Mining Turtle - Self-saving miner

-- Only for test purposes right now.

w,h = term.getSize()

function printCenter(string,ypos) -- Prints text on center of the screen.
  if ypos == nil then
    x,y = term.getCursorPos()
    term.setCursorPos(w/2 - #string/2, y+1)
    term.write(string)
  else
    term.setCursorPos(w/2 - #string/2, ypos)
    term.write(string)
  end
end


function decoration() -- Decoration on main menu.
  for i=1,h do
    term.setCursorPos(1,i)
    term.write(":")
  end
  term.setCursorPos(2,1)
  term.write(string.rep("-",w-1))
  term.setCursorPos(2,h)
  term.write(string.rep("-",w-1))
  for i=1,h do
    term.setCursorPos(w,i)
    term.write(":")
  end
end

function fuel() -- Displaying fuel level on main menu.
  tText = "Fuel Level: "
  tFuel = tostring(turtle.getFuelLevel())
  term.setCursorPos(w - #tFuel - #tText - 2,h - 1)
  term.write(tText)
  term.write(tFuel)
end

function mainMenu() -- Main menu.
  term.clear()
  decoration()
  fuel()
  printCenter("Miner V0.2",2)
  printCenter("[Enter] - Start to mine.",h/2)
  printCenter("[E] - Exit",h/2 + 2)
  while true do
    event, p1 = os.pullEvent()
    if event == "key" and p1 == keys.enter then
         running = 1
         savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
         os.reboot()
    elseif event == "key" and p1 == keys.e then
      term.clear()
      term.setCursorPos(1,1)
      error()
    end
    end
  end

function checkPos() -- Loads all cords(if they exist).
  if not fs.exists("mine/cords") then
    local file = fs.open("mine/cords","a")
    file.close()
  end
  local file = fs.open("mine/cords","r")
  line = file.readLine()
  if line == nil then line = 0 end
  turtleX = tonumber(line)
  line = file.readLine()
  if line == nil then line = 0 end
  turtleY = tonumber(line)
  line = file.readLine()
  if line == nil then line = 0 end
  running = tonumber(line)
  line = file.readLine()
  if line == nil then line = 0 end
  times = tonumber(line)
  line = file.readLine()
  if line == nil then line = 1 end
  tForw = tonumber(line)
  line = file.readLine()
  if line == nil then line = "front" end
  tSide = line
  line = file.readLine()
  if line == nil then line = 0 end
  dig = tonumber(line)
  file.close()
end

function savePos(x,y,running,times,tForw,tSide,dig) -- Saves all cords.
  local file = fs.open("mine/cords","w")
  file.write(x)
  file.write("\n")
  file.write(y)
  file.write("\n")
  file.write(running)
  file.write("\n")
  file.write(times)
  file.write("\n")
  file.write(tForw)
  file.write("\n")
  file.write(tSide)
  file.write("\n")
  file.write(dig)
  file.close()
end

function tForward() -- Moves forward.
  for i=1,tForw do
    turtleX = turtleX + 1
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    if not turtle.forward() then
      turtle.dig()
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.forward()
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    end
  end
  tForw = tForw + 1
  savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
end


function tDown() -- Digs down.
  dig = 1
  savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
  bottom = false
  repeat
    turtle.digDown()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)

    if not turtle.down() then
      dig = 0
      turtleY = turtleY - 1
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      bottom = true
    end

    turtleY = turtleY + 1
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)

    -- Checking for sides
    if tSide == "front" then
      tSide = "left"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnLeft()
      turtle.dig()
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnRight()
      tSide = "right"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnRight()
      turtle.dig()
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnLeft()
    elseif tSide == "left" then
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnRight()
    elseif tSide == "right" then
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnLeft()
    end
  until bottom == true
    end

function tUp() -- Get's back up to surface.
  if turtleY <= 0 then
    return
  else
    repeat
      turtleY = turtleY - 1
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      if not turtle.up() then
        turtle.digUp()
        turtle.up()
      end
    until turtleY == 0
  end
end

function checkSide() -- Checks if turtle is facing front.
  if tSide == "front" then
      return
    elseif tSide == "left" then
          turtle.dig()
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnRight()
    elseif tSide == "right" then
          turtle.dig()
      tSide = "front"
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.turnLeft()
    end
end

function tBack() -- Returns up to surface.
  if turtleX <= 0 then
    return
  else
    repeat

      turtleX = turtleX - 1
      savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
      turtle.back()
    until turtleX == 0
  end
end

function tDrop() -- Drops materials inside chest.
  for i=1,16 do
    turtle.select(i)
    turtle.dropDown()
  end
end

fs.makeDir("mine")
checkPos()
checkSide()
sleep(1)

if dig == 1 then -- Checks if turtle finished it's tDown function before chunks unloaded.
  checkSide()
  tDown()
end

if times ~= 10 then -- Turtle should loop this 10 times when first started.
  if running == 1 then
  repeat
    tUp()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tBack()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tDrop()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tForward()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    times = times + 1
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tDown()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tUp()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tBack()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
    tDrop()
    savePos(turtleX,turtleY,running,times,tForw,tSide,dig)
  until times >= 10
  fs.delete("mine")
  else
  term.clear()
  mainMenu()
    end
  end