AuctioneerSuite/Stubby/Stubby.lua

--[[
	Stubby AddOn for World of Watcraft (tm)
	Version: 5.9.4961 (WhackyWallaby)
	Revision: $Id: Stubby.lua 275 2010-10-03 14:00:39Z kandoko $
	URL: http://auctioneeraddon.com/dl/Stubby/

	Stubby is an addon that allows you to register boot code for
	your addon.

	This bootcode will be run whenever your addon does not demand
	load on startup so that you can setup your own conditions for
	loading.

	A quick example of this is:
	-------------------------------------------
		Stubby.RegisterBootCode("myAddOn", "CommandHandler", [=[
			local function cmdHandler(msg)
				LoadAddOn("myAddOn")
				MyAddOn_Command(msg)
			end
			SLASH_MYADDON1 = "/myaddon"
			SlashCmdList['MYADDON'] = cmdHandler
		]=])
	-------------------------------------------
	So, what did this just do? It registered some boot code
	(called "CommandHandler") with Stubby that Stubby will
	(in the case you are not demand loaded) execute on your
	behalf.

	In the above example, your boot code sets up a command handler
	which causes your addon to load and process the command.

	Another example:
	-------------------------------------------
	Stubby.CreateAddOnLoadBootCode("myAddOn", "Blizzard_AuctionUI")
	-------------------------------------------
	Ok, what was that? Well you just setup some boot code
	for your addon that will register an addon hook when
	Stubby loads and your addon doesn't. This addon hook
	will cause your addon to load when the AuctionUI does.


	The primary functions that you will be interested in are:
		CreateAddOnLoadBootCode(ownerAddOn, triggerAddOn)
		CreateEventLoadBootCode(ownerAddOn, triggerEvent)
		CreateFunctionLoadBootCode(ownerAddOn, triggerFunction)
	And the manual, but vastly more powerful:
		RegisterBootCode(ownerAddOn, bootName, bootCode)


	Stubby can also save variables for you if you wish to retain
	stateful information in your boot code. (maybe you have
	recieved notification from your user that they wish always
	to have your addon load for the current toon?)

	These are the variable functions:
		SetConfig(ownerAddOn, variable, value, isGlobal)
	GetConfig(ownerAddOn, variable)
		ClearConfig(ownerAddOn, variable)

	The SetConfig function sets the configuration variable
	"variable" for ownerAddOn to value. The variable is
	per-toon unless isGlobal is set.

	The GetConfig function gets "variable" for ownerAddOn
	it will return per-toon values before global ones.

	The ClearConfig function clears the toon specific and
	global "variable" for ownerAddOn.


	The following functions are also available for you to use
	if you need to use some manual boot code and want to
	hook into some function, addon or event within your boot
	code:
		Stubby.RegisterFunctionHook(triggerFunction, position, hookFunction, ...)
		Stubby.RegisterAddOnHook(triggerAddOn, ownerAddOn, hookFunction, ...)
		Stubby.RegisterEventHook(triggerEvent, ownerAddOn, hookFunction, ...)

	RegisterFunctionHook allows you to hook into a function.
	* The triggerFunction is a string that names the function you
		want to hook into. eg: "GameTooltip.SetOwner"
	* The position is a negative or positive number that defines
		the actual calling order of the addon. The smaller or more
		negative the number, the earlier in the call sequence your
		hookFunction will be called, the larger the number, the
		later your hook will be called. The actual original (hooked)
		function is called at position 0, so if your addon is hooked
		at a negative position, you will not have access to any
		return values.
	* You pass (by reference) your function that you wish called
		as hookFunction. This function will be called with the
		following parameters:
			hookFunction(hookParams, returnValue, hook1, hook2 .. hookN)
		- hookParams is a table containing the additional parameters
		passed to the RegisterFunctionHook function (the "..." params)
		- returnValue is an array of the returned values of the function
		or nil if none.
		- hook1..hookN are the original parameters of the hooked
		function in the original order.
	  The passed function can return one of the following three special commands:
	    - "abort" will abort the function call imidiatly and any hook positioned
	              after the function won't be called (this includes the original
	              function, if position of the function retunring "abort" is < 0)
	    - "killorig" causes the original function tonot being called. All other
	                 hooked functions will still be called. If position of the
	                 functions returning "killorig" is > 0, this has no affect
	                 (since the original function was already called before)
	    - "setreturn" sets the return value according to the second return value
	                  which must be a table. All function hooks which are called
	                  after the function hook which set the return value, will
	                  receive this new return value as their second parameter. Note
	                  that the original function still resets the return value. So
	                  in case you want the complete function hook to return
	                  something different than the original function's return value,
	                  make sure to set the position > 0.
	                  Also note, that any hooked function called after this one can
	                  change the return value again.
	                  Examples:
	                     return "setreturn", {1} sets the return value to 1
	                     return "setreturn", {} sets the return value to nil
	                     return "setreturn", {{[1] = "foo", [2] = "bar"}}
	                        sets the return value to the table:
	                        {[1] = "foo", [2] = "bar"}

