excavateNether v3

----------------------------------------------
-- Nether Excavation Turtle
-- 1) Upload code to your turtle with "pastebin get Bb9DsaFX excavateNether"
-- 2) Dig down to the edge of a lava lake (level 32).
-- 3) Place chest behind your turtle. Place one bucket of lava into the first slot of its inventory.
-- 4) Run code using "excavateNether <bore size>" replacing <bore size> with the width of the hole you wish to dig
-- 5) It will draw as much lava as is necessary to mine and bore upwards and deposit items in the chest as it gets full.

-- Note: If you run this program in the overworld you WILL lose your turtle.
----------------------------------------------
-- Credit to leftler for his lava refueling code: https://pastebin.com/nFSUKiYE
----------------------------------------------
-- V1 - basic dig up Function
-- V2 - added lava refueling
-- V3 - added findCeiling function to start digging faster
----------------------------------------------

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

local size = tonumber( tArgs[1] )

-- Mine in a quarry pattern until we hit something we can't dig
if size < 1 then
    print( "Excavate diameter must be positive" )
    return
end

local height = 0
local unloaded = 0
local collected = 0

local xPos,zPos = 0,0
local xDir,zDir = 0,1

local goTo -- Filled in further down
local refuel -- Filled in further down

local function unload( _bKeepOneFuelStack )
    print( "Unloading items..." )
    for n=1,16 do
        local nCount = turtle.getItemCount(n)
        if nCount > 0 then
            turtle.select(n)
            local bDrop = true
            if _bKeepOneFuelStack and turtle.refuel(0) then
                bDrop = false
                _bKeepOneFuelStack = false
            end
            if bDrop then
                turtle.drop()
                unloaded = unloaded + nCount
            end
        end
    end
    collected = 0
    turtle.select(1)
end

local function returnSupplies()
    local x,y,z,xd,zd = xPos,height,zPos,xDir,zDir
    print( "Returning to surface..." )
    goTo( 0,0,0,0,-1 )

    local fuelNeeded = 2*(x+y+z) + 1
    if not refuel( fuelNeeded ) then
        unload( true )
        print( "Waiting for fuel" )
        while not refuel( fuelNeeded ) do
            os.pullEvent( "turtle_inventory" )
        end
    else
        unload( true )
    end

    print( "Resuming mining..." )
    goTo( x,y,z,xd,zd )
end

local function collect()
    local bFull = true
    local nTotalItems = 0
    for n=1,16 do
        local nCount = turtle.getItemCount(n)
        if nCount == 0 then
            bFull = false
        end
        nTotalItems = nTotalItems + nCount
    end

    if nTotalItems > collected then
        collected = nTotalItems
        if math.fmod(collected + unloaded, 50) == 0 then
            print( "Mined "..(collected + unloaded).." items." )
        end
    end

    if bFull then
        print( "No empty slots left." )
        return false
    end
    return true
end

function refuel( ammount )
    local fuelLevel = turtle.getFuelLevel()
    if fuelLevel == "unlimited" then
        return true
    end

    local needed = ammount or (xPos + zPos + height + 2)
    if turtle.getFuelLevel() < needed then
        local fueled = false
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                turtle.select(n)
                if turtle.refuel(1) then
                    while turtle.getItemCount(n) > 0 and turtle.getFuelLevel() < needed do
                        turtle.refuel(1)
                    end
                    if turtle.getFuelLevel() >= needed then
                        turtle.select(1)
                        return true
                    end
                end
            end
        end
        turtle.select(1)
        return false
    end

    return true
end

local function tryForwards()
    if not refuel() then
        print( "Not enough Fuel" )
        returnSupplies()
    end

    while not turtle.forward() do
        if turtle.detect() then
            if turtle.dig() then
                if not collect() then
                    returnSupplies()
                end
            else
                return false
            end
        elseif turtle.attack() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.5 )
        end
    end

    xPos = xPos + xDir
    zPos = zPos + zDir
    return true
end

local function tryUp()
    if not refuel() then
        print( "Not enough Fuel" )
        returnSupplies()
    end

    while not turtle.up() do
        if turtle.detectUp() then
            if turtle.digUp() then
                if not collect() then
                    returnSupplies()
                end
            else
                return false
            end
        elseif turtle.attackUp() then
            if not collect() then
                returnSupplies()
            end
        else
            sleep( 0.5 )
        end
    end

    height = height + 1
    if math.fmod( height, 10 ) == 0 then
        print( "Ascended "..height.." metres." )
    end

    return true
end

local function turnLeft()
    turtle.turnLeft()
    xDir, zDir = -zDir, xDir
end

local function turnRight()
    turtle.turnRight()
    xDir, zDir = zDir, -xDir
end

function goTo( x, y, z, xd, zd )
    while height > y do
        if turtle.down() then
            height = height - 1
        elseif turtle.digDown() or turtle.attackDown() then
            collect()
        else
            sleep( 0.5 )
        end
    end

