miner

local CIDFile = "/.cid";
local locFile = "/.minerLocation";
local controllerID = nil;
local currentChunk = 1;
local offset = 0;
local mineFacing = 0;
local importantDir = "";

-- load cID
if fs.exists(CIDFile) then
  local f = fs.open(CIDFile,"r");
  controllerID = tonumber(f.readLine());
  f.close();
end

if fs.exists(locFile) then
  local f = fs.open(locFile,"r");
  currentChunk = tonumber(f.readLine());
  offset = tonumber(f.readLine());
  mineFacing = tonumber(f.readLine());
  importantDir = f.readLine();
  f.close();

  -- we're resuming. Get set up.
  -- Get to the travel y...
  while t.getPos().y < 80 do
    t.up();
  end
  -- Face the right way
  while mineFacing ~= t.getPos().f do
    t.turnLeft();
  end
  -- and move back to the previous mining position
  local out = 5 - ((t.getPos()[importantDir] - offset) % 5);
  if out > 0 and out < 5 then
    t.backward(out);
  end
else
  -- first run, do setup
  -- Which direction do we care about?
  local f = t.getPos().f;
  local dir;
  if f == 0 or f == 2 then
    dir = "z";
  else
    dir = "x";
  end
  importantDir = dir;

  -- Math out the values we need
  currentChunk = math.floor(t.getPos()[dir] / 16);
  offset = t.getPos()[dir] % 5;
  mineFacing = t.getPos().f;
  local f = fs.open(locFile,"w");
  f.writeLine(currentChunk);
  f.writeLine(offset);
  f.writeLine(mineFacing);
  f.writeLine(importantDir);
  f.close();
end

function ready()
  local packet = {
    ['type'] = "ROUTED_PACKET",
    ['src']  = os.getComputerID(),
    ['dest'] = controllerID or rednet.CHANNEL_BROADCAST,
    ['data'] = "ready"
  }
  print("Send to " .. packet.dest);
  rednet.sendPacket(packet);

  local recvd = false;
  local timer = os.startTimer(5);
  while true do
    local evt = {os.pullEvent()};
    if evt[1] == "timer" and evt[2] == timer then
      timer = os.startTimer(5);
      if not recvd then
      print("resend");
        rednet.sendPacket(packet);
      end
    end
    if evt[1] == "packet_recv" then
      if evt[2].type == "ACK" and evt[2].dest == os.getComputerID() then
        recvd = true;
        controllerID = evt[2].src;
        local f = fs.open(CIDFile,"w");
        f.writeLine(controllerID);
        f.close();
      end
      if evt[2].type == "ROUTED_PACKET" and evt[2].data == "mine" and evt[2].src == controllerID then
        local resp = {
          ['type'] = "ACK",
          ['src']  = os.getComputerID(),
          ['dest'] = controllerID,
          ['data'] = "mine"
        }
        print("Sending ack for mine");
        rednet.sendPacket(resp);
        return;
      end
    end
  end
end


local fwd = 0;
function mine()
  local depth = 0;
  while t.down(1, true) do
    depth = depth + 1;
    t.dig();
    t.turnLeft();
    t.dig();
    t.turnLeft();
    t.dig();
    t.turnLeft();
    t.dig();
    t.turnLeft();
  end
  t.up(depth);
  t.forward(5);
  local cChunk = math.floor(t.getPos()[importantDir] / 16);
  if cChunk > currentChunk then
    local f = fs.open(locFile,"w");
    f.writeLine(cChunk);
    f.writeLine(offset);
    f.writeLine(mineFacing);
    f.writeLine(importantDir);
    f.close();
    return;
  end
end

while true do
  ready();
  mine();
end