	RegisterAddOnHook is very much like the register function hook
	call except that there is no positioning (you may get notified in
	any order with respect to any other addons which may be hooked)
	* The triggerAddOn specifies the name of the addon of which you
		want to be notified of it's loading.
	* The ownerAddOn is your addon's name (used for removing hooks)
	* The hookFunction is a function that gets called when the
		triggerAddOn loads or if it is already loaded straight away.
		This function will be called with the following parameters
			hookFunction(hookParams)
		- hookParams is a table containing the additional parameters
		passed to the RegisterAddOnHook function (the "..." params)

	RegisterEventHook allows you to hook an event in much the same
	way as the above functions.
	* The triggerEvent is an event which causes your hookFunction to
		be executed.
	* The ownerAddOn is your addon's name (used for removing hooks)
	* The hookFunction is a function that gets called whenever the
		triggerEvent fires (until canceled with UnregisterEventHook)
		This function will be called with the following parameters:
			hookFunction(hookParams, event, hook1, hook2 .. hookN)
	- hookParams is a table containing the additional parameters
	passed to the RegisterEventHook function (the "..." params)
	- event is the event string that has just been fired
	- hook1..hookN are the original parameters of the event
	function in the original order.

	Other functions which may be of interest are:
		UnregisterFunctionHook(triggerFunction, hookFunc)
		UnregisterAddOnHook(triggerAddOn, ownerAddOn)
		UnregisterEventHook(triggerEvent, ownerAddOn)
		UnregisterBootCode(ownerAddOn, bootName)

	There is also a single exposed 'constant' allowing you to do
	some basic version checking for compatibility:
	Stubby.VERSION                (introduced in revision 507)
	This constant is Stubby's revision number, a simple positive
	integer that will increase by an arbitrary amount with each
	new version of Stubby.
	Current $Revision: 275 $

	Example:
	-------------------------------------------
	if (Stubby.VERSION and Stubby.VERSION >= 507) then
		-- Register boot code
	else
		Stubby.Print("You need to update your version of Stubby!")
	end
	-------------------------------------------

	License:
		This program is free software; you can redistribute it and/or
		modify it under the terms of the GNU General Public License
		as published by the Free Software Foundation; either version 2
		of the License, or (at your option) any later version.

		This program is distributed in the hope that it will be useful,
		but WITHOUT ANY WARRANTY; without even the implied warranty of
		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
		GNU General Public License for more details.

		You should have received a copy of the GNU General Public License
		along with this program(see GPL.txt); if not, write to the Free Software
		Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

	Note:
		This AddOn's source code is specifically designed to work with
		World of Warcraft's interpreted AddOn system.
		You have an implicit license to use this AddOn with these facilities
		since that is its designated purpose as per:
		http://www.fsf.org/licensing/licenses/gpl-faq.html#InterpreterIncompat
]]
LibStub("LibRevision"):Set("$URL: http://svn.norganna.org/libs/trunk/Stubby/Stubby.lua $","$Rev: 275 $","5.1.DEV.", 'auctioneer', 'libs')

-------------------------------------------------------------------------------
-- Error codes
-------------------------------------------------------------------------------
-- 0 = no error / function call succeeded
-- 1 = Trying to remove the hooked function from the trigger function failed
--     as the hooked function is not hooked in the trigger function at all.
-- 2 = Trying to remove the hook from a function failed, as the specified is not
--     hooked at all.
-- 3 = Trying to remove the hook from a function failed, as another function
--     meanwhile hooked into the same function.
-- 4 = Invalid function call. One or more parameters are missing or invalid.
-- 5 = Failed to compiling a hook.

local cleanList
local config = {
	hooks = { functions={}, origFuncs={} },
	calls = { functions={}, callList={} },
	loads = {},
	events = {},
}

local DebugLib = LibStub("DebugLib")
local debug, assert
if DebugLib then
	debug, assert = DebugLib("Stubby")
else
	function debug() end
	assert = debug
end

StubbyConfig = {}

-- temporary table used in tableRemoveNilSafe() to modify another table
local tempTable = {}

-- Function prototypes
local chatPrint                  -- chatPrint(...)
local checkAddOns                -- checkAddOns()
local clearConfig                -- clearConfig(ownerAddOn, variable)
local createAddOnLoadBootCode    -- createAddOnLoadBootCode(ownerAddOn, triggerAddOn)
local createEventLoadBootCode    -- createEventLoadBootCode(ownerAddOn, triggerEvent)
local createFunctionLoadBootCode -- createFunctionLoadBootCode(ownerAddOn, triggerFunction)
local errorHandler               -- errorHandler(stackLevel, ...)
local eventWatcher               -- eventWatcher(event)
local events                     -- events(event, param)
local getConfig                  -- getConfig(ownerAddOn, variable)
local getOrigFunc                -- getOrigFunc(triggerFunction)
local getRevision                -- getRevision()
local hookCall                   -- hookCall(funcName, ...)
local hookInto                   -- hookInto(triggerFunction)
local inspectAddOn               -- inspectAddOn(addonName, title, info)
local loadWatcher                -- loadWatcher(loadedAddOn)
local onLoaded                   -- onLoaded()
local onWorldStart               -- onWorldStart()
local rebuildNotifications       -- rebuildNotifications(notifyItems)
local registerAddOnHook          -- registerAddOnHook(triggerAddOn, ownerAddOn, hookFunction, ...)
local registerBootCode           -- registerBootCode(ownerAddOn, bootName, bootCode)
local registerEventHook          -- registerEventHook(triggerEvent, ownerAddOn, hookFunction, ...)
local registerFunctionHook       -- registerFunctionHook(triggerFunction, position, hookFunc, ...)
local runBootCodes               -- runBootCodes()
local searchForNewAddOns         -- searchForNewAddOns()
local cleanUpAddOnData           -- cleanUpAddOnData()
local cleanUpAddOnConfigs        -- cleanUpAddOnConfigs()
local setConfig                  -- setConfig(ownerAddOn, variable, value, isGlobal)
local shouldInspectAddOn         -- shouldInspectAddOn(addonName)
local unhookFrom                 -- unhookFrom(triggerFunction)
local unregisterAddOnHook        -- unregisterAddOnHook(triggerAddOn, ownerAddOn)
local unregisterBootCode         -- unregisterBootCode(ownerAddOn, bootName)
local unregisterEventHook        -- unregisterEventHook(triggerEvent, ownerAddOn)
local unregisterFunctionHook     -- unregisterFunctionHook(triggerFunction, hookFunc)
local tableRemoveNilSafe         -- tableRemoveNilSafe(table, [pos])

