-- Minecraft Open Computers String Farm Robot
-- Code by WolpertingerLP.de
-- Have fun :)

local robot = require("robot")
local os = require("os")
local component = require("component")

local waitTime = 100

local maintainSlot = robot.inventorySize()
local nextToolSlot = maintainSlot - 1
local compareSlot = nextToolSlot - 1
local buttonSlot = compareSlot - 1

local currentDirection = nil
local searchForButtonDirectionForth = "left"
local searchForButtonDirectionBack = "right"

local searchForLeavesDirectionForth = "left"
local searchForLeavesDirectionBack = "right"

function updateDirection()
	if currentDirection == nil then 
		currentDirection = "forth"
	elseif currentDirection == "forth" then
		currentDirection = "back"
	elseif currentDirection == "back" then
		currentDirection = "forth"
	end
end

function checkDirection()
	updateDirection()
	
	turns = 0
	turnDirection = nil
	
	if currentDirection == "forth" then
		turnDirection = searchForLeavesDirectionForth
	elseif currentDirection == "back" then
		turnDirection = searchForLeavesDirectionBack
	end
	
	robot.select(compareSlot)
	for x = 0, 4 do
		if robot.compare() then
			if turns < 3 then
				if currentDirection == "forth" then
					if turnDirection == "left" then
						searchForLeavesDirectionForth = "left"
					elseif turnDirection == "right" then
						searchForLeavesDirectionForth = "right"
					end
				elseif currentDirection == "back" then
					if turnDirection == "left" then
						searchForLeavesDirectionBack = "left"
					elseif turnDirection == "right" then
						searchForLeavesDirectionBack = "right"
					end
				end
			else
				if currentDirection == "forth" then
					if turnDirection == "left" then
						searchForLeavesDirectionForth = "right"
						print("Changing search for leaves direction to right")
					elseif turnDirection == "right" then
						searchForLeavesDirectionForth = "left"
						print("Changing search for leaves direction to left")
					end
				elseif currentDirection == "back" then
					if turnDirection == "left" then
						searchForLeavesDirectionBack = "right"
						print("Changing search for leaves direction to right")
					elseif turnDirection == "right" then
						searchForLeavesDirectionBack = "left"
						print("Changing search for leaves direction to left")
					end
				end
			end
			robot.select(1)
			return
		else
			turns = turns + 1
			if turnDirection == "left" then
				robot.turnLeft()
			elseif turnDirection == "right" then
				robot.turnRight()
			end
		end		
	end
	print("Could not determine correct direction :(")
end

function pressButton()
	robot.select(buttonSlot)
	turns = 0
	turnDirection = nil
	
	if currentDirection == "forth" then
		turnDirection = searchForButtonDirectionForth
	elseif currentDirection == "back" then
		turnDirection = searchForButtonDirectionBack
	end
	
	for x = 0, 4 do
		if robot.compare() then
			if turns < 3 then
				if currentDirection == "forth" then
					if turnDirection == "left" then
						searchForButtonDirectionForth = "left"
					elseif turnDirection == "right" then
						searchForButtonDirectionForth = "right"
					end
				elseif currentDirection == "back" then
					if turnDirection == "left" then
						searchForButtonDirectionBack = "left"
					elseif turnDirection == "right" then
						searchForButtonDirectionBack = "right"
					end
				end
			else
				if currentDirection == "forth" then
					if turnDirection == "left" then
						searchForButtonDirectionForth = "right"
						print("Changing search for button direction to right")
					elseif turnDirection == "right" then
						searchForButtonDirectionForth = "left"
						print("Changing search for button direction to left")
					end
				elseif currentDirection == "back" then
					if turnDirection == "left" then
						searchForButtonDirectionBack = "right"
						print("Changing search for button direction to right")
					elseif turnDirection == "right" then
						searchForButtonDirectionBack = "left"
						print("Changing search for button direction to left")
					end
				end
			end
			robot.use()
			break
		else
			turns = turns + 1
			if turnDirection == "left" then
				robot.turnLeft()
			elseif turnDirection == "right" then
				robot.turnRight()
			end
		end
	end
end

function isNextToolAlreadyInInventory()
	toolItem = component.inventory_controller.getStackInInternalSlot(nextToolSlot)
	if toolItem == nil then return false end
	if toolItem.label == "Shears" then
		return true
	end
	return false
end

function getToolItem()
	robot.select(maintainSlot)
	component.inventory_controller.equip()
	toolItem = component.inventory_controller.getStackInInternalSlot(maintainSlot)
	component.inventory_controller.equip()
	robot.select(1)
	return toolItem
end

function checkTool()
	if isNextToolAlreadyInInventory() == false then
		robot.select(nextToolSlot)
		if robot.suckDown(1) then
			print("Equipping next tool from external storage")
		end
	end
	robot.select(maintainSlot)
	toolItem = getToolItem()
	if toolItem == nil then
		robot.select(nextToolSlot)
		if component.inventory_controller.equip() then
			print("New tool equipped in tool slot")
		else
			print("I´m not happy with my job. Without tools i will quit... for now")
		end
	else
		print(string.format("Current tool damage: %s of %s",toolItem.damage, toolItem.maxDamage))
	end
end

function dropAll()
	for x = 1, buttonSlot-1 do 
		robot.select(x)
		robot.drop()
	end
	robot.select(1)
end

function rest()
	step = waitTime / 10
	print(string.format("\nSleeping for %s seconds...",waitTime))
	for x = 0,9 do
		os.sleep(step)
		print(string.format("Still sleeping for about %s seconds",waitTime - (x+1)*step))
	end
	print("\nGood Morning little SchoolGirl")
	print("A new day another chance\n")
end

function doWork()
	haveWork = true
	while haveWork do
		checkTool()
		robot.select(compareSlot)
		somethingToDo = robot.compare()
		robot.select(1)
		if somethingToDo then
			robot.swing()
			robot.forward()
		else
			robot.forward()
			haveWork = false
		end
	end
end

function startUp()
	print("Starting string farm program ...\n")
	os.sleep(1)
	print("Checking inventory ...")
	print("Warmup finished/n")
	while true do 
		checkDirection()
		doWork()
		dropAll()
		pressButton()
		rest()
	end
end

startUp()