Added data up-/down-grading

diff --git a/Upgrade.lua b/Upgrade.lua
new file mode 100644
index 0000000..604d062
--- /dev/null
+++ b/Upgrade.lua
@@ -0,0 +1,155 @@
+function WeightsWatcher:Upgrade(dataType)
+	local oldMinorVersion, oldMajorVersion, newMinorVersion, newMajorVersion, vars, funcTable, direction, downgradeFunctions
+
+	if dataType == "account" then
+		vars = ww_vars
+		newMinorVersion = defaultVars.dataMinorVersion
+		newMajorVersion = defaultVars.dataMajorVersion
+		funcTable = upgradeAccountFunctions
+		downgradeFunctions = downgradeAccountFunctions
+	elseif dataType == "character" then
+		vars = ww_charVars
+		newMinorVersion = defaultCharVars.dataMinorVersion
+		newMajorVersion = defaultCharVars.dataMajorVersion
+		funcTable = upgradeCharFunctions
+		downgradeFunctions = downgradeCharFunctions
+	else
+		print("WeightsWatcher: error: invalid data type \"" .. dataType .. "\" passed to Upgrade().")
+		return nil
+	end
+
+	if vars then
+		oldMinorVersion = vars.dataMinorVersion
+		oldMajorVersion = vars.dataMajorVersion
+	end
+	if not oldMinorVersion then
+		oldMinorVersion = 0
+	end
+	if not oldMajorVersion then
+		oldMajorVersion = 0
+	end
+
+	if newMajorVersion == oldMajorVersion and newMinorVersion == oldMinorVersion then
+		return vars
+	end
+
+	if newMajorVersion > oldMajorVersion or (newMajorVersion == oldMajorVersion and newMinorVersion > oldMinorVersion) then
+		direction = "up"
+	else
+		direction = "down"
+		funcTable = stringsToFuncs(vars.downgradeFunctions)
+	end
+
+	if funcTable == nil then
+		print("WeightsWatcher: error: no " .. direction .. "grade function table found.")
+		return nil
+	end
+
+	if oldMajorVersion == 0 and oldMinorVersion == 0 then
+		print("WeightsWatcher: no " .. dataType .. " data found, loading defaults.")
+	else
+		print("WeightsWatcher: attempting to " .. direction .. "grade " .. dataType .. " data from version " .. oldMajorVersion .. "." .. oldMinorVersion .. " to " .. newMajorVersion .. "." .. newMinorVersion .. ".")
+	end
+
+	local newVars = deepTableCopy(vars)
+
+	while oldMajorVersion ~= newMajorVersion or oldMinorVersion ~= newMinorVersion do
+		if not funcTable[oldMajorVersion] or not funcTable[oldMajorVersion][oldMinorVersion] then
+			print("WeightsWatcher: error: No " .. dataType .. " data " .. direction .. "grade path found.")
+			return nil
+		end
+		newVars = funcTable[oldMajorVersion][oldMinorVersion](newVars)
+		if not newVars or not newVars.dataMinorVersion then
+			print("WeightsWatcher: " .. dataType .. " data " .. direction .. "grade error.")
+			return nil
+		elseif oldMinorVersion == newVars.dataMinorVersion and oldMajorVersion == newVars.dataMajorVersion then
+			print("WeightsWatcher: error: infinite loop in " .. dataType .. " data " .. direction .. "grade.")
+			return nil
+		end
+		oldMinorVersion = newVars.dataMinorVersion
+		if newVars.dataMajorVersion then
+			oldMajorVersion = newVars.dataMajorVersion
+		else
+			oldMajorVersion = 0
+		end
+	end
+
+	newVars.downgradeFunctions = downgradeFunctions
+
+	print("WeightsWatcher: successfully " .. direction .. "graded " .. dataType .. " data.")
+
+	return newVars
+end
+
+function deepTableCopy(object)
+    local lookup_table = {}
+    local function _copy(object)
+        if type(object) ~= "table" then
+            return object
+        elseif lookup_table[object] then
+            return lookup_table[object]
+        end
+        local new_table = {}
+        lookup_table[object] = new_table
+        for index, value in pairs(object) do
+            new_table[_copy(index)] = _copy(value)
+        end
+        return setmetatable(new_table, _copy(getmetatable(object)))
+    end
+    return _copy(object)
+end
+
+function stringsToFuncs(strTable)
+	local funcTable = {}
+
+	for major, tbl in pairs(strTable) do
+		funcTable[major] = {}
+		for minor, funcStr in pairs(tbl) do
+			funcTable[major][minor] = loadstring(funcStr)()
+		end
+	end
+
+	return funcTable
+end
+
+function copyDefaultAccountVars()
+	return deepTableCopy(defaultVars)
+end
+
+function createActiveWeights(class)
+	local activeWeights = {}
+
+	activeWeights[class] = {}
+	for name, _ in pairs(ww_vars.weightsList[class]) do
+		table.insert(activeWeights[class], name)
+	end
+
+	return activeWeights
+end
+
+function copyDefaultCharVars()
+	local charVars
+	local _, class = UnitClass("player")
+
+	charVars = deepTableCopy(defaultCharVars)
+	charVars.activeWeights = createActiveWeights(class)
+	return charVars
+end
+
+upgradeAccountFunctions = {
+	[0] = {
+		[0] = function(vars) return copyDefaultAccountVars() end,
+	},
+}
+
+downgradeAccountFunctions = {
+}
+
+upgradeCharFunctions = {
+	[0] = {
+		[0] = function(vars) return copyDefaultCharVars() end,
+	},
+}
+
+downgradeCharFunctions = {
+}
diff --git a/WeightsWatcher.lua b/WeightsWatcher.lua
index b54d8d7..4ed94a5 100644
--- a/WeightsWatcher.lua
+++ b/WeightsWatcher.lua
@@ -3,12 +3,28 @@ if not WeightsWatcher then
 end

