Lockette

--# Lockette - Computer access limiter. v1.1
--# Made By Wojbie
--# http://pastebin.com/cGM4iF1d

--   Copyright (c) 2015-2021 Wojbie (wojbie@wojbie.net)
--   Redistribution and use in source and binary forms, with or without modification, are permitted (subject to the limitations in the disclaimer below) provided that the following conditions are met:
--   1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
--   2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
--   3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
--   4. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
--   5. The origin of this software must not be misrepresented; you must not claim that you wrote the original software.
--   NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. YOU ACKNOWLEDGE THAT THIS SOFTWARE IS NOT DESIGNED, LICENSED OR INTENDED FOR USE IN THE DESIGN, CONSTRUCTION, OPERATION OR MAINTENANCE OF ANY NUCLEAR FACILITY.

--Basic settings

local pass = "unlock"   --Password used to unlock.
local passtime = 30 --Time of inactivity that causes system to autolock.

local sProgram = "/rom/programs/shell" --Path to program to run
local tArguments = {} --Table of arguments for Program
local ShutdownOnExit = true --If set to true computer will turn off after the program exits.

local lockscreen = true --Display lockscreen. If set to false computer will not display System Locked screen but still lockdown inputs.
local scrap = false --Changes lockscreen from basic one to messed up one. Basicly fills screen with random letters and cllors.


--Advanced settings

local lockkey = keys.scollLock  --Key for manual locking. Set to scroolLock
local message="System Locked" --Message on lockscreen
local bor={"+","-","|"} --Border of Messege window

local Events={char=true,key=true,key_up=true,paste=true,monitor_touch=false,mouse_click=true,mouse_up=true,mouse_scroll=true,mouse_drag=true,terminate=true} --Events that are not allowed to pass in locked mode. To stop monitor clicks event change false to true next to monitor_touch.
local ActionEvents={char=true,key=true,key_up=true,paste=true,mouse_click=true,mouse_up=true,mouse_scroll=true,mouse_drag=true} --Events that cause inactivity timer to restart. Only change if you know what you are doing.


--Program setup.

local parentTerm = term.current()
local shutdown = os.shutdown

--Initializing coorutine

local co = coroutine.create( function()
    local run=os.run
    local tEnv={[ "shell" ] = shell,[ "multishell" ] = multishell,}
    run(tEnv, sProgram, unpack( tArguments ) )
end )

local function resume( ... )
    local ok, param = coroutine.resume( co, ... )
    if not ok then
        printError( param )
    end
    return param
end

--terminal stuff

local passon=true
local passer=setmetatable({},{["__index"]=function(t,k) if parentTerm[k] then if passon then return parentTerm[k] else return function() end end else return nil end end,["__newindex"]=function(t,k,v) end,})
local saveWindow
local lockWindow


do
    local w,h = parentTerm.getSize()
    saveWindow=window.create(parentTerm,1,1,w,h,false)
    lockWindow=window.create(parentTerm,1,1,w,h,false)
end

local saveWindowsetVisible = saveWindow.setVisible
local saveWindowreposition = saveWindow.reposition
saveWindow.setVisible = function() end
saveWindow.reposition = function() end
--saveWindow.redraw = function() end
--saveWindow.restoreCursor = function() end
--saveWindow.getPosition = function() end

local function createMultitable(...)

    local tab = {...}
    if #tab==1 and tab[1] and type(tab[1])=="table" then tab = tab[1] end
    if #tab==0 then error("Expected table of tables or any tables to table. I know it makes no sense.", 2) end

    local manymeta={ --Anytime index is requested fist table is used as refference.
    ["__index"]=function (parent , key)
        if tab and tab[1] and tab[1][key] then --If it has value it tested then
            if type(tab[1][key]) =="function" then --If its function then a function that calls all tables in row is made
                return function(...)
                    local ret={}
                    local tArgs={...}
                    for i,k in ipairs(tab) do
                        if k[key] then
                            if #ret==0 then ret={k[key](table.unpack(tArgs))} --ret contains returns from first table that returned anything.
                            else k[key](table.unpack(tArgs)) end
                        end
                    end
                    return table.unpack(ret)
                end
            else
                return tab[1][key]  --If its not a function then its just given out.
            end
        else
            return nil --Of it not exist in first table give nothing
        end
    end,
    ["__newindex"]=function (parent, key, value) --If someone wants to add anything to the table
        --do nothing.
    end,
    ["__call"]=function (parent, key) --If someone calls table like function give him direct acces to table list.
        --if key then tab = key end changing of content disalowed in static mode
        return tab
    end,
    ["__len"]=function (parent, key) --Not sure if it works but this is giving the leanght of first table or 0 if there is no first table.
        return (tab[1] and #tab[1]) or 0
    end,
    ["__metatable"]=false,--No touching the metatable.
    --["__type"]="WojbieManyMeta",--Custom type? Not in current version and not sure if wise. Commented out for now.
    }

    local out = {}
    for key,fun in pairs(tab[1]) do --create static table of multitable functions using first one as template
        out[key] = function(...)
            local ret={}
            local tArgs={...}
            for i,k in ipairs(tab) do
                if k[key] then
                    if #ret==0 then ret={k[key](table.unpack(tArgs))} --ret contains returns from first table that returned anything.
                    else k[key](table.unpack(tArgs)) end
                end
            end
            return table.unpack(ret)
        end
    end
    return setmetatable(out,manymeta) --create acctual manymeta table and return it

