Mining Program

function updateResumingFlag()

  if (resuming == true) then
    if ((resumeMiningState == currMiningState) and (resumeX == currX) and (resumeY == currY) and (resumeZ == currZ) and (resumeOrient == currOrient)) then
      resuming = false
    end
  end

end


function saveLocation()

  -- Write the x, y, z and orientation to the file
  if ((supportResume == true) and (resuming == false)) then
    local outputFile = io.open(oreQuarryLocation, "w")
    outputFile:write(currMiningState)
    outputFile:write("\n")
    outputFile:write(currX)
    outputFile:write("\n")
    outputFile:write(currY)
    outputFile:write("\n")
    outputFile:write(currZ)
    outputFile:write("\n")
    outputFile:write(currOrient)
    outputFile:write("\n")
    outputFile:close()
  end

end

-- Variables used to support a resume
local startupParamsFile = "OreQuarryParams.txt"
local oreQuarryLocation = "OreQuarryLocation.txt"
local returnToStartFile = "OreQuarryReturn.txt"
local startupBackup = "startup_bak"
local supportResume = true -- Determines whether the turtle is being run in the mode that supports resume
local resuming = false -- Determines whether the turtle is currently in the process of resuming
local resumeX
local resumeY
local resumeZ
local resumeOrient
local resumeMiningState

-- Variables to store the current location and orientation of the turtle. x is right, left, y is up, down and
-- z is forward, back with relation to the starting orientation. Y is the actual turtle level, x and z are
-- in relation to the starting point (i.e. the starting point is (0, 0))
local currX
local currY
local currZ
local currOrient
local currMiningState = miningState.START

-- Command line parameters
local startHeight -- Represents the height (y co-ord) that the turtle started at
local quarryWidth -- Represents the length of the mines that the turtle will dig



  if (resuming == true) then
    -- Get the stored parameters from the necessary file
    local resumeFile = fs.open(returnToStartFile, "r")
    if (resumeFile ~= nil) then
      -- Restore the parameters from the file
      local beenAtZero = resumeFile.readLine()
      if (beenAtZero == "y") then
        haveBeenAtZeroZeroOnLayer = true
      else
        haveBeenAtZeroZeroOnLayer = false
      end

      local miningPointFlag = resumeFile.readLine()
      if (miningPointFlag == "y") then
        returnBackToMiningPoint = true
      else
        returnBackToMiningPoint = false
      end

      currX = readNumber(resumeFile)
      currY = readNumber(resumeFile)
      currZ = readNumber(resumeFile)
      currOrient = readNumber(resumeFile)
      levelToReturnTo = readNumber(resumeFile)
      prevMiningState = readNumber(resumeFile)
      orientationAtZeroZero = readNumber(resumeFile)
      resumeFile.close()

    else
      writeMessage("Failed to read return to start file", messageLevel.ERROR)
    end
  elseif (supportResume == true) then

    local outputFile = io.open(returnToStartFile, "w")

    if (haveBeenAtZeroZeroOnLayer == true) then
      outputFile:write("y\n")
    else
      outputFile:write("n\n")
    end
    if (returnBackToMiningPoint == true) then
      outputFile:write("y\n")
    else
      outputFile:write("n\n")
    end

    outputFile:write(currX)
    outputFile:write("\n")
    outputFile:write(currY)
    outputFile:write("\n")
    outputFile:write(currZ)
    outputFile:write("\n")
    outputFile:write(currOrient)
    outputFile:write("\n")
    outputFile:write(levelToReturnTo)
    outputFile:write("\n")
    outputFile:write(prevMiningState)
    outputFile:write("\n")
    outputFile:write(orientationAtZeroZero)
    outputFile:write("\n")

    outputFile:close()
  end

  storedX = currX
  storedY = currY
  storedZ = currZ
  storedOrient = currOrient

  -- Store the current location and orientation so that it can be returned to
  currMiningState = miningState.EMPTYINVENTORY
  writeMessage("last item count = "..turtle.getItemCount(lastEmptySlot), messageLevel.DEBUG)

  if ((turtle.getItemCount(lastEmptySlot) > 0) or (returnBackToMiningPoint == false)) then

    writeMessage("Heading back to surface", messageLevel.INFO)

    -- Move down to the correct layer to return via
    if (currY > levelToReturnTo) then
      while (currY > levelToReturnTo) do
        turtleDown()
      end
    elseif (currY < levelToReturnTo) then
      while (currY < levelToReturnTo) do
        turtleUp()
      end
    end

    if ((haveBeenAtZeroZeroOnLayer == false) or (orientationAtZeroZero == direction.FORWARD)) then
      -- Move back to the correct X position first
      if (currX > 0) then
        turtleSetOrientation(direction.LEFT)
        while (currX > 0) do
          turtleForward()
        end
      elseif (currX < 0) then
        -- This should never happen
        writeMessage("Current x is less than 0 in returnToStartAndUnload", messageLevel.ERROR)
      end

      -- Then move back to the correct Z position
      if (currZ > 0) then
        turtleSetOrientation(direction.BACK)
        while (currZ > 0) do
          turtleForward()
        end
      elseif (currZ < 0) then
        -- This should never happen
        writeMessage("Current z is less than 0 in returnToStartAndUnload", messageLevel.ERROR)
      end
    else
      -- Move back to the correct Z position first
      if (currZ > 0) then
        turtleSetOrientation(direction.BACK)
        while (currZ > 0) do
          turtleForward()
        end
      elseif (currZ < 0) then
        -- This should never happen
        writeMessage("Current z is less than 0 in returnToStartAndUnload", messageLevel.ERROR)
      end

      -- Then move back to the correct X position
      if (currX > 0) then
        turtleSetOrientation(direction.LEFT)
        while (currX > 0) do
          turtleForward()
        end
      elseif (currX < 0) then
        -- This should never happen
        writeMessage("Current x is less than 0 in returnToStartAndUnload", messageLevel.ERROR)
      end
    end

    -- Return to the starting layer
    if (currY < startHeight) then
      while (currY < startHeight) do
        turtleUp()
      end
    elseif (currY > startHeight) then
      -- This should never happen
      writeMessage("Current height is greater than start height in returnToStartAndUnload", messageLevel.ERROR)
    end