-- --------------------
-- TellMeWhen
-- Originally by NephMakes

-- Other contributions by:
--		Sweetmms of Blackrock, Oozebull of Twisting Nether, Oodyboo of Mug'thol,
--		Banjankri of Blackrock, Predeter of Proudmoore, Xenyr of Aszune

-- Currently maintained by
-- Cybeloras of Aerie Peak
-- --------------------


if not TMW then return end

local TMW = TMW
local L = TMW.L
local print = TMW.print

local strfind, strlower, pairs
    = strfind, strlower, pairs
local InCombatLockdown, C_TradeSkillUI
    = InCombatLockdown, C_TradeSkillUI
local debugprofilestop = debugprofilestop

local GetSpellTexturePlain = C_Spell and C_Spell.GetSpellTexture or GetSpellTexture
local GetSpellInfo = TMW.GetSpellInfo
local GetSpellName = TMW.GetSpellName

local clientBuild = select(2, GetBuildInfo())

local SpellCache = TMW:NewModule("SpellCache", "AceEvent-3.0", "AceTimer-3.0")

local Cache

 -- Keep this pretty low. Ideally, the framerate impact is completely unnoticable.
 -- It'll be set significantly higher if the icon editor is opened.
local NumCachePerFrame = 70
local IsCaching


SpellCache.CONST = {
	-- A rough estimate of the highest spellID in the game.
	-- This is also the minimum id to stop at, since Classic SOD added new spells
	-- after retail spells, in the IDs around 430000.
	-- Since we save ranges of invalid IDs to skip, this won't matter for perf at all
	-- in any spell scan where SpellCacheInvalidRanges has nonstale data.
	MAX_SPELLID_GUESS = 1732790,
	
	-- Maximum number of non-existant spellIDs that will be checked before the cache is declared complete.
	-- This used to be a much smaller number, but Blizzard went off the rails around 11.0.7 and put huge gaps in the SpellIDs.
	-- The biggest known gap at the time of this comment is a gap of 379444 at ID 556607.
	MAX_FAILED_SPELLS = 500000,
	
	WHITELIST = {
		-- A list of spells that will fail other filters, but are still desired
		[8178] = true, -- Grounding Totem Effect
		[255016] = true, -- Grounding Totem Effect
		[228911] = true, -- Odyn's test
		[227626] = true, -- Odyn's test
		[275529] = true, -- Test of Might
		[275531] = true, -- Test of Might
		[275532] = true, -- Test of Might
		[275540] = true, -- Test of Might

		-- Classic:
		[3355] = true, -- Freezing Trap Effect
		[14308] = true, -- Freezing Trap Effect
		[14309] = true, -- Freezing Trap Effect
		[19675] = true, -- Feral Charge Effect
	},

	-- A list of spells that should be excluded from the cache
	INVALID_SPELLS = {
		[1852] = true, -- GM spell named silenced
	  [250168] = true, -- Crashes the 9.0 PTR
	  [255616] = TMW.wowMajor == 12, -- Crashes the 12.0 Alpha
	 [1249911] = TMW.wowMajor == 12, -- Crashes the 12.0 Alpha
	},

	BLACKLIST_TRADESKILL_TEXTURES = {
		[136240] = true, -- ["Interface\\Icons\\Trade_Alchemy"] = true, 
		[136241] = true, -- ["Interface\\Icons\\Trade_BlackSmithing"] = true, 

		-- We can't include engineering because there are many valid "tradeskills" that use this icon,
		-- just because its basically the default icon.
		-- We will exclude all engineering tradeskills specifically.
		-- Examples include the class "tradeskills" ("Druid", etc...) and the racial tradeskills ("Racial - Night Elf")
		--[136243] = true, -- ["Interface\\Icons\\Trade_Engineering"] = true, 

		[136247] = true, -- ["Interface\\Icons\\Trade_LeatherWorking"] = true, 

		[136244] = true, -- ["Interface\\Icons\\Trade_Engraving"] = true, -- (enchanting)
		[136245] = true, -- ["Interface\\Icons\\Trade_Fishing"] = true, 
		[136246] = true, -- ["Interface\\Icons\\Trade_Herbalism"] = true, 
		[136248] = true, -- ["Interface\\Icons\\Trade_Mining"] = true, 
		[136249] = true, -- ["Interface\\Icons\\Trade_Tailoring"] = true, 
		[237171] = true, -- ["Interface\\Icons\\INV_Inscription_Tradeskill01"] = true, 

