Resolve PDF viewer issues

try {
  const instance = await NutrientViewer.load({
    container: "#pspdfkit",
    document: "document.pdf",
    licenseKey: "YOUR_LICENSE_KEY"
  });
  console.log("Viewer loaded successfully");
} catch (error) {
  console.error("Failed to load viewer:", error.message);

  // Check for specific error types.
  if (error.message.includes("container")) {
    console.error("Container element not found. Ensure the element exists in the DOM.");
  } else if (error.message.includes("document")) {
    console.error("Document could not be loaded. Check the file path and format.");
  } else if (error.message.includes("network")) {
    console.error("Network error. Check your internet connection and server status.");
  }
}

// Diagnose CORS issues.
async function loadWithCORSDiagnostics() {
  const documentUrl = "https://example.com/document.pdf";

  // First, test if the document is accessible.
  try {
    const response = await fetch(documentUrl, { method: "HEAD" });
    if (!response.ok) {
      console.error(`Document not accessible: HTTP ${response.status}`);
      return;
    }
  } catch (error) {
    console.error("CORS or network error:", error.message);
    console.error("Ensure the server includes these headers:");
    console.error("  Access-Control-Allow-Origin: *");
    console.error("  Access-Control-Allow-Methods: GET, HEAD");
    return;
  }

  // If fetch succeeds, proceed with loading.
  try {
    const instance = await NutrientViewer.load({
      container: "#pspdfkit",
      document: documentUrl,
      licenseKey: "YOUR_LICENSE_KEY"
    });
  } catch (error) {
    console.error("Viewer load error:", error);
  }
}

NutrientViewer.load({
  container: "#pspdfkit",
  document: "document.pdf",
  licenseKey: "YOUR_LICENSE_KEY"
}).then(instance => {
  console.log("License valid, viewer loaded");
}).catch(error => {
  if (error.message.includes("license")) {
    console.error("License error detected:", error.message);

    // Common license issues.
    console.log("Troubleshooting steps:");
    console.log("1. Verify the license key is correct (no extra spaces)");
    console.log("2. Check if the license has expired");
    console.log("3. Ensure the domain matches your license");
    console.log("4. For trial licenses, check usage limits");
  }
});

// Monitor memory usage (Chrome only).
function checkMemoryUsage() {
  if (performance.memory) {
    const used = Math.round(performance.memory.usedJSHeapSize / 1048576);
    const total = Math.round(performance.memory.totalJSHeapSize / 1048576);
    const limit = Math.round(performance.memory.jsHeapSizeLimit / 1048576);

    console.log(`Memory: ${used}MB used / ${total}MB allocated / ${limit}MB limit`);

    if (used > limit * 0.8) {
      console.warn("High memory usage detected!");
    }
  }
}

// Properly unload the viewer when done.
function cleanupViewer(instance) {
  if (instance) {
    NutrientViewer.unload(instance);
    console.log("Viewer unloaded, memory freed");
  }
}

// Example: Load with memory management.
let viewerInstance = null;

async function loadDocument(documentPath) {
  // Unload previous instance first.
  if (viewerInstance) {
    cleanupViewer(viewerInstance);
  }

  viewerInstance = await NutrientViewer.load({
    container: "#pspdfkit",
    document: documentPath,
    licenseKey: "YOUR_LICENSE_KEY"
  });

  checkMemoryUsage();
  return viewerInstance;
}

// Check WebAssembly support before loading.
function checkWebAssemblySupport() {
  try {
    if (typeof WebAssembly === "object"
        && typeof WebAssembly.instantiate === "function") {
      // Test basic WebAssembly functionality.
      const module = new WebAssembly.Module(
        Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00)
      );
      if (module instanceof WebAssembly.Module) {
        console.log("WebAssembly is supported");
        return true;
      }
    }
  } catch (e) {
    console.error("WebAssembly check failed:", e);
  }

  console.error("WebAssembly is not supported in this browser");
  return false;
}

// Load with WebAssembly diagnostics.
async function loadWithWasmDiagnostics() {
  if (!checkWebAssemblySupport()) {
    alert("Your browser doesn't support WebAssembly. Please use a modern browser.");
    return;
  }

  try {
    const instance = await NutrientViewer.load({
      container: "#pspdfkit",
      document: "document.pdf",
      licenseKey: "YOUR_LICENSE_KEY"
    });
    return instance;
  } catch (error) {
    if (error.message.includes("wasm") || error.message.includes("WebAssembly")) {
      console.error("WebAssembly error:", error.message);
      console.log("Possible causes:");
      console.log("1. WASM files not found - check baseUrl configuration");
      console.log("2. Server not serving .wasm with correct MIME type");
      console.log("3. Content Security Policy blocking WASM execution");
    }
    throw error;
  }
}

AddType application/wasm .wasm

types {
    application/wasm wasm;
}

app.use(express.static("public", {
  setHeaders: (res, path) => {
    if (path.endsWith(".wasm")) {
      res.set("Content-Type", "application/wasm");
    }
  }
}));