feat: add 3 new plugin hooks : onBeforeBlobUpload, onBeforeDraftAutoSave, onBeforeEditDraft (#586)

Co-authored-by: Linus Rath <minipixxelinfo@gmail.com>

lib/plugin-hooks.ts

@@ -183,7 +183,14 @@ export const emailHooks = {
   onComposerOpen: new HookBus(),
   onBeforeEmailSend: new HookBus(),
   onAfterEmailSend: new HookBus(),
+  // Transform hook - fires before the draft is auto-saved to the server.
+  // Receive fields passed to client.createDraft and may mutate fields in place.
+  // Return false to cancel the auto-save or a the fields.
+  onBeforeDraftAutoSave: new HookBus(),
   onDraftAutoSave: new HookBus(),
+  // Transform hook - fires before a draft is created from an email in draft mailbox.
+  // Receive a Email object and may mutate fields in place.
+  onBeforeEditDraft: new HookBus(),
   onBeforeEmailDelete: new HookBus(),
   onAfterEmailDelete: new HookBus(),
   onBeforeEmailMove: new HookBus(),
@@ -232,6 +239,12 @@ export const emailHooks = {
   // attachment. Handler receives AttachmentInfo (size/type/name only - the
   // raw file is not exposed). Return false to refuse the upload.
   onBeforeAttachmentUpload: new HookBus(),
+  // Intercept hook fired before a file is uploaded to JMAP server. 
+  // It is fired after onBeforeAttachmentUpload.
+  // Handler receive the {file: File, blobId: 'undefined'} object. 
+  // If it uploaded, it must return the object with true blobId. 
+  // Here, the raw file sended is exposed and can be modified or replaced. 
+  onBeforeBlobUpload: new HookBus(),
   // Observer fired after an attachment has been uploaded and its blobId is
   // available. Handler receives AttachmentInfo with `blobId` populated.
   onAfterAttachmentUpload: new HookBus(),

lib/plugin-sandbox/consent.ts

@@ -60,6 +60,7 @@ const PERMISSION_LABELS: Record<string, { title: string; body: string }> = {
   'crypto:full':      { title: 'Full cryptographic access (high risk)', body: 'Runs with full cryptographic access in a privileged, same-origin context. It can read your message bodies and private keys, store key material, and sign/encrypt on your behalf. Only enable plugins you fully trust — this is comparable to a full-access browser extension.' },
   'email:raw-send':   { title: 'Send raw messages',                body: 'Submit fully-formed (e.g. signed or encrypted) messages on your behalf.' },
   'email:blob-read':  { title: 'Read raw message content',        body: 'Fetch the raw bytes of your messages and attachments (needed to decrypt and verify them).' },
+  'email:blob-write':  { title: 'Alterate raw message content',        body: 'get the raw file content before it is uploaded to alterate it just before is is sended to server. (needed to encrypt)' },
   'email:render-takeover': { title: 'Replace rendered email content', body: 'Replace the displayed content of an opened message (e.g. to show decrypted text and a signature-verification badge).' },
   'calendar:read':    { title: 'Read your calendar',             body: 'Access events, calendars, RSVPs, and reminders.' },
   'calendar:write':   { title: 'Modify your calendar',           body: 'Create, edit, or delete events.' },

lib/plugin-sandbox/host-api.ts

@@ -9,6 +9,8 @@ import { useAuthStore } from '@/stores/auth-store';
 import { useEmailStore } from '@/stores/email-store';
 import { apiFetch } from '../browser-navigation';
 import { awaitDialog } from './host-dialog';
+import { fileStorage} from '../plugin-storage'
+import { generateUUID } from '../utils';
 
 /**
  * Methods only callable from the privileged (same-origin) tier. These expose
@@ -19,6 +21,8 @@ import { awaitDialog } from './host-dialog';
 const PRIVILEGED_ONLY_METHODS = new Set<string>([
   'jmap.fetchBlob',
   'jmap.sendRaw',
+  'upfiles.get',
+  'upfiles.set',
 ]);
 
 const PERM_PER_METHOD: Record<string, Permission | null> = {
@@ -38,6 +42,11 @@ const PERM_PER_METHOD: Record<string, Permission | null> = {
   // jmap (privileged-tier only; see PRIVILEGED_ONLY_METHODS)
   'jmap.fetchBlob': 'email:blob-read',
   'jmap.sendRaw': 'email:raw-send',
+  // uploaded files (privileged-tier only) : 
+  // Used only to get a file before it is uploaded to alterate it. 
+  // To just read, use jmap.fetchBlob.
+  'upfiles.get' : 'email:blob-write',
+  'upfiles.save' : 'email:blob-write',
   // admin
   'admin.getConfig': 'admin:config',
   'admin.getAllConfig': 'admin:config',
@@ -263,6 +272,19 @@ async function doJmapSendRaw(
   );
 }
 