		[133971] = true, -- Cooking
		[134071] = true, -- JC
		[134366] = true, -- Skinning
		[134708] = true, -- Mining
	},

	-- Any spell that uses these textures should be excluded.
	INVALID_TEXTURES = {
		-- These are the worst offenders by far.
		-- Engineering is especially bad because its icon is used for tons of internal spells
		-- that the player never sees.
		[136243] = true, -- ["Interface\\Icons\\Trade_Engineering"] = true, 
		[136240] = true, -- ["Interface\\Icons\\Trade_Alchemy"] = true, 
		[136241] = true, -- ["Interface\\Icons\\Trade_BlackSmithing"] = true, 
		[136247] = true, -- ["Interface\\Icons\\Trade_LeatherWorking"] = true, 

		-- These aren't as bad as the rest, but still don't have any real spells that should be in the list.
		[136244] = true, -- ["Interface\\Icons\\Trade_Engraving"] = true, 
		[136245] = true, -- ["Interface\\Icons\\Trade_Fishing"] = true, 
		[136246] = true, -- ["Interface\\Icons\\Trade_Herbalism"] = true, 
		[136248] = true, -- ["Interface\\Icons\\Trade_Mining"] = true, 
		[136249] = true, -- ["Interface\\Icons\\Trade_Tailoring"] = true, 
		[237171] = true, -- ["Interface\\Icons\\INV_Inscription_Tradeskill01"] = true, 
	},
}
local CONST = SpellCache.CONST


TMW.IE:RegisterDatabaseDefaults{
	locale = {
		SpellCacheLength = CONST.MAX_SPELLID_GUESS,
		SpellCacheWoWVersion = 0,

		-- Keys are spellIDs that are known to be invalid. Values are the number of spells after the key that are also invalid.
		SpellCacheInvalidRanges = {

		},
	},
}

TMW.IE:RegisterUpgrade(71016, {
	global = function(self)
		TMW.IE.db.global.SpellCache = nil
		TMW.IE.db.global.CacheLength = nil
		TMW.IE.db.global.IncompleteCache = nil
		TMW.IE.db.global.WoWVersion = nil
	end,
})

-- Force a re-cache - If a re-cache is needed, just update this version num to the latest version.
-- 11010101 - Increased MAX_FAILED_SPELLS to handle huge gaps in spellIDs 
TMW.IE:RegisterUpgrade(11010101, {
	locale = function(self, locale)
		locale.SpellCacheWoWVersion = 0
	end,
})

TMW.IE:RegisterUpgrade(84405, {
	-- I managed to make the spell cache fast enough that its no longer worth persisting to disk.
	-- We're going to recreate it on each load of TMW_Options.
	-- This eliminates the significant factor in the load time of TMW_Options, and will also increase logout speeds.
	locale = function(self, locale)
		TMW.IE.db.locale.SpellCache = nil
		TMW.IE.db.locale.IncompleteSpellCache = nil
	end,
})

-- PUBLIC:

--[[ Returns the main cache table. Structure:
Cache = {
	[spellID] = 1,
}
]]
function SpellCache:GetCache()
	if not Cache then
		error("SpellCache is not yet initialized", 2)
	end
	
	return Cache
end

-- Sets the number of spells that will be checked per frame.
function SpellCache:SetNumCachePerFrame(num)
	TMW:ValidateType(2, "SpellCache:SetNumCachePerFrame()", num, "number")
	
	if NumCachePerFrame ~= num then
		NumCachePerFrame = num
		TMW:Fire("TMW_SPELLCACHE_NUMCACHEPERFRAME_CHANGED", num)
	end
end

-- Gets the number of spells that will be checked per frame.
function SpellCache:GetNumCachePerFrame()
	return NumCachePerFrame
end

-- Gets the expected length of the finished cache.
function SpellCache:GetExpectedCacheLength()
	return TMW.IE.db.locale.SpellCacheLength
end

-- Returns whether or not the cache is currently in progress.
function SpellCache:IsCaching()
	return IsCaching
end

-- END PUBLIC




-- PRIVATE:

TMW:RegisterCallback("TMW_OPTIONS_LOADED", function()

	Cache = {}

	local SpellCacheInvalidRanges = TMW.IE.db.locale.SpellCacheInvalidRanges

	local haveSpellCacheInvalidRanges = true
	if TMW.IE.db.locale.SpellCacheWoWVersion ~= clientBuild then
		wipe(SpellCacheInvalidRanges)
		haveSpellCacheInvalidRanges = false
	end

