Support reading progress synchronization across platforms (#34)

apps/readest-app/src/libs/sync.ts

@@ -0,0 +1,79 @@
+import { supabase } from '@/utils/supabase';
+import { Book, BookConfig, BookNote, BookDataRecord } from '@/types/book';
+import { READEST_WEB_BASE_URL } from '@/services/constants';
+
+const BASE_URL = process.env['NODE_ENV'] === 'production' ? READEST_WEB_BASE_URL : '';
+
+export type SyncType = 'books' | 'configs' | 'notes';
+export type SyncOp = 'push' | 'pull' | 'both';
+
+interface BookRecord extends BookDataRecord, Book {}
+interface BookConfigRecord extends BookDataRecord, BookConfig {}
+interface BookNoteRecord extends BookDataRecord, BookNote {}
+
+export interface SyncResult {
+  books: BookRecord[];
+  notes: BookNoteRecord[];
+  configs: BookConfigRecord[];
+}
+
+export interface SyncData {
+  books?: Partial<BookRecord>[];
+  notes?: Partial<BookNoteRecord>[];
+  configs?: Partial<BookConfigRecord>[];
+}
+
+export class SyncClient {
+  /**
+   * Pull incremental changes since a given timestamp (in ms).
+   * Returns updated or deleted records since that time.
+   */
+  async pullChanges(since: number, type?: SyncType, book?: string): Promise<SyncResult> {
+    const token = await this.getAccessToken();
+    if (!token) throw new Error('Not authenticated');
+
+    const url = `${BASE_URL}/api/sync?since=${encodeURIComponent(since)}&type=${type ?? ''}&book=${book ?? ''}`;
+    const res = await fetch(url, {
+      headers: {
+        Authorization: `Bearer ${token}`,
+      },
+    });
+
+    if (!res.ok) {
+      const error = await res.json();
+      throw new Error(`Failed to pull changes: ${error.error || res.statusText}`);
+    }
+
+    return res.json();
+  }
+
+  /**
+   * Push local changes to the server.
+   * Uses last-writer-wins logic as implemented on the server side.
+   */
+  async pushChanges(payload: SyncData): Promise<SyncResult> {
+    const token = await this.getAccessToken();
+    if (!token) throw new Error('Not authenticated');
+
+    const res = await fetch(`${BASE_URL}/api/sync`, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/json',
+        Authorization: `Bearer ${token}`,
+      },
+      body: JSON.stringify(payload),
+    });
+
+    if (!res.ok) {
+      const error = await res.json();
+      throw new Error(`Failed to push changes: ${error.error || res.statusText}`);
+    }
+
+    return res.json();
+  }
+
+  private async getAccessToken(): Promise<string | null> {
+    const { data } = await supabase.auth.getSession();
+    return data?.session?.access_token ?? null;
+  }
+}