Initial Commit

src/services/sync-client.ts

@@ -0,0 +1,162 @@
+/**
+ * Sync Server Client - HTTP client for sync-server communication.
+ * 
+ * Handles:
+ * - Creating/updating invitations on the server
+ * - Fetching invitations by ID
+ * - ExtJSON encoding/decoding for data transfer
+ */
+
+import type { XOInvitation } from '@xo-cash/types';
+import { encodeExtendedJson, decodeExtendedJson } from '../utils/ext-json.js';
+
+/**
+ * Response from the sync server.
+ */
+export interface SyncServerResponse<T> {
+  success: boolean;
+  data?: T;
+  error?: string;
+}
+
+/**
+ * HTTP client for sync-server communication.
+ */
+export class SyncClient {
+  /** Base URL of the sync server */
+  private baseUrl: string;
+
+  /**
+   * Creates a new sync client.
+   * @param baseUrl - Base URL of the sync server (e.g., http://localhost:3000)
+   */
+  constructor(baseUrl: string) {
+    // Remove trailing slash if present
+    this.baseUrl = baseUrl.replace(/\/$/, '');
+  }
+
+  /**
+   * Makes an HTTP request to the sync server.
+   * @param method - HTTP method
+   * @param path - Request path
+   * @param body - Optional request body
+   * @returns Response data
+   */
+  private async request<T>(
+    method: 'GET' | 'POST' | 'PUT' | 'DELETE',
+    path: string,
+    body?: unknown,
+  ): Promise<T> {
+    const url = `${this.baseUrl}${path}`;
+    
+    const headers: Record<string, string> = {
+      'Content-Type': 'application/json',
+      'Accept': 'application/json',
+    };
+
+    const options: RequestInit = {
+      method,
+      headers,
+    };
+
+    if (body !== undefined) {
+      // Encode body using ExtJSON for proper BigInt and Uint8Array serialization
+      options.body = encodeExtendedJson(body);
+    }
+
+    const response = await fetch(url, options);
+
+    if (!response.ok) {
+      const errorText = await response.text();
+      throw new Error(`HTTP ${response.status}: ${errorText}`);
+    }
+
+    const responseText = await response.text();
+    
+    // Return empty object if no response body
+    if (!responseText) {
+      return {} as T;
+    }
+
+    // Decode response using ExtJSON
+    return decodeExtendedJson(responseText) as T;
+  }
+
+  // ============================================================================
+  // Invitation Operations
+  // ============================================================================
+
+  /**
+   * Posts an invitation to the sync server (create or update).
+   * @param invitation - Invitation to post
+   * @returns The stored invitation
+   */
+  async postInvitation(invitation: XOInvitation): Promise<XOInvitation> {
+    return this.request<XOInvitation>('POST', '/invitations', invitation);
+  }
+
+  /**
+   * Gets an invitation from the sync server.
+   * @param invitationIdentifier - Invitation ID to fetch
+   * @returns The invitation or undefined if not found
+   */
+  async getInvitation(invitationIdentifier: string): Promise<XOInvitation | undefined> {
+    try {
+      // Use query parameter for GET request (can't have body)
+      const response = await this.request<XOInvitation>(
+        'GET', 
+        `/invitations?invitationIdentifier=${encodeURIComponent(invitationIdentifier)}`
+      );
+      return response;
+    } catch (error) {
+      // Return undefined if not found (404)
+      if (error instanceof Error && error.message.includes('404')) {
+        return undefined;
+      }
+      throw error;
+    }
+  }
+
+  /**
+   * Updates an invitation on the sync server.
+   * @param invitation - Updated invitation
+   * @returns The updated invitation
+   */
+  async updateInvitation(invitation: XOInvitation): Promise<XOInvitation> {
+    // Uses the same POST endpoint which handles both create and update
+    return this.postInvitation(invitation);
+  }
+
+  // ============================================================================
+  // Health Check
+  // ============================================================================
+
+  /**
+   * Checks if the sync server is healthy.
+   * @returns True if server is healthy
+   */
+  async isHealthy(): Promise<boolean> {
+    try {
+      const response = await this.request<{ status: string }>('GET', '/health');
+      return response.status === 'ok';
+    } catch {
+      return false;
+    }
+  }
+
+  /**
+   * Gets the base URL of the sync server.
+   */
+  getBaseUrl(): string {
+    return this.baseUrl;
+  }
+
+  /**
+   * Gets the SSE endpoint URL for an invitation.
+   * @param invitationId - Invitation ID to subscribe to
+   * @returns SSE endpoint URL
+   */
+  getSSEUrl(invitationIdentifier: string): string {
+    return `${this.baseUrl}/invitations?invitationIdentifier=${encodeURIComponent(invitationIdentifier)}`;
+  }
+}