	TMW:Fire("TMW_SPELLCACHE_EXPECTEDCACHELENGTH_UPDATED", TMW.IE.db.locale.SpellCacheLength)

	local INVALID_TEXTURES = CONST.INVALID_TEXTURES
	local BLACKLIST_TRADESKILL_TEXTURES = CONST.BLACKLIST_TRADESKILL_TEXTURES
	local WHITELIST_TRADESKILLS = CONST.WHITELIST_TRADESKILLS
	local WHITELIST = CONST.WHITELIST
	local MAX_FAILED_SPELLS = CONST.MAX_FAILED_SPELLS
	local GetTradeSkillLineForRecipe = C_TradeSkillUI and C_TradeSkillUI.GetTradeSkillLineForRecipe
	local GetTradeSkillTexture = C_TradeSkillUI and C_TradeSkillUI.GetTradeSkillTexture
	local classLocalizedName = UnitClass("player")

	local function findword(name, word)
		return strfind(name, word) and strfind(name, "%f[%a]" .. word .. "%f[%A]")
	end

 	local tradeSkillBlacklist = {
		-- We don't blacklist mounts [777] because mounts are often checked as buffs.
		[778] = false, -- Companions - no compelling reason to cache battle pet summon spells.

		-- Forms of engineering (see BLACKLIST_TRADESKILL_TEXTURES above for why engineering is special)
		[202] = false,
		[2499] = false,
		[2500] = false,
		[2501] = false,
		[2502] = false,
		[2503] = false,
		[2504] = false,
		[2505] = false,
		[2506] = false,
	}
	local isNameGood = { [""] = false }
	local spellID, spellsFailed = 0, 0

	-- The most recent failed spellID that was seen after a success.
	-- nil if the last spellID was a success.
	local lastFail = nil
	local excludeEffect = ClassicExpansionAtLeast(LE_EXPANSION_MISTS_OF_PANDARIA)
	local INVALID_SPELLS = CONST.INVALID_SPELLS

	local function SpellCacher()
		local numToCheck = InCombatLockdown() and 10 or NumCachePerFrame

		for _ = 1, numToCheck do
			spellID = spellID + 1

			local skip = SpellCacheInvalidRanges[spellID]
			if skip then
				spellID = spellID + skip
			end

			local name = not INVALID_SPELLS[spellID] and GetSpellName(spellID)

			local fail = false
			if name then
				local icon = GetSpellTexturePlain(spellID)
				spellsFailed = 0

				-- This is our best filter by far - about 70k spells are filtered out by this.
				fail = INVALID_TEXTURES[icon] or false

				if not fail then
					if GetTradeSkillLineForRecipe then
						-- Get the tradeskillID of the spell.
						-- There are tons of these. Some examples are
						-- - "Druid"
						-- - "Engineering"
						-- - "Northrend Tailoring"
						-- - "Racial - Night Elf"
						-- - "Mounts"
						-- - "Companions" (battlepets)

						-- What we want to do is filter out anything that has a tradeskill that is some variant of an actual profession.
						-- We do this by getting the texture of the tradeskill, since all variants of profession tradeskills use the same texture.
						-- I couldn't find any other way to correlate this data without doing it by hand for hundreds of these.
						local tradeSkillID, tradeSkillName = GetTradeSkillLineForRecipe(spellID)
						local isTradeSkillOk = not tradeSkillID or tradeSkillBlacklist[tradeSkillID]
						if isTradeSkillOk == nil then
							-- We haven't made a determination yet for this tradeskill. Look for its texture.
							local tex = GetTradeSkillTexture(tradeSkillID)
							-- This tradeskill is ok if its texture isn't found in BLACKLIST_TRADESKILL_TEXTURES
							isTradeSkillOk = not BLACKLIST_TRADESKILL_TEXTURES[tex]
							tradeSkillBlacklist[tradeSkillID] = isTradeSkillOk
						end

