branch

local tArgs = { ... }
if #tArgs ~= 1 then
    print( "Usage: branch <length>" )
    return
end

local length = tonumber( tArgs[1] )
if length < 1 then
    print( "Branch length must be positive" )
    return
end

local depth = 0

local function tryDig()
    while turtle.detect() do
        if turtle.dig() then
            sleep(0.5)
        else
            return false
        end
    end
    return true
end

local function tryDigUp()
    while turtle.detectUp() do
        if turtle.digUp() then
            sleep(0.5)
        else
            return false
        end
    end
    return true
end

local function tryDigDown()
    while turtle.detectDown() do
        if turtle.digDown() then
            sleep(0.5)
        else
            return false
        end
    end
    return true
end

local function refuel()
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" or fuelLevel > 0 then
        return
    end

    local function tryRefuel()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    turtle.select(1)
                    return true
                end
            end
        end
        turtle.select(1)
        return false
    end

    if not tryRefuel() then
        print( "Add more fuel to continue." )
        while not tryRefuel() do
            sleep(1)
        end
        print( "Resuming Tunnel." )
    end
end

local function tryUp()
    refuel()
    while not turtle.up() do
        if turtle.detectUp() then
            if not tryDigUp() then
                return false
            end
        elseif turtle.attackUp() then
            -- nothing
        else
            sleep( 0.5 )
        end
    end
    return true
end

local function tryDown()
    refuel()
    while not turtle.down() do
        if turtle.detectDown() then
            if not tryDigDown() then
                return false
            end
        elseif turtle.attackDown() then
            -- nothing
        else
            sleep( 0.5 )
        end
    end
    return true
end

local function tryForward()
    refuel()
    while not turtle.forward() do
        if turtle.detect() then
            if not tryDig() then
                return false
            end
        elseif turtle.attack() then
            -- nothing
        else
            sleep( 0.5 )
        end
    end
    return true
end

local function placeTorch()
    turtle.select(16)
    turtle.place()
end

local function pokeHoles()
    tryUp()
    turtle.turnRight()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        turtle.back()
        turtle.back()
        turtle.back()
        turtle.back()
    turtle.turnLeft()
    turtle.turnLeft()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        tryForward()
        tryDig()
        turtle.back()
        turtle.back()
        turtle.back()
        turtle.back()
    turtle.turnRight()
    tryDown()
end

print( "Branching..." )
print("Put Cobblestone in Slot 15" )
print("and Torches in Slot 16")
sleep (2)


for n=1,length do
    tryDig()
    tryForward()
    tryDigUp()
    turtle.select(15)
    turtle.placeDown()
    depth = depth + 1
    if depth % 7 == 0 then
        turtle.turnLeft()
        tryDig()
        placeTorch()
        turtle.turnRight()
    end
    if depth % 3 == 0 then
        pokeHoles()
    end
end

print( "Branch complete." )