-- Function definitions

-- This function takes all the items and their requested orders
-- and assigns an actual ordering to them.
function rebuildNotifications(notifyItems)
	local notifyFuncs = {}
	for hookType, hData in pairs(notifyItems) do
		notifyFuncs[hookType] = {}

		-- Sort all hooks for this type in ascending numerical order.
		local sortedPositions = {}
		for requestedPos in pairs(hData) do
			table.insert(sortedPositions, requestedPos)
		end
		table.sort(sortedPositions)

		-- Process the sorted request list and insert in correct
		-- order into the call list.
		for _,requestedPos in ipairs(sortedPositions) do
			local func = hData[requestedPos]
			table.insert(notifyFuncs[hookType], func)
		end
	end
	return notifyFuncs
end

local callDetail = {}
local function callDebugger(...)
	local msg = tostring(...)
	for i = 2, select("#", ...) do
		msg = msg.." "..tostring(select(i, ...))
	end

	if (Swatter and Swatter.IsEnabled()) then
		return Swatter.OnError("Error while calling hook:\n{{{Hook name:}}}\n  "..tostring(callDetail[1]).."\n"..msg.."\n{{{Instantiated from:}}}\n  "..callDetail[2].n, StubbyHook, debugstack(2, 20, 20))
	else
		return Stubby.Print("Error while calling hook for: "..tostring(callDetail[1])..". "..msg, "\nCall Chain:\n", debugstack(2, 3, 6))
	end
end

local function callRunner(...)
	local funcName, func, retVal, callParams = unpack(callDetail)
	local callParamsLen = callParams[1]
	if (funcName) then
		return func.f(func.a, retVal, unpack(callParams, 2, callParamsLen+1))
	end
end


-- This function's purpose is to execute all the attached
-- functions in order and the original call at just before
-- position 0.
function hookCall(funcName, ...)
	local orig = Stubby.GetOrigFunc(funcName)
	if (not orig) then return end

	local res
	local retVal
	local callParams = { select("#",...), ... }

	local callees
	if config.calls and config.calls.callList and config.calls.callList[funcName] then
		callees = config.calls.callList[funcName]
	end

	if (callees) then
		for _, func in ipairs(callees) do
			if (orig and func.p >= 0) then
				retVal = {pcall(orig, ...)}

				-- After pcall, the first element in the table is either true, if
				-- pcall succeeded, or false, if it failed.
				-- So we remove this result code and check if the call was
				-- successful. If it wasn't, an errormessage is printed.
				-- We also have to use a nil-safe variation of table.remove() since
				-- there are blizard functions which return tables containing
				-- holes, which are not processed as required by table.remove().
				if (not tableRemoveNilSafe(retVal, 1)) then
					local ErrorString = "Error: Original call failed while running hooks: "..tostring(funcName)
					for key, value in pairs(retVal) do
						ErrorString = ErrorString.."\n"..tostring(key).." : "..tostring(value)
					end
					Stubby.ErrorHandler(2, ErrorString)
				end
				orig = nil
			end

			callDetail[1] = funcName
			callDetail[2] = func
			callDetail[3] = retVal
			callDetail[4] = callParams
			local result, res, addit = xpcall(callRunner, callDebugger)
			if (result) then
				if (res == 'abort') then
					return
				elseif (res == 'killorig') then
					orig = nil
				elseif (res == 'setreturn') then
					retVal = addit
					returns = true
				end
			end
		end
	end

	if (orig) then
		retVal = {pcall(orig, ...)}
		if (not tableRemoveNilSafe(retVal, 1)) then
			Stubby.ErrorHandler(2, "Error: Original call failed after running hooks for: ", tostring(funcName), "\n", retVal[1])
		end
	end

	if (retVal) then
		return unpack(retVal, 1, table.maxn(retVal))
	end
end

-------------------------------------------------------------------------------
-- This function automatically hooks Stubby in place of the
-- original function, dynamically.
--
-- returns:
--    first value:
--       0 - if hooking into the triggerFunction was successful
--      >0 - errorcode
--    second value:
--       nil      - if hooking into the triggerFunction was successful
--       (string) - errormessage
--
-- remarks:
--    Refere to the Error codes section to get a list of possible errors.
-------------------------------------------------------------------------------
Stubby_OldFunction = nil
Stubby_NewFunction = nil
function hookInto(triggerFunction)
	assert(triggerFunction, "No trigger function specified when calling hookInto!")

