Xp Turtle Gather

--TODO :        make check for slot 1 being empty
--                      create exit for when chest is full


--Load the saved Turtle state from disk if available, if not set to 0
function loadState()
        if fs.exists("xpTurtleState") then
                local file = fs.open("xpTurtleState","r")
                data = file.readAll()
                file.close()
                data=tonumber(data)
                moveState=data
        else
                print("debug -- no xpTurtleState found, setting movement state to 0\n")
                moveState = 0
        end
end

-- Save the current state to disk
function saveState(a)
        local file = fs.open("xpTurtleState","w")
        file.write(a)
        file.close()
--      io.write(string.format("debug -- wrote %s to file\n",a))

end

-- Check where the turtle is right now, and it it isn't at block 0, move there
function moveToStart()
        loadState()
--      io.write(string.format("debug -- Moving %s blocks to starting point\n", moveState))
        if moveState~=nil then
                printStatus("moving to start", getLvl())
                moveForward(moveState)
        end
end

-- Move forward with checking for blockage and save the move state
function moveForward(nDistance)
        printStatus("moving to start", getLvl())
--      print("moveForward nDistance is  ", nDistance)
        while nDistance > 0 do
                if turtle.forward() then
                        nDistance=nDistance-1
                        moveState = moveState -1
                        saveState(moveState)
                else
                        sleep(0.5)
                end
        end
end

-- Move back with checking for blockage and save the move state
function moveBack(nDistance)
        while nDistance > 0 do
                printStatus("moving to enchant area", curLev)
--              print("moveBack () nDistance is  ", nDistance)
                if turtle.back() then
                        nDistance=nDistance-1
                        moveState = moveState +1
                        saveState(moveState)
                else
                        sleep(0.5)
                end
        end
end


-- check if there's enough fuel, if not refuel from slot 16. If no fuel available, exit.
function checkFuel()
        if turtle.getFuelLevel()<20 then
                if      turtle.getItemCount(16)>=1 then
                        turtle.select(16)
                        turtle.refuel(1)
                else
                        exitMsg(1)
                end
        end

end

-- get the current level of the turtle
function getLvl()
        curLev = m.getLevels()
        return curLev
end

-- Check if nLvl(default=30) levels have been reached, if not wait, if yes, return true.
function checkLevel(nLvl)
        getLvl()
        if curLev<nLvl then
                printStatus("gathering XP", curLev)
                return false
        else
                printStatus("moving to enchant area", getLvl())
                return true
        end

end

-- Look for items to enchant in slots 2 through 14, if there are none, default to findBooks()
function getItems()
        for i=2,14 do
                if turtle.getItemCount(i)>0 then
                        turtle.select(i)
                        turtle.transferTo(1,1)
                        turtle.select(1)
                        return true
                end
        end
--              print("no items found, trying to find books")
        if findBook() then
        --              print("Books found")
                return true
        else
                return false
        end

end

-- Get books from inventory slot 15 and put 1 in slot 1, returning true, if not return false
function findBook()
        if turtle.getItemCount(15)>=1 then
                turtle.select(15)
                turtle.transferTo(1,1)
                turtle.select(1)
                return true
        else
                return false
        end
end

-- enchant the book in slot one and drop it into the chest underneath the turtle
function enchantBook(nLvl)
        if m.enchant(nLvl) then
                turtle.dropDown()
        else
                error("Unexpected error while trying to enchant")
        end

end

-- End program with a message

function exitMsg(exitNr)
        if exitNr == 1 then exitStr="Out of fuel. Place more fuel in slot 16 and restart the program"
        elseif exitNr == 2 then exitStr="No more items or books"
--      elseif exitNr == 3 then exitStr=""
--      elseif exitNr == 4 then exitStr=""
--      elseif exitNr == then exitStr=""

        end
        term.clear()
        term.setCursorPos(2,2)
        sleep(0.5)
        print(exitStr)
        run.state="end"
end



function printIntro()
        term.clear()
        print("---------------------------------------")
        print("------- XPturtle 0.2 by Gili710 -------")
        print("---------------------------------------")
        print()
        print("This turtle will automatically enchant items in its inventory")
        print("Place any items in slots 2 through 14")
        print("Place some books in slot 15.")
        print("Place some fuel in slot 16")
        print("Press any key to start")
        print()

end

function printStatus(curTask, curLvl)
        term.clear()
        term.setCursorPos(1,1)
        print("------- XPturtle 0.2 by Gili710 -------")
        term.setCursorPos(2,4)
        io.write(string.format("Current Task: %s", curTask))
        term.setCursorPos(2,6)
        io.write(string.format("Current Level: %s", curLvl))
end


--INIT
m=peripheral.wrap("right")
m.setAutoCollect(true)
nLvl=30
run = {}
run.state="running"
screenw, screenh = term.getSize()

-- Main Program

printIntro()
os.pullEvent()
checkFuel()
if run.state=="running" then
        moveToStart()
end



-- start main loop
while run.state=="running" do
        while not checkLevel(nLvl) do
                sleep(1)

        end
        checkFuel()
        loadState()

        --      Extra safety here
        while moveState ~= 5 do
                moveToStart()
                moveBack(5)
        end
        printStatus("enchanting", getLvl())
        sleep(2)
        if getItems() then
                enchantBook(nLvl)
                sleep(2)
                moveForward(5)
        else
                exitMsg(2)
        end
end