local mainPath = ".sysmail"
local yourID = os.getComputerID()
local onlyUseWiredModems = false

local config = {
	channel = 1024,
	keyPath = fs.combine(mainPath, "keys"),
	mailPath = fs.combine(mainPath, "mail"),
	apiPath = fs.combine(mainPath, "api"),
	nameFile = fs.combine(mainPath, "names"),
	attachmentPath = "attachments"
}

-- used for picking attachments

local lddfm = {scroll = 0, ypaths = {}}

lddfm.scr_x, lddfm.scr_y = term.getSize()

lddfm.setPalate = function(_p)
	if type(_p) ~= "table" then _p = {} end
	lddfm.p = { --the DEFAULT color palate
		bg =        _p.bg or colors.gray,			-- whole background color
		d_txt =     _p.d_txt or colors.yellow,		-- directory text color
		d_bg =      _p.d_bg or colors.gray,			-- directory bg color
		f_txt =     _p.f_txt or colors.white,		-- file text color
		f_bg =      _p.f_bg or colors.gray,			-- file bg color
		p_txt =     _p.p_txt or colors.black,		-- path text color
		p_bg =      _p.p_bg or colors.lightGray,	-- path bg color
		close_txt = _p.close_txt or colors.gray,	-- close button text color
		close_bg =  _p.close_bg or colors.lightGray,-- close button bg color
		scr =       _p.scr or colors.lightGray,		-- scrollbar color
		scrbar =    _p.scrbar or colors.gray,		-- scroll tab color
	}
end

lddfm.setPalate()

lddfm.foldersOnTop = function(floop,path)
	local output = {}
	for a = 1, #floop do
		if fs.isDir(fs.combine(path,floop[a])) then
			table.insert(output,1,floop[a])
		else
			table.insert(output,floop[a])
		end
	end
	return output
end

lddfm.filterFileFolders = function(list,path,_noFiles,_noFolders,_noCD,_doHidden)
	local output = {}
	for a = 1, #list do
		local entry = fs.combine(path,list[a])
		if fs.isDir(entry) then
			if entry == ".." then
				if not (_noCD or _noFolders) then table.insert(output,list[a]) end
			else
				if not ((not _doHidden) and list[a]:sub(1,1) == ".") then
					if not _noFolders then table.insert(output,list[a]) end
				end
			end
		else
			if not ((not _doHidden) and list[a]:sub(1,1) == ".") then
				if not _noFiles then table.insert(output,list[a]) end
			end
		end
	end
	return output
end

lddfm.isColor = function(col)
	for k,v in pairs(colors) do
		if v == col then
			return true, k
		end
	end
	return false
end

lddfm.clearLine = function(x1,x2,_y,_bg,_char)
	local cbg, bg = term.getBackgroundColor()
	local x,y = term.getCursorPos()
	local sx,sy = term.getSize()
	if type(_char) == "string" then char = _char else char = " " end
	if type(_bg) == "number" then
		if lddfm.isColor(_bg) then bg = _bg
		else bg = cbg end
	else bg = cbg end
	term.setCursorPos(x1 or 1, _y or y)
	term.setBackgroundColor(bg)
	if x2 then --it pains me to add an if statement to something as simple as this
		term.write((char or " "):rep(x2-x1))
	else
		term.write((char or " "):rep(sx-(x1 or 0)))
	end
	term.setBackgroundColor(cbg)
	term.setCursorPos(x,y)
end

lddfm.render = function(_x1,_y1,_x2,_y2,_rlist,_path,_rscroll,_canClose,_scrbarY)
	local px,py = term.getCursorPos()
	local x1, x2, y1, y2 = _x1 or 1, _x2 or lddfm.scr_x, _y1 or 1, _y2 or lddfm.scr_y
	local rlist = _rlist or {"Invalid directory."}
	local path = _path or "And that's terrible."
	ypaths = {}
	local rscroll = _rscroll or 0
	for a = y1, y2 do
		lddfm.clearLine(x1,x2,a,lddfm.p.bg)
	end
	term.setCursorPos(x1,y1)
	term.setTextColor(lddfm.p.p_txt)
	lddfm.clearLine(x1,x2+1,y1,lddfm.p.p_bg)
	term.setBackgroundColor(lddfm.p.p_bg)
	term.write(("/"..path):sub(1,x2-x1))
	for a = 1,(y2-y1) do
		if rlist[a+rscroll] then
			term.setCursorPos(x1,a+(y1))
			if fs.isDir(fs.combine(path,rlist[a+rscroll])) then
				lddfm.clearLine(x1,x2,a+(y1),lddfm.p.d_bg)
				term.setTextColor(lddfm.p.d_txt)
				term.setBackgroundColor(lddfm.p.d_bg)
			else
				lddfm.clearLine(x1,x2,a+(y1),lddfm.p.f_bg)
				term.setTextColor(lddfm.p.f_txt)
				term.setBackgroundColor(lddfm.p.f_bg)
			end
			term.write(rlist[a+rscroll]:sub(1,x2-x1))
			ypaths[a+(y1)] = rlist[a+rscroll]
		else
			lddfm.clearLine(x1,x2,a+(y1),lddfm.p.bg)
		end
	end
	local scrbarY = _scrbarY or math.ceil( (y1+1)+( (_rscroll/(#_rlist-(y2-(y1+1))))*(y2-(y1+1)) ) )
	for a = y1+1, y2 do
		term.setCursorPos(x2,a)
		if a == scrbarY then
			term.setBackgroundColor(lddfm.p.scrbar)
		else
			term.setBackgroundColor(lddfm.p.scr)
		end
		term.write(" ")
	end
	if _canClose then
		term.setCursorPos(x2-4,y1)
		term.setTextColor(lddfm.p.close_txt)
		term.setBackgroundColor(lddfm.p.close_bg)
		term.write("close")
	end
	term.setCursorPos(px,py)
	return scrbarY
end