 function WeightsWatcher:OnInitialize()
+	local tempVars
+
 	SLASH_WEIGHTSWATCHER1="/ww"
 	SLASH_WEIGHTSWATCHER2="/weightswatcher"
 	SlashCmdList["WEIGHTSWATCHER"] =
 		function(msg)
 			commandHandler(msg)
 		end
+
+	tempVars = WeightsWatcher:Upgrade("account")
+	if tempVars then
+		ww_vars = tempVars
+	else
+		-- TODO: disable the addon
+	end
+-- 	print("WeightsWatcher: be sure to restore the default weights if you want the new default weights.")
+	tempVars = WeightsWatcher:Upgrade("character")
+	if tempVars then
+		ww_charVars = tempVars
+	else
+		-- TODO: disable the addon
+	end
 end

 function commandHandler(msg)
diff --git a/WeightsWatcher.toc b/WeightsWatcher.toc
index 2bfebaf..9c8520c 100644
--- a/WeightsWatcher.toc
+++ b/WeightsWatcher.toc
@@ -17,6 +17,7 @@ Libs\AceHook-2.1\AceHook-2.1.lua
 GemIds.lua
 config.lua
 Regexps.lua
+Upgrade.lua
 HiddenTooltip.xml
 WeightsWatcher.lua
 WeightsWatcher.xml
diff --git a/config.lua b/config.lua
index d19dd1a..25512e4 100644
--- a/config.lua
+++ b/config.lua
@@ -1,4 +1,6 @@
 defaultVars = {
+	dataMajorVersion = 0,
+	dataMinorVersion = 1,
 	weightsList = {
 		["ROGUE"] = {
 			["Default"] = {
@@ -59,5 +61,7 @@ defaultVars = {
 }

 defaultCharVars = {
+	dataMajorVersion = 0,
+	dataMinorVersion = 1,
 	activeWeights = {},
 }