!752

p {
  serveHttp(7799);
}

static int lastImageSize;
static RGBImage lastImage;
static S lastImageID;
static BufferedImage diff;

// TODO: better auth check
static synchronized NanoHTTPD.Response serve(S uri, NanoHTTPD.Method method,
  Map<S,S> header, Map<S,S> parms, Map<S,S> files) ctex {
  
  if (eq(uri, "/favicon.ico")) ret serveHTML(""); // who cares
  
  S pw = trim(loadSecretTextFile("vnc-pw"));
  if (nempty(pw))
    assertEq(pw, parms.get("pw"));
  
  if (eq(uri, "/mouse")) {
    int x = toInt(parms.get("x"));
    int y = toInt(parms.get("y"));
    S type = parms.get("type");
    print("Mouse event! " + type + " " + x + " " + y);
    
    new Robot robot;
    robot.mouseMove(x, y);
    if (eq(type, "down"))
      robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
    else if (eq(type, "up")) {
      sleepSeconds(0.1);
      robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
    }
      
    ret serveHTML("");
  }
  
  if (eq(uri, "/diff.png")) {
    byte[] data = convertToPNG(diff);
    ret NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Status.OK,
      "image/png", new ByteArrayInputStream(data),
      l(data));
  }
  
  if (eq(uri, "/image.png")) {
    BufferedImage img = shootScreen2();
    lastImage = new RGBImage(img);
    lastImageID = randomID(10);
    byte[] data = convertToPNG(img);
    lastImageSize = l(data);
    ret NanoHTTPD.newFixedLengthResponse(NanoHTTPD.Status.OK,
      "image/png", new ByteArrayInputStream(data),
      l(data));
  }
  
  if (eq(uri, "/diff")) {
    S lastID = parms.get("lastid");
    if (eq(lastID, lastImageID)) {
      // todo: serve diff
      BufferedImage img = shootScreen2();
      RGBImage image = new RGBImage(img);
      Rectangle r = findDiffArea(lastImage, image);
      if (r.width <= 0 && r.height <= 0)
        ret serveHTML("no change");
        
      diff = image.clip(r).getBufferedImage();
      lastImage = image;
      lastImageID = randomID(10);
      ret serveHTML(r.x + " " + r.y + " " + r.width + " " + r.height + lastImageID);
    }
    ret serveHTML("full");
  }
  
  print("Serving HTML.");
  S html = htitle("Mini-VNC") +
    hjavascript([[
    function httpGetAsync(theUrl, callback) {
      var xmlHttp = new XMLHttpRequest();
      xmlHttp.onreadystatechange = function() { 
          if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
              if (callback != null)
                callback(xmlHttp.responseText);
      }
      xmlHttp.open("GET", theUrl, true); // true for asynchronous 
      xmlHttp.send(null);
    }

    function FindPosition(oElement) {
      if (typeof(oElement.offsetParent) != "undefined") {
        for(var posX = 0, posY = 0; oElement; oElement = oElement.offsetParent) {
          posX += oElement.offsetLeft;
          posY += oElement.offsetTop;
        }
        return [ posX, posY ];
      } else {
        return [ oElement.x, oElement.y ];
      }
    }
    
    function sendMouse(e, type) {
      var PosX = 0;
      var PosY = 0;
      var ImgPos;
      ImgPos = FindPosition(myImg);
      if (!e) var e = window.event;
      if (e.pageX || e.pageY) {
        PosX = e.pageX;
        PosY = e.pageY;
      } else if (e.clientX || e.clientY) {
        PosX = e.clientX + document.body.scrollLeft
          + document.documentElement.scrollLeft;
        PosY = e.clientY + document.body.scrollTop
          + document.documentElement.scrollTop;
      }
      PosX = PosX - ImgPos[0];
      PosY = PosY - ImgPos[1];
      
      httpGetAsync("/mouse?pw=$PW$&type=" + type + "&x=" + PosX + "&y=" + PosY, null);
      
      if (type == "up")
        setTimeout(function() {
          thescreen.src = "image.png?pw=$PW$&_=" + new Date().getTime();
        }, 1000);
      
      //document.getElementById("y").innerHTML = PosY;
    }
    ]].replace("$PW$", urlencode(pw)))
    + himg("image.png?pw=" + urlencode(pw), "id", "thescreen")
    + hjavascript([[
      var myImg = document.getElementById("thescreen");
      myImg.ondragstart = function() { return false; };
      //myImg.onmouseover = GetCoordinates;
      myImg.onmousemove = function(e) {};
      myImg.onmousedown = function(e) { sendMouse(e, "down"); };
      myImg.onmouseup = function(e) { sendMouse(e, "up"); };
    ]])
    + (lastImageSize == 0 ? "" : "<br><br>Last image size: " + toK(lastImageSize) + "K");
  ret serveHTML(html);
}

static Rectangle findDiffArea(RGBImage a, RGBImage b) {
  int w = a.getWidth(), h = a.getHeight();
  int x1 = 0, y1 = 0, x2 = w, y2 = h;
  
  // left side
  
  out0: while (x1 < x2) {
    for (int y=y1; y < y2; y++)
      if (different(a, b, x1, y)) break out0;
    ++x1;
  }

  // top side

  out1: while (y1 < y2) {
    for (int x=x1; x < x2; x++)
      if (different(a, b, x, y1)) break out1;
    ++y1;
  }

  // right side
  
  out2: while (x2 > x1) {
    for (int y=y1; y < y2; y++)
      if (different(a, b, x2-1, y)) break out2;
    --x2;
  }

  // bottom side
  
  out3: while (y2 > y1) {
    for (int x=x1; x < x2; x++)
      if (different(a, b, x, y2-1)) break out3;
    --y2;
  }
  
  ret new Rectangle(x1, y1, x2-x1, y2-y1);
}

static bool different(RGBImage a, RGBImage b, int x, int y) {
  ret a.getInt(x, y) != b.getInt(x, y);
}