lddfm.coolOutro = function(x1,y1,x2,y2,_bg,_txt,char)
	local cx, cy = term.getCursorPos()
	local bg, txt = term.getBackgroundColor(), term.getTextColor()
	term.setTextColor(_txt or colors.white)
	term.setBackgroundColor(_bg or colors.black)
	local _uwah = 0
	for y = y1, y2 do
		for x = x1, x2 do
			_uwah = _uwah + 1
			term.setCursorPos(x,y)
			term.write(char or " ")
			if _uwah >= math.ceil((x2-x1)*1.63) then sleep(0) _uwah = 0 end
		end
	end
	term.setTextColor(txt)
	term.setBackgroundColor(bg)
	term.setCursorPos(cx,cy)
end

lddfm.scrollMenu = function(amount,list,y1,y2)
	if #list >= y2-y1 then
		lddfm.scroll = lddfm.scroll + amount
		if lddfm.scroll < 0 then
			lddfm.scroll = 0
		end
		if lddfm.scroll > #list-(y2-y1) then
			lddfm.scroll = #list-(y2-y1)
		end
	end
end

lddfm.makeMenu = function(_x1,_y1,_x2,_y2,_path,_noFiles,_noFolders,_noCD,_noSelectFolders,_doHidden,_p,_canClose)
	if _noFiles and _noFolders then
		return false, "C'mon, man..."
	end
	if _x1 == true then
		return false, "arguments: x1, y1, x2, y2, path, noFiles, noFolders, noCD, noSelectFolders, doHidden, palate, canClose" -- a little help
	end
	lddfm.setPalate(_p)
	local path, list = _path or ""
	lddfm.scroll = 0
	local _pbg, _ptxt = term.getBackgroundColor(), term.getTextColor()
	local x1, x2, y1, y2 = _x1 or 1, _x2 or lddfm.scr_x, _y1 or 1, _y2 or lddfm.scr_y
	local keysDown = {}
	local _barrY
	while true do
		list = lddfm.foldersOnTop(lddfm.filterFileFolders(fs.list(path),path,_noFiles,_noFolders,_noCD,_doHidden),path)
		if (fs.getDir(path) ~= "..") and not (_noCD or _noFolders) then
			table.insert(list,1,"..")
		end
		_res, _barrY = pcall( function() return lddfm.render(x1,y1,x2,y2,list,path,lddfm.scroll,_canClose) end)
		if not _res then
			error(_barrY)
		end
		local evt = {os.pullEvent()}
		if evt[1] == "mouse_scroll" then
			lddfm.scrollMenu(evt[2],list,y1,y2)
		elseif evt[1] == "mouse_click" then
			local butt,mx,my = evt[2],evt[3],evt[4]
			if (butt == 1 and my == y1 and mx <= x2 and mx >= x2-4) and _canClose then
				--lddfm.coolOutro(x1,y1,x2,y2)
				term.setTextColor(_ptxt) term.setBackgroundColor(_pbg)
				return false
			elseif ypaths[my] and (mx >= x1 and mx < x2) then --x2 is reserved for the scrollbar, breh
				if fs.isDir(fs.combine(path,ypaths[my])) then
					if _noCD or butt == 3 then
						if not _noSelectFolders or _noFolders then
							--lddfm.coolOutro(x1,y1,x2,y2)
							term.setTextColor(_ptxt) term.setBackgroundColor(_pbg)
							return fs.combine(path,ypaths[my])
						end
					else
						path = fs.combine(path,ypaths[my])
						lddfm.scroll = 0
					end
				else
					term.setTextColor(_ptxt) term.setBackgroundColor(_pbg)
					return fs.combine(path,ypaths[my])
				end
			end
		elseif evt[1] == "key" then
			keysDown[evt[2]] = true
			if evt[2] == keys.enter and not (_noFolders or _noCD or _noSelectFolders) then --the logic for _noCD being you'd normally need to go back a directory to select the current directory.
				--lddfm.coolOutro(x1,y1,x2,y2)
				term.setTextColor(_ptxt) term.setBackgroundColor(_pbg)
				return path
			end
			if evt[2] == keys.up then
				lddfm.scrollMenu(-1,list,y1,y2)
			elseif evt[2] == keys.down then
				lddfm.scrollMenu(1,list,y1,y2)
			end
			if evt[2] == keys.pageUp then
				lddfm.scrollMenu(y1-y2,list,y1,y2)
			elseif evt[2] == keys.pageDown then
				lddfm.scrollMenu(y2-y1,list,y1,y2)
			end
			if evt[2] == keys.home then
				lddfm.scroll = 0
			elseif evt[2] == keys["end"] then
				if #list > (y2-y1) then
					lddfm.scroll = #list-(y2-y1)
				end
			end
			if evt[2] == keys.h then
				if keysDown[keys.leftCtrl] or keysDown[keys.rightCtrl] then
					_doHidden = not _doHidden
				end
			elseif _canClose and (evt[2] == keys.x or evt[2] == keys.q or evt[2] == keys.leftCtrl) then
				--lddfm.coolOutro(x1,y1,x2,y2)
				term.setTextColor(_ptxt) term.setBackgroundColor(_pbg)
				return false
			end
		elseif evt[1] == "key_up" then
			keysDown[evt[2]] = false
		end
	end
end