	if config.hooks.origFuncs[triggerFunction] then
		-- Stubby is already hooked into this function. No need to do it again.
		return 0
	end
	local stringToLoad = [[
		Stubby_OldFunction = ]]..triggerFunction..[[;
		local functionString = ']]..triggerFunction..[[';

		if (not (type(Stubby_OldFunction) == "function")) then
			return Stubby.ErrorHandler(3, "Error occured while compiling hook: ", tostring(functionString), "is not a valid function")
		end

		Stubby_NewFunction = function(...)
			return Stubby.HookCall(functionString, ...);
		end;
		]]..triggerFunction..[[ = Stubby_NewFunction
	]];
	local loadedFunction, errorMessage = loadstring(stringToLoad, "StubbyHookingFunction")

	if (loadedFunction) then
		loadedFunction()
	else
		Stubby_NewFunction = nil
		Stubby_OldFunction = nil

		Stubby.ErrorHandler(2, "Error occured while compiling hook:", tostring(triggerFunction), "\n", errorMessage)
		return 5, "Error occured while compiling hook for "..triggerFunction..". Errormessage: "..errorMessage
	end

	config.hooks.functions[triggerFunction] = Stubby_NewFunction
	config.hooks.origFuncs[triggerFunction] = Stubby_OldFunction

	Stubby_NewFunction = nil
	Stubby_OldFunction = nil

	return 0
end

-------------------------------------------------------------------------------
-- Unhooks stubby's hooked function from the given trigger function.
--
-- calls:
--    getglobal()  - if there is a hooked function present
--
-- called by:
--    TODO
--
-- paramaeters:
--    triggerFunction - (string) the name of the function to be unhooked
--
-- returns:
--    first value:
--       0 - if unhooking was successful
--      >0 - errorcode
--    second value:
--       nil      - if unhooking was successful
--       (string) - errormessage
--
-- remarks:
--    Refere to the Error codes section to get a list of possible errors.
-------------------------------------------------------------------------------
function unhookFrom(triggerFunction)
	-- check, if the trigger function is really hooked
	if not config.hooks.origFuncs[triggerFunction] then
		return 2, "Failed to unhook the trigger function: "..triggerFunction.." since it is not hooked at all."
	end

	-- make sure, that no other addon hooked this function meanwhile
	if _G[triggerFunction] == config.hooks.origFuncs[triggerFunction] then
		triggerFunction = config.hooks.origFuncs[triggerFunction]
		config.hooks.origFuncs[triggerFunction] = nil
		config.hooks.functions[triggerFunction] = nil
		return 0
	end

	return 3, "Could not unhook the trigger function "..triggerFunction..", since another addon hooked it meanwhile."
end

function errorHandler(stackLevel, ...)
	local msg = tostring(...)
	for i = 2, select("#", ...) do
		msg = msg.." "..tostring(select(i, ...))
	end

	stackLevel = (stackLevel or 1) + 1

	if (Swatter and Swatter.IsEnabled()) then
		return Swatter.OnError(msg, Stubby, debugstack(stackLevel, 20, 20))
	else
		return Stubby.Print(msg, "\nCall Chain:\n", debugstack(2, 3, 6))
	end
end

function getOrigFunc(triggerFunction)
	if (config.hooks) and (config.hooks.origFuncs) then
		return config.hooks.origFuncs[triggerFunction]
	end
end

-------------------------------------------------------------------------------
--[[
	This function causes a given function to be hooked by stubby and configures the hook function to be called at the given position.
	The original function gets executed a position 0. Use a negative number to get called before the original function, and positive
	number to get called after the original function. Default position is 200. If someone else is already using your number, you will get
	automatically moved up for after or down for before. Please also leave space for other people who may need to position their hooks
	in between your hook and the original.
 ]]
-- returns:
--    first value:
--       0 - if registering the function hook was successful
--      >0 - errorcode
--    second value:
--       nil      - if registering the function hook was successful
--       (string) - errormessage
--
-- remarks:
--    Refere to the Error codes section to get a list of possible errors.
-------------------------------------------------------------------------------
function registerFunctionHook(triggerFunction, position, hookFunc, ...)
	if (not (triggerFunction and hookFunc)) then
		return debug("Invalid function call. No trigger function and/or hook function specified. Usage Stubby.RegisterFunctionHook(triggerFunction, position, hookFunction,...).",
								4, DebugLib.Level.Error)
	end

	local insertPos = tonumber(position) or 200
	local funcObj
	local hookFuncName = strsplit("\n", debugstack(2,1,0), 2)
	if (select("#", ...) == 0) then
		funcObj = {
			f = hookFunc,
			n = hookFuncName,
			p = position,
		}
	else
		funcObj = {
			f = hookFunc,
			n = hookFuncName,
			a = {...},
			p = position
		}
	end

