Overpower]) and (PlayerSpellCache[L.Spell_Revenge]) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateOverpowerAndRevenge")

		elseif ((PlayerSpellCache[L.Spell_Overpower])) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateOverpower")

		elseif ((PlayerSpellCache[L.Spell_Revenge])) then
			self:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED", "UpdateRevenge")
		end

	end
end

local PopulateClassicDatabase = function(self)
	if (not IsClassic) then
		return
	end

	if (playerClass == "DRUID") then

		-- Omen of Clarity (Proc)
		HighlightTypeByAuraID[16870] = "CLEARCAST"
		HighlightSpellsByAuraID[16870] = {
			[6807] = true, -- Maul (Rank 1)
			[6808] = true, -- Maul (Rank 2)
			[6809] = true, -- Maul (Rank 3)
			[8972] = true, -- Maul (Rank 4)
			[9745] = true, -- Maul (Rank 5)
			[9880] = true, -- Maul (Rank 6)
			[9881] = true, -- Maul (Rank 7)
			[6785] = true, -- Ravage (Rank 1)
			[6787] = true, -- Ravage (Rank 2)
			[9866] = true, -- Ravage (Rank 3)
			[9867] = true, -- Ravage (Rank 4)
			[8936] = true, -- Regrowth (Rank 1)
			[8938] = true, -- Regrowth (Rank 2)
			[8939] = true, -- Regrowth (Rank 3)
			[8940] = true, -- Regrowth (Rank 4)
			[8941] = true, -- Regrowth (Rank 5)
			[9750] = true, -- Regrowth (Rank 6)
			[9856] = true, -- Regrowth (Rank 7)
			[9857] = true, -- Regrowth (Rank 8)
			[9858] = true, -- Regrowth (Rank 9)
			[5221] = true, -- Shred (Rank 1)
			[6800] = true, -- Shred (Rank 2)
			[8992] = true, -- Shred (Rank 3)
			[9829] = true, -- Shred (Rank 4)
			[9830] = true  -- Shred (Rank 5)
		}
	
		ComboFinishersBySpellID[22568] = true -- Ferocious Bite (Rank 1)
		ComboFinishersBySpellID[22827] = true -- Ferocious Bite (Rank 2)
		ComboFinishersBySpellID[22828] = true -- Ferocious Bite (Rank 3)
		ComboFinishersBySpellID[22829] = true -- Ferocious Bite (Rank 4)
		ComboFinishersBySpellID[31018] = true -- Ferocious Bite (Rank 5) (The Beast - Content Phase 6)
		ComboFinishersBySpellID[ 1079] = true -- Rip (Rank 1)
		ComboFinishersBySpellID[ 9492] = true -- Rip (Rank 2)
		ComboFinishersBySpellID[ 9493] = true -- Rip (Rank 3)
		ComboFinishersBySpellID[ 9752] = true -- Rip (Rank 4)
		ComboFinishersBySpellID[ 9894] = true -- Rip (Rank 5)
		ComboFinishersBySpellID[ 9896] = true -- Rip (Rank 6)
	
	end
	
	if (playerClass == "HUNTER") then
		ReactiveSpellsBySpellID[L.Spell_Counterattack] = { 19306, 20909, 20910 }
		ReactiveSpellsBySpellID[L.Spell_MongooseBite] = { 1495, 14269, 14270, 14271 }
	end 
	
	if (playerClass == "PALADIN") then
		ReactiveSpellsBySpellID[L.Spell_Exorcism] = { 879, 5614, 5615, 10312, 10313, 10314 }
		ReactiveSpellsBySpellID[L.Spell_HammerOfWrath] = { 24239, 24274, 24275 }
	end 
	
	if (playerClass == "ROGUE") then
		ReactiveSpellsBySpellID[L.Spell_Riposte] = { 14251 }
	
