local branchLength = 32
local turnRight = true

local robot = require("robot");
local component = require("component")
local inv = component.inventory_controller

function turnInBranchDir()
  if turnRight then
    robot.turnRight()
  else
    robot.turnLeft()
  end
end

function swingIfTool()
  if robot.durability() == nil then
    error('ERROR: no tool')
  end
  robot.swing()
  raiseIfInventoryFull()
end

function swingUpIfTool()
  if robot.durability() == nil then
    error('ERROR: no tool')
  end
  robot.swingUp()
  raiseIfInventoryFull()
end

function swingDownIfTool()
  if robot.durability() == nil then
    error('ERROR: no tool')
  end
  robot.swingDown()
  raiseIfInventoryFull()
end

function raiseIfInventoryFull()
  local allFull = true
  for i = 1, robot.inventorySize(), 1 do
    if inv.getStackInInternalSlot(i) == nil then
      allFull = false
    end
  end
  if allFull then
    error('ERROR: inventory full')
  end
end

function grabTool()

end

function mineForward()
  swingIfTool()
  robot.forward()
  swingUpIfTool()
  if not robot.detectDown() then
    robot.placeDown()
  end
  if not robot.detectDown() then
    error("ERROR: place failed!")
  end
end

function branch()
  turnInBranchDir()
  for i = 1, branchLength, 1 do
    mineForward()
  end
  robot.turnAround()
  for i = 1, branchLength, 1 do
    robot.forward()
  end
  turnInBranchDir()
end

-- while true do
--   for i = 1, 4, 1 do
--     mineForward()
--   end
--   branch()
-- end