Item Retrieval Turtle

-- Num's item retrieval turtle

-- Inventory slot usage:
-- 1: Outgoing ender chest
-- 2: Returns ender chest
-- 3: Emptied barrels
-- 5-8: Grabbed stacks
-- 9-12: To be delivered
-- 13: To be returned

----------------------

function forward()
    while (not turtle.forward()) do sleep(3) end
end

function back()
    while (not turtle.back()) do sleep(3) end
end

function left()
    turtle.turnLeft()
end

function right()
    turtle.turnRight()
end

function select(a)
    turtle.select(a)
end

function reset()
    turtle.select(1)
    for i = 1, 16 do turtle.back() end
    right()
    for i = 1, 16 do turtle.back() end
    left()
    if(turtle.detectUp()) then doError("Failed to reset!") end
end

function refuel()
    rednet.send(13, "2 Refueling...", true)
    goto(fuelBarrel)
    grabStack()
    if(turtle.getItemCount(5) < 64) then
        turtle.refuel(turtle.getItemCount())
        removeBarrel()
        doError("No more fuel!")
    end
    turtle.refuel(64)
end

function removeBarrel()
    rednet.send(13, "3 Removed a barrel!", true)
    turtle.select(3)
    turtle.digUp()
    turtle.suckUp()
end

function goto(target)
    startX = x
    startY = y
    targetX = target%16
    targetY = math.floor(target/16)

    while(x ~= targetX) do
        if(x < targetX) then
            forward()
            x = x + 1
        else
            back()
            x = x - 1
        end
    end

    if(y ~= targetY) then
        turtle.turnRight()
        while(y ~= targetY) do
            if(y < targetY) then
                forward()
                y = y + 1
            else
                back()
                y = y - 1
            end
        end
        turtle.turnLeft()
    end
end

function grabStack()
    select(5)
    turtle.suckUp()
end

function prepDelivery(amount)
    if(amount <= 0) then return end
    if(amount > 256) then amount = 256 end

    stacks = 1
    if(amount > 64) then stacks = stacks + 1 end
    if(amount > 128) then stacks = stacks + 1 end
    if(amount > 192) then stacks = stacks + 1 end

    fullStacks = stacks - 1
    lastStackSize = 64
    if(amount % 64 == 0) then fullStacks = stacks
    else lastStackSize = amount - (fullStacks * 64) end

    for i = 1, stacks do grabStack() end
    if(turtle.getItemCount(4 + stacks) < 64) then removeBarrel() end

    for i = 1, fullStacks do
        select(4 + i)
        turtle.transferTo(8 + i)
    end

    select(4 + stacks)
    turtle.transferTo(12, lastStackSize)
    turtle.transferTo(13)
end

function deliver(amount)
    prepDelivery(amount)
    select(1)
    while (not turtle.placeDown()) do sleep(3) end
    for i = 9, 12 do
        select(i)
        turtle.dropDown()
    end
    rednet.send(13, "1 Done!", true)
    select(1)
    turtle.digDown()
end

function dropExtra()
    select(2)
    while (not turtle.placeDown()) do sleep(3) end
    select(13)
    turtle.dropDown()
    select(2)
    turtle.digDown()
end

function check()
    if(turtle.getFuelLevel() < 100) then refuel() end
end

function doError(msg)
    turtle.select(1)
    rednet.send(13, "3 "..msg, true)
    error(msg)
end

------------------------

sleep(1)
rednet.open("right")
rednet.send(13, "2 Resetting...", true)
reset()
x = 0
y = 0
barrelNum = 0
fuelBarrel = 15
rednet.send(13, "1 Ready!", true)

while true do
    turtle.select(1)

    id, msg = rednet.receive()

    words = {}
    wordCount = 0
    for word in string.gmatch(msg, "%S+") do
        words[wordCount] = word
        wordCount = wordCount + 1
    end

    barrelNum = 0
    -- row 1
    if(words[1] == "iron") then barrelNum = 1
    elseif(words[1] == "copper") then barrelNum = 2
    elseif(words[1] == "tin") then barrelNum = 3
    elseif(words[1] == "gold") then barrelNum = 4
    elseif(words[1] == "silver") then barrelNum = 5
    elseif(words[1] == "lead") then barrelNum = 6
    elseif(words[1] == "refinediron") then barrelNum = 7
    elseif(words[1] == "uranium") then barrelNum = 8
    elseif(words[1] == "dullshard") then barrelNum = 9
    elseif(words[1] == "fireshard") then barrelNum = 10
    elseif(words[1] == "airshard") then barrelNum = 11
    elseif(words[1] == "earthshard") then barrelNum = 12
    elseif(words[1] == "watershard") then barrelNum = 13
    elseif(words[1] == "visshard") then barrelNum = 14
    elseif(words[1] == "coalcoke") then barrelNum = 15
    -- row 2
    elseif(words[1] == "redstone") then barrelNum = 16
    elseif(words[1] == "lapis") then barrelNum = 17
    elseif(words[1] == "forcicium") then barrelNum = 18
    elseif(words[1] == "flint") then barrelNum = 19
    elseif(words[1] == "quartz") then barrelNum = 20
    elseif(words[1] == "quartzdust") then barrelNum = 21
    elseif(words[1] == "apatite") then barrelNum = 22
    elseif(words[1] == "amber") then barrelNum = 23
    elseif(words[1] == "quicksilver") then barrelNum = 24
    elseif(words[1] == "forcegem") then barrelNum = 25
    elseif(words[1] == "aluminum") then barrelNum = 26
    elseif(words[1] == "ferrousore") then barrelNum = 27
    --
    elseif(words[1] == "coal") then barrelNum = 31
    -- row 3
    elseif(words[1] == "dirt") then barrelNum = 32
    elseif(words[1] == "gravel") then barrelNum = 33
    elseif(words[1] == "obsidian") then barrelNum = 34
    elseif(words[1] == "netherrack") then barrelNum = 35
    elseif(words[1] == "quarriedblock") then barrelNum = 36
    elseif(words[1] == "ironscaffold") then barrelNum = 37
    elseif(words[1] == "redcobble") then barrelNum = 38
    -- row 4
    elseif(words[1] == "oakplank") then barrelNum = 48
    elseif(words[1] == "stick") then barrelNum = 49
    elseif(words[1] == "fence") then barrelNum = 50
    elseif(words[1] == "track") then barrelNum = 51
    elseif(words[1] == "sign") then barrelNum = 52
    elseif(words[1] == "bamboo") then barrelNum = 53
    -- row 5
    elseif(words[1] == "seeds") then barrelNum = 64
    elseif(words[1] == "bone") then barrelNum = 65
    elseif(words[1] == "string") then barrelNum = 66
    elseif(words[1] == "sugar") then barrelNum = 67
    elseif(words[1] == "gunpowder") then barrelNum = 68
    elseif(words[1] == "minium") then barrelNum = 69
    elseif(words[1] == "blueslime") then barrelNum = 70
    elseif(words[1] == "flesh") then barrelNum = 71

    --
    else rednet.send(13, "3 Invalid item!", true) end

    if(barrelNum ~= 0) then
        rednet.send(13, "2 Getting "..words[0].." "..words[1].."...", true)
        goto(barrelNum)
        deliver(tonumber(words[0]))
        dropExtra()
        check()
    end
end