Mine opti v1.1

function select_fuel()
    local slot = 1
    local data = turtle.getItemDetail(slot)

  if select_item("minecraft:lava_bucket") then
    return true
  end
    while slot <= 16 do
        if data and (data.name == "minecraft:coal" or data.name == "minecraft:planks" or data.name == "minecraft:log"or data.name == "minecraft:stick") then
            break
        end
        slot = slot + 1
        if slot <= 16 then
            turtle.select(slot)
            data = turtle.getItemDetail(slot)
        end
    end
    if (slot > 16) then
        return false
    end
    turtle.select(slot)
  return true
end

function check_fuel()
    select_fuel()
    if turtle.getFuelLevel() < 1000 then
        while turtle.refuel(1) == false do
            print("No fuel available. Retrying refuel in 10 seconds")
            sleep(10)
        end
    end
end

function avance(x)
    while x > 0 do
    if quick_inspect("front") == "minecraft:lava" or quick_inspect("front") == "minecraft:flowing_lava" then
      search_and_fill_lava()
    end
        while turtle.forward() == false do
            check_fuel()
      search_and_mine_ore()
            turtle.dig()
        end
        x = x - 1
    end
end

function line(maxx, maxz)
    local z = 0
    while z <= maxz do
        avance(maxx)
        turtle.turnLeft()
        turtle.turnLeft()
        avance(maxx)
        turtle.turnRight()
        turtle.turnRight()
        while turtle.up() == false do
            check_fuel()
            turtle.digUp()
        end
        z = z + 1
    end
    while z > 0 do
        while turtle.down() == false do
            check_fuel()
            turtle.digDown()
        end
        z = z - 1
    end
end

function select_item(item)
    local slot = 1

    while slot <= 16 do
        local data = turtle.getItemDetail(slot)
        if data and data.name == item then
            turtle.select(slot)
            return true
        end
        slot = slot + 1
    end
    return false
end

function search_bloc(bloc)
  if quick_inspect("up") == bloc then return "up"
  elseif quick_inspect("front") == bloc then return "front"
  elseif quick_inspect("down") == bloc then return "down"
  end
  turtle.turnLeft()
  if quick_inspect("front") == bloc then
    turtle.turnRight()
    return "left"
  end
  turtle.turnRight()
  turtle.turnRight()
  if quick_inspect("front") == bloc then
    turtle.turnLeft()
    return "right"
  end
  turtle.turnLeft()
  return "none"
end

function quick_inspect(direction)
  local success = false
  local data

  if direction == "up" then success, data = turtle.inspectUp()
  elseif direction == "front" then success, data = turtle.inspect()
  elseif direction == "down" then success, data = turtle.inspectDown()
  end
  if success then
    return data.name
  else
    return "none"
  end
end


function search_and_fill_lava()
  local direction = search_bloc("minecraft:lava")

  if direction ~= "none" and select_item("minecraft:lava_bucket") then
    turtle.refuel()
  end
  if direction ~= "none" and select_item("minecraft:bucket") then
    if direction == "up" then turtle.placeUp()
    elseif direction == "down" then turtle.placeDown()
    elseif direction == "left" then
      turtle.turnLeft()
      turtle.place()
      turtle.turnRight()
    elseif direction == "right" then
      turtle.turnRight()
      turtle.place()
      turtle.turnLeft()
    elseif direction == "front" then
      turtle.place()
    end
  end
end


function search_and_mine_ore()
  if  quick_inspect("up") == "minecraft:iron_ore" or
      quick_inspect("up") == "minecraft:gold_ore" or
      quick_inspect("up") == "minecraft:diamond_ore" or
      quick_inspect("up") == "minecraft:emerald_ore" or
      quick_inspect("up") == "minecraft:lapis_ore" or
      quick_inspect("up") == "minecraft:redstone_ore" or
      quick_inspect("up") == "minecraft:coal_ore" then
    turtle.digUp()
    return "up"
  elseif  quick_inspect("front") == "minecraft:iron_ore" or
          quick_inspect("front") == "minecraft:gold_ore" or
          quick_inspect("front") == "minecraft:diamond_ore" or
          quick_inspect("front") == "minecraft:emerald_ore" or
          quick_inspect("front") == "minecraft:lapis_ore" or
          quick_inspect("front") == "minecraft:redstone_ore" or
          quick_inspect("front") == "minecraft:coal_ore" then
    turtle.dig()
    return "front"
  elseif  quick_inspect("") == "minecraft:iron_ore" or
          quick_inspect("down") == "minecraft:gold_ore" or
          quick_inspect("down") == "minecraft:diamond_ore" or
          quick_inspect("down") == "minecraft:emerald_ore" or
          quick_inspect("down") == "minecraft:lapis_ore" or
          quick_inspect("down") == "minecraft:redstone_ore" or
          quick_inspect("down") == "minecraft:coal_ore" then
    turtle.digDown()
    return "down"
  end
  turtle.turnLeft()
  if  quick_inspect("front") == "minecraft:iron_ore" or
      quick_inspect("front") == "minecraft:gold_ore" or
      quick_inspect("front") == "minecraft:diamond_ore" or
      quick_inspect("front") == "minecraft:emerald_ore" or
      quick_inspect("front") == "minecraft:lapis_ore" or
      quick_inspect("front") == "minecraft:redstone_ore" or
      quick_inspect("front") == "minecraft:coal_ore" then
    turtle.dig()
    return "left"
  end
  turtle.turnRight()
  turtle.turnRight()
  if  quick_inspect("front") == "minecraft:iron_ore" or
      quick_inspect("front") == "minecraft:gold_ore" or
      quick_inspect("front") == "minecraft:diamond_ore" or
      quick_inspect("front") == "minecraft:emerald_ore" or
      quick_inspect("front") == "minecraft:lapis_ore" or
      quick_inspect("front") == "minecraft:redstone_ore" or
      quick_inspect("front") == "minecraft:coal_ore" then
    turtle.dig()
    return "right"
  end
  turtle.turnLeft()
  return "none"
end
function is_inventory_full()
  local slot = 1

