(function() {
  // --- Outer scope variables for camera state ---
  let cameraInstance = null;
  let controlsInstance = null;
  let initialCameraPosition = null;
  let initialCameraRotation = null;
  
  // Generate a unique identifier for this widget instance.
  const instanceId = Math.random().toString(36).substr(2, 8);

  // Helper: Get query parameters from THIS script’s src URL.
  function getScriptQueryParam(param) {
    var params = new URLSearchParams("");
    if (document.currentScript && document.currentScript.src.indexOf('?') !== -1) {
      var queryString = document.currentScript.src.split('?')[1];
      params = new URLSearchParams(queryString);
    } else {
      params = new URLSearchParams(window.location.search);
    }
    return params.get(param);
  }

  // Read required URLs.
  var gifUrl = getScriptQueryParam("gif_url");
  var plyUrl = getScriptQueryParam("ply_url");

  // Determine the aspect ratio.
  // Default aspect: 1:1 (i.e. 100% padding-bottom)
  var aspectPercent = "100%";
  var aspectParam = getScriptQueryParam("aspect");
  if (aspectParam) {
    // Expected format: "width:height" (e.g. "16:9") or a decimal number.
    if (aspectParam.indexOf(":") !== -1) {
      var parts = aspectParam.split(":");
      var w = parseFloat(parts[0]);
      var h = parseFloat(parts[1]);
      if (!isNaN(w) && !isNaN(h) && w > 0) {
        aspectPercent = (h / w * 100) + "%";
      }
    } else {
      var aspectValue = parseFloat(aspectParam);
      if (!isNaN(aspectValue) && aspectValue > 0) {
        aspectPercent = (100 / aspectValue) + "%";
      }
    }
  } else {
    // If no aspect parameter is provided, compute the aspect ratio from the parent element.
    var parentContainer = document.currentScript.parentNode;
    var containerWidth = parentContainer.offsetWidth;
    var containerHeight = parentContainer.offsetHeight;
    if (containerWidth > 0 && containerHeight > 0) {
      aspectPercent = (containerHeight / containerWidth * 100) + "%";
    }
  }

  // Optional parameters for zoom and rotation limits.
  // Defaults: zoom from 0 to 20; rotation from 0 to 360.
  var minZoom = parseFloat(getScriptQueryParam("minZoom") || "0");
  var maxZoom = parseFloat(getScriptQueryParam("maxZoom") || "20");
  var minAngle = parseFloat(getScriptQueryParam("minAngle") || "0");
  var maxAngle = parseFloat(getScriptQueryParam("maxAngle") || "360");

  // Detect if the device is iOS.
  var isIOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;