local alphasort = function(tbl)
	table.sort(tbl, function(a,b)
		if type(a) == "table" then
			return string.lower(a.time) > string.lower(b.time)
		else
			return string.lower(a) > string.lower(b)
		end
	end)
	return tbl
end

local readFile = function(path)
	if fs.exists(path) then
		local file = fs.open(path, "r")
		local contents = file.readAll()
		file.close()
		return contents
	else
		return nil
	end
end

local writeFile = function(path, contents)
	if fs.isReadOnly(path) then
		return false
	else
		local file = fs.open(path, "w")
		file.write(contents)
		file.close()
		return true
	end
end

local keyList, names = {}, {}

local makeKey = function(ID, key)
	return writeFile(fs.combine(config.keyPath, ID), key)
end

local getKey = function(ID)
	return readFile(fs.combine(config.keyPath, ID))
end

local readNames = function()
	return textutils.unserialize(readFile(config.nameFile) or "{}") or {}
end

local writeNames = function(_names)
	return writeFile(config.nameFile, textutils.serialize(_names or names))
end

-- keyList[id] = key
-- names[id] = name

-- get personal key file
keyList[yourID] = ""
if fs.exists(fs.combine(config.keyPath, tostring(yourID))) then
	keyList[yourID] = readFile(fs.combine(config.keyPath, tostring(yourID)))
else
	for i = 1, 64 do
		keyList[yourID] = keyList[yourID] .. string.char(math.random(11, 255))
	end
	writeFile(fs.combine(config.keyPath, tostring(yourID)), keyList[yourID])
end

local getAllKeys = function()
	local list = fs.list(config.keyPath)
	local output = {}
	for i = 1, #list do
		if tonumber(list[i]) then
			output[tonumber(list[i])] = getKey(list[i])
		end
	end
	return output
end

names = readNames()
keyList = getAllKeys()

local apiData = {
	["aeslua"] = {
		path = "aeslua.lua",
		url = "https://gist.githubusercontent.com/SquidDev/86925e07cbabd70773e53d781bd8b2fe/raw/aeslua.lua",
		useLoadAPI = true,
	}
}

for name, data in pairs(apiData) do
	data.path = fs.combine(config.apiPath, data.path)
	if not fs.exists(data.path) then
		local net = http.get(data.url)
		if net then
			local file = fs.open(data.path, "w")
			file.write(net.readAll())
			file.close()
			net.close()
		else
			error("Could not download " .. name)
		end
	end
	if data.useLoadAPI then
		local res = os.loadAPI(data.path)
		--error(res)
	else
		_ENV[name] = dofile(data.path)
	end
end

local function interpretArgs(tInput, tArgs)
	local output = {}
	local errors = {}
	local usedEntries = {}
	for aName, aType in pairs(tArgs) do
		output[aName] = false
		for i = 1, #tInput do
			if not usedEntries[i] then
				if tInput[i] == aName and not output[aName] then
					if aType then
						usedEntries[i] = true
						if type(tInput[i+1]) == aType or type(tonumber(tInput[i+1])) == aType then
							usedEntries[i+1] = true
							if aType == "number" then
								output[aName] = tonumber(tInput[i+1])
							else
								output[aName] = tInput[i+1]
							end
						else
							output[aName] = nil
							errors[1] = errors[1] and (errors[1] + 1) or 1
							errors[aName] = "expected " .. aType .. ", got " .. type(tInput[i+1])
						end
					else
						usedEntries[i] = true
						output[aName] = true
					end
				end
			end
		end
	end
	for i = 1, #tInput do
		if not usedEntries[i] then
			output[#output+1] = tInput[i]
		end
	end
	return output, errors
end

local argList = {
	["--server"] = false
}

local argData, argErrors = interpretArgs({...}, argList)
local isServer = argData["--server"]
local serverName = argData[1] or "server"

if ccemux and (not peripheral.find("modem")) then
	ccemux.attach("top", "wireless_modem")
end

local modem
local getModem = function(doNotPickWireless)
	local output, periphList
	for try = 1, 40 do
		periphList = peripheral.getNames()
		for i = 1, #periphList do
			if peripheral.getType(periphList[i]) == "modem" then
				output = peripheral.wrap(periphList[i])
				if not (doNotPickWireless and output.isWireless()) then
					output.open(config.channel)
					return output
				end
			end
		end
		sleep(0.15)
	end
	error("No modems were found after 40 tries. That's as many as four tens. And that's terrible.")
end

