stairway

require("turtleLib")

function setupTorchesInInventory()
    local torchesPresent = false
    local previousSlot = turtle.getSelectedSlot()
    local torchesIndex = searchInventoryForItem("minecraft:torch")
    if torchesIndex > -1 then
        torchesPresent = true
        turtle.select(torchesIndex)
        turtle.transferTo(16)
        turtle.select(previousSlot)
    end
    return torchesPresent
end

function placeTorch()
    if turtle.getItemDetail(16) ~= nil then
        if turtle.getItemDetail(16).name == "minecraft:torch" then
            local previousSlot = turtle.getSelectedSlot()
            local torchIndex = searchInventoryForItem("minecraft:torch")
            turtle.select(torchIndex)
            turtle.placeUp()
            turtle.select(previousSlot)
        end
    end
end


local torches = setupTorchesInInventory()
local depth = 0;
-- Dig forward a couple blocks for a doorway
turtle.dig()
goForward()
turtle.digUp()
turtle.dig()
goForward()
turtle.digUp()
turtle.digDown()

-- Start digging the stairway
local success, data = turtle.inspectDown()
while data.name ~= "minecraft:bedrock" do
    turtle.dig()
    goForward()
    turtle.digUp()
    if (depth%5)==0 then
        placeTorch()
    end
    turtle.digDown()
    goDown()
    turtle.digDown()
    depth = depth + 1
    success, data = turtle.inspectDown()
end

-- Continue until reaching bedrock
-- turn around
turtle.turnRight()
turtle.turnRight()

local stairsIndex = searchInventoryForItem("minecraft:cobblestone_stairs")
local stairsPresent = (stairsIndex > -1)

-- Return to surface
for i=1, depth do -- fixme. use for loop and counter
    goForward()
    -- if stairs present in inventory
    if stairsPresent then
        local preselectedSlot = turtle.getSelectedSlot()
        local itemDetail = turtle.getItemDetail(stairsIndex)
        -- Because staircase can be more than 64 deep...
        -- Make sure we still have stairs selected
        if(itemDetail == nil or itemDetail.name ~= "minecraft:cobblestone_stairs") then
            stairsIndex = searchInventoryForItem("minecraft:cobblestone_stairs")
            stairsPresent = (stairsIndex > -1)
        end
        turtle.select(stairsIndex)
        turtle.digDown()
        turtle.placeDown()
        -- check to make sure stairs are right side up
        local success, data = turtle.inspectDown()
        if success and data.state.half == "top" then
            -- stair is upsidown
            turtle.digDown()
            goDown()
            local fillerBlockIndex = searchInventoryForItem("minecraft:cobblestone")
            if fillerBlockIndex > -1 then
                turtle.select(fillerBlockIndex)
            else
                fillerBlockIndex = searchInventoryForItem("minecraft:cobbled_deepslate")
                if fillerBlockIndex > -1 then
                    turtle.select(fillerBlockIndex)
                end
            end
            turtle.placeDown()
            goUp()
            turtle.select(stairsIndex)
            turtle.placeDown()
        end
        if(i==depth) then
            turtle.dig()
            turtle.place()
        end
        turtle.select(preselectedSlot)
        else
    end
    -- endif
    goUp()
end