  // Inject CSS styles into the document head, scoped with the unique id.
  var styleEl = document.createElement('style');
  styleEl.textContent = `
    /* Widget container styling */
    #ply-widget-container-${instanceId} {
      position: relative;
      width: 100%;
      height: 0;
      padding-bottom: ${aspectPercent};
    }
    /* When in fake fullscreen mode (iOS fallback) */
    #ply-widget-container-${instanceId}.fake-fullscreen {
      position: fixed !important;
      top: 0 !important;
      left: 0 !important;
      width: 100vw !important;
      height: 100vh !important;
      padding-bottom: 0 !important;
      z-index: 9999 !important;
    }
    /* GIF Preview styling */
    #gif-preview-container-${instanceId} {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      border: 1px solid #474558;
      border-radius: 10px;
      overflow: hidden;
      cursor: pointer;
    }
    #gif-preview-container-${instanceId} img {
      width: 100%;
      height: 100%;
      object-fit: cover;
    }
    /* Viewer Container styling */
    #viewer-container-${instanceId} {
      display: none;
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: #FEFEFD;
      border: 1px solid #474558;
      border-radius: 10px;
    }
    /* Canvas fills the viewer container */
    #canvas-${instanceId} {
      width: 100%;
      height: 100%;
      display: block;
    }
    /* Progress dialog styling (as a centered div) */
    #progress-dialog-${instanceId} {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      border: none;
      background: rgba(255,255,255,0.9);
      padding: 20px;
      border-radius: 5px;
      z-index: 1000;
      display: none;
    }
    /* Menu (instructions) content styling */
    #menu-content-${instanceId} {
      display: none;
      position: absolute;
      top: 62px;
      right: 70px;
      background: #FFFEF4;
      border: 1px solid #474558;
      border-radius: 5px;
      padding: 10px;
      font-size: 15px;
      line-height: 1.4;
      color: #474558;
    }
    /* Button styling */
    .widget-button {
      position: absolute;
      width: 45px;
      height: 45px;
      background-color: #FFFEF4;
      border: 1px solid #474558;
      border-radius: 50%;
      cursor: pointer;
      font-size: 14px;
      color: #474558;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    /* Positions: Close at top-left, fullscreen at top-right, help (instructions) below fullscreen */
    #close-btn-${instanceId} {
      top: 17px;
      left: 15px;
    }
    #fullscreen-toggle-${instanceId} {
      top: 17px;
      right: 15px;
    }
    #help-toggle-${instanceId} {
      top: 72px;
      right: 15px;
    }
    /* Reset Camera Button below the help button */
    #reset-camera-btn-${instanceId} {
      top: 127px;
      right: 15px;
    }
    /* Adjust the reset icon position within the reset camera button */
    .reset-icon {
      display: inline-block;
      transform: translateY(-3px);
    }
  `;
  document.head.appendChild(styleEl);

  // Create the widget container and set its inner HTML.
  var widgetContainer = document.createElement('div');
  widgetContainer.id = 'ply-widget-container-' + instanceId;
  widgetContainer.innerHTML = `
    <!-- GIF Preview Container -->
    <div id="gif-preview-container-${instanceId}">
      <img id="preview-image-${instanceId}" alt="Preview" crossorigin="anonymous">
    </div>
    <!-- Viewer Container -->
    <div id="viewer-container-${instanceId}">
      <canvas id="canvas-${instanceId}"></canvas>
      <div id="progress-dialog-${instanceId}">
        <progress id="progress-indicator-${instanceId}" max="100" value="0"></progress>
      </div>
      <button id="close-btn-${instanceId}" class="widget-button">X</button>
      <button id="fullscreen-toggle-${instanceId}" class="widget-button">⇱</button>
      <button id="help-toggle-${instanceId}" class="widget-button">?</button>
      <button id="reset-camera-btn-${instanceId}" class="widget-button">
        <span class="reset-icon">🗘</span>
      </button>
      <div id="menu-content-${instanceId}">
        - Rotate with right click<br>
        - Zoom in/out with middle click<br>
        - Translate with left click
      </div>
    </div>
  `;
  document.currentScript.parentNode.appendChild(widgetContainer);

  // Grab element references using the unique IDs.
  var gifPreview = document.getElementById('gif-preview-container-' + instanceId);
  var viewerContainer = document.getElementById('viewer-container-' + instanceId);
  var previewImage = document.getElementById('preview-image-' + instanceId);
  var closeBtn = document.getElementById('close-btn-' + instanceId);
  var fullscreenToggle = document.getElementById('fullscreen-toggle-' + instanceId);
  var helpToggle = document.getElementById('help-toggle-' + instanceId);
  var resetCameraBtn = document.getElementById('reset-camera-btn-' + instanceId);
  var menuContent = document.getElementById('menu-content-' + instanceId);
  var canvas = document.getElementById('canvas-' + instanceId);
  var progressDialog = document.getElementById('progress-dialog-' + instanceId);
  var progressIndicator = document.getElementById('progress-indicator-' + instanceId);

  // Set the preview image if provided.
  if (gifUrl) {
    previewImage.src = gifUrl;
  }

