update.lua

--Check whether you enable/disable dgs update system..
--If you don't trust dgs.. Please Disable It In "config.txt"

local check = fileExists("update.cfg") and fileOpen("update.cfg") or fileCreate("update.cfg")
local verRaw = fileRead(check, fileGetSize(check))
fileClose(check)
setElementData(resourceRoot, "Version", verRaw)
local version = tonumber(verRaw) or 0

if not DGSConfig.updater then
	return
end

local _fetchRemote = fetchRemote

function fetchRemote(...)
	if not hasObjectPermissionTo(resource, "function.fetchRemote", true) then
		outputDGSMessage("fetchRemote' was called, but access was denied. To resolve this issue, use the command 'aclrequest allow dgs all'.", 2)

		return false
	end

	return _fetchRemote(...)
end

RemoteVersion = 0
ManualUpdate = false
updateTimer = false
updatePeriodTimer = false

function checkUpdate()
	outputDGSMessage("Checking for updates..", nil, "Updater")
	fetchRemote("https://raw.githubusercontent.com/thisdp/dgs/master/update.cfg", function(data, err)
		if err == 0 then
			RemoteVersion = tonumber(data)

			if not ManualUpdate then
				if RemoteVersion > version then
					outputDGSMessage("New update available: "..version.." > "..data..". Consider updating your DGS using /"..DGSConfig.updateCommand, "Updater")
					outputDGSMessage("Please check the changelogs at https://github.com/thisdp/dgs/releases to avoid breaking changes.", "Updater")

					if isTimer(updateTimer) then
						killTimer(updateTimer)
					end

					updateTimer = setTimer(function()
						if RemoteVersion > version then
							outputDGSMessage("New update available: "..version.." > "..data..". Consider updating your DGS using /"..DGSConfig.updateCommand, "Updater")
							outputDGSMessage("Please check the changelogs at https://github.com/thisdp/dgs/releases before to avoid breaking changes.", "Updater")
						else
							killTimer(updateTimer)
						end
					end, DGSConfig.updateCheckNoticeInterval*60000, 0)
				else
					outputDGSMessage("Current version ("..version..") is the latest!", "Updater")
				end
			else
				startUpdate()
			end
		else
			outputDGSMessage("The remote version could not be retrieved ("..err..")", "Updater", 2)
		end
	end)
end

if DGSConfig.updateCheckAuto then
	checkUpdate()
	updatePeriodTimer = setTimer(checkUpdate, DGSConfig.updateCheckInterval*3600000, 0)
end

addCommandHandler(DGSConfig.updateCommand, function(player)
	local account = getPlayerAccount(player)
	local isPermit = hasObjectPermissionTo(player, "command."..DGSConfig.updateCommand, false)

	if not isPermit then
		local accName = getAccountName(account)
		local adminGroup = aclGetGroup("Admin")
		local consoleGroup = aclGetGroup("Console")

		isPermit = isPermit or (adminGroup and isObjectInACLGroup("user."..accName, adminGroup))
		isPermit = isPermit or (consoleGroup and isObjectInACLGroup("user."..accName, consoleGroup))
	end

	if isPermit then
		outputDGSMessage(getPlayerName(player).." attempt to update dgs (Allowed)", "Updater")
		outputDGSMessage("Preparing to update dgs", "Updater", 0, {player, "console"})

		if RemoteVersion > version then
			startUpdate()
		else
			ManualUpdate = true
			checkUpdate()
		end
	else
		outputDGSMessage("Access Denied!", "Updater", 1, player)
		outputDGSMessage(getPlayerName(player).." attempt to update dgs (Denied)", "Updater", 2)
	end
end)

function startUpdate()
	ManualUpdate = false
	setTimer(function()
		outputDGSMessage("Requesting update data (From GitHub)...", "Updater")
		fetchRemote("https://raw.githubusercontent.com/thisdp/dgs/master/meta.xml", function(data, err)
			if err == 0 then
				outputDGSMessage("Update data retrieved successfully.", "Updater")

				if fileExists("updated/meta.xml") then
					fileDelete("updated/meta.xml")
				end

				local meta = fileCreate("updated/meta.xml")
				fileWrite(meta, data)
				fileClose(meta)
				outputDGSMessage("Requesting verification data...", "Updater")
				getGitHubTree()
			else
				outputDGSMessage("Unable to retrieve remote update data ("..err..")", "Updater", 2)
			end
		end)
	end, 50, 1)
end

preUpdate = {}
fileHash = {}
UpdateCount = 0

function getGitHubTree(path, nextPath)
	nextPath = nextPath or ""
	fetchRemote(path or "https://api.github.com/repos/thisdp/dgs/git/trees/master?recursive=1", function(data, err)
		if err == 0 then
			local theTable = fromJSON(data)

			for k, v in pairs(theTable.tree) do
				if (v.path ~= "styleMapper.lua" and fileExists("styleManager/styleMapper.lua")) and v.path ~= "meta.xml" then
					local thePath = nextPath..(v.path)

					if v.mode ~= "040000" then
						fileHash[thePath] = v.sha
					end
				end
			end

			checkFiles()
		else
			outputDGSMessage("Failed to get verification data, please try again later (API Cool Down 60 mins)", "Updater", 2)
		end
	end)
end

function checkFiles()
	local xml = xmlLoadFile("updated/meta.xml")

	for k, v in ipairs(xmlNodeGetChildren(xml)) do
		repeat
			if xmlNodeGetName(v) == "script" or xmlNodeGetName(v) == "file" then
				local path = xmlNodeGetAttribute(v, "src")

