-- Turtle Block Replacer
-- Breaks block below and replaces with dirt in a defined area
-- Uses dirt from all available slots

-- Get area dimensions from user
print("Enter area width (x):")
local width = tonumber(read())
print("Enter area length (z):")
local length = tonumber(read())

-- Calculate total dirt across all slots
local totalDirt = 0
for slot = 1, 16 do
    local item = turtle.getItemDetail(slot)
    if item and item.name:find("dirt") then
        totalDirt = totalDirt + item.count
    end
end

-- Calculate required dirt and check inventory
local requiredDirt = width * length
print("Total dirt available: "..totalDirt)
print("Dirt needed: "..requiredDirt)

if totalDirt < requiredDirt then
    print("Not enough dirt! Need "..requiredDirt..", have "..totalDirt)
    return
end

-- Check fuel requirements (1 fuel per move + 1 per dig/place)
local requiredFuel = (width * length * 3) + (width + length)
local currentFuel = turtle.getFuelLevel()

if currentFuel < requiredFuel then
    print("Warning: Low fuel! Need "..requiredFuel..", have "..currentFuel)
    print("Place fuel in any slot to continue or type 'cancel'")
    local input = read()
    if input:lower() == "cancel" then return end

    -- Refuel from all slots that contain fuel
    for slot = 1, 16 do
        turtle.select(slot)
        if turtle.refuel(0) then  -- Check if item is fuel
            turtle.refuel()
        end
    end
    currentFuel = turtle.getFuelLevel()
    if currentFuel < requiredFuel then
        print("Still not enough fuel! Canceling operation.")
        return
    end
end

-- Main operation function
local function findDirtSlot()
    for slot = 1, 16 do
        local item = turtle.getItemDetail(slot)
        if item and item.name:find("dirt") and item.count > 0 then
            return slot
        end
    end
    return nil
end

-- Begin replacement pattern
for z = 1, length do
    for x = 1, width do
        -- Break block below
        while not turtle.digDown() do
            sleep(0.5)
        end

        -- Find and select dirt
        local dirtSlot = findDirtSlot()
        if not dirtSlot then
            print("Ran out of dirt unexpectedly!")
            return
        end
        turtle.select(dirtSlot)

        -- Place dirt block
        turtle.placeDown()

        -- Move forward if not at end of row
        if x < width then
            while not turtle.forward() do
                turtle.dig()
                sleep(0.5)
            end
        end
    end

    -- Return to start of row if not on last row
    if z < length then
        if z % 2 == 0 then
            turtle.turnLeft()
            turtle.forward()
            turtle.turnLeft()
        else
            turtle.turnRight()
            turtle.forward()
            turtle.turnRight()
        end
    end
end

print("Area processed successfully!")
print("Blocks replaced: "..(width * length))
print("Fuel remaining: "..turtle.getFuelLevel())