require = requireInjector(getfenv(1))
local Point = require('point')

local checkedNodes = { }
local nodes = { }

local function addNode(node)

  local key = table.concat({ node.x, node.z }, ':')

  for i = 0, 3 do
    local hi = turtle.getHeadingInfo(i)
    local testNode = { x = node.x + hi.xd, z = node.z + hi.zd }

    key = table.concat({ testNode.x, testNode.z }, ':')
    if not checkedNodes[key] then
      nodes[key] = testNode
    end
  end
end

local function findObsidian()
  while true do
    local _,b = turtle.inspectDown()
    local node = { x = turtle.point.x, z = turtle.point.z }
    local key = table.concat({ node.x, node.z }, ':')

    checkedNodes[key] = true
    nodes[key] = nil

    if b and b.name == 'minecraft:obsidian' then
      turtle.digDown()
      addNode(node)
    end

    print(string.format('%d nodes remaining', Util.size(nodes)))

    if Util.size(nodes) == 0 then
      break
    end

    local node = Point.closest(turtle.point, nodes)
    if not turtle.gotoPoint(node) then
      break
    end

  end
end

turtle.reset()
turtle.setPolicy(turtle.policies.digOnly)
local s, m = turtle.run(function() findObsidian() end)
if not s and m then
  error(m)
end
turtle.goto(0, 0, 0, 0)
turtle.reset()