stairdigger

local args = { ... }
local levels = 5
if #args ~= 0 then
    if tonumber(args[1]) == nil then
        error("input must be a number")
    else
        levels = tonumber(args[1])
    end
end

local COBBLE = "minecraft:cobblestone"
local DEEPSLATE = "minecraft:cobbled_deepslate"
local COLLBE_STAIRS = "minecraft:cobblestone_stairs"
local DEEPSLATE_STAIRS = "minecraft:cobbled_deepslate_stairs"
local TORCH = "minecraft:torch"

local preferredBuildingBlock = COBBLE
local preferredStairBlock = COLLBE_STAIRS

local function selectItem(itemname)
    local function isItem()
        local details = turtle.getItemDetail()
        if details ~= nil then
            if details.name == itemname then
                return true
            end
        end
        return false
    end
    if isItem() then return true end
    for i = 1, 16, 1 do
        turtle.select(i)
        if isItem() then return true end
    end
    return false
end


---@enum Directions
local Directions = {
    forward = 0,
    up = 2,
    down = 4,
}

local function selectAlternateBlock(blockname)
    if blockname == COBBLE then
        if selectItem(DEEPSLATE) then
            preferredBuildingBlock = DEEPSLATE
        else
            error(COBBLE .. " and " .. DEEPSLATE .. " not found in inventory")
        end
    elseif blockname == COLLBE_STAIRS then
        if selectItem(DEEPSLATE_STAIRS) then
            preferredStairBlock = DEEPSLATE_STAIRS
        else
            error(COLLBE_STAIRS .. " and " .. DEEPSLATE_STAIRS .. " not found in inventory")
        end
    else
        error(blockname .. " not found in inventory")
    end
end

---@param direction Directions
local function placeBlock(direction, blockname)
    if blockname == nil then
        blockname = preferredBuildingBlock
    end
    if not selectItem(blockname) then
        selectAlternateBlock(blockname)
    end
    if direction == Directions.forward then
        turtle.place()
    end
    if direction == Directions.down then
        turtle.placeDown()
    end
    if direction == Directions.up then
        turtle.placeUp()
    end
end

local function surroundingsSafe()
    if turtle.inspectDown() or turtle.inspectUp() then
        return false
    end
    return true
end

---comment
---@return boolean
---@param placeTorch boolean
local function digLevel(placeTorch)
    preferredBuildingBlock = COBBLE
    local function moveToNextLevel()
        turtle.dig()
        turtle.forward()
        turtle.digDown()
        turtle.down()
        turtle.turnLeft()
        placeBlock(Directions.forward)
        turtle.turnLeft()
        turtle.dig()
        turtle.forward()
        placeBlock(Directions.up, COLLBE_STAIRS)
        turtle.back()
        turtle.turnRight()
    end
    local function digOneUp()
        while not turtle.up() do
            turtle.digUp()
        end
        placeBlock(Directions.forward)
    end
    moveToNextLevel()
    turtle.up()
    placeBlock(Directions.forward)
    digOneUp()
    digOneUp()
    digOneUp()
    placeBlock(Directions.up)
    turtle.turnRight()
    turtle.turnRight()
    placeBlock(Directions.forward)
    turtle.down()
    placeBlock(Directions.forward)
    turtle.down()
    placeBlock(Directions.forward)
    if placeTorch then
        placeBlock(Directions.up, TORCH)
    end
    turtle.down()
    placeBlock(Directions.forward)
    if not surroundingsSafe() then
        turtle.turnLeft()
        turtle.down()
        return false
    end
    turtle.down()
    placeBlock(Directions.forward)
    turtle.turnLeft()
    return true
end

local safe = true
local counter = 0
local function levelsAndTorch()
    for i = 1, 5, 1 do
        if not safe then return false end
        if counter >= levels then return false end
        if i < 5 then
            safe = digLevel(false)
        else
            safe = digLevel(true)
        end
        counter = counter + 1
    end
    return true
end

local canResume = true
while canResume do
    canResume = levelsAndTorch()
end