v3: added comment likes, added votes/likes list view, added db migrations mechanism, updated project dependencies

api/services/comment-like-service.ts

@@ -0,0 +1,107 @@
+import {
+  APIErrorCode,
+  APIException,
+  type User,
+} from "../model/interfaces.ts";
+import { db, isUserRow, userRowToApi } from "../model/db.ts";
+import { notifyCommentOwnerLike } from "./notification-service.ts";
+
+export function castCommentLike(commentId: string, userId: string): number {
+  let likeCount: number;
+  try {
+    db.exec("BEGIN;");
+    db.prepare(
+      `INSERT INTO comment_likes (comment_id, user_id, created_at) VALUES (?, ?, ?);`,
+    ).run(commentId, userId, new Date().toISOString());
+    db.prepare(
+      `UPDATE comments SET like_count = like_count + 1 WHERE id = ?;`,
+    ).run(commentId);
+    const row = db.prepare(
+      `SELECT like_count FROM comments WHERE id = ?;`,
+    ).get(commentId) as { like_count: number } | undefined;
+    db.exec("COMMIT;");
+    likeCount = row?.like_count ?? 0;
+  } catch (err) {
+    try {
+      db.exec("ROLLBACK;");
+    } catch { /* ignore if no active transaction */ }
+    if (err instanceof Error && err.message.includes("UNIQUE constraint")) {
+      throw new APIException(
+        APIErrorCode.VALIDATION_ERROR,
+        409,
+        "Already liked",
+      );
+    }
+    throw err;
+  }
+  // Notification is best-effort — must not prevent like_ack from being sent
+  try {
+    notifyCommentOwnerLike(userId, commentId);
+  } catch { /* ignore */ }
+  return likeCount;
+}
+
+export function removeCommentLike(commentId: string, userId: string): number {
+  try {
+    db.exec("BEGIN;");
+    const result = db.prepare(
+      `DELETE FROM comment_likes WHERE comment_id = ? AND user_id = ?;`,
+    ).run(commentId, userId);
+    if (result.changes === 0) {
+      db.exec("ROLLBACK;");
+      throw new APIException(APIErrorCode.NOT_FOUND, 404, "Like not found");
+    }
+    db.prepare(
+      `UPDATE comments SET like_count = like_count - 1 WHERE id = ?;`,
+    ).run(commentId);
+    const row = db.prepare(
+      `SELECT like_count FROM comments WHERE id = ?;`,
+    ).get(commentId) as { like_count: number } | undefined;
+    db.exec("COMMIT;");
+    return row?.like_count ?? 0;
+  } catch (err) {
+    if (err instanceof APIException) throw err;
+    db.exec("ROLLBACK;");
+    throw err;
+  }
+}
+
+export function getUserCommentLikes(userId: string): string[] {
+  const rows = db.prepare(
+    `SELECT comment_id FROM comment_likes WHERE user_id = ?;`,
+  ).all(userId) as { comment_id: string }[];
+  return rows.map((r) => r.comment_id);
+}
+
+export function getCommentLikers(
+  commentId: string,
+  page: number,
+  limit: number,
+): { items: User[]; total: number } {
+  const offset = (page - 1) * limit;
+
+  const totalRow = db.prepare(
+    `SELECT COUNT(*) as count FROM comment_likes WHERE comment_id = ?;`,
+  ).get(commentId) as { count: number } | undefined;
+
+  const rawRows = db.prepare(
+    `SELECT u.id, u.username, u.password_hash, u.is_admin, u.created_at, u.updated_at,
+            u.avatar_mime, u.description, u.invited_by, u.email,
+            i.username as invited_by_username
+     FROM users u
+     LEFT JOIN users i ON i.id = u.invited_by
+     INNER JOIN comment_likes cl ON cl.comment_id = ? AND cl.user_id = u.id
+     ORDER BY cl.created_at DESC
+     LIMIT ? OFFSET ?;`,
+  ).all(commentId, limit, offset);
+
+  if (!rawRows.every(isUserRow)) {
+    throw new APIException(
+      APIErrorCode.SERVER_ERROR,
+      500,
+      "Malformed user data",
+    );
+  }
+
+  return { items: rawRows.map(userRowToApi), total: totalRow?.count ?? 0 };
+}