# Miner

local SLOT_FEUL = 1

function get_place_dig_suck_drop_in_empty_space()
  local success, data = turtle.inspect()
  if not success then
    return turtle.place, turtle.dig, turtle.suck, turtle.drop
  end

  success, data = turtle.inspectUp()
  if not success then
    return turtle.placeUp, turtle.digUp, turtle.suckUp, turtle.dropUp
  end

  success, data = turtle.inspectDown()
  if not success then
    return turtle.placeDown, turtle.digDown, turtle.suckDown, turtle.dropDown
  end

  error("No empty space in front, above, or below the turtle")
end

function try_with_rotation(func)
  for i=1,4 do
    vals = {pcall(func)}
    if vals[1] then
      for j = 1,(i-1) do
        turtle.turnRight()
      end
      table.remove(vals, 1)
      return unpack(vals)
    end
    turtle.turnLeft()
  end

  error("Could not execute function in any orientation")
end

function refuel_from_chest(slot)
  print("Refueling from chest in slot " .. tostring(slot) .. ". Fuel: " .. tostring(turtle.getFuelLevel()) .. "/" .. tostring(turtle.getFuelLimit()))
  local place, dig, suck, drop = try_with_rotation(get_place_dig_suck_drop_in_empty_space)
  local prev_slot = turtle.getSelectedSlot()
  turtle.select(slot)
  local success = place()
  assert(success, "Could not place chest")
  while turtle.getFuelLevel() ~= turtle.getFuelLimit() do
    success = suck()
    assert(success, "Could not obtain fuel from chest")
    success = turtle.refuel()
    assert(success, "Could not use item obtained from chest as fuel")
  end
  success = dig()
  assert(success, "Could not remove chest")
  print("Finished refueling. Fuel: " .. tostring(turtle.getFuelLevel()) .. "/" .. tostring(turtle.getFuelLimit()))
  turtle.select(prev_slot)
end

function handle_fuel()
  if turtle.getFuelLevel() / turtle.getFuelLimit() < 0.1 then
    refuel_from_chest(SLOT_FEUL)
    return true
  end
  return false
end


function inspect_vertical()
  local _, up_data = turtle.inspectUp()
  local _, front_data = turtle.inspect()
  local _, down_data = turtle.inspectDown()
  return {down_data, front_data, up_data}
end

function inspect_vertical_simple()
  local up_data = turtle.inspectUp()
  local front_data = turtle.inspect()
  local down_data = turtle.inspectDown()
  return {down_data, front_data, up_data}
end

function mine_down_until(condition)
  local retval = false
  while not condition() do
    local block_exists = turtle.inspectDown()
    if block_exists then
      assert(turtle.digDown(), "Could not dig down")
    end
    assert(turtle.down(), "Could not move down")
    retval = true
  end
  return retval
end

function mine_into_ground()
  return mine_down_until(function()
    local v_state = inspect_vertical_simple()
    return v_state[1] == true and v_state[2] == true
  end)
end

function mine_into_shaft()
  local v_state = inspect_vertical_simple()
  if vstate_[1] == true and v_state[2] == true and v_state[3] == false then
    assert(turtle.digDown(), "Could not dig down")
    assert(turtle.down(), "Could not move down")
    assert(turtle.dig(), "Could not dig forwards")
    assert(turtle.forward(), "Could not move forward")
    return true
  end
  return false
end

function mine_forward_shaft()
  turtle.digUp() -- allowed to fail
  turtle.digDown() -- allowed to fail

  local success = turtle.dig()
  assert(success, "Unable to dig forward")

  success = turtle.forward()
  assert(success, "Unable to move forward after mining forward")
  return true
end

function loop_logic()
  while true do
    logic_funcs = {handle_fuel, mine_into_ground, mine_into_shaft, mine_forward_shaft}
    for _, func in ipairs(logic_funcs) do
      if func() then
        break
      end
    end
    print("Hit enter to continue...")
    io.read()
  end
end

loop_logic()