-- allowed IDs
local userIDs = {}

-- all data recorded
local DATA = {}

local transmit = function(msg, msgID)
	modem = getModem(onlyUseWiredModems)
	modem.transmit(config.channel, config.channel, {
		msg = msg,
		encrypted = false,
		msgID = msgID
	})
end

local encTransmit = function(msg, msgID, recipient, encID)
	modem = getModem(onlyUseWiredModems)
	local key = keyList[encID or recipient]
	if not key then
		error("You do not possess the key of the recipient.")
	else
		modem.transmit(config.channel, config.channel, {
			msg = aeslua.encrypt(key, textutils.serialize(msg)),
			encrypted = true,
			msgID = msgID,
			recipient = recipient
		})
	end
end

local receive = function(msgID, specifyCommand, encID, timer)
	local evt, msg, tID
	if timer then
		tID = os.startTimer(timer)
	end
	modem = getModem()
	while true do
		evt = {os.pullEvent()}
		if evt[1] == "modem_message" then
			if type(evt[5]) == "table" then
				if evt[5].encrypted then
					if true then
						if encID then
							msg = aeslua.decrypt(keyList[encID], evt[5].msg)
						else
							for id, key in pairs(keyList) do
								if msg then break end
								if id ~= encID then
									msg = aeslua.decrypt(key, evt[5].msg)
								end
							end
						end
						if msg then
							msg = textutils.unserialize(msg)
						end
					end
				else
					msg = evt[5].msg
				end
				if (not msgID) or (evt[5].msgID == msgID) then
					if (not specifyCommand) or (msg.command == specifyCommand) then
						return msg, evt[5].encrypted, evt[5].msgID
					end
				end
			end
		elseif evt[1] == "timer" and evt[2] == tID then
			return nil, nil, nil
		end
	end
end

local getNameID = function(name)
	for k,v in pairs(names) do
		if v == name then
			return k
		end
	end
end

local client = {}	-- all client-specific commands
local server = {}	-- all server-specific commands

----                       ----
----    CLIENT COMMANDS    ----
----                       ----

-- if you want a super duper secure network, manually enter the server ID into this
client.findServer = function(srv)
	local msgID = math.random(1, 2^30)
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(tonumber(srv) or (not srv), "invalid server")
	transmit({
		id = yourID,
		command = "find_server"
	}, msgID)
	local reply, isEncrypted = receive(msgID, "find_server_respond", srv)
	if type(reply) == "table" then
		if reply.server then
			return reply.server
		end
	end
end

-- Registers your ID to a name.
client.register = function(srv, username)
	local msgID = math.random(1, 2^30)
	assert(srv, "register( server, username )")
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(srv, "invalid server")
	encTransmit({
		id = yourID,
		command = "register",
		name = username
	}, msgID, srv, yourID)
	local reply, isEncrypted = receive(msgID, "register_respond", yourID)
	if reply then
		return reply.result
	else
		return false
	end
end

-- Gets a list of all registered ID names
client.getNames = function(srv)
	local msgID = math.random(1, 2^30)
	assert(srv, "getNames( server )")
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(srv, "invalid server")
	encTransmit({
		id = yourID,
		command = "get_names"
	}, msgID, srv, yourID)
	local reply, isEncrypted = receive(msgID, "get_names_respond", yourID)
	if type(reply) == "table" then
		return reply.names
	else
		return nil
	end
end

-- Sends an email to a recipient ID.
client.sendMail = function(srv, recipient, subject, message, attachments)
	assert(srv, "sendMail( server, recipient, subject, message, attachments )")
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(srv, "invalid server")
	assert(type(subject) == "string", "invalid subject")
	assert(type(message) == "string", "invalid message")
	local msgID = math.random(1, 2^30)
	if type(recipient) == "string" then
		recipient = getNameID(recipient)
	end
	assert(recipient, "invalid recipient")
	encTransmit({
		command = "send_mail",
		id = yourID,
		recipient = recipient,
		subject = subject,
		message = message,
		attachments = attachments
	}, msgID, srv, yourID)
	local reply, isEncrypted = receive(msgID, "send_mail_respond", yourID)
	if (isEncrypted and type(reply) == "table") then
		return reply.result
	else
		return false
	end
end

client.getMail = function(srv)
	local msgID = math.random(1, 2^30)
	assert(srv, "getMail( server )")
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(srv, "invalid server")
	encTransmit({
		command = "get_mail",
		id = yourID,
	}, msgID, srv, yourID)
	local reply, isEncrypted = receive(msgID, "get_mail_respond", yourID)
	if (isEncrypted and type(reply) == "table") then
		if reply.mail then
			return alphasort(reply.mail)
		end
	end
end

client.deleteMail = function(srv, mail)
	local msgID = math.random(1, 2^30)
	assert(srv, "deleteMail( server, mailEntryNumber )")
	srv = type(srv) == "number" and srv or getNameID(srv)
	assert(srv, "invalid server")
	assert(type(mail) == "number", "invalid mail entry")
	encTransmit({
		command = "delete_mail",
		id = yourID,
		mail = mail,
	}, msgID, srv, yourID)
	local reply, isEncrypted = receive(msgID, "delete_mail_respond", yourID)
	if (isEncrypted and type(reply) == "table") then
		return reply.result
	else
		return false
	end
end

