first commit

background.js

@@ -0,0 +1,82 @@
+// background.js
+const blobs = new Set();
+
+function isExtensionUrl(url) {
+  return url.startsWith(browser.runtime.getURL(''));
+}
+
+function viewerUrlFor(originalUrl) {
+  return browser.runtime.getURL('viewer.html') + '?src=' + encodeURIComponent(originalUrl);
+}
+
+// Redirect obvious .pdf URLs (but skip extension pages)
+browser.webRequest.onBeforeRequest.addListener(
+  details => {
+    const url = details.url;
+    if (isExtensionUrl(url)) return {};
+    const path = url.split('?')[0].toLowerCase();
+    if (path.endsWith('.pdf')) {
+      return { redirectUrl: viewerUrlFor(details.url) };
+    }
+    return {};
+  },
+  { urls: ["<all_urls>"], types: ["main_frame"] },
+  ["blocking"]
+);
+
+// Redirect when response headers indicate PDF
+browser.webRequest.onHeadersReceived.addListener(
+  details => {
+    const url = details.url;
+    if (isExtensionUrl(url)) return {};
+    const headers = details.responseHeaders || [];
+    for (let h of headers) {
+      if (!h.name || !h.value) continue;
+      const n = h.name.toLowerCase();
+      const v = h.value.toLowerCase();
+      if (n === "content-type" && v.includes("application/pdf")) {
+        return { redirectUrl: viewerUrlFor(details.url) };
+      }
+      // some servers force download with content-disposition
+      if (n === "content-disposition" && v.includes("attachment") && v.includes(".pdf")) {
+        return { redirectUrl: viewerUrlFor(details.url) };
+      }
+    }
+    return {};
+  },
+  { urls: ["<all_urls>"], types: ["main_frame"] },
+  ["blocking", "responseHeaders"]
+);
+
+// Message API: fetch PDF and return a blob: URL (no large binary through messaging)
+browser.runtime.onMessage.addListener(async (msg) => {
+  if (!msg || !msg.type) return;
+
+  if (msg.type === "fetch-pdf" && msg.url) {
+    try {
+      // Ensure you have host permission for the target (manifest had "<all_urls>")
+      const res = await fetch(msg.url, { credentials: "include" });
+      if (!res.ok) {
+        return { error: `HTTP ${res.status} ${res.statusText}` };
+      }
+      const arrayBuffer = await res.arrayBuffer();
+      const contentType = res.headers.get("content-type") || "application/pdf";
+      const blob = new Blob([arrayBuffer], { type: contentType });
+      const blobUrl = URL.createObjectURL(blob);
+      blobs.add(blobUrl);
+      return { blobUrl, contentType };
+    } catch (err) {
+      return { error: String(err) };
+    }
+  }
+
+  // allow viewer to tell us to free the blob URL when it's done
+  if (msg.type === "revoke-blob" && msg.blobUrl) {
+    if (blobs.has(msg.blobUrl)) {
+      blobs.delete(msg.blobUrl);
+      try { URL.revokeObjectURL(msg.blobUrl); } catch(e) {}
+      return { revoked: true };
+    }
+    return { revoked: false };
+  }
+});