bridge turtle

-- Bridge Building Program for CC:Tweaked Turtle

-- Function to count building blocks in inventory
local function countBuildingBlocks()
    local total = 0
    for i = 1, 16 do
        local item = turtle.getItemDetail(i)
        if item then
            total = total + item.count
        end
    end
    return total
end

-- Function to check and refuel if necessary
local function refuel(neededFuel)
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then return true end

    for i = 1, 16 do
        turtle.select(i)
        if turtle.refuel(0) then
            local needed = neededFuel - fuelLevel
            if needed > 0 then
                turtle.refuel(needed)
            end
            return true
        end
    end
    return false
end

-- Function to find and select a block for placement
local function selectBlock()
    for i = 1, 16 do
        if turtle.getItemCount(i) > 0 then
            turtle.select(i)
            return true
        end
    end
    return false
end

-- Main program
print("Bridge Building Program")
print("Enter the length of the bridge:")
local length = tonumber(read())

if not length or length < 1 then
    print("Invalid length. Please enter a positive number.")
    return
end

local blocksNeeded = length
local blocksAvailable = countBuildingBlocks()

print("Blocks needed: " .. blocksNeeded)
print("Blocks available: " .. blocksAvailable)

if blocksAvailable < blocksNeeded then
    print("Not enough blocks to complete the bridge.")
    return
end

local fuelNeeded = length * 2  -- Move forward and back
local currentFuel = turtle.getFuelLevel()

if currentFuel ~= "unlimited" and currentFuel < fuelNeeded then
    print("Attempting to refuel...")
    if not refuel(fuelNeeded) then
        print("Not enough fuel to complete the bridge.")
        return
    end
end

print("Starting bridge construction...")

-- Build the bridge
for i = 1, length do
    if not selectBlock() then
        print("Ran out of blocks unexpectedly.")
        break
    end
    turtle.placeDown()
    if i < length then
        turtle.forward()
    end
end

-- Return to start
turtle.turnRight()
turtle.turnRight()
for i = 1, length - 1 do
    turtle.forward()
end

print("Bridge construction complete!")