	if (not config.calls) then config.calls = {} end
	if (not config.calls.functions) then config.calls.functions = {} end
	if (config.calls.functions[triggerFunction]) then
		while (config.calls.functions[triggerFunction][insertPos]) do
			if (position >= 0) then
				insertPos = insertPos + 1
			else
				insertPos = insertPos - 1
			end
		end
		config.calls.functions[triggerFunction][insertPos] = funcObj
	else
		config.calls.functions[triggerFunction] = {}
		config.calls.functions[triggerFunction][insertPos] = funcObj
	end
	config.calls.callList = rebuildNotifications(config.calls.functions)
	local iErrorCode, strErrorMessage = hookInto(triggerFunction)
	if iErrorCode > 0 then
		return debug(strErrorMessage, iErrorCode, DebugLib.Level.Error)
	else
		return 0
	end
end

-------------------------------------------------------------------------------
-- Unregisters the hooked function. If the hooked function is hooked multiple
-- times, all these hooks are removed.
--
-- calls:
--    unhookFrom()          - if unregistering the last hooked function
--    rebuildNotification() - always
--
-- called by:
--    TODO
--
-- paramaeters:
--    TODO
--
-- returns:
--    first value:
--       >0 - number of how many times the given hooked function has been
--            unhooked
--        0 - indicates an error
--    second value:
--       0 - if unhooking was successful
--      >0 - errorcode
--    third value:
--       nil      - if unhooking was successful
--       (string) - errormessage
--
-- remarks:
--    Refere to the Error codes section to get a list of possible errors.
-------------------------------------------------------------------------------
function unregisterFunctionHook(triggerFunction, hookFunc)
	if not (config.calls and config.calls.functions and config.calls.functions[triggerFunction]) then
		return 0, debug("Failed to unregister function hook for "..triggerFunction.." since it is not hooked at all",
		                     1, DebugLib.Level.Error)
	end

	local iHooked  = 0
	local iRemoved = 0
	for pos, funcObj in pairs(config.calls.functions[triggerFunction]) do
		iHooked = iHooked + 1
		if (funcObj and funcObj.f == hookFunc) then
			config.calls.functions[triggerFunction][pos] = nil
			iRemoved = iRemoved + 1
		end
	end

	-- config.calls.functions[triggerFunction] should never be empty. If there
	-- are no hooked functions, it should be nil!
	-- Otherwise this could produce incorrect error messages.
	assert(iHooked > 0, "config.calls.functions["..triggerFunction.."] is an empty array!")

	-- clean up the hooking tables, if no more hooked functions are present
	if(iHooked == iRemoved) then
		config.calls.functions[triggerFunction] = nil
		-- make sure that unhooking was sucessful, or could not be done due to another addon hooking the trigger function meanwhile
		-- TODO: add something like if canBeUnhooked(triggerFunction) then to disable false error messages
		assert(unhookFrom(triggerFunction) ~= 2, "unhookFrom() reports the trigger function: "..triggerFunction.." not to be hooked, although it should be!")
	end

	if iRemoved == 0 then
		return 0, debug("Failed to unregister function hook for "..triggerFunction..". The given function is not hooked in this trigger function.",
		                     1, DebugLib.Level.Error)
	end

	-- rebuild the call list, so that the removed functions are also removed from
	-- the call list
	config.calls.callList = rebuildNotifications(config.calls.functions)

	return iRemoved, 0
end

--[[
	This function registers a given function to be called when a given addon is loaded, or immediatly if it is already loaded (this can be
	used to setup a hooking function to execute when an addon is loaded but not before)
	In certain cenarios IsAddOnLoaded returns 1 even though addon is not fully loaded yet. See http://jira.norganna.org/browse/STUB-8
	for details. In these cases the hook function will be called twice. It should check by querting a global variable form the addon
	if the addon was actually loaded, before accessing its functionality
 ]]
function registerAddOnHook(triggerAddOn, ownerAddOn, hookFunction, ...)
	if (IsAddOnLoaded(triggerAddOn)) then
		if (select("#", ...) == 0) then
			hookFunction()
		else
			hookFunction({...})
		end
	end
	local addon = triggerAddOn:lower()
	if (not config.loads[addon]) then config.loads[addon] = {} end
	config.loads[addon][ownerAddOn] = nil
	if (hookFunction) then
		if (select("#", ...) == 0) then
			config.loads[addon][ownerAddOn] = {
				f = hookFunction,
			}
		else
			config.loads[addon][ownerAddOn] = {
				f = hookFunction,
				a = {...},
			}
		end
	end
end

function unregisterAddOnHook(triggerAddOn, ownerAddOn)
	local addon = triggerAddOn:lower()
	if (config.loads and config.loads[addon] and config.loads[addon][ownerAddOn]) then
		config.loads[addon][ownerAddOn] = nil
	end
end

function loadWatcher(loadedAddOn)
	local addon = loadedAddOn:lower()
	if (config.loads[addon]) then
		for ownerAddOn, hookDetail in pairs(config.loads[addon]) do
			hookDetail.f(hookDetail.a)
		end
	end
end

