// STL 3D Preview for Forgejo
// Based on Codeberg's stlview.js implementation
// Uses Three.js r160 ESM modules

console.log("[stlview] Script loaded");

function updateLoading(text) {
  var el = document.getElementById('stl-loading');
  if (el) el.textContent = text;
}

(async function () {
  // Check if current page is an STL file view
  var path = window.location.pathname;
  if (!path.toLowerCase().endsWith(".stl")) {
    console.log("[stlview] Not an STL page, skipping");
    return;
  }
  console.log("[stlview] STL page detected:", path);

  // Build raw URL by replacing /src/ with /raw/
  var raw_url = path.replace(/\/src\//, '/raw/');
  console.log("[stlview] Raw URL:", raw_url);

  // Find the file content container to replace
  var container = document.querySelector('.file-view');
  if (!container) {
    console.log("[stlview] No .file-view container found, trying alternatives...");
    container = document.querySelector('.non-diff-file-content .ui.bottom.attached.segment');
  }
  if (!container) {
    console.error("[stlview] No suitable container found to inject viewer");
    return;
  }
  console.log("[stlview] Found container:", container.className);

  // Remove stl-page CSS class (hides raw content / shows ::before loading message)
  document.documentElement.classList.remove('stl-page');
  container.innerHTML = '<div id="stl-loading" style="padding:3em;text-align:center;color:#888;font-size:1.2em">Loading 3D view\u2026</div>';

  try {
    console.log("[stlview] Loading Three.js modules...");
    var THREE = await import("./three.js/build/three.module.min.js");
    var STL = await import("./three.js/examples/jsm/loaders/STLLoader.js");
    var TBC = await import("./three.js/examples/jsm/controls/TrackballControls.js");
    console.log("[stlview] Three.js modules loaded successfully");
    updateLoading("Loading 3D model\u2026");

    var GL = new THREE.WebGLRenderer({ antialias: true, alpha: true });
    if (!GL) {
      console.error("[stlview] Failed initializing WebGL");
      return;
    }
    console.log("[stlview] WebGL renderer created");

    console.log("[stlview] Loading STL model from:", raw_url);
    (new STL.STLLoader()).load(raw_url, function (geometry) {
      console.log("[stlview] STL model loaded, vertices:", geometry.attributes.position.count);
      var center = new THREE.Vector3();
      var scene = new THREE.Scene();

      scene.background = new THREE.Color(0x72645b);

      var material = undefined;
      if (geometry.hasColors) {
        material = new THREE.MeshPhongMaterial({ opacity: geometry.alpha, vertexColors: true });
      } else {
        material = new THREE.MeshPhongMaterial({ color: 0xf0cc33, specular: 200, shininess: 50 });
      }

      geometry.computeBoundingBox();
      geometry.boundingBox.getCenter(center);
      var largestDimension = Math.max(
        geometry.boundingBox.max.x - geometry.boundingBox.min.x,
        geometry.boundingBox.max.y - geometry.boundingBox.min.y,
        geometry.boundingBox.max.z - geometry.boundingBox.min.z
      );
      console.log("[stlview] Bounding box largest dimension:", largestDimension);

      var mesh = new THREE.Mesh(geometry, material);
      mesh.position.x = -center.x;
      mesh.position.y = -center.y;
      mesh.position.z = -center.z;
      mesh.castShadow = true;
      mesh.receiveShadow = true;
      scene.add(mesh);

      scene.add(new THREE.HemisphereLight(0x404040, 0x111122));
      addShadowedLight(1000, 1000, 1000, 0xffffcc, 0.6);
      addShadowedLight(-1000, 1000, -1000, 0xffffcc, 0.8);
      addShadowedLight(-1000, -1000, 1000, 0xffffcc, 0.6);
      GL.shadowMap.enabled = true;

      var width = container.clientWidth;
      var height = window.innerHeight;
      console.log("[stlview] Renderer size:", width, "x", height);

      GL.setSize(width, height);
      GL.setPixelRatio(window.devicePixelRatio);

      var camera = new THREE.PerspectiveCamera(45, width / height, 0.01 * largestDimension, 100 * largestDimension);
      var controls = new TBC.TrackballControls(camera, container);
      controls.dynamicDampingFactor = 0.1;
      controls.target.set(0, 0, 0);

      window.addEventListener('resize', function () {
        GL.setSize(container.clientWidth, container.clientHeight);
        camera.aspect = container.clientWidth / container.clientHeight;
        camera.updateProjectionMatrix();
        controls.handleResize();
      }, false);

      camera.position.z = largestDimension * 1.5;
      controls.update();

      function reset() {
        controls.reset();
        camera.position.z = largestDimension * 1.5;
        animate();
      }

      container.addEventListener("dblclick", function (e) {
        reset();
      });

      var timeout = null;
      container.addEventListener('touchend', function (e) {
        if (e.touches.length > 0)
          return;
        if (timeout) {
          clearTimeout(timeout);
          timeout = null;
          reset();
          e.preventDefault();
        } else {
          timeout = setTimeout(function () { clearTimeout(timeout); timeout = null; }, 500);
        }
      });

      function animate() {
        requestAnimationFrame(animate);
        controls.update();
        GL.render(scene, camera);
      }
      // Replace loading indicator with the canvas
      container.innerHTML = '';
      container.appendChild(GL.domElement);
      GL.domElement.style.width = '100%';
      GL.domElement.style.height = '100%';

      animate();
      console.log("[stlview] Viewer ready");

      function addShadowedLight(x, y, z, color, intensity) {
        var directionalLight = new THREE.DirectionalLight(color, intensity);
        var d = 1;
        directionalLight.position.set(x, y, z);
        directionalLight.castShadow = true;
        directionalLight.shadow.camera.left = -d;
        directionalLight.shadow.camera.right = d;
        directionalLight.shadow.camera.top = d;
        directionalLight.shadow.camera.bottom = -d;
        directionalLight.shadow.camera.near = 1;
        directionalLight.shadow.camera.far = 4;
        directionalLight.shadow.bias = -0.002;
        scene.add(directionalLight);
      }
    }, function (progress) {
      if (progress.total) {
        var pct = Math.round(progress.loaded / progress.total * 100);
        console.log("[stlview] Loading progress:", pct + "%");
        updateLoading("Loading 3D model\u2026 " + pct + "%");
      }
    }, function (error) {
      console.error("[stlview] Failed to load STL model:", error);
      updateLoading("Failed to load 3D model.");
    });
  } catch (error) {
    console.error("[stlview] Error creating viewer:", error);
    updateLoading("Error loading 3D viewer.");
  }
})();