computercraft mining turtle strip mine

-- drop slots are 2 and 13-16, fuel slot is 1, torch slots are 3 and 4

print("Enter desired length of tunnels")

local branchLength = read()

print("Is this turtle on the right:r or left:l")

local turtleSide = read()

print("How many branches?")

local branches = read()

local shaftLength = 1

local totalLength = shaftLength * 2 + branchLength * 2

local fuelStuff = 0

local dig_var = 0

local exceptions = {2, 13, 14, 15, 16}

function exceptionDrop()
  for q=5,12 do
    select(q)
    for p=0,4 do
      if turtle.compareTo(exceptions[p]) then
      turtle.drop()
    end
  end
end

function diggyDiggy()
  dig_var = dig_var + 1
  turtle.forward()
  if dig_var == 12 then
    exceptionDrop()
    turtle.select(4)
    turtle.back()
    if turtle.compareTo(3) then
      turtle.placeDown()
    else
      turtle.select(3)
      turtle.placeDown()
    end
    dig_var = 0
    turtle.forward()
  end
  exceptionDrop()
  turtle.digUp()
  turtle.digDown()
  turtle.dig()
end

function gravel()
  turtle.detect()
  if turtle.detect() == true then
    diggyDiggy()
    gravelception()
  end
end

function gravelception()
  turtle.detect()
  if turtle.detect() == true then
    diggyDiggy()
    gravel()
  end
end

function re_fuel(m)
  for k=1,16 do
    turtle.select(k)
    turtle.refuel(m)
  end
end

function awYiss()
  totalLength = branchLength * 2 + shaftLength * 2
  turtle.getFuelLevel()
  fuelStuff = (totalLength - turtle.getFuelLevel()) / 96
  if fuelStuff < turtle.getItemCount(1) then
    if fuelStuff < 5 then
      if fuelStuff < 4 then
        if fuelStuff < 3 then
          if fuelStuff < 2 then
            if fuelStuff < 1 then
              if fuelStuff < 0 then
              print ("requires no fuel")
              else
                re_fuel(1)
              end
            else
              re_fuel(2)
            end
          else
            re_fuel(3)
          end
        else
          re_fuel(4)
        end
      else
        re_fuel(5)
      end
      turtle.dig()
      for i = 1,shaftLength do
        diggyDiggy()
        turtle.detect()
        if turtle.detect() == true then
          gravelception()
        end
      end
      if turtleSide == "r" then
        turtle.turnRight()
      end
      if turtleSide == "l" then
        turtle.turnLeft()
      end
      turtle.dig()
      for i = 1,branchLength do
        diggyDiggy()
        turtle.detect()
        if turtle.detect() == true then
          gravelception()
        end
      end
      turtle.turnRight()
      turtle.turnRight()
      for i = 1,branchLength do
        turtle.forward()
      end
      if turtleSide == "r" then
        turtle.turnLeft()
      end
      if turtleSide == "l" then
        turtle.turnRight()
      end
      for i = 1,shaftLength do
        turtle.forward()
      end
      shaftLength = shaftLength + 3
    else
    print("I declare the distance I must travel to be far too long!")
    end
  else
  print("not enough fuel to continue")
  end
end

for i = 1,branches do
  awYiss()
  if turtleSide == "r" then
    turtle.turnLeft()
  end
  if turtleSide == "l" then
    turtle.turnRight()
  end
  for j=5,12 do
    turtle.select(1)
    if turtle.compareTo(j) ~= true then
      turtle.select(j)
      turtle.drop()
    end
  end
  turtle.select(1)
  if turtleSide == "r" then
    turtle.turnLeft()
  end
  if turtleSide == "l" then
    turtle.turnRight()
  end
end