SapBot v4 alpha

--Sap farming turtle.

local rows = 1
local compass = 0
local x = 0
local y = 0
local z = 0

function spin()
  print "spinning"
  turtle.turnRight()
  turtle.turnRight()
  compass = (compass + 2) % 4
end

function forward()
  print "going forward"
  if not turtle.forward() then
    return false
  end
  if compass == 0 then
    x = x + 1
  elseif compass == 1 then
    y = y + 1
  elseif compass == 2 then
    x = x - 1
  elseif compass == 3 then
    y = y - 1
  else
    print "what are you doing!?! Not a valid compass value."
  end
  return true
end

function up()
  print "going up"
  if turtle.up() then
    z = z + 1
    return true
  else
    return false
  end
end

function down()
  "print going down"
  if turtle.down() then
    z = z - 1
    return true
  else
    return false
  end
end

function turnRight()
  print "turning right"
  if turtle.turnRight() then
    compass = (compass + 1) % 4
    return true
  else
    return false
  end
end

function turnLeft()
  print "turning left"
  if turtle.turnLeft() then
    compass = math.abs((compass - 1) % 4)
    return true
  else
    return false
  end
end

function emptyInv() -- may as well empty our inventory while we're here.


end

function recharge() --Find and use turtle recharging station.


end

function returnToBase()
  --This code will go up to a respectable Z, then go to 0 x and 0 y, then drop down to 0 z. This is the starting point, and should be where we keep the recharging station and ender chest.
  for i = 0, 20 do
    up()
  end
  repeat
    turnRight()
  until compass == 2
  while x ~= 0 do
    forward()
  end
  repeat
    turnRight()
  until compass == 3
  while y ~= 0 do
    forward()
  end
  repeat
    turnRight()
  until compass == 0
  while z ~= 0 do
    down()
  end
  emptyInv()
  recharge()
end

function rotateCounterClockwise()
  print "rotating counter clockwise"
  turnRight()
  forward()
  turnLeft()
  forward()
  turnLeft()
end
function rotateClockwise()
  print "rotating clockwise"
  turnLeft()
  forward()
  turnRight()
  forward()
  turnRight()
end

function harvestFrontBack()
  repeat
    turtle.dig()
    if not up() then
      turtle.digUp()
      up()
    end
  until not turtle.detect()
  forward()
  forward()
  spin()
  while z do
    if not down() then
      print "breaking to go down"
      turtle.digDown()
      down()
    end
    turtle.dig()
  end
end

function harvestTree() --Starting with turtle facinga a tree, it gets all the resin from each side of the tree and returns to its start position.
  print "Starting"
  harvestFrontBack()
  rotateCounterClockwise()
  harvestFrontBack()
  rotateClockwise()
end

function turn(dir)
  if dir % 2 == 1 then
    turnLeft()
  elseif dir % 2 == 0 then
    turnRight()
  end
end

function nextRow(rows)
  if rows % 2 then
    local dir = 2
    turn(dir)
  else
    local dir = 3
    turn(dir)
  end
  forward()
  forward()
  local rowFound = false
  while not rowFound do
    if not turtle.forward() then
      returnToBase()
      sleep(3600)
    end
    turn(dir)
    rowFound = turtle.detect()
    turn(dir - 1)
  end
  rows = rows + 1
end

function nextTree()
  local detectTree = false
  repeat
    turtle.turnRight()
    if not turtle.forward() then
      nextRow()
      break
    end
    turnLeft()
  until turtle.detect()
end



function main()
  --while true do
    harvestTree()
    nextTree()
  --end
end