-- This function registers a given function to be called when a given
-- event is fired (this can be used to activate an addon upon receipt
-- of a given event etc)
function registerEventHook(triggerEvent, ownerAddOn, hookFunction, ...)
	if (not config.events[triggerEvent]) then
		config.events[triggerEvent] = {}
		StubbyFrame:RegisterEvent(triggerEvent)
	end
	config.events[triggerEvent][ownerAddOn] = nil
	if (hookFunction) then
		if (select("#", ...) == 0) then
			config.events[triggerEvent][ownerAddOn] = {
				f = hookFunction,
			}
		else
			config.events[triggerEvent][ownerAddOn] = {
				f = hookFunction,
				a = {...},
			}
		end
	end
end

function unregisterEventHook(triggerEvent, ownerAddOn)
	if (config.events and config.events[triggerEvent] and config.events[triggerEvent][ownerAddOn]) then
		config.events[triggerEvent][ownerAddOn] = nil

		-- events is indexed using the addons name as the key value,
		-- so we have to use next() to check, if the table is empty
		-- Debugged by ccox and Cera
		if ( not next( config.events[triggerEvent] ) ) then
			config.events[triggerEvent] = nil
			-- Never unregister ADDON_LOADED, because this is used by RegisterAddOnHook()
			if (triggerEvent ~= "ADDON_LOADED") then
				StubbyFrame:UnregisterEvent(triggerEvent)
			end
		end
	end
end

function eventWatcher(event, ...)
	if (config.events[event]) then
		for ownerAddOn, hookDetail in pairs(config.events[event]) do
			hookDetail.f(hookDetail.a, event, ...)
		end
	end
end

-- This function registers boot code. This is a piece of code
-- specified as a string, which Stubby will execute on your behalf
-- when we are first loaded. This code can do anything a normal
-- lua script can, such as create global functions, register a
-- command handler, hook into functions, load your addon etc.
-- Leaving bootCode nil will remove your boot.
function registerBootCode(ownerAddOn, bootName, bootCode)
	local ownerIndex = ownerAddOn:lower()
	local bootIndex = bootName:lower()
	if (not StubbyConfig.boots) then StubbyConfig.boots = {} end
	if (not StubbyConfig.boots[ownerIndex]) then StubbyConfig.boots[ownerIndex] = {} end
	StubbyConfig.boots[ownerIndex][bootIndex] = nil
	if (bootCode) then
		StubbyConfig.boots[ownerIndex][bootIndex] = bootCode
	end
end

function unregisterBootCode(ownerAddOn, bootName)
	local ownerIndex = ownerAddOn:lower()
	local bootIndex = bootName:lower()
	if not (StubbyConfig.boots) then return end
	if not (ownerIndex and StubbyConfig.boots[ownerIndex]) then return end
	if (bootIndex == nil) then
		StubbyConfig.boots[ownerIndex] = nil
	else
		StubbyConfig.boots[ownerIndex][bootIndex] = nil
	end
end

function createAddOnLoadBootCode(ownerAddOn, triggerAddOn)
	registerBootCode(ownerAddOn, triggerAddOn.."AddOnLoader",
		'local function hookFunction() '..
			'LoadAddOn("'..ownerAddOn..'") '..
			'Stubby.UnregisterAddOnHook("'..triggerAddOn..'", "'..ownerAddOn..'") '..
		'end '..
		'Stubby.RegisterAddOnHook("'..triggerAddOn..'", "'..ownerAddOn..'", hookFunction)'
	)
end

function createFunctionLoadBootCode(ownerAddOn, triggerFunction)
	registerBootCode(ownerAddOn, triggerFunction.."FunctionLoader",
		'local function hookFunction() '..
			'LoadAddOn("'..ownerAddOn..'") '..
			'Stubby.UnregisterFunctionHook("'..triggerFunction..'", hookFunction) '..
		'end '..
		'Stubby.RegisterFunctionHook("'..triggerFunction..'", 200, hookFunction)'
	)
end

function createEventLoadBootCode(ownerAddOn, triggerEvent)
	registerBootCode(ownerAddOn, triggerEvent.."FunctionLoader",
		'local function hookFunction() '..
			'LoadAddOn("'..ownerAddOn..'") '..
			'Stubby.UnregisterEventHook("'..triggerEvent..'", "'..ownerAddOn..'") '..
		'end '..
		'Stubby.RegisterEventHook("'..triggerEvent..'", "'..ownerAddOn..'", hookFunction)'
	)
end

-- Functions to check through all addons for dependants.
-- If any exist that we don't know about, and have a dependancy of us, then we will load them
-- once to give them a chance to register themselves with us.
function checkAddOns()
	if not StubbyConfig.inspected then return end
	local goodList = {}
	local addonCount = GetNumAddOns()
	local name, title, notes
	for i=1, addonCount do
		name, title, notes = GetAddOnInfo(i)
		if (StubbyConfig.inspected and StubbyConfig.inspected[name]) then
			local infoCompare = title.."|"..(notes or "")
			if (infoCompare == StubbyConfig.addinfo[name]) then
				goodList[name] = true
			end
		end
	end
	for name in pairs(StubbyConfig.inspected) do
		if (not goodList[name]) then
			StubbyConfig.inspected[name] = nil
			StubbyConfig.addinfo[name] = nil
		end
	end
end