----                       ----
----    SERVER COMMANDS    ----
----                       ----

-- check whether or not a name is valid to be used
server.checkValidName = function(name)
	if type(name) == "string" then
		if #name >= 3 or #name <= 24 then
			return true
		end
	end
	return false
end

-- check whether or not an ID is registered
server.checkRegister = function(id)
	-- I make the code this stupid looking in case I add other stipulations
	if names[id] or getNameID(names[id]) then
		return true
	else
		return false
	end
end

server.registerID = function(id, name)
	local path = fs.combine(config.mailPath, tostring(id))
	if ((not server.checkRegister(name)) or getNameID(name) == id) then
		fs.makeDir(path)
		names[id] = name
		writeNames()
		return true, names[id]
	else
		return false, "name already exists"
	end
end

-- records a full email to file
server.recordMail = function(sender, _recipient, subject, message, attachments)
	local time = os.epoch("utc")
	local recipient

	if _recipient == "*" then
		recipient = fs.list(config.mailPath)
	elseif type(_recipient) ~= "table" then
		recipient = {tostring(_recipient)}
	end

	local msg = textutils.serialize({
		sender = sender,
		time = time,
		read = false,
		subject = subject,
		message = message,
		attachments = attachments
	})

	local requiredSpace = #msg + 2
	if fs.getFreeSpace(config.mailPath) < requiredSpace then
		return false, "Cannot write mail, not enough space!"
	end

	local path, file
	for i = 1, #recipient do
		server.registerID(recipient[i])
		path = fs.combine(config.mailPath, recipient[i])
		file = fs.open(fs.combine(path, tostring(time)), "w")
		file.write(msg)
		file.close()
	end
	return true
end

-- returns every email in an ID's inbox
server.getMail = function(id)
	local output, list = {}, {}
	local mails = fs.list(fs.combine(config.mailPath, tostring(id)))
	local file
	for k,v in pairs(mails) do
		list[v] = k
	end
	for k,v in pairs(list) do
		file = fs.open(fs.combine(config.mailPath, "/" .. id .. "/" .. k), "r")
		if file then
			output[#output + 1] = textutils.unserialize(file.readAll())
			file.close()
		end
	end
	return output
end

server.deleteMail = function(id, del)
	local mails = alphasort( fs.list(fs.combine(config.mailPath, tostring(id))) )
	if mails[del] then
		fs.delete(fs.combine(config.mailPath, tostring(id) .. "/" .. mails[del]))
		return true
	else
		return false
	end
end

server.setName = function(newName)
	if server.checkValidName(newName) then
		names[yourID] = newName
	end
end

-- receives messages and sends the appropriate response
server.makeServer = function(verbose)
	local msg, isEncrypted, msgID

	local say = function(text, id)
		if verbose then
			return print(text .. (id and (" (" .. id .. ")") or ""))
		end
	end

	while true do

		msg, isEncrypted, msgID = receive()

		if msg then
			if not isEncrypted then
				if msg.command == "find_server" then
					transmit({
						command = msg.command .. "_respond",
						server = yourID,
					}, msgID, msg.id, yourID)
					say("find_server")
				end
			elseif type(msg.id) == "number" and type(msg.command) == "string" then
				if msg.command == "register" then
					if (
						type(msg.id) == "number" and
						type(msg.name) == "string"
					) then
						local reply
						local result, name = server.registerID(msg.id, msg.name)
						if result then
							reply = {
								command = msg.command .. "_respond",
								result = result,
								name = name,
							}
							say("user " .. tostring(msg.id) .. " registered as " .. name)
						else
							reply = {
								command = msg.command .. "_respond",
								result = result,
							}
							say("user " .. tostring(msg.id) .. " failed to register as " .. tostring(msg.name) .. ": " .. name)
						end
						encTransmit(reply, msgID, msg.id, msg.id)
					end
				elseif not server.checkRegister(msg.id) then
					encTransmit({
						command = msg.command .. "_respond",
						result = false,
						errorMsg = "not registered"
					}, msgID, msg.id, msg.id)
					say("unregistered user attempt to use")
				else

					-- all the real nice stuff

					if msg.command == "find_server" then
						encTransmit({
							command = msg.command .. "_respond",
							server = yourID,
							result = true
						}, msgID, msg.id, msg.id)
						say("find_server (aes)")
					elseif msg.command == "get_names" then
						encTransmit({
							command = msg.command .. "_respond",
							result = true,
						}, msgID, msg.id, msg.id)
						say("get_names", msg.id)
					elseif msg.command == "send_mail" then
						if (
							msg.recipient and
							type(msg.subject) == "string" and
							type(msg.message) == "string"
						) then
							local reply = {
								command = msg.command .. "_respond",
								result = server.recordMail(msg.id, msg.recipient, msg.subject, msg.message, msg.attachments)
							}
							encTransmit(reply, msgID, msg.id, msg.id)
							say("send_mail", msg.id)
						end
					elseif msg.command == "get_mail" then
						local mail = server.getMail(msg.id)
						local reply = {
							command = msg.command .. "_respond",
							result = true,
							mail = mail,
						}
						encTransmit(reply, msgID, msg.id, msg.id)
						say("get_mail", msg.id)
					elseif msg.command == "delete_mail" then
						local result = false
						if type(msg.mail) == "number" then
							result = server.deleteMail(msg.id, msg.mail, yourID)
						end
						encTransmit({
							command = msg.command .. "_respond",
							result = result,
						}, msgID, msg.id, msg.id)
						say("delete_mail", msg.id)
					end

