feat(extension): auto-intercept https→pap, unit tests, refactor

apps/papillon-extension/src/background/service-worker.ts

@@ -10,6 +10,7 @@
  */
 
 import { parsePapUri, httpsUrlToPap } from "../lib/uri.js";
+import { NATIVE_APP_ID } from "../lib/native-messaging.js";
 import type { PapManifest } from "../lib/discovery.js";
 import type {
   ExtensionMessage,
@@ -18,6 +19,17 @@ import type {
   PapSiteResponse,
 } from "../lib/types.js";
 
+// ── Local constants ─────────────────────────────────────────────────────
+
+/** Badge background color when sessions are active (CSS --gold). */
+const BADGE_COLOR_GOLD = "#f0a030";
+
+/** Badge background color for PAP-capable sites (CSS --purple). */
+const BADGE_COLOR_PURPLE = "#6c5ce7";
+
+/** Context menu item ID for "Open with PAP protection". */
+const CONTEXT_MENU_UPGRADE_ID = "pap-upgrade-link";
+
 // ── State ──────────────────────────────────────────────────────────────
 
 const activeSessions = new Map<string, ActiveSession>();
@@ -119,16 +131,14 @@ function updateBadge() {
   const count = activeSessions.size;
   if (count > 0) {
     chrome.action.setBadgeText({ text: String(count) });
-    chrome.action.setBadgeBackgroundColor({ color: "#f0a030" }); // --gold
+    chrome.action.setBadgeBackgroundColor({ color: BADGE_COLOR_GOLD });
   } else {
     chrome.action.setBadgeText({ text: "" });
   }
 }
 
 // ── Native Messaging ───────────────────────────────────────────────────
 
-const NATIVE_APP_ID = "com.baur_software.papillon";
-
 function connectNative(): chrome.runtime.Port | null {
   try {
     const port = chrome.runtime.connectNative(NATIVE_APP_ID);
@@ -161,6 +171,16 @@ chrome.runtime.onMessage.addListener(
         openHandshakeTab(msg.uri);
         break;
 
+      // Content script: user left-clicked an https:// link (auto-intercept)
+      case "HTTPS_LINK_CLICKED": {
+        // Convert https://example.com/path → pap://example.com/path
+        // resolve_pap_uri() treats dotted authorities as HttpsEndpoint, so
+        // pap:// is the canonical form; pap+https:// is the transport detail.
+        const papUri = msg.httpsUrl.replace(/^https:\/\//, "pap://");
+        openHandshakeTab(papUri, undefined, undefined, msg.httpsUrl);
+        break;
+      }
+
       // Handshake page: start the protocol
       case "START_HANDSHAKE":
         ensureOffscreen().then(() => {
@@ -271,7 +291,7 @@ chrome.runtime.onMessage.addListener(
         // overrides per-tab when set; when global clears, per-tab shows through.
         chrome.action.setBadgeText({ text: "PAP", tabId });
         chrome.action.setBadgeBackgroundColor({
-          color: "#6c5ce7", // --purple
+          color: BADGE_COLOR_PURPLE,
           tabId,
         });
         break;
@@ -365,7 +385,7 @@ chrome.tabs.onUpdated.addListener((tabId, changeInfo) => {
 
 if (chrome.contextMenus) {
   chrome.contextMenus.onClicked.addListener((info) => {
-    if (info.menuItemId === "pap-upgrade-link" && info.linkUrl) {
+    if (info.menuItemId === CONTEXT_MENU_UPGRADE_ID && info.linkUrl) {
       try {
         const papUri = httpsUrlToPap(info.linkUrl);
         openHandshakeTab(papUri, undefined, undefined, info.linkUrl);
@@ -389,7 +409,7 @@ chrome.runtime.onInstalled.addListener(async () => {
   // Register context menu for HTTPS link upgrade (if API available)
   if (chrome.contextMenus) {
     chrome.contextMenus.create({
-      id: "pap-upgrade-link",
+      id: CONTEXT_MENU_UPGRADE_ID,
       title: "Open with PAP protection",
       contexts: ["link"],
       targetUrlPatterns: ["https://*/*"],

apps/papillon-extension/src/content/content-script.ts

@@ -11,9 +11,53 @@
  */
 
 import { fetchManifest } from "../lib/discovery.js";
+import { resolveInterceptUrl } from "./intercept-logic.js";
+import { STORAGE_AUTO_INTERCEPT, STORAGE_EXCLUDED_DOMAINS } from "../lib/constants.js";
 
 const PAP_SCHEMES = ["pap://", "pap+https://", "pap+wss://"];
 