				if string.find(path, "styleMapper.lua") then
					break
				end

				if path == "meta.xml" then
					break
				end

				if string.find(path, "test.lua") and not DGSConfig.testFile then
					break
				end

				local sha = ""

				if fileExists(path) then
					local file = fileOpen(path)
					local size = fileGetSize(file)
					local text = fileRead(file, size)

					fileClose(file)
					sha = hash("sha1", "blob " .. size .. "\0" ..text)
				end

				if sha ~= fileHash[path] then
					outputDGSMessage("Update required: ("..path..")", "Updater")
					table.insert(preUpdate, path)
				end
			end
		until true
	end

	xmlUnloadFile(xml)
	DownloadFiles()
end

function DownloadFiles()
	UpdateCount = UpdateCount + 1

	if not preUpdate[UpdateCount] then
		DownloadFinish()

		return
	end

	outputDGSMessage("Requesting ("..UpdateCount.."/"..(#preUpdate or "Unknown").."): "..tostring(preUpdate[UpdateCount]), "Updater")
	fetchRemote("https://raw.githubusercontent.com/thisdp/dgs/master/"..preUpdate[UpdateCount], function(data, err, path)
		if err == 0 then
			local size = 0

			if fileExists(path) then
				local file = fileOpen(path)
				size = fileGetSize(file)
				fileClose(file)
				fileDelete(path)
			end

			local file = fileCreate(path)
			fileWrite(file, data)
			local newsize = fileGetSize(file)
			fileClose(file)
			outputDGSMessage("Got ("..UpdateCount.."/"..#preUpdate.."): "..path.." [ "..size.."B -> "..newsize.."B ]", "Updater")
		else
			outputDGSMessage("Download failed: "..path.." ("..err..")!", "Updater", 2)
		end

		if preUpdate[UpdateCount+1] then
			DownloadFiles()
		else
			DownloadFinish()
		end
	end, "", false, preUpdate[UpdateCount])
end

function DownloadFinish()
	outputDGSMessage("Updating version file", "Updater")

	if fileExists("update.cfg") then
		fileDelete("update.cfg")
	end

	local file = fileCreate("update.cfg")
	fileWrite(file, tostring(RemoteVersion))
	fileClose(file)

	if fileExists("meta.xml") then
		backupStyleMapper()
		fileDelete("meta.xml")
	end

	recoverStyleMapper()

	if not DGSConfig.testFile then	--Remove test.lua from meta.xml
		local xml = xmlLoadFile("meta.xml")

		for k, v in ipairs(xmlNodeGetChildren(xml)) do
			if xmlNodeGetName(v) == "script" then
				if string.find(xmlNodeGetAttribute(v, "src"), "test.lua") then
					xmlDestroyNode(v)
					break
				end
			end
		end

		xmlSaveFile(xml)
		xmlUnloadFile(xml)
	end

	outputDGSMessage("Update successful: "..#preUpdate.." file"..(#preUpdate==1 and "" or "s").." have been updated.", "Updater", {root, "console"})
	outputDGSMessage("Please restart DGS", "Updater")

	preUpdate = {}
	UpdateCount = 0
end

addCommandHandler("dgsver", function(pla, cmd)
	local vsdd

	if fileExists("update.cfg") then
		local file = fileOpen("update.cfg")
		local vscd = fileRead(file, fileGetSize(file))

		fileClose(file)
		vsdd = tonumber(vscd)

		if vsdd then
			outputDGSMessage("Current version: "..vsdd, nil, 3, pla)
		else
			outputDGSMessage("Version file is damaged! Please use /"..DGSConfig.updateCommand.." to update", nil, 2, pla)
		end
	else
		outputDGSMessage("Version file is damaged! Please use /"..DGSConfig.updateCommand.." to update", nil, 2, pla)
	end
end)

styleBackupStr = ""
locator = [[	<export]]

function backupStyleMapper()
	if DGSConfig.metaBackup then
		fileCopy("meta.xml", "meta.xml.bak", true)
	end

	if not fileExists("meta.xml") then
		return outputDGSMessage("Please rename the meta xml as meta.xml", nil, "Updater", 2)
	end

	local meta = fileOpen("meta.xml")
	local str = fileRead(meta, fileGetSize(meta))
	local startStr = "<!----$Add Your Styles Here---->"
	local endStr = "<!----&Add Your Styles Here---->"
	local startPos = str:find(startStr)
	local endPos = str:find(endStr)

	styleBackupStr = str:sub(startPos, endPos-1).."<!--&Add Your Styles Here-->"
	fileClose(meta)

	if fileExists("styleMapperBackup.bak") then
		fileDelete("styleMapperBackup.bak")
	end

	if DGSConfig.metaStyleBackup then
		local file = fileCreate("styleMapperBackup.bak")
		fileWrite(file, styleBackupStr)
		fileClose(file)
	end
end

function recoverStyleMapper()
	if styleBackupStr == "" then
		return outputDGSMessage("Failed to recover style mapper", "Updater", 2)
	end

	local meta = fileOpen("updated/meta.xml")
	local str = fileRead(meta, fileGetSize(meta))

	fileClose(meta)
	local newMeta = fileCreate("meta.xml")
	local startStr = "<!----$Add Your Styles Here---->"
	local startPos = str:find(startStr)
	local exportPos = str:find(locator)
	local scriptsStr = str:sub(1, startPos-1)
	local exportsStr = str:sub(exportPos)

	fileWrite(newMeta, scriptsStr..styleBackupStr.."\r\n"..exportsStr)
	fileClose(newMeta)
	fileDelete("updated/meta.xml")
end