stairs

--[[
  Simple 1-block-wide stairs maker by Miki_Tellurium
  Version: 1.0
  Make a 1-block-wide staircase of specified height (min = 3).
  Usage:
  <fileName> -- default to 5
  or
  <fileName> height
  ]]
if not turtle then
    error("Computer is not a turtle.")
end

local arg = ...
local maxHeight = 5

if arg then
    local n = tonumber(arg)
    if n then
        maxHeight = n
    end
end

-- Max height less than 3 breaks digNext()
-- also a player wouldn't fit in the stairs
if maxHeight < 3 then
    error("Height can't be less than 3.")
end

local fuel = turtle.getFuelLevel()
if fuel == 0 then
    error("No fuel.")
elseif fuel < maxHeight * 50 then
    local ogColor = term.getTextColor()
    term.setTextColor(colors.orange)
    print("Low fuel level, consider refueling.")
    term.setTextColor(ogColor)
end

-- Handle falling blocks
-- try to advance for 10 seconds and return false if no success
local function advance()
    local function timeout()
        sleep(10)
        print("Timeout reached, giving up.")
    end
    local function tryAdvance()
        while not turtle.forward() do
            turtle.dig()
        end
    end
    local result = parallel.waitForAny(tryAdvance, timeout)
    if result == 1 then
        return true
    else
        return false
    end
end

-- Return false if an unbreakable block is found
local function digNext(height)
    local toMove = height - 2 -- Exclude top and bottom block
    if not advance() then return false end
    turtle.digDown()
    for _ = 1,toMove do
        turtle.down()
        if turtle.detectDown() and not turtle.digDown() then
            return false
        end
    end
    if toMove == maxHeight-2 then toMove = toMove - 1 end -- Move up one block less if we are doing full stairs height
    for _ = 1,toMove do
        turtle.up()
    end
    return true
end

local keepGoing = true
local currentHeight = 3
local steps = 0

print("Selected block height: "..maxHeight)
turtle.digUp()
turtle.up()
while keepGoing do
    if turtle.getFuelLevel() == 0 then
        error("Run out of fuel.")
    end

    keepGoing = digNext(currentHeight)
    if keepGoing then
        if currentHeight < maxHeight then
            currentHeight = currentHeight + 1
        end
        steps = steps + 1
    else
        print("Unbreakable block found.")
    end
end

print("Finished stairs with "..steps.." steps.")