-- Cleans up boot codes for removed addons and prompts for deletion of their
-- configurations.
function cleanUpAddOnData()
	if (not StubbyConfig.boots) then return end

	for b in pairs(StubbyConfig.boots) do
		local _,title = GetAddOnInfo(b)
		if (not title) then
			StubbyConfig.boots[b] = nil

			if (StubbyConfig.configs) then
				if (cleanList == nil) then cleanList = {} end
				table.insert(cleanList, b)
			end
		end
	end

	if (cleanList) then cleanUpAddOnConfigs() end
end

-- Shows confirmation dialogs to clean configuration for addons that have
-- just been removed. Warning: Calls itself recursively until done.
function cleanUpAddOnConfigs()
	if (not cleanList) then return end

	local addonIndex = #cleanList
	local addonName = cleanList[addonIndex]

	if (addonIndex == 1) then
		cleanList = nil
	else
		table.remove(cleanList, addonIndex)
	end

	StaticPopupDialogs["CLEANUP_STUBBY" .. addonIndex] = {
		text = "The AddOn \"" .. addonName .. "\" is no longer available. Do you wish to delete it's loading preferences?",
		button1 = "Delete",
		button2 = "Keep",
		OnAccept = function()
			StubbyConfig.configs[addonName] = nil
			cleanUpAddOnConfigs()
		end,
		OnCancel = function()
			cleanUpAddOnConfigs()
		end,
		timeout = 0,
		whileDead = 1,
	}
	StaticPopup_Show("CLEANUP_STUBBY" .. addonIndex, "","")
end

function shouldInspectAddOn(addonName)
	if not StubbyConfig.inspected[addonName] then return true end
	return false
end

function inspectAddOn(addonName, title, info)
	LoadAddOn(addonName)
	StubbyConfig.inspected[addonName] = true
	StubbyConfig.addinfo[addonName] = title.."|"..(info or "")
end

function searchForNewAddOns()
	local addonCount = GetNumAddOns()
	local name, title, notes, enabled, loadable, reason, security, requiresLoad
	for i=1, addonCount do
		requiresLoad = false
		name, title, notes, enabled, loadable, reason, security = GetAddOnInfo(i)
		if (IsAddOnLoadOnDemand(i) and shouldInspectAddOn(name) and loadable) then
			local addonDeps = { GetAddOnDependencies(i) }
			for _, dependancy in pairs(addonDeps) do
				if (dependancy:lower() == "stubby") then
					requiresLoad = true
				end
			end
		end

		if (requiresLoad) then inspectAddOn(name, title, notes) end
	end
end

-- This function runs through the boot scripts we have, and if the
-- related addon is not loaded yet, runs the boot script.
function runBootCodes()
	if (not StubbyConfig.boots) then return end
	for addon, boots in pairs(StubbyConfig.boots) do
		if (not IsAddOnLoaded(addon) and IsAddOnLoadOnDemand(addon)) then
			local _, _, _, _, loadable = GetAddOnInfo(addon)
			if (loadable) then
				for bootname, boot in pairs(boots) do
					RunScript(boot)
				end
			end
		end
	end
end


function onWorldStart()
	-- Check for expired or updated addons and remove their boot codes.
	checkAddOns()

	-- Run all of our boots to setup the respective addons functions.
	runBootCodes()

	-- The search for new life and new civilizations... or just addons maybe.
	searchForNewAddOns()

	-- Delete data for removed addons
	cleanUpAddOnData()
end

function onLoaded()
	if (not (type(StubbyConfig) == "table")) then
		StubbyConfig = {}
	end
	if (not StubbyConfig.inspected) then
		StubbyConfig.inspected = {}
	end
	if (not StubbyConfig.addinfo) then
		StubbyConfig.addinfo = {}
	end
	Stubby.RegisterEventHook("PLAYER_LOGIN", "Stubby", onWorldStart)
end

function events(event, ...)
	if (not event) then event = "" end
	local firstArg = ...
	if (event == "ADDON_LOADED") then
		if (firstArg and (firstArg:lower() == "stubby")) then
			onLoaded()
		end
		Stubby.LoadWatcher(...)
	end
	Stubby.EventWatcher(event, ...)
end

function chatPrint(...)
	if ( DEFAULT_CHAT_FRAME ) then
		local msg = ""
		for i = 1, select("#", ...) do
			if (i == 1) then
				msg = select(i, ...)
			else
				msg = msg.." "..select(i, ...)
			end
		end
		DEFAULT_CHAT_FRAME:AddMessage(msg, 1.0, 0.35, 0.15)
	end
end

-- This function allows boot code to store a configuration variable
-- by default the variable is per character unless isGlobal is set.
function setConfig(ownerAddOn, variable, value, isGlobal)
	local ownerIndex = ownerAddOn:lower()
	local varIndex = variable:lower()
	if (not isGlobal) then
		varIndex = UnitName("player"):lower() .. ":" .. varIndex
	end

	if (not StubbyConfig.configs) then StubbyConfig.configs = {} end
	if (not StubbyConfig.configs[ownerIndex]) then StubbyConfig.configs[ownerIndex] = {} end
	StubbyConfig.configs[ownerIndex][varIndex] = value
end

