trenchminer

-- A ComputerCraft script for mining in a straight line forward.

local tArgs = {...}
local depth = 0
local distance = 0
local MAX_DISTANCE

if tonumber(tArgs[1]) == nil then
  MAX_DISTANCE = 8
else
  MAX_DISTANCE = tonumber(tArgs[1])
end


local success, lastDistance, lastDepth



local function unloadInventory()
  local i
  print('Emptying inventory...')
  -- TODO: check for chest?
  turtle.turnLeft()
  turtle.turnLeft()
  for i = 1,16 do
    turtle.select(i)
    turtle.drop(64)
  end
  turtle.turnLeft()
  turtle.turnLeft()
end

local function refuelIfNeeded()
  local i, itemData, coalNeeded
  coalNeeded = math.floor((turtle.getFuelLimit() - turtle.getFuelLevel()) / 80)

  for i = 1,16 do
    itemData = turtle.getItemDetail(i)
    if itemData ~= nil and itemData[name] == 'minecraft:coal' and coalNeeded > 0 then
      print('Refueling, coal needed = ' .. coalNeeded)
      turtle.refuel(coalNeeded)
      coalNeeded = math.floor((turtle.getFuelLimit() - turtle.getFuelLevel()) / 80)
    end
  end
end

local function returnHome()
  local i
  print('Returning home...')
  for i = 1,depth do
    turtle.up()
    depth = depth - 1
  end
  for i = 1,distance do
    turtle.back()
    distance = distance - 1
  end

  unloadInventory()
end

local function mustUnloadInventory()
  -- check for free inventory space
  refuelIfNeeded() -- clear out any coal inventory

  local filledUp = true
  for i = 1,16 do
    if turtle.getItemCount(i) == 0 then
      filledUp = false
    end
  end
  if filledUp then
    print('Must unload inventory.')
    lastDistance = distance
    lastDepth = depth
    returnHome()
    if lastDepth + lastDistance < turtle.getFuelLevel() then
      for i = 1,lastDistance do
        turtle.forward()
        distance = distance + 1
      end
      for i = 1,lastDepth do
        turtle.down()
        depth = depth + 1
      end
    end
  end
  return false
end

local function mustRefuel()
  refuelIfNeeded()
  if depth + distance >= turtle.getFuelLevel() then
    print('Not enough fuel to continue.')
    returnHome()
    return true
  end
  return false
end

local function main()
  local i, blockData
  while true do
    -- fuel check
    if mustRefuel() then break end

    -- dig left, right, down
    turtle.turnLeft()
    if turtle.inspect() ~= false then turtle.dig() end
    turtle.turnRight()
    if mustUnloadInventory() then break end
    turtle.turnRight()
    if turtle.inspect() ~= false then turtle.dig() end
    turtle.turnLeft()
    if mustUnloadInventory() then break end
    if turtle.inspectDown() ~= false then turtle.digDown() end
    if mustUnloadInventory() then break end

    blockExists, blockData = turtle.inspectDown()
    if blockExists == true and blockData ~= nil and blockData['name'] == 'minecraft:bedrock' then
      -- hit bedrock, return home
      print('Hit bedrock')
      for i = 1,depth do
        turtle.up()
        depth = depth - 1
      end
      if distance == MAX_DISTANCE - 1 then
        print('Reached max distance.')
        returnHome()
        break
      end
      -- move forward
      if turtle.inspect() ~= false then turtle.dig() end
      if mustUnloadInventory() then break end
      turtle.forward()
      distance = distance + 1
      if mustRefuel() then break end
    else
      -- go down
      turtle.down()
      depth = depth + 1
      if mustRefuel() then break end
    end
  end
end

main()