Pause a program (WIP)

local w,h = term.getSize()
local args = {...}

-- Log API by HPWebcamAble

local log = {}
local name

function create(setName)
  name = setName
  if fs.exists(name) then
    fs.delete(name)
  end
end

function save(text)
  if not name then return false end
  local f = fs.open(name,"a")
  if not f then return false end
  f.writeLine(text)
  f.close()
end

function info(text)
  text = "[Info] "..text
  table.insert(log,text)
  save(text)
end

function logError(text)
  text = "[ERROR] "..text
  table.insert(log,text)
  save(text)
end
-- End Log API

create("debug")
info("Log initialized")

local function usages()
  local name = shell.getRunningProgram()
  print("Usages:")
  print(name.." <program>")
end

local function printC(text,y,screen)--Prints text centered at y on screen (term or monitor)
  if not text then error("expected string,number",2) end
  y = tonumber(y)
  if not y then error("expected string,number",2) end
  screen = screen or term
  local tLenght = #tostring(text)
  local sStart = math.ceil(w/2-tLenght/2)
  local sEnd = sStart + tLenght
  screen.setCursorPos(sStart,y)
  screen.write(text)
  return sStart,sEnd
end

local function color( text,back )
  if text then term.setTextColor(text) end
  if back then term.setBackgroundColor(back) end
end

local function getPaintColor( color )
    if type(color) == "number" then
        local value = math.floor( math.log(color) / math.log(2) ) + 1
        if value >= 1 and value <= 16 then
            return string.sub( "0123456789abcdef", value, value )
        end
    end
    return " "
end

local function createBuffer(backColor)
  local tempBuffer = {}
  for a = 1, w do
    tempBuffer[a] = {}
    for b = 1, h do
      tempBuffer[a][b] = {textCol = colors.white, backCol = backColor, text = ""}
    end
  end
  return tempBuffer
end

local function main()
  if not args[1] then
    usages()
    return
  end

  local buffer = createBuffer(colors.black)

  local newShell = {}
  for a,b in pairs(shell) do
    newShell[a] = b
  end
  newShell.getRunningProgram = function()
    return fs.getName(args[1])
  end

  local newTerm = {}
  for a,b in pairs(term) do
    newTerm[a] = b
  end
  newTerm.write = function(text)
    local x,y = term.getCursorPos()
    term.write(text)
    for i = 1, #text do
      buffer[x+i-1][y] = {textCol = term.getTextColor(), backCol = term.getBackgroundColor(), text = text:sub(i,i)}
    end
  end
  newTerm.clear = function()
    buffer = createBuffer(term.getBackgroundColor())
    term.clear()
  end


  local program = coroutine.create( setfenv( loadfile(args[1]) , setmetatable({shell = newShell,term = newTerm},{__index = _G}) ) )

  coroutine.resume(program)

  local paused = false
  while coroutine.status(program) ~= "dead" do
    local eventData = { os.pullEvent() }

    -- Toggle pause.
    if eventData[1] == "key" and eventData[2] == keys.home then
      paused = not paused

      if paused then
        local f = fs.open("debug2","w")
        for x = 1, #buffer do
          for y = 1, #buffer[x] do
            f.write(buffer[x][y])
          end
          f.write("\n")
        end
        f.close()
      end

      -- Neutralize event.
      eventData = {}
    end

    -- Distribute events if the program isn't paused.
    if not paused then
      coroutine.resume(program, unpack(eventData))
    elseif eventData[1] == "mouse_click" then
      -- Construct horizontal bar
      local toWriteText = ""
      local toWriteBackCol = ""
      local toWriteTextCol = ""
      for i = 1, w do
        if i == eventData[3] then
          toWriteText = toWriteText.."X"
        else
          toWriteText = toWriteText.."-"
        end
        local back = buffer[i][eventData[4]].backCol
        toWriteBackCol = toWriteBackCol..getPaintColor(back)
        if back == colors.black then
          toWriteTextCol = toWriteTextCol..getPaintColor(colors.white)
        else
          toWriteTextCol = toWriteTextCol..getPaintColor(colors.black)
        end
      end
      term.setCursorPos(1,eventData[4])
      term.blit(toWriteText,toWriteTextCol,toWriteBackCol)

      -- Construct vertical bar

    end
  end
end

local state, err = pcall(main)

if not state then
  if string.find(err,"Terminated") then
    color(colors.white,colors.black)
    term.clear()
    term.setCursorPos(1,1)
    print("Program Terminated")
  elseif err:find("FORCEQUIT") then
    -- Do nothing
  else
    color(colors.black,colors.red)
    term.write("X")
    printC("Error - Press 'Enter'",1)
    repeat
      local event,key = os.pullEvent("key")
    until key == keys.enter
    color(colors.white,colors.black)
    term.clear()
    printC("An Error Occured:",1)
    term.setCursorPos(1,3)
    print(err or "Unknown")
  end
end