  while slot <= 16 do
    if not turtle.getItemDetail(slot) then
      return false
    end
    slot = slot + 1
  end
  return true
end

function drop_all_shit()
  local slot = 1
  local data

  while slot <= 16 do
    data = turtle.getItemDetail(slot)
    if data and (data.name == "minecraft:cobblestone" or data.name == "minecraft:granite" or data.name == "minecraft:diorite" or data.name == "minecraft:andesite" or data.name == "minecraft:gravel" or data.name == "minecraft:dirt") then
      turtle.select(slot)
      turtle.drop()
    end
    slot = slot + 1
  end
end
function go_drop_ores(xbase, ybase, zbase)
  local x, y, z = secure_gps()

  goto_coordinates(xbase, ybase, zbase)
  wait_chest()
  drop_all_non_fuel()
  goto_coordinates(x, y, z)
end
function drop_all_non_fuel()
  local slot = 1
  local data

  while slot <= 16 do
    data = turtle.getItemDetail(slot)
    if  data and data.name ~= "minecraft:coal" and
        data.name ~= "minecraft:planks" and
        data.name ~= "minecraft:log"and
        data.name ~= "minecraft:stick" then
      turtle.select(slot)
      turtle.dropDown()
    end
    slot = slot + 1
  end
end
function wait_chest()
  while quick_inspect("down") ~= "minecraft:chest" do
    print("Waiting for chest bottom me. Retrying in 20 secs")
    sleep(20)
  end
end
function secure_gps()
  local x, y, z = gps.locate()
  local i = 0

  while not x do
    print("Can't communicate with GPS. Retrying in 10 seconds. I will shutdown after 50 try")
    x, y, z = gps.locate()
    i = i + 1
    if i >= 50 then os.shutdown() end
  end
  return x, y, z
end

function goto_coordinates(x, y, z)
  local xn, yn, zn = secure_gps()

  look_at_north(xn, zn)
  xn, yn, zn = secure_gps()
  if (z - zn) < 0 then
    turtle.turnLeft()
    turtle.turnLeft()
    avance(abs(z - zn))
    turtle.turnRight()
    turtle.turnRight()
  else
    avance(abs(z - zn))
  end
  if (x - xn) < 0 then
    turtle.turnLeft()
  elseif (x - xn) > 0 then
    turtle.turnRight()
  end
  avance(abs(x - xn))
  if (z - zn) < 0 then
    descend(abs(z - zn))
  elseif (z - zn) > 0 then
    ascend(abs(z - zn))
  end
end
function look_at_north(x, z)
  local xn, yn, zn

    if turtle.detect() then
        check_fuel()
        while not turtle.back() do
            check_fuel()
        end
        xn, yn, zn = get_coords()
        if x > xn then turtle.turnRight()
        elseif x < xn then turtle.turnLeft()
        elseif z < zn then
            turtle.turnLeft()
            turtle.turnLeft()
        end
        return true
    end
    check_avance()
    xn, yn, zn = get_coords()
    if x < xn then turtle.turnRight()
    elseif x > xn then turtle.turnLeft()
    elseif z > zn then
        turtle.turnLeft()
        turtle.turnLeft()
    end
    return true
end
function abs(x)
  if x < 0 then return -x end return x
end


function move_to_direction(direction)
  if direction == "front" then avance(1)
  elseif direction == "back" then
    turtle.turnLeft()
    turtle.turnLeft()
    avance(1)
    turtle.turnLeft()
    turtle.turnLeft()
  elseif direction == "left" then
    turtle.turnLeft()
    avance(1)
    turtle.turnRight()
  elseif direction == "right" then
    turtle.turnRight()
    avance(1)
    turtle.turnLeft()
  elseif direction == "down" then
    descend(1)
  elseif direction == "up" then
    ascend(1)
  end
end
function descend(max)
  local i = 0

  while i < max do
    if turtle.down() == false then
      check_fuel()
      turtle.digDown()
    else
      i = i + 1
    end
  end
end
function ascend(max)
  local i = 0

  while i < max do
    if turtle.up() == false then
      check_fuel()
      turtle.digUp()
    else
      i = i + 1
    end
  end
end

function check_inventory(x, y, z)
  if is_inventory_full() then
    go_drop_ores(x, y, z)
  end
end
local xhome, yhome, zhome = secure_gps()

print("Don't forget to put chest bottom me before I start !")
io.write("Nbr of blocs to mine in front of: ")
local maxx = tonumber(read())
io.write("Nbr of blocs to mine at right: ")
local maxz = tonumber(read())
io.write("Nbr of blocs to mine at top: ")
local maxy = tonumber(read())
local z = 0
while z < maxz do
    line(maxx, maxy)
  drop_all_shit()
  check_inventory()
    turtle.turnRight()
    line(3, maxy)
    avance(4)
    turtle.turnLeft()
    z = z + 3
end