				end
			end
		end

	end
end

local clientInterface = function(srv)
	local scr_x, scr_y = term.getSize()
	local inbox = {}
	local refresh = function()
		inbox = client.getMail(srv)
	end
	local cwrite = function(text, y)
		local cx, cy = term.getCursorPos()
		term.setCursorPos(scr_x / 2 - #text / 2, y or cy)
		term.write(text)
	end
	local explode = function(div, str, replstr, includeDiv)
		if (div == '') then
			return false
		end
		local pos, arr = 0, {}
		for st, sp in function() return string.find(str, div, pos, false) end do
			table.insert(arr, string.sub(replstr or str, pos, st - 1 + (includeDiv and #div or 0)))
			pos = sp + 1
		end
		table.insert(arr, string.sub(replstr or str, pos))
		return arr
	end
	local dialogueBox = function(msg)
		local height = 7
		local baseY = scr_y / 2 - height / 2
		for y = 1, height do
			term.setCursorPos(1, (scr_y / 2) - (baseY / 2) + (y - 1))
			term.clearLine()
		end
		cwrite(("="):rep(scr_x), baseY)
		cwrite(msg, baseY + height / 2)
		cwrite(("="):rep(scr_x), baseY + height - 1)
		sleep(1)
	end
	srv = srv or tonumber( client.findServer(argData[1]) )
	if not srv then
		error("No server was found!")
	end
	for k,v in pairs(client.getNames(srv) or {}) do
		names[k] = v
	end

	if not names[yourID] then
		term.setBackgroundColor(colors.black)
		term.setTextColor(colors.white)
		term.clear()
		local attempt
		cwrite("Enter your name:", 3)
		while true do
			term.setCursorPos(2, 5)
			term.write(":")
			attempt = read()
			if server.checkValidName(attempt) then
				names[yourID] = attempt
				writeNames()
				client.register(srv, attempt)
				break
			else
				term.clear()
				cwrite("Bad name! Enter your name:", 3)
			end
		end
	end

	refresh()

	local keyWrite = function(text, pos)
		local txcol = term.getTextColor()
		term.write(text:sub(1, pos - 1))
		term.setTextColor(colors.yellow)
		term.write(text:sub(pos, pos))
		term.setTextColor(txcol)
		term.write(text:sub(pos + 1))
	end

	local writeHeader = function(left, right, y)
		if y then
			term.setCursorPos(1, y)
		end
		term.setTextColor(colors.lightGray)
		term.write(left)
		term.setTextColor(colors.white)
		term.write(" " .. right)
	end

	local area_inbox = function()
		local scroll = 0
		local render = function(scroll)
			local y = 1
			term.setBackgroundColor(colors.black)
			term.clear()
			for i = 1 + scroll, scroll + scr_y - 1 do
				if inbox[i] then
					term.setCursorPos(1, y)
					term.setTextColor(colors.white)
					term.write(names[inbox[i].sender]:sub(1, 10))

					term.setCursorPos(11, y)
					term.setTextColor(colors.white)
					term.write(inbox[i].subject:sub(1, 18))

					term.setCursorPos(30, y)
					term.setTextColor(colors.gray)
					term.write(inbox[i].message:sub(1, scr_x - 30))
				end
				y = y + 1
			end
			term.setCursorPos(1, scr_y)
			term.setBackgroundColor(colors.gray)
			term.clearLine()
			term.setTextColor(colors.white)
			--term.write(names[yourID] .. ": ")
			keyWrite("Quit ", 1)
			keyWrite("New ", 1)
			keyWrite("Refresh ", 1)
		end

		-- logic(k)
		local evt, key, mx, my
		local adjY	-- mouse Y adjusted for scroll
		while true do
			render(scroll)
			inbox = alphasort(inbox)
			evt, key, mx, my = os.pullEvent()
			if evt == "mouse_click" then
				adjY = my + scroll
				if inbox[adjY] then
					return "view_mail", {adjY}
				end
			elseif evt == "mouse_scroll" then
				scroll = scroll + key
			elseif evt == "key" then
				if key == keys.n then
					return "new_mail"
				elseif key == keys.r then
					return "refresh"
				elseif key == keys.q then
					return "exit"
				end
			end
		end
	end