  // --- Button Event Handlers ---

  gifPreview.addEventListener('click', function() {
    gifPreview.style.display = 'none';
    viewerContainer.style.display = 'block';
    initializeViewer();
  });

  closeBtn.addEventListener('click', function() {
    if (document.fullscreenElement === widgetContainer) {
      if (document.exitFullscreen) {
        document.exitFullscreen();
      }
    }
    widgetContainer.classList.remove('fake-fullscreen');
    viewerContainer.style.display = 'none';
    gifPreview.style.display = 'block';
  });

  fullscreenToggle.addEventListener('click', function() {
    if (isIOS) {
      if (!widgetContainer.classList.contains('fake-fullscreen')) {
        widgetContainer.classList.add('fake-fullscreen');
      } else {
        widgetContainer.classList.remove('fake-fullscreen');
      }
      fullscreenToggle.textContent = widgetContainer.classList.contains('fake-fullscreen') ? '⇲' : '⇱';
    } else {
      if (!document.fullscreenElement) {
        if (widgetContainer.requestFullscreen) {
          widgetContainer.requestFullscreen();
        } else if (widgetContainer.webkitRequestFullscreen) {
          widgetContainer.webkitRequestFullscreen();
        } else if (widgetContainer.mozRequestFullScreen) {
          widgetContainer.mozRequestFullScreen();
        } else if (widgetContainer.msRequestFullscreen) {
          widgetContainer.msRequestFullscreen();
        }
      } else {
        if (document.exitFullscreen) {
          document.exitFullscreen();
        }
      }
    }
  });

  document.addEventListener('fullscreenchange', function() {
    if (document.fullscreenElement === widgetContainer) {
      fullscreenToggle.textContent = '⇲';
    } else {
      fullscreenToggle.textContent = '⇱';
    }
  });

  helpToggle.addEventListener('click', function(e) {
    e.stopPropagation();
    menuContent.style.display = (menuContent.style.display === 'block') ? 'none' : 'block';
  });

  resetCameraBtn.addEventListener('click', function() {
    console.log("Reset camera button clicked.");
    if (cameraInstance && initialCameraPosition && initialCameraRotation) {
      cameraInstance.position = initialCameraPosition.clone();
      cameraInstance.rotation = initialCameraRotation.clone();
      if (typeof cameraInstance.update === 'function') {
        cameraInstance.update();
      }
      if (controlsInstance && typeof controlsInstance.update === 'function') {
        controlsInstance.update();
      }
    }
  });

  // --- Initialize the 3D PLY Viewer ---
  async function initializeViewer() {
    const SPLAT = await import("https://cdn.jsdelivr.net/npm/gsplat@latest");
    progressDialog.style.display = 'block';
    const renderer = new SPLAT.WebGLRenderer(canvas);
    const scene = new SPLAT.Scene();
    const camera = new SPLAT.Camera();
    const controls = new SPLAT.OrbitControls(camera, canvas);

    cameraInstance = camera;
    controlsInstance = controls;
    initialCameraPosition = camera.position.clone();
    initialCameraRotation = camera.rotation.clone();

    canvas.style.background = "#FEFEFD";
    controls.maxZoom = maxZoom;
    controls.minZoom = minZoom;
    controls.minAngle = minAngle;
    controls.maxAngle = maxAngle;

    controls.update();

    try {
      await SPLAT.PLYLoader.LoadAsync(
        plyUrl,
        scene,
        (progress) => {
          progressIndicator.value = progress * 100;
        }
      );
      progressDialog.style.display = 'none';
    } catch (error) {
      console.error("Error loading PLY file:", error);
      progressDialog.innerHTML = `<p style="color: red">Error loading model: ${error.message}</p>`;
    }

    const frame = () => {
      controls.update();
      renderer.render(scene, camera);
      requestAnimationFrame(frame);
    };

    const handleResize = () => {
      renderer.setSize(canvas.clientWidth, canvas.clientHeight);
    };

    handleResize();
    window.addEventListener("resize", handleResize);
    requestAnimationFrame(frame);
  }
})();