-- This function gets a config variable stored by the above function
-- it will prefer a player specific variable over a global with the
-- same name
function getConfig(ownerAddOn, variable)
	local ownerIndex = ownerAddOn:lower()
	local globalIndex = variable:lower()
	local playerIndex = UnitName("player"):lower() .. ":" .. globalIndex

	if (not StubbyConfig.configs) then return end
	if (not StubbyConfig.configs[ownerIndex]) then return end
	local curValue = StubbyConfig.configs[ownerIndex][playerIndex]
	if (curValue == nil) then
		curValue = StubbyConfig.configs[ownerIndex][globalIndex]
	end
	return curValue
end

-- This function clears the config variable specified (both the
-- global and player specific) or all config variables for the
-- ownerAddOn if no variable is specified
function clearConfig(ownerAddOn, variable)
	local ownerIndex = ownerAddOn:lower()
	if (not StubbyConfig.configs) then return end
	if (not StubbyConfig.configs[ownerIndex]) then return end
	if (variable) then
		local globalIndex = variable:lower()
		local playerIndex = UnitName("player"):lower() .. ":" .. globalIndex
		StubbyConfig.configs[ownerIndex][globalIndex] = nil
		StubbyConfig.configs[ownerIndex][playerIndex] = nil
	else
		StubbyConfig.configs[ownerIndex] = nil
	end
end

-- Extract the revision number from SVN keyword string
function getRevision()
	return tonumber(("$Revision: 275 $"):match("(%d+)"))
end

-------------------------------------------------------------------------------
-- This function is a modified and slower version of the table.remove()
-- function. It is designed to work with lists even those which contain holes.
--
-- The function removes the element at the given position, which can be any key.
-- The removed value is returned. In advance if the key is a number greater than
-- zero, all elements starting at [pos+1] to table.max(n) will be shifted by
-- one index.
-- All elements with either negative, or hashed keys (i.e. keys which use
-- strings, functions, or anything like this) as well as t[0] are not shifted
-- or changed, except if the element is the one to be removed, in which case the
-- element is being erased from the table.
--
-- If t[pos] does not exist, no elements will be removed, but all elements with
-- indexes above pos will be shifted by one.
--
-- called by:
--    hookCall() - after the original function has been called
--
-- parameters:
--    t   - (list) table to be adjusted
--    pos - (number) the position of the element which is to be removed
--                   the specified number must be greater than 0
--          (anything else) the element at this position will be removed but
--                          no shifting is being performed
--          nil, to remove the element at position: table.maxn(t)
--
-- returns:
--    The value of the removed element.
--
-- remarks:
--    The behaviour of table.remove() when working with tables which contain
--    holes is undefined. For example {nil, true, nil} will correctly return
--    nil when calling table.remove(), but the index of true, is not changed
--    and will still be [2] after the function call.
--    If this behaviour is not wanted, use this modified version of the
--    original function.
--    Also note that the runtime of this function is O(n), so use it with
--    precaution.
-------------------------------------------------------------------------------
function tableRemoveNilSafe(t, pos)
	pos = pos or table.maxn(t)

	if pos == nil then
		pos = table.maxn(t)
		if pos == 0 then
			-- the table does not contain any numeric indexes greater than 0, so there
			-- is nothing todo for us
			return
		end
	end

	-- clearing the temporary table
	for key, data in pairs(tempTable) do
		tempTable[key] = nil
	end

	-- retrieve the key from the table and remove it
	local ret = t[pos]
	t[pos] = nil

	-- construct the new table and clear the current one
	for key, data in pairs(t) do
		if (type(key) == 'number') and (key > pos) then
			tempTable[key-1] = data
		else
			tempTable[key] = data
		end
		t[key] = nil
	end

	-- copy the temporary table to the current one
	for key, data in pairs(tempTable) do
		t[key] = data
	end

	return ret
end

-- Setup our Stubby global object. All interaction is done
-- via the methods exposed here.
Stubby = {
	VERSION = getRevision(),
	Print = chatPrint,
	Events = events,
	HookCall = hookCall,
	SetConfig = setConfig,
	GetConfig = getConfig,
	ClearConfig = clearConfig,
	GetOrigFunc = getOrigFunc,
	LoadWatcher = loadWatcher,
	ErrorHandler = errorHandler,
	EventWatcher = eventWatcher,
	RegisterBootCode = registerBootCode,
	RegisterEventHook = registerEventHook,
	RegisterAddOnHook = registerAddOnHook,
	RegisterFunctionHook = registerFunctionHook,
	UnregisterBootCode = unregisterBootCode,
	UnregisterEventHook = unregisterEventHook,
	UnregisterAddOnHook = unregisterAddOnHook,
	UnregisterFunctionHook = unregisterFunctionHook,
	CreateAddOnLoadBootCode = createAddOnLoadBootCode,
	CreateEventLoadBootCode = createEventLoadBootCode,
	CreateFunctionLoadBootCode = createFunctionLoadBootCode,
	GetName = function() return "Stubby" end
}

StubbyHook = {
	GetName = function() return "Hooked Function" end,
}