	local niftyRead = function(prebuffer, startX, startY, startCursorMX, startCursorMY, allowEnter, maxLines, maxLength, history)
		local cx, cy = term.getCursorPos()
		local histPos = 0
		startX, startY = startX or cx, startY or cy
		local buffer = {{}}
		local unassemble = function(pBuffer)
			local output = {{""}}
			local y = 1
			local x = 1
			for i = 1, #pBuffer do
				if pBuffer:sub(i,i) == "\n" then
					x = 1
					y = y + 1
					output[y] = {""}
				else
					output[y][x] = pBuffer:sub(i,i)
					x = x + 1
				end
			end
			return output
		end
		if prebuffer then
			buffer = unassemble(prebuffer)
		end
		local curY = startCursorMY and math.max(1, math.min(startCursorMY - (startY - 1), #buffer)) or 1
		local curX = startCursorMX and math.max(1, math.min(startCursorMX - (startX - 1), #buffer[curY] + 1)) or 1
		local biggestHeight = math.max(1, #buffer)
		local getLength = function()
			local output = 0
			for ln = 1, #buffer do
				output = output + #buffer[ln]
				if ln ~= #buffer then	-- account for newline chars
					output = output + 1
				end
			end
			return output
		end
		local render = function()
			for y = startY, startY + (biggestHeight - 1) do
				term.setCursorPos(startX, y)
				term.write((" "):rep(maxLength))
			end
			term.setCursorPos(startX, startY)
			local words
			local x = startX
			local y = startY
			for ln = 1, #buffer do
				words = explode(" ", table.concat(buffer[ln]), nil, true)
				for i = 1, #words do
					if x + #words[i] > scr_x and y < maxLines then
						x = startX
						y = y + 1
					end
					term.setCursorPos(x, y)
					term.write(words[i])
					x = x + #words[i]
				end
				term.write(" ")
				if ln ~= #buffer then
					y = y + 1
					x = startX
				end
			end
			term.setCursorPos(curX + startX - 1, curY + startY - 1)
			biggestHeight = math.max(#buffer, biggestHeight)
		end

		local assemble = function(buffer)
			local output = ""
			for ln = 1, #buffer do
				output = output .. table.concat(buffer[ln])
				if ln ~= #buffer then
					output = output .. "\n"
				end
			end
			return output
		end

		if history then
			history[0] = assemble(buffer)
		end

		local evt, key, mx, my
		local keysDown = {}
		term.setCursorBlink(true)
		while true do
			render()
			evt, key, mx, my = os.pullEvent()
			if evt == "char" then
				if getLength() < maxLength then
					table.insert(buffer[curY], curX, key)
					curX = curX + 1
					if histPos == 0 and history then
						history[histPos] = assemble(buffer)
					end
				end
			elseif evt == "key_up" then
				keysDown[key] = nil
			elseif evt == "mouse_click" then
				if key == 1 then
					if my - (startY - 1) > maxLines or my < startY then
						term.setCursorBlink(false)
						return assemble(buffer), "mouse_click", mx, my
					else
						curY = math.max(1, math.min(my - (startY - 1), #buffer))
						curX = math.max(1, math.min(mx - (startX - 1), #buffer[curY] + 1))
					end
				end
			elseif evt == "key" then
				keysDown[key] = true
				if key == keys.left then
					if curX == 1 then
						if curY > 1 then
							curY = curY - 1
							curX = #buffer[curY] + 1
						end
					elseif curX > 1 then
						curX = curX - 1
					end
				elseif key == keys.right then
					if curX == #buffer[curY] + 1 then
						if curY < #buffer then
							curY = curY + 1
							curX = 1
						end
					elseif curX < #buffer[curY] then
						curX = curX + 1
					end
				elseif key == keys.up then
					if history then
						if histPos < #history then
							histPos = histPos + 1
							buffer = unassemble(history[histPos])
							curY = #buffer
							curX = #buffer[curY] + 1
						end
					else
						if curY > 1 then
							curY = curY - 1
							curX = math.min(curX, #buffer[curY] + 1)
						else
							curX = 1
						end
					end
				elseif key == keys.down then
					if history then
						if histPos > 0 then
							histPos = histPos - 1
							buffer = unassemble(history[histPos])
							curY = #buffer
							curX = #buffer[curY] + 1
						end
					else
						if curY < #buffer then
							curY = curY + 1
							curX = math.min(curX, #buffer[curY] + 1)
						else
							curX = #buffer[curY] + 1
						end
					end
				elseif key == keys.enter then
					if allowEnter and not (keysDown[keys.leftAlt] or keysDown[keys.rightAlt]) and #buffer < maxLines then
						curY = curY + 1
						table.insert(buffer, curY, {})
						for i = curX, #buffer[curY - 1] do
							buffer[curY][#buffer[curY] + 1] = buffer[curY - 1][i]
							buffer[curY - 1][i] = nil
						end
						curX = 1
					else
						term.setCursorBlink(false)
						return assemble(buffer), "key", keys.enter
					end
				elseif key == keys.tab or (key == keys.q and (keysDown[keys.leftAlt] or keysDown[keys.rightAlt])) then
					term.setCursorBlink(false)
					return assemble(buffer), "key", key
				elseif key == keys.backspace then
					if curX > 1 then
						table.remove(buffer[curY], curX - 1)
						curX = curX - 1
					elseif curY > 1 then
						curX = #buffer[curY - 1] + 1
						for i = 1, #buffer[curY] do
							buffer[curY - 1][#buffer[curY - 1] + 1] = buffer[curY][i]
						end
						table.remove(buffer, curY)
						curY = curY - 1
					end
				elseif key == keys.delete then
					if buffer[curY][curX] then
						table.remove(buffer[curY], curX)
					end
				end
			end
		end
	end