end

local multiplex=createMultitable(saveWindow,passer)

local function drawLock()
    local w,h = lockWindow.getSize()
    local messagesize=message:len()
    if scrap then --fill the screan with (s)crap.
        if parentTerm.isColor() then
            for i = 1 , h do
                lockWindow.setCursorPos(1,i)
                for j = 1,w do
                    lockWindow.setTextColor(2^math.random(0,15))
                    lockWindow.setBackgroundColor(2^math.random(0,15))
                    lockWindow.write(string.char(math.random(32,126)))
                end
            end
        else
            local col = {colors.black , colors.white , colors.gray , colors.lightGray}
            for i = 1 , h do
                lockWindow.setCursorPos(1,i)
                for j = 1,w do
                    lockWindow.setTextColor(col[math.random(#col)])
                    lockWindow.setBackgroundColor(col[math.random(#col)])
                    lockWindow.write(string.char(math.random(32,126)))
                end
            end
        end
    elseif h < 5 or w < messagesize+4 then --write in middle
        lockWindow.setBackgroundColor(colors.black)
        lockWindow.clear()
        lockWindow.setTextColor(colors.white)
        lockWindow.setBackgroundColor(colors.black)
        lockWindow.setCursorPos(math.floor(w / 2 - messagesize / 2 )+1, math.floor(h / 2 )+1)
        lockWindow.write(message)

    else --write window in middle
        local offsetLeft = math.floor(w / 2 - (messagesize+4) / 2)+1
        local offsetTop = math.floor(h / 2 - 5/2)+1
        local filler = string.rep (" ", messagesize+2)
        local line = string.rep (bor[2], messagesize+2)
        lockWindow.setBackgroundColor(colors.black)
        lockWindow.clear()
        lockWindow.setTextColor(colors.white)
        lockWindow.setBackgroundColor(colors.black)
        lockWindow.setCursorPos(offsetLeft, offsetTop)
        lockWindow.write(bor[1]..line..bor[1])
        lockWindow.setCursorPos(offsetLeft, offsetTop+1)
        lockWindow.write(bor[3]..filler..bor[3])
        lockWindow.setCursorPos(offsetLeft, offsetTop+2)
        lockWindow.write(bor[3].." "..message.." "..bor[3])
        lockWindow.setCursorPos(offsetLeft, offsetTop+3)
        lockWindow.write(bor[3]..filler..bor[3])
        lockWindow.setCursorPos(offsetLeft, offsetTop+4)
        lockWindow.write(bor[1]..line..bor[1])
    end
end

--state stuff

local curr
local locked
local lockdown

local function lock()
    locked=true
    curr=""
    if lockdown then os.cancelTimer(lockdown) end
    lockdown=nil
    if lockscreen then
        passon=false
        drawLock()
        lockWindow.setVisible(true)
    end
end

local function unlock()
    locked=false
    curr=""
    if lockdown then os.cancelTimer(lockdown) end
    lockdown=os.startTimer(passtime)
    if lockscreen then
        lockWindow.setVisible(false)
        saveWindowsetVisible(true) --this restores contents of terminal before passon lets program write on it again.
        saveWindowsetVisible(false)
        passon=true
    end
end

term.redirect(multiplex)
term.setCursorPos(1,1)
term.clear()
local ok, param = pcall( function()
    lock()
    local sFilter = resume()
    while coroutine.status( co ) ~= "dead" do
        local tEvent = { os.pullEventRaw() }
        if tEvent[1]=="term_resize" then
            -- Resize event
            local w,h = parentTerm.getSize()
            saveWindowreposition(1,1,w,h)
            lockWindow.setVisible(false)
            lockWindow.reposition(1,1,w,h)
            drawLock()
            lockWindow.setVisible(lockscreen and locked)
        end
        if locked then
            --See if chars or paste fit password
            if tEvent[1]=="char" then
                curr=curr..tEvent[2]
                if #curr>#pass then curr=curr:sub(2,#curr) end
                if curr==pass then unlock() end
            elseif tEvent[1]=="paste" then
                if tEvent[2]==pass then unlock() end
            end
            --Pass event if its allowed to go on.
            if not Events[tEvent[1]] then
                if sFilter == nil or tEvent[1] == sFilter or tEvent[1] == "terminate" then
                    sFilter = resume( unpack( tEvent ) )
                end
            end
        else
            --See if you dont need to lockdown
            if tEvent[1]=="timer" and tEvent[2]==lockdown then
                lock()
            elseif tEvent[1]=="key" and tEvent[2]==lockkey then
                lock()
            end
            --Update lockdown counter if one of ActionEvents
            if ActionEvents[tEvent[1]] then
                if lockdown then os.cancelTimer(lockdown) end
                lockdown=os.startTimer(passtime)
            end
            --Pass event on
            if sFilter == nil or tEvent[1] == sFilter or tEvent[1] == "terminate" then
                sFilter = resume( unpack( tEvent ) )
            end
        end
    end
end )
--redirect back to start one
term.redirect( parentTerm )
--print errors
if not ok then
    printError( param )
end
--if Shutdown then shutdown
if ShutdownOnExit then shutdown() end