JUtils

-- Print anerror message and a stack trace.
function err(msg)
    if msg then textutils.pagedPrint(msg) end
    textutils.pagedPrint(debug.traceback())
    error()
end

-- Check if item is at the selected slot, returns the detail of the item if found, else nil.
function checkSelected(item)
    local data = turtle.getItemDetail()
    if data then
        if data.name == item then
            return data
        end
    end
    return nil
end

-- Count number of occurenses of type item in the inventory and return it.
function getItemCount(item)
    local count = 0
    for i=1, 16, 1 do
        turtle.select(i)
        local data = checkSelected(item)
        if data then
            count = count + data.count
        end
    end
    return count
end

-- Count number of occurenses of type item in the inventory and check if it is the same or more than count. If it is less than count, pause and ask for refill.
function hasNumItems(item, count)
    local c = getItemCount(item)
    print("Has only", c, "items of type", count, "need", count,", add items and press 'enter' when done.")
    while c < count do
        local action, key = os.pullEventRaw()
        if action == "key" then
            if key == keys.enter then
                c = getItemCount(item)
                if c >= count then
                    print("Refilled!")
                    return
                else
                    print("That was not of type", item, ", try again and press 'enter' when done!")
                end
            end
        end
    end
end

-- Check if an item exists in the inventory.
function findItem(item)
    for i=1, 16, 1 do
        turtle.select(i)
        local data = checkSelected(item)
        if data then
            return data
        end
    end
    return nil
end

-- Refule with fuelType if fuel level is less then minFuelLevel. If no fuel was found, pause and ask for refill.
function refuel(fuelType, minFuelLevel, refuelAmount)
    local level = turtle.getFuelLevel()
    if level < minFuelLevel then
        local fuel = findItem(fuelType)
        local hasFuel = -1
        if turtle.refuel(refuelAmount) then hasFuel = 1 end
        while hasFuel <= 0 do
            if hasFuel == -1 then
                print("No fuel (coal) in inventory! Add fuel and press 'enter' key to continue.")
                hasFuel = 0
            end
            action, key = os.pullEventRaw()
            if action == "key" then
                if key == keys.enter then
                    fuel = findItem(fuelType)
                    if turtle.refuel(refuelAmount) then
                        print("Refilled fuel!")
                        hasFuel = 1
                    else
                        print("That was not fuel, try again and press 'enter' when done!")
                    end
                end
            end
        end
    end
end

-- Get the selected slot at the specified item. If no item was found, pause and ask for refill.
function selectItem(item)
    -- Check if item is in inventory
    local data = checkSelected(item)
    if data then
        return data
    else
        data = findItem(item)
        if data then
            return data
        end
    end

    -- Item was not found, ask for it.
    print(item, "was found, add", item, "and press 'enter' when done!")
    local hasItem = false
    while hasItem == false do
        local action, key = os.pullEventRaw()
        if action == "key" then
            if key == keys.enter then
                data = findItem(item)
                if data then
                    hasItem = true
                else
                    print("That was not ", item, ", try again and press 'enter' when done!")
                end
            end
        end
    end

    return selectItem(item)
end