local inet = require("internet")
local json = require("json")
local fs = require("filesystem")
local comp = require("component")
local function dl(url)
	local dat = ""
	for chunk in internet.request(url) do
		dat = dat .. chunk
	end
end

local function writefile(p2, dat)
	local f = io.open(p2, "wb")
	f:write(dat)
	f:close()
end

local magic = 0x5f7d
local magic_rev = 0x7d5f
local header_fmt = "I2I2I2I2I2I6I6"
local en = string.unpack("=I2", string.char(0x7d, 0x5f)) == magic -- true = LE, false = BE
local function get_end(e)
	return (e and "<") or ">"
end
local function read_header(dat)
	local e = get_end(en)
	local m = string.unpack(e.."I2", dat)
	if m ~= magic and m ~= magic_rev then return nil, "bad magic" end
	if m ~= magic then
		e = get_end(not en)
	end
	local ent = {}
	ent.magic, ent.namesize, ent.mode, ent.uid, ent.gid, ent.filesize, ent.mtime = string.unpack(e..header_fmt, dat)
	return ent
end

local arc = {}

function arc:fetch(path)
	for i=1, #self.tbl do
		if (self.tbl[i].name == path and self.tbl[i].mode & 32768 > 0) then
			self.seek(self.tbl[i].pos-self.seek(0))
			return self.read(self.tbl[i].filesize), self.tbl[i]
		end
	end
	return nil, "file not found"
end

function arc:exists(path)
	for i=1, #self.tbl do
		if (self.tbl[i].name == path) then
			return true
		end
	end
	return false
end

function arc:list(path)
	if path:sub(#path) ~= "/" then path = path .. "/" end
	local ent = {}
	for i=1, #self.tbl do
		if (self.tbl[i].name:sub(1, #path) == path and not self.tbl[i].name:find("/", #path+1, false)) then
			ent[#ent+1] = self.tbl[i].name
		end
	end
	return ent
end

function arc:close()
	self.close()
end

local tsar = {
	read = function(read, seek, close)
		local tbl = {}
		local lname = ""
		while lname ~= "TRAILER!!!" do
			local dat = read(22)
			local e = read_header(dat)
			e.name = read(e.namesize)
			e.pos = seek(e.namesize & 1)
			seek(e.filesize + (e.filesize & 1))
			lname = e.name
			if lname ~= "TRAILER!!!" then
				tbl[#tbl+1] = e
			end
		end
		return setmetatable({tbl = tbl, read = read, seek = seek, close = close}, {__index=arc})
	end
}

local arc = ""
local arc_p = 1

local function _r(a)
	local dat = arc:sub(arc_p, arc_p+a-1)
	arc_p = arc_p + a
	return dat
end

local function _s(a)
	arc_p = arc_p + a
	return arc_p
end
local rdat = json.decode(dl("https://api.github.com/repos/Adorable-Catgirl/Zorya-NEO/releases"))[1]
print("Newest release: "..rdat.tag_name)
print("Downloading zorya-neo-update.tsar...")
for i=1, #rdat.assets do
	if (rdat.assets[i].name == "zorya-neo-update.tsar") then
		arc = dl(rdat.assets[i].browser_download_url)
		goto arc_downloaded
	end
end
io.stderr:write("ERROR: zorya-neo-update.tsar not found!\n")
return
::arc_downloaded::
local update = tsar.read(_r, _s, function() end)
for ent in fs.list("/etc/zorya-neo/mods") do
	if (update:exists("mods/"..ent)) then
		writefile("/etc/zorya-neo/mods/"..ent, update:fetch("mods/"..ent))
	end
end

for ent in fs.list("/etc/zorya-neo/lib") do
	if (update:exists("lib/"..ent)) then
		writefile("/etc/zorya-neo/lib/"..ent, update:fetch("lib/"..ent))
	end
end

if (comp.eeprom.address == "vdev-ZY_VBIOS") then
	io.stderr:write("WARNING: Updating Zorya NEO in a vBIOS does not update Zorya NEO completely!\n")
else
	print("Flashing EEPROM! Do not turn off the computer!")
	comp.eeprom.set(update:fetch("bios/managed.bios"))
	print("Flashing complete.")
end

print("Running zyneo-geninitramfs to finish the update...")
os.execute("zyneo-geninitramfs")
print("Update complete. Please restart your computer.")