CC Auto Crafting

-- Front chest is the chest where turtle retrieves crafting ingredients from.
-- Top chest is the chest where turtle puts final product.
-- Bottom chest is the chest where turtle dumps unrelated items.

local UNMATCHED = -1
local EMPTY = 0
local INSUFFICIENT = 1
local MATCHED = 2

local string_recipe = {
    {
        name="immersiveengineering:hemp_fiber",
        count=64
    },
    {
        name="immersiveengineering:hemp_fiber",
        count=64
    },
    {
        name="immersiveengineering:hemp_fiber",
        count=64
    },
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
    nil,
}

function compare_item_detail(src_item_detail, dst_item_detail)
    if dst_item_detail == nil then
        if src_item_detail ~= nil then
            return UNMATCHED
        end
        return MATCHED
    end
    if src_item_detail == nil then
        return EMPTY
    elseif src_item_detail.name == dst_item_detail.name then
        if src_item_detail.count < dst_item_detail.count then
            return INSUFFICIENT
        end
        return MATCHED
    end
    return UNMATCHED
end

function do_nothing()
end

function dump_unrelated_item(slot)
    turtle.select(slot)
    turtle.dropDown()
end

function suck_more_item(slot, count)
    turtle.select(slot)
    turtle.suck(count)
end

function is_ready_to_craft(recipe, on_unmatched_func, on_insufficient_func)
    local is_ready = true

    for slot=1,16 do
        turtle.select(slot)
        local item_detail = turtle.getItemDetail()
        local comparison = compare_item_detail(item_detail, recipe[slot])

        if comparison == UNMATCHED then
            is_ready = false
            on_unmatched_func(slot)
        elseif comparison == EMPTY then
            is_ready = false
            local missing_count = recipe[slot].count
            on_insufficient_func(slot, missing_count)
        elseif comparison == INSUFFICIENT then
            is_ready = false
            local missing_count = recipe[slot].count - item_detail.count
            on_insufficient_func(slot, missing_count)
        end
    end

    return is_ready
end

function main()
    while true do
        if is_ready_to_craft(string_recipe, dump_unrelated_item, suck_more_item) then
            turtle.craft()
            turtle.dropUp()
        end
        os.sleep(1)
    end
end

main()