+// ─── Uploaded files in IndexedDB (privileged tier) ──────────────────────────
+
+async function getFile(fileID:string): Promise<File | null> {
+  return await fileStorage.getFile(fileID)
+}
+
+async function saveFile(formerFileID:string, file: File): Promise<string> {
+  const fileId = generateUUID();
+  await fileStorage.saveFile(fileId, file);
+  await fileStorage.deleteFile(formerFileID);
+  return fileId;
+}
+
 // ─── admin config (same as before) ────────────────────────────
 
 async function adminGetAll(pluginId: string): Promise<Record<string, unknown>> {
@@ -335,6 +357,8 @@ export async function dispatchApiCall(
       args[1] as string,
       args[2] as { delayedUntil?: string; envelopeRecipients?: string[] } | undefined,
     );
+    case 'upfiles.get' : return getFile(args[0] as string);
+    case 'upfiles.save' : return saveFile(args[0] as string, args[1] as File);
 
     case 'admin.getConfig':    return adminGet(plugin.id, args[0] as string);
     case 'admin.getAllConfig': return adminGetAll(plugin.id);

lib/plugin-sandbox/runtime.tsx

@@ -189,6 +189,16 @@ function buildPluginApi(manifest: PluginManifest) {
         opts?: { delayedUntil?: string; envelopeRecipients?: string[] },
       ) => callApi('jmap.sendRaw', [rawBytes, identityId, opts]),
     },
+    /**
+     * Used to alterate files before they are uploaded to server.
+     * Edited files are saved on indexedDB and remove once the upload to server begins.
+     */
+    upfiles: {
+      save: (formerFileId:string, file:File) =>
+        callApi('upfiles.save', [formerFileId, file]) as Promise<string>,
+      get: (fileId:string) =>
+        callApi('upfiles.get', [fileId]) as Promise<File>,
+    },
     toast: {
       success: (m: string) => { void callApi('toast.success', [m]); },
       error: (m: string) => { void callApi('toast.error', [m]); },

lib/plugin-storage.ts

@@ -1,12 +1,13 @@
 // IndexedDB storage for plugin/theme binary blobs (JS bundles, CSS, previews)
 
 const DB_NAME = 'bulwark-plugins';
-// Bumped to 2 to add the theme-skin store; existing stores are preserved.
-const DB_VERSION = 2;
+// Bumped to 3 to add the file-plugin store; existing stores are preserved.
+const DB_VERSION = 3;
 const STORE_PLUGINS = 'plugin-code';
 const STORE_THEMES = 'theme-css';
 const STORE_THEME_SKINS = 'theme-skin';
 const STORE_PREVIEWS = 'previews';
+const STORE_FILE_ACCESS_PLUGIN = 'file-plugin'
 
 function openDB(): Promise<IDBDatabase> {
   return new Promise((resolve, reject) => {
@@ -26,6 +27,9 @@ function openDB(): Promise<IDBDatabase> {
       if (!db.objectStoreNames.contains(STORE_PREVIEWS)) {
         db.createObjectStore(STORE_PREVIEWS);
       }
+      if (!db.objectStoreNames.contains(STORE_FILE_ACCESS_PLUGIN)) {
+        db.createObjectStore(STORE_FILE_ACCESS_PLUGIN);
+      }
     };
 
     request.onsuccess = () => resolve(request.result);
@@ -33,7 +37,7 @@ function openDB(): Promise<IDBDatabase> {
   });
 }
 
-async function putItem(storeName: string, key: string, value: string | Blob): Promise<void> {
+async function putItem(storeName: string, key: string, value: string | Blob | File): Promise<void> {
   const db = await openDB();
   return new Promise((resolve, reject) => {
     const tx = db.transaction(storeName, 'readwrite');
@@ -111,3 +115,19 @@ export const pluginStorage = {
     await deleteItem(STORE_PREVIEWS, id);
   },
 };
+
+/**
+ * Used in host-api for plugins to access to raw data files
+ * to modify them before they are uploaded.
+ */
+export const fileStorage = {
+      async saveFile(fileId: string, file: File): Promise<void> {
+    await putItem(STORE_FILE_ACCESS_PLUGIN, fileId, file);
+  },
+  async getFile(fileId: string): Promise<File | null> {
+    return getItem<File>(STORE_FILE_ACCESS_PLUGIN, fileId);
+  },
+  async deleteFile(fileId: string): Promise<void> {
+    await deleteItem(STORE_FILE_ACCESS_PLUGIN, fileId);
+  },
+}

lib/plugin-types.ts

@@ -674,6 +674,22 @@ export interface OutgoingEmail {
   /** Free-form custom headers added by the composer or earlier handlers */
   headers?: Record<string, string>;
 }
+/**
+ * Passed to onBeforeDraftAutoSave handlers as a transform value.
+ */
+export interface AlmostSavedDraft{
+   to: string[],
+    subject: string,
+    body: string,
+    cc?: string[],
+    bcc?: string[],
+    identityId?: string,
+    fromEmail?: string,
+    draftId?: string,
+    attachments?: Array<{ blobId: string; name: string; type: string; size: number; disposition?: 'attachment' | 'inline'; cid?: string }>,
+    fromName?: string,
+    htmlBody?: string
+}
 
 /**
  * Passed to onBeforeReply / onBeforeReplyAll / onBeforeForward intercept hooks.
@@ -885,6 +901,8 @@ export const ALL_PERMISSIONS = [
   'email:raw-send',
   // Fetch a message blob's raw bytes by blobId (for decrypt/verify).
   'email:blob-read',
+  // Upload a file to server (for encrypt).
+  'email:blob-write',
   // Replace the rendered body of an opened email (render-takeover).
   'email:render-takeover',
   'calendar:read', 'calendar:write',