	local area_new_mail = function(recipient, subject, message)
		recipient = recipient or ""
		subject = subject or ""
		message = message or ""
		local attachments = {}
		sleep(0.05)
		local mode = "recipient"
		render = function()
			term.setTextColor(colors.white)
			term.setBackgroundColor(colors.black)
			term.clear()
			writeHeader("To:", recipient, 1)
			writeHeader("Subject:", subject, 2)
			writeHeader("Attachments:", "", 3)
			for name, contents in pairs(attachments) do
				term.write(name .. " ")
			end
			term.setCursorPos(1, 4)
			term.setBackgroundColor(colors.gray)
			term.setTextColor(colors.lightGray)
			term.clearLine()
			cwrite("(Alt+Enter = SEND, Alt+Q = QUIT)")
			term.setTextColor(colors.white)
			term.setBackgroundColor(colors.black)
			if mode ~= "message" then
				term.setCursorPos(1, 5)
				write(message)
			end
		end
		local mx, my, evt = 1, 1
		local _mx, _my, userList
		while true do
			render()
			if mode == "message" then
				message, evt, _mx, _my = niftyRead(message, 1, 5, mx, my, true, 16, 512)
			elseif mode == "subject" then
				subject, evt, _mx, _my = niftyRead(subject, 10, 2, mx, 1, false, 1, 64)
			elseif mode == "recipient" then
				names = client.getNames(srv) or names
				userList = {}
				for k,v in pairs(names) do
					userList[#userList + 1] = v
				end
				recipient, evt, _mx, _my = niftyRead(recipient, 5, 1, mx, 1, false, 1, 24, userList)
			end
			if evt == "mouse_click" then
				mx, my = _mx, _my
				if my == 1 then
					mode = "recipient"
				elseif my == 2 then
					mode = "subject"
				elseif my == 3 then
					local newAttachment = lddfm.makeMenu(1, 4, scr_x, scr_y, "", false, false, false, true, false, nil, true)
					if newAttachment then
						local name = fs.getName(newAttachment)
						if attachments[name] then
							attachments[name] = nil
						else
							attachments[name] = readFile(newAttachment)
						end
					end
				elseif my >= 5 then
					mode = "message"
				end
			elseif evt == "key" then
				if _mx == keys.enter or _mx == keys.tab then
					if mode == "recipient" then
						mode = "subject"
					elseif mode == "subject" then
						mode = "message"
					elseif mode == "message" and _mx == keys.enter then
						local recip
						names = client.getNames(srv) or names
						if tonumber(recipient) then
							recip = tonumber(recipient)
							if not names[recip] then
								recip = nil
							end
						else
							recip = getNameID(recipient)
						end
						if recip then
							client.sendMail(srv, recip, subject, message)
							dialogueBox("Message sent!")
							refresh()
							return
						else
							dialogueBox("There's no such recipient.")
						end
					end
				elseif _mx == keys.q then
					return
				end
			end
		end
		niftyRead(nil, 1, 1, nil, true)
	end

	local area_view_mail = function(mailEntry)
		local scroll = 0
		local mail = inbox[mailEntry]
		local render = function(scroll)
			term.setBackgroundColor(colors.black)
			term.setTextColor(colors.lightGray)
			term.clear()
			local y
			writeHeader("From", names[mail.sender], 1)
			writeHeader("Subject", mail.subject, 2)
			if type(mail.attachments) == "table" then
				writeHeader("Attachments:","",3)
				y = 4
			else
				y = 3
			end
			local words = explode(" ", mail.message, nil, true)
			local buffer = {""}
			for i = 1, #words do
				words[i] = words[i]:gsub("\n", (" "):rep(scr_x))
				if #buffer[#buffer] + #words[i] > scr_x then
					buffer[#buffer+1] = words[i]
				else
					buffer[#buffer] = buffer[#buffer] .. words[i]
				end
			end
			for i = scroll + 1, scroll + scr_y - y do
				if buffer[i] then
					term.setCursorPos(1, y)
					term.write(buffer[i])
				end
				y = y + 1
			end
			term.setCursorPos(1, scr_y)
			term.setBackgroundColor(colors.gray)
			term.setTextColor(colors.white)
			term.clearLine()
			keyWrite("Quit ", 1)
			keyWrite("Reply ", 1)
			keyWrite("Delete ", 1)
		end

		local evt, key, mx, my
		while true do
			render(scroll)
			evt, key, mx, my = os.pullEvent()
			if evt == "key" then
				if key == keys.r then
					area_new_mail(names[mail.sender], "Re: " .. mail.subject, "\n\n~~~\nAt UTC epoch " .. mail.time .. ", " .. names[mail.sender] .. " wrote:\n\n" .. mail.message)
				elseif key == keys.d then
					client.deleteMail(srv, mailEntry)
					refresh()
					return
				elseif key == keys.q then
					return "exit"
				end
			elseif evt == "mouse_scroll" then
				scroll = scroll + key
			end
		end
	end

	local res, output
	while true do
		res, output = area_inbox()
		if res == "exit" then
			term.setCursorPos(1, scr_y)
			term.setBackgroundColor(colors.black)
			term.clearLine()
			sleep(0.05)
			return
		elseif res == "refresh" then
			refresh()
		elseif res == "view_mail" then
			area_view_mail(table.unpack(output or {}))
		elseif res == "new_mail" then
			area_new_mail(table.unpack(output or {}))
		end
	end
end

if isServer then
	names[yourID] = names[yourID] or serverName
	writeNames()
	server.makeServer(true)
elseif shell then
	clientInterface()
end

return {client = client, server = server}