Computercraft Flint Farming Bot

--[[            Simple Flint Farming Bot

    This program will process all gravel blocks in its inventory in to flint.

--]]

-- Clear the terminal, write startup message
term.clear()
term.setCursorPos(1, 1)
print ("Starting gravel program.")



--                  Variable and function declarations

-- Main loop control variable
local running = true

-- A function that cycles through the entire inventory to select any gravel we still have. If none is found, ends the main loop
local function select_gravel()

    -- For each of the 16 inventory spaces
    for slot = 1, 16, 1 do

        -- if there is an item in that slot
        if turtle.getItemCount(slot) > 0 then

            -- if that item is a stack of gravel
            if turtle.getItemDetail(slot).name == "minecraft:gravel" then

                -- Select that slot
                turtle.select(slot)

                -- Break out of the for loop to stop selecting
                break
            end
        end

        -- If we made it this far, and we are on the last inventory spot, we are out of gravel
        if slot == 16 then

            -- End the main loop
            running = false

            print("Out of gravel, ending the program.")

        end
    end
end



--                  Start of main program loop

-- Make sure we are selecting a stack of gravel
select_gravel()

-- Main Loop
while running do

    -- Detect if there is a block in front of us
    local has_block, block = turtle.inspect()

    -- If there is a block in front of us
    if has_block then

        -- If that block is a piece of gravel
        if block.name == "minecraft:gravel" then

            -- Dig it baby
            turtle.dig()

        else

            -- If we have anything other than gravel, end the program without digging
            running = false

            print("Block other than gravel detected, ending the program.")

        end

    else -- No Block in front of us, attempt to place a piece of gravel

        -- If we have an item in the selected inventory slot and that item is gravel
        if turtle.getItemCount(turtle.getSelectedSlot()) > 0 and turtle.getItemDetail(turtle.getSelectedSlot()).name == "minecraft:gravel" then

            -- Place the piece of gravel in front of us
            turtle.place()

        else -- Else the selected inventory slot is empty or does not contain gravel

            -- Search the inventory for more gravel
            select_gravel()

        end
    end
end