		ComboFinishersBySpellID[ 8647] = true -- Expose Armor (Rank 1)
		ComboFinishersBySpellID[ 8649] = true -- Expose Armor (Rank 2)
		ComboFinishersBySpellID[ 8650] = true -- Expose Armor (Rank 3)
		ComboFinishersBySpellID[11197] = true -- Expose Armor (Rank 4)
		ComboFinishersBySpellID[11198] = true -- Expose Armor (Rank 5)
		ComboFinishersBySpellID[ 2098] = true -- Eviscerate (Rank 1)
		ComboFinishersBySpellID[ 6760] = true -- Eviscerate (Rank 2)
		ComboFinishersBySpellID[ 6761] = true -- Eviscerate (Rank 3)
		ComboFinishersBySpellID[ 6762] = true -- Eviscerate (Rank 4)
		ComboFinishersBySpellID[ 8623] = true -- Eviscerate (Rank 5)
		ComboFinishersBySpellID[ 8624] = true -- Eviscerate (Rank 6)
		ComboFinishersBySpellID[11299] = true -- Eviscerate (Rank 7)
		ComboFinishersBySpellID[11300] = true -- Eviscerate (Rank 8)
		ComboFinishersBySpellID[31016] = true -- Eviscerate (Rank 9) (Blackhand Assasin - Content Phase 6)
		ComboFinishersBySpellID[ 1943] = true -- Rupture (Rank 1)
		ComboFinishersBySpellID[ 8639] = true -- Rupture (Rank 2)
		ComboFinishersBySpellID[ 8640] = true -- Rupture (Rank 3)
		ComboFinishersBySpellID[11273] = true -- Rupture (Rank 4)
		ComboFinishersBySpellID[11274] = true -- Rupture (Rank 5)
		ComboFinishersBySpellID[11275] = true -- Rupture (Rank 6)
		ComboFinishersBySpellID[ 5171] = true -- Slice and Dive (Rank 1)
		ComboFinishersBySpellID[ 6774] = true -- Slice and Dive (Rank 2)
	
	end 
	
	if (playerClass == "SHAMAN") then
	end
	
	if (playerClass == "WARLOCK") then
	
		HighlightTypeByAuraID[17941] = "REACTIVE"
		HighlightSpellsByAuraID[17941] = { -- Shadow Trance
			[  686] = true, -- Shadow Bolt (Rank 1)
			[  695] = true, -- Shadow Bolt (Rank 2)
			[  705] = true, -- Shadow Bolt (Rank 3)
			[ 1088] = true, -- Shadow Bolt (Rank 4)
			[ 1106] = true, -- Shadow Bolt (Rank 5)
			[ 7641] = true, -- Shadow Bolt (Rank 6)
			[11659] = true, -- Shadow Bolt (Rank 7)
			[11660] = true, -- Shadow Bolt (Rank 8)
			[11661] = true, -- Shadow Bolt (Rank 9)
			[25307] = true, -- Shadow Bolt (Rank 10)
		}
		ReactiveSpellsBySpellID[L.Spell_Nightfall] = { 18094, 18095 }
	end 
	
	if (playerClass == "WARRIOR") then
		ReactiveSpellsBySpellID[L.Spell_Execute] = { 5308, 20658, 20660, 20661, 20662 }
		ReactiveSpellsBySpellID[L.Spell_Overpower] = { 7384, 7887, 11584, 11585 }
		ReactiveSpellsBySpellID[L.Spell_Revenge] = { 6572, 6574, 7379, 11600, 11601, 25288 }
	end
	
	-- Cache all spellIDs that have a triggering auraID,
	-- and store their overlay types.
	for auraID,spells in pairs(HighlightSpellsByAuraID) do
		for spellID in pairs(spells) do
			SpellIDToAuraID[spellID] = auraID
			HighlightTypeBySpellID[spellID] = HighlightTypeByAuraID[auraID]
		end
	end
	
	-- Store overlay type of reative spells
	for spellName, spells in pairs(ReactiveSpellsBySpellID) do
		for _,spellID in ipairs(spells) do
			HighlightTypeBySpellID[spellID] = "REACTIVE"
		end
	end

	-- Store overlay type of combo point finishers
	for spellID in pairs(ComboFinishersBySpellID) do
		HighlightTypeBySpellID[spellID] = "FINISHER"
	end

end

-- Upgrade existing embeds, if any
for target in pairs(LibSpellHighlight.embeds) do
	LibSpellHighlight:Embed(target)
end

-- Module embedding
local embedMethods = {
	IsSpellOverlayed = true,
	GetSpellOverlayType = true
}

LibSpellHighlight.Embed = function(self, target)
	for method in pairs(embedMethods) do
		target[method] = self[method]
	end
	self.embeds[target] = true
	return target
end

if (IsClassic) then
	-- Register initialization events
	if (playerClass == "DRUID") then
		LibSpellHighlight:RegisterEvent("SPELLS_CHANGED", "UpdateClassicEvents")
		LibSpellHighlight:RegisterEvent("UNIT_DISPLAYPOWER", "UpdateClassicEvents")
		LibSpellHighlight:RegisterEvent("PLAYER_ENTERING_WORLD", "UpdateClassicEvents")
	elseif (playerClass == "HUNTER")
		or (playerClass == "PALADIN")
		or (playerClass == "ROGUE")
		or (playerClass == "WARLOCK")
		or (playerClass == "WARRIOR")
	then
		LibSpellHighlight:RegisterEvent("SPELLS_CHANGED", "UpdateClassicEvents")
		LibSpellHighlight:RegisterEvent("PLAYER_ENTERING_WORLD", "UpdateClassicEvents")
	end
	-- Add the classic highlight database
	PopulateClassicDatabase()
end