    if xPos > x then
        while xDir ~= -1 do
            turnLeft()
        end
        while xPos > x do
            if turtle.forward() then
                xPos = xPos - 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    elseif xPos < x then
        while xDir ~= 1 do
            turnLeft()
        end
        while xPos < x do
            if turtle.forward() then
                xPos = xPos + 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    end

    if zPos > z then
        while zDir ~= -1 do
            turnLeft()
        end
        while zPos > z do
            if turtle.forward() then
                zPos = zPos - 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    elseif zPos < z then
        while zDir ~= 1 do
            turnLeft()
        end
        while zPos < z do
            if turtle.forward() then
                zPos = zPos + 1
            elseif turtle.dig() or turtle.attack() then
                collect()
            else
                sleep( 0.5 )
            end
        end
    end

    while height < y do
        if turtle.up() then
            height = height + 1
        elseif turtle.digUp() or turtle.attackUp() then
            collect()
        else
            sleep( 0.5 )
        end
    end

    while zDir ~= zd or xDir ~= xd do
        turnLeft()
    end
end


-- Function to find nether ceiling first.
local function findCeiling()
    while turtle.detectUp() == false do
      if turtle.up() then
            height = height + 1
        end
    end
end

----
-- Lava Refuel Program (leftler's code)

local fuelReq = 93*size*size+93
local lavaBuckets = (fuelReq*0.001)*0.5

--Number of blocks to travel to get the lava
local maxDistance = math.ceil(lavaBuckets)+math.ceil(0.25*size)

--local counter for how far the turtle has travle
local traveled = 0

--A helper function to try and move up, it will attempt to dig if it is blocked.
local function moveUp()
  if turtle.up() == false then
    --Failed to move, see if we can dig our way down
    while turtle.digUp() do
          --Keep digging till we can't dig any more, in case gravel is falling.
        end
        if turtle.up() == false then
          print("I am either blocked or out of fuel.")
          return false
        end
  end
  return true
end

--A helper function to try and move forward, it will attempt to dig if it is blocked.
local function moveForward()
  if turtle.forward() == false then
    --Failed to move, see if we can dig our way forward
    while turtle.dig() do
          --Keep digging till we can't dig any more, in case gravel is falling.
        end
        if turtle.forward() == false then
          print("I am either blocked or out of fuel.")
          return false
        end
  end
  return true
end

------
-- Program Start
------

if turtle.refuel() == false then
  print("The turtle must have at least one lava bucket to start with.")
  return
elseif turtle.getFuelLevel() == "unlimited" then
  print("This turtle does not use fuel to move")
  return
end

for i = 1, maxDistance do
  if moveForward() == false then
    print("Could not move forward the full requested distance, starting U-Turn early.")
        break
  end
  traveled = traveled + 1

  --grab the fule
  turtle.placeDown()
  if turtle.refuel() == false then
    --Whatever we picked up is invalid for fuel, put it back down
    turtle.placeDown()
  end
end

--Turn around move a block over and get more lava
turtle.turnRight()
moveForward()
turtle.turnRight()

--Travel back the same number of blocks we came
for i = 1, traveled do
  turtle.placeDown()
  turtle.refuel()

  if moveForward() == false then
    --We are stuck, attempt to go up a level to get home
        if drop > 0 then
          repeat
            moveUp()
            drop = drop - 1
                lastMove = moveForward()
          until lastMove == true or drop == 0

          if lastMove == false then
            print("I am stuck!")
          end
        end
  end
end

turtle.turnRight()
moveForward()
turtle.turnRight()

print( "Finding ceiling... ")

findCeiling()

print( "Excavating..." )

local reseal = false
turtle.select(1)
if turtle.digUp() then
    reseal = true
end

local alternate = 0
local done = false
while not done do
    for n=1,size do
        for m=1,size-1 do
            if not tryForwards() then
                done = true
                break
            end
        end
        if done then
            break
        end
        if n<size then
            if math.fmod(n + alternate,2) == 0 then
                turnLeft()
                if not tryForwards() then
                    done = true
                    break
                end
                turnLeft()
            else
                turnRight()
                if not tryForwards() then
                    done = true
                    break
                end
                turnRight()
            end
        end
    end
    if done then
        break
    end

    if size > 1 then
        if math.fmod(size,2) == 0 then
            turnRight()
        else
            if alternate == 0 then
                turnLeft()
            else
                turnRight()
            end
            alternate = 1 - alternate
        end
    end

    if not tryUp() then
        done = true
        break
    end
end

print( "Returning to surface..." )

-- Return to where we started
goTo( 0,0,0,0,-1 )
unload( false )
goTo( 0,0,0,0,1 )

-- Seal the hole
if reseal then
    turtle.placeUp()
end

print( "Mined "..(collected + unloaded).." items total." )