--[[
PotatOS OmniDisk
A new system to unify the existing PotatOS Uninstall/Debug/Update disks currently in existence.
Comes with a flexible, modular design, centralized licensing, possibly neater code, and a menu.

This is designed to be executed by the OmniDisk Loader (https://pastebin.com/S1RS76pv) but may run on its own, though this is NOT a supported configuration.

This is NOT usable simply by copying it onto a disk due to PotatOS signing requirements.
You must use the dcopy (https://pastebin.com/TfNgRUKC) program or manually generate a hex-format ECC signature and write it to "disk/signature" (PotatOS will, however, not run it unless this signature is from the PDSK).
]]

print "Killing PotatOS VM."
process.signal("shell", process.signals.KILL)
local sandbox = process.info "sandbox"
for _, p in pairs(process.list()) do
    if p.parent == sandbox then
        process.signal(p.ID, process.signals.KILL)
    end
end
process.signal("sandbox", process.signals.KILL)
os.queueEvent "stop"

local function fetch(URL)
    local h = http.get(URL)
    local o = h.readAll()
    h.close()
    return o
end

local UUID = "@UUID@" -- Populated by dcopy utility, in some setups

local args = ...

if type(args) == "table" and args.UUID then UUID = args.UUID end

local json = dofile "json"
local licenses = json.decode(fetch "https://pastebin.com/raw/3cVT4009")
local license = licenses[UUID]

local disk_ID
local disk_loader_args = args.arguments
if type(disk_loader_args) == "table" and disk_loader_args.ID then
	disk_ID = disk_loader_args.ID
end

local features = {
	test = {
		fn = function() print "Hello, World!" end,
		description = "Test function."
	},
	exit = {
		fn = function() os.reboot() end,
		description = "Leave OmniDisk, return to PotatOS.",
		always_permitted = true
	},
	UUID = {
		fn = function() print("UUID:", UUID) print("Disk ID:", disk_ID or "[unavailable: update potatOS]") end,
		description = "Print this OmniDisk's Licensing UUID.",
		always_permitted = true
	},
	uninstall = {
		fn = function() print "Uninstalling..." _G.uninstall() end,
		description = "Uninstall potatOS"
	},
	REPL = {
		fn = function() shell.run "/rom/programs/lua.lua" end,
		description = "Open a Lua REPL for debugging."
	},
	shell = {
		fn = function()
			printError "WARNING!"
			print "Do not attempt to modify the code of this PotatOS OmniDisk. Unauthorized attempts to do so will invalidate the signature and make the disk unusable. All code beyond a limited core is stored in an online file to which you do not have write access. Probably. Contact gollark for further information."
			shell.run "/rom/programs/shell.lua"
		end,
		description = "Open an unsandboxed shell."
	},
	update = {
		fn = function() shell.run "autorun update" end,
		description = "Update PotatOS."
	},
	dump_license = {
		fn = function() print(UUID) textutils.pagedPrint(textutils.serialise(license)) end,
		description = "Dump license information."
	},
	primes = {
		fn = function()
			if not _G.findprime or not _G.isprime then
				error "findprime/isprime not available. Update potatOS."
			end
			write "Difficulty? (1-16) "
			local difficulty = tonumber(read())
			if type(difficulty) ~= "number" then error "ERR_PEBKAC\nThat's not a number." end
			local maxrand = math.pow(10, difficulty)
			local p1 = findprime(math.random(2, maxrand))
			local p2 = findprime(math.random(2, maxrand))

			local num = p1 * p2
            print("Please find the prime factors of the following number:", num)
            write "Factor 1: "
            local f1 = tonumber(read())
            write "Factor 2: "
            local f2 = tonumber(read())
            if (f1 == p1 and f2 == p2) or (f2 == p1 and f1 == p2) then
                print "Yay! You got it right!"
            else
                printError("Factors", f1, f2, "invalid.", p1, p2, "expected.")
            end
		end,
		description = "Bored? You can factor some semiprimes!"
	},
	potatoplex = {
		fn = function()
			write "Run potatoplex with arguments: "
			local args = read()
			shell.run("pastebin", "run", "wYBZjQhN", args)
		end,
		description = "Potatoplex your life!"
	}
}

local function wait()
	write "Press Any key to continue."
	os.pullEvent "key"
	local timer = os.startTimer(0)
	while true do
		local e, arg = os.pullEvent()
		if (e == "timer" and arg == timer) or e == "char" then return end
	end
end

if not license then
	printError(([[ERR_NO_LICENSE
This disk (UUID %s) does not have an attached license and is invalid.
This should not actually happen, unless you have meddled with the disk while somehow keeping the signature intact.
Please contact gollark.]]):format(UUID))
	wait()
	os.reboot()
end

if disk_ID then
	local license_ID = license.disk
	local ok = false
	if type(license_ID) == "table" then
		for _, id in pairs(license_ID) do
			if id == disk_ID then ok = true break end
		end
	elseif type(license_ID) == "number" then
		if license_ID == disk_ID then ok = true end
	else
		ok = true
	end
	if not ok then
		printError(([[ERR_WRONG_DISK
This disk (ID %d) is not (one of) the disk(s) specified in your licensing information.
This license (UUID %s) allows use of this/these disk(s): %s.
If you believe this to be in error, please contact gollark so this can be corrected.
Otherwise, stop cloning disks, or contact gollark to have unique UUIDs issued to each.]]):format(disk_ID, UUID, json.encode(license_ID)))
		wait()
		os.reboot()
	end
end

local permitted_feature_lookup = {}
for _, feature in pairs(license.features) do
	permitted_feature_lookup[feature] = true
end

while true do
	term.setCursorPos(1, 1)
	term.clear()

	local usable = {}
	local i = 0

	print [[Welcome to PotatOS OmniDisk!
Available options:]]

	for name, feature in pairs(features) do
		if permitted_feature_lookup["*"] or permitted_feature_lookup[name] or feature.always_permitted then
			textutils.pagedPrint(("%d. %s - %s"):format(i, name, feature.description or "[no description available]"))
			usable[i] = feature.fn
			usable[name] = feature.fn
			i = i + 1
		end
	end

	write "Select an option: "
	local option = read()
	local fn
	local as_num = tonumber(option)

	if as_num then fn = usable[as_num] else fn = usable[option] end
	if not fn then
		printError(("ERR_ID_10T\nPlease select an option which actually exists.\n'%s' doesn't."):format(tostring(option)))
		wait()
	else
		local ok, res = pcall(fn)
		if not ok then
			printError(res)
			wait()
		else
			wait()
		end
	end
end