+// ── Auto-intercept HTTPS links ──────────────────────────────────────────
+
+/** Live-updated from chrome.storage.sync. Default: on. */
+let autoInterceptEnabled = true;
+
+/** Live-updated from chrome.storage.sync. Hostname strings only. */
+let excludedDomains = new Set<string>();
+
+// Load initial values from storage before any click can arrive.
+chrome.storage.sync.get(
+  [STORAGE_AUTO_INTERCEPT, STORAGE_EXCLUDED_DOMAINS],
+  (result) => {
+    if (typeof result[STORAGE_AUTO_INTERCEPT] === "boolean") {
+      autoInterceptEnabled = result[STORAGE_AUTO_INTERCEPT] as boolean;
+    }
+    if (Array.isArray(result[STORAGE_EXCLUDED_DOMAINS])) {
+      excludedDomains = new Set<string>(
+        (result[STORAGE_EXCLUDED_DOMAINS] as unknown[]).filter(
+          (d): d is string => typeof d === "string"
+        )
+      );
+    }
+  }
+);
+
+// Keep in-memory state in sync when the user changes settings in the popup.
+chrome.storage.onChanged.addListener((changes, area) => {
+  if (area !== "sync") return;
+  if (STORAGE_AUTO_INTERCEPT in changes) {
+    const next = changes[STORAGE_AUTO_INTERCEPT].newValue;
+    if (typeof next === "boolean") autoInterceptEnabled = next;
+  }
+  if (STORAGE_EXCLUDED_DOMAINS in changes) {
+    const next = changes[STORAGE_EXCLUDED_DOMAINS].newValue;
+    if (Array.isArray(next)) {
+      excludedDomains = new Set<string>(
+        (next as unknown[]).filter((d): d is string => typeof d === "string")
+      );
+    }
+  }
+});
+
 function isPapLink(el: HTMLAnchorElement): boolean {
   const href = el.getAttribute("href");
   if (!href) return false;
@@ -51,6 +95,36 @@ function interceptClick(e: MouseEvent) {
   });
 }
 
+/**
+ * Auto-intercept plain left-clicks on https:// links and route through PAP.
+ * Guard logic is in resolveInterceptUrl (intercept-logic.ts) for testability.
+ */
+function interceptHttpsClick(e: MouseEvent): void {
+  const link = (e.target as HTMLElement).closest("a") as HTMLAnchorElement | null;
+  const rawHref = link?.getAttribute("href") ?? null;
+  const hasDownload = link?.hasAttribute("download") ?? false;
+
+  const url = resolveInterceptUrl(
+    e,
+    rawHref,
+    hasDownload,
+    document.baseURI,
+    autoInterceptEnabled,
+    excludedDomains
+  );
+  if (!url) return;
+
+  e.preventDefault();
+  e.stopPropagation();
+
+  chrome.runtime.sendMessage({
+    type: "HTTPS_LINK_CLICKED",
+    httpsUrl: url,
+    pageTitle: document.title,
+    pageUrl: window.location.href,
+  });
+}
+
 function scanLinks(root: ParentNode = document) {
   const links = root.querySelectorAll<HTMLAnchorElement>("a[href]");
   for (const link of links) {
@@ -85,9 +159,10 @@ observer.observe(document.body, {
   subtree: true,
 });
 
-// ── Click handler ──────────────────────────────────────────────────────
+// ── Click handlers ─────────────────────────────────────────────────────
 
 document.addEventListener("click", interceptClick, true);
+document.addEventListener("click", interceptHttpsClick, true);
 
 // ── Layer 0+1: PAP site discovery ─────────────────────────────────────
 
@@ -154,4 +229,5 @@ if (proto === "https:" || proto === "http:") {
 window.addEventListener("pagehide", () => {
   observer.disconnect();
   document.removeEventListener("click", interceptClick, true);
+  document.removeEventListener("click", interceptHttpsClick, true);
 });