						fail = not isTradeSkillOk
					end

					if not fail then
						-- Keep track of known good names. Don't do name checking on known good names.
						-- Cache by the name before lowering it to avoid strlower() hits.
						-- We store the lowered name as the value for good names, otherwise false.
						local knownGood = isNameGood[name]
						if knownGood == false then
							fail = true
						elseif knownGood ~= nil then
							name = knownGood
						else 
							local nameOriginal = name
							name = strlower(name)
							fail = 
								(strfind(name, "quest") and strfind(name, "%f[%a]quest%f[%A]")) or
								(strfind(name, "trigger") and strfind(name, "%f[%a]trigger%f[%A]")) or
								strfind(name, "[%]%[%%%+%?]") or -- no brackets, plus signs, percent signs, or question marks
								(strfind(name, "visual") and strfind(name, "%f[%a]visual%f[%A]")) or
								(strfind(name, "dnd") and strfind(name, "%f[%a]dnd%f[%A]")) or
								(strfind(name, "event") and strfind(name, "%f[%a]event%f[%A]")) or
								(strfind(name, "test") and strfind(name, "%f[%a]test%f[%A]")) or
								strfind(name, "%d.%d") or -- Number Dot Number is probably a patch number, used often for internal spells
								(strfind(name, "vehicle") and strfind(name, "%f[%a]vehicle%f[%A]")) or
								(strfind(name, "credit") and strfind(name, "%f[%a]credit%f[%A]")) or
								
								-- 'effect' is used quite bit in older expansions for lots of real things.
								(excludeEffect and strfind(name, "effect") and strfind(name, "%f[%a]effect%f[%A]")) or

								(strfind(name, "camera") and strfind(name, "%f[%a]camera%f[%A]")) or
								-- "ph" was removed because it is so short and non-specific
								-- that it interferes with words like Phönixflammen (https://de.wowhead.com/spell=194466/ph%C3%B6nixflammen)
								-- due to the fact that lua isn't unicode aware.
								--(strfind(name, "ph") and strfind(name, "%f[%a]ph%f[%A]")) or
								(strfind(name, "proc") and strfind(name, "%f[%a]proc%f[%A]")) or
								(strfind(name, "debug") and strfind(name, "%f[%a]debug%f[%A]")) or
								(strfind(name, "bunny") and strfind(name, "%f[%a]bunny%f[%A]")) or
								strfind(name, ":%s?%d") or -- interferes with colon duration syntax
								(strfind(name, "dmg") and strfind(name, "%f[%a]dmg%f[%A]"))

							isNameGood[nameOriginal] = not fail and name or false
						end

						if not fail then
							Cache[spellID] = name
						end
					end
				end

			else
				fail = true
				spellsFailed = spellsFailed + 1
			end

			if not haveSpellCacheInvalidRanges then
				if fail then
					if not lastFail then lastFail = spellID end
				elseif lastFail then
					-- spellID was successful (fail is false).
					-- Record the range if its big enough to be significant.
					local range = spellID - lastFail
					if range > 2 then
						SpellCacheInvalidRanges[lastFail] = range
					end
					lastFail = nil
				end
			end
		end

		TMW:Fire("TMW_SPELLCACHE_NUMCACHED_CHANGED", spellID)
		if spellID > TMW.IE.db.locale.SpellCacheLength then
			TMW.IE.db.locale.SpellCacheLength = spellID
			TMW:Fire("TMW_SPELLCACHE_EXPECTEDCACHELENGTH_UPDATED", TMW.IE.db.locale.SpellCacheLength)
		end
	end

	IsCaching = true
	TMW:Fire("TMW_SPELLCACHE_STARTED")

	local f = CreateFrame("Frame")
	local hadError = false
	local totalTime = 0
	f:SetScript("OnUpdate", function()
		local start = debugprofilestop()

		local success = TMW.safecall(SpellCacher)		
		
		-- if TMW.wowMajor == 12 and spellID >= 1230000 and TELLMEWHEN_VERSION_MINOR == "dev" then
		-- 	print("cache skip due to crash")
		-- 	success = false
		-- end
		
		if success and (spellsFailed < MAX_FAILED_SPELLS or spellID < CONST.MAX_SPELLID_GUESS) then
			-- Carry on. Keep iterating.
		else
			-- We're done, or we errored.

			if success then
				-- We didn't error.
				TMW.IE.db.locale.SpellCacheWoWVersion = clientBuild
			end

			-- We're done, or we errored.
			--print("Cache complete in " .. totalTime)

			f:SetScript("OnUpdate", nil)

			for spellID in pairs(CONST.INVALID_SPELLS) do
				Cache[spellID] = nil
			end
			for spellID in pairs(CONST.WHITELIST) do
				local name = GetSpellName(spellID)
				if name then
					Cache[spellID] = strlower(name)
				end
			end

			IsCaching = nil
			TMW:Fire("TMW_SPELLCACHE_COMPLETED")
		end
		totalTime = totalTime + debugprofilestop() - start
	end)
end)

-- END PRIVATE

