Add engine switch and Sweetistics endpoints for tweet reading

src/lib/sweetistics-client.ts

@@ -10,6 +10,33 @@ export interface SweetisticsTweetResult {
   error?: string;
 }
 
+export interface SweetisticsTweet {
+  id: string;
+  text: string;
+  author: {
+    username: string;
+    name: string;
+  };
+  createdAt?: string;
+  replyCount?: number;
+  retweetCount?: number;
+  likeCount?: number;
+  conversationId?: string;
+  inReplyToStatusId?: string;
+}
+
+export interface SweetisticsTimelineResult {
+  success: boolean;
+  tweets?: SweetisticsTweet[];
+  error?: string;
+}
+
+export interface SweetisticsReadResult {
+  success: boolean;
+  tweet?: SweetisticsTweet;
+  error?: string;
+}
+
 function normalizeBaseUrl(value: string): string {
   const trimmed = value.trim();
   if (!trimmed) return 'https://sweetistics.com';
@@ -67,4 +94,57 @@ export class SweetisticsClient {
 
     return { success: true, tweetId };
   }
+
+  async read(tweetId: string): Promise<SweetisticsReadResult> {
+    return this.fetchJson<SweetisticsReadResult>(`${this.baseUrl}/api/twitter/tweet/${tweetId}`);
+  }
+
+  async replies(tweetId: string): Promise<SweetisticsTimelineResult> {
+    return this.fetchJson<SweetisticsTimelineResult>(`${this.baseUrl}/api/twitter/tweet/${tweetId}/replies`);
+  }
+
+  async thread(tweetId: string): Promise<SweetisticsTimelineResult> {
+    return this.fetchJson<SweetisticsTimelineResult>(`${this.baseUrl}/api/twitter/tweet/${tweetId}/thread`);
+  }
+
+  async search(query: string, count: number): Promise<SweetisticsTimelineResult> {
+    const url = new URL(`${this.baseUrl}/api/twitter/search`);
+    url.searchParams.set('q', query);
+    url.searchParams.set('count', String(count));
+    return this.fetchJson<SweetisticsTimelineResult>(url.toString());
+  }
+
+  private async fetchJson<T extends { success: boolean; error?: string }>(
+    url: string,
+    init?: RequestInit,
+  ): Promise<T> {
+    const response = await fetch(url, {
+      ...init,
+      headers: {
+        authorization: `Bearer ${this.apiKey}`,
+        ...(this.userAgent ? { 'user-agent': this.userAgent } : {}),
+        ...(init?.headers ?? {}),
+      },
+    });
+
+    let data: unknown;
+    try {
+      data = await response.json();
+    } catch (error) {
+      return {
+        success: false,
+        error: `Sweetistics response parse failed: ${error instanceof Error ? error.message : String(error)}`,
+      } as T;
+    }
+
+    if (!response.ok || !(data as { success?: unknown })?.success) {
+      const message =
+        (typeof (data as { error?: unknown })?.error === 'string'
+          ? (data as { error?: string }).error
+          : undefined) || `HTTP ${response.status}`;
+      return { ...(data as object), success: false, error: message } as T;
+    }
+
+    return data as T;
+  }
 }