startup

local function FileEnding( _str )
local x = string.len(_str)
local ok = false
local result = ""
while x > 0 do
	if string.char(string.byte(_str , x)) == "." then
		ok = true
		break
		end
	x = x - 1
	end
if ok then
	result = string.sub(_str,x)
	end
return result
end

local function Values( _str , _seperator )
local _seperator, fields = _seperator or " ", {}
local pattern = string.format("([^%s]+)", _seperator)
_str:gsub(pattern, function(c) fields[#fields+1] = c end)
while #fields > 2 do 
	fields[#fields-1] = fields[#fields-1] .. fields[#fields]
	fields[#fields] = nil
	end
return fields
end

local function SelectColor(acolor)
if term.isColor and term.isColor() then
	term.setTextColor(acolor or colors.white)
	end
end

local MGRUB_PATH = "/MGRUB"
local OSs = {}
OSs.__index = OSs

function OSs.create(_file)
	local acnt = {}
	setmetatable(acnt,OSs)
	acnt.name = ""
	acnt.file = _file
	acnt.owner = "unknown"
	acnt.lastboot = 0
	acnt.bootcount = 0
	acnt.bootfile = nil
	acnt.version = "unknown"
	acnt.checkInstall = nil
	return acnt
end

function OSs:GetInfo()
local file = fs.open(MGRUB_PATH .. "/" .. self.file,"r")
if file then
	local  sLine = ""
	local puffer = {}
	sLine = file:readLine()
	while sLine do
		puffer = Values(sLine, " ")
		if puffer[1] == "name" then self.name = puffer[2] end
		if puffer[1] == "owner" then self.owner = puffer[2] end
		if puffer[1] == "lastboot" then self.lastboot = tonumber(puffer[2]) end
		if puffer[1] == "bootcount" then self.bootcount = tonumber(puffer[2]) end
		if puffer[1] == "bootfile" then self.bootfile = puffer[2] end
		if puffer[1] == "version" then self.version = puffer[2] end
		if puffer[1] == "checkInstall" then self.checkInstall = puffer[2] end
		sLine = file:readLine()
		end
	file:close()
	end
return (file ~= nil)
end

function OSs:IsInstalled()
if self.checkInstall and (self.checkInstall ~= "") then
	return fs.exists(self.checkInstall)
	end
return true
end

function OSs:WriteInfo()
fs.delete(MGRUB_PATH .. "/" .. self.file)
local file = fs.open(MGRUB_PATH .. "/" .. self.file,"w")
file.writeLine("name ".. (self.name or ""))
file.writeLine("owner ".. (self.owner or ""))
file.writeLine("lastboot ".. (self.lastboot or ""))
file.writeLine("bootcount ".. (self.bootcount or ""))
file.writeLine("bootfile ".. (self.bootfile or ""))
file.writeLine("version ".. (self.version or ""))
file.writeLine("checkInstall ".. (self.checkInstall or ""))
file.close()
end

function OSs:Boot()
self.lastboot = os.time()
self.bootcount = self.bootcount + 1
self:WriteInfo()
if self.bootfile ~= nil then
	if string.char(string.byte(self.bootfile , 1)) == "/" then
		shell.run(self.bootfile)
		else
		shell.run(MGRUB_PATH .. "/" .. self.bootfile)
		end
	end
end



-- STARTING --
-- LOADING SETTINGS --

local standart = ""
local timeout = 10
local bootsleep = 4
local current = 0
local runto = 0
local MGRUB_VERSION = "0.98.4"

-- Load Boot API -- 
os.loadAPI(MGRUB_PATH .. "/boot")

boot.BootMsg("MGRUB " .. MGRUB_VERSION .. " - BOOT LOADER")
local file = fs.open(MGRUB_PATH .. "/settings","r")
if file then
	local  sLine = ""
	local puffer = {}
	sLine = file:readLine()
	while sLine do
		puffer = Values(sLine, " ")
		if puffer[1] == "standart" then standart = puffer[2] end
		if puffer[1] == "timeout" then timeout = tonumber(puffer[2]) end
		if puffer[1] == "bootsleep" then bootsleep = tonumber(puffer[2]) end
		sLine = file:readLine()
		end
		
	file:close()
	boot.BootMsg("Loading settings to Boot")
	boot.BootMsg("standart OS: " .. standart)
	boot.BootMsg("timeout : " .. timeout)
	else
	boot.BootMsg("unable to load settings")
	boot.BootMsg("please check the '".. MGRUB_PATH .. "/settings' File !" )
	end
sleep(bootsleep)

-- CHECK FOR OSs --
for i,obj in ipairs(fs.list(MGRUB_PATH)) do
	if FileEnding( obj ) == ".mgrub" then
		local new = OSs.create(obj)
		if not new:GetInfo() then
			boot.BootMsg("Failed to Load OS: " .. obj)
			else
			if new:IsInstalled() then
				OSs[#OSs+1] = new
				if obj == standart then
					current = #OSs
					end
				end
			end
		end
	end

-- AUSWAHL -- 
local function Render()
term.clear()
term.setCursorPos(1,1)
print("MGRUB " .. MGRUB_VERSION .. " - BOOT LOADER")
print("")
for i,obj in ipairs(OSs) do
	if i == current then
		SelectColor(colors.green)
		print("  > " .. obj.name .. " <  ")
		SelectColor(colors.white)
		else
		print("    " .. obj.name .. "    ")
		end
	end
print("")
print("")
local t = math.floor(runto - os.clock())
if (t < 3) and (term.isColor()) then
	write("timeout ")
	SelectColor(colors.red)
	print(t)
	SelectColor(colors.white)
	else
	print("timeout ".. tostring(t))
	end

local x,y = term.getSize()
term.setCursorPos(1,y)
write("xMAC94x")
local astr = "GPL2.0 - http://goo.gl/8Axgz"
term.setCursorPos(x-string.len(astr),y)
write(astr)

end	

function GetEvents( _atime )
local timer = os.startTimer( (_atime or 0) )
local event, p1, p2, p3, p4, p5 = 0
local i,obj
while true do
	event, p1, p2, p3, p4, p5 = os.pullEvent()
	if ((event == "timer") and (p1 == timer)) then 
		break 
	elseif  event == "key" then
		if (p1 == 17) or (p1 == 200) then 
			current = current - 1
			if current < 1 then current = #OSs end
			runto = os.clock() + timeout + 5
			end
		if (p1 == 31) or (p1 == 208) then 
			current = current + 1
			if current > #OSs then current = 1 end
			runto = os.clock() + timeout + 5
			end
		if (p1 == 28) then 
			runto = -1
			end
		end
	end
end

runto = os.clock() + timeout
while os.clock() < runto do
	Render()
	if current < 1 then
		runto = os.clock() + timeout + 5
		end
	GetEvents(0.05)
	end

if current > 0 then
	boot.BootMsg("booting into " .. OSs[current].name)
	OSs[current]:Boot()
	end