Implement per-user post permissions and move stats into dedicated pages

lib/posts.ts

@@ -0,0 +1,96 @@
+import { SessionPayload, isAdminSession } from "@/lib/auth";
+import { DEFAULT_OPC_SIGNAL } from "@/lib/opc";
+import { Post } from "@/types/post";
+
+function buildLegacyAuthorFilter(session: SessionPayload) {
+  if (!session.name) {
+    return null;
+  }
+
+  return {
+    $and: [
+      {
+        $or: [{ ownerId: { $exists: false } }, { ownerId: null }]
+      },
+      { author: session.name }
+    ]
+  };
+}
+
+export function buildOwnedPostFilter(session?: SessionPayload | null) {
+  if (!session?.uid) {
+    return { _id: { $exists: false } };
+  }
+
+  const filters: Record<string, unknown>[] = [{ ownerId: session.uid }];
+  const legacyAuthorFilter = buildLegacyAuthorFilter(session);
+  if (legacyAuthorFilter) {
+    filters.push(legacyAuthorFilter);
+  }
+
+  return { $or: filters };
+}
+
+export function buildPostScopeFilter(session?: SessionPayload | null) {
+  return buildOwnedPostFilter(session);
+}
+
+export function isPostOwner(doc: any, session?: SessionPayload | null) {
+  if (!session?.uid) {
+    return false;
+  }
+
+  if (doc?.ownerId === session.uid) {
+    return true;
+  }
+
+  return !doc?.ownerId && Boolean(session.name) && doc?.author === session.name;
+}
+
+export function buildScopedPostFilter(
+  session: SessionPayload | null | undefined,
+  filters: Record<string, unknown>[] = []
+) {
+  const scopedFilters = [buildPostScopeFilter(session), ...filters].filter(
+    (item) => Object.keys(item).length > 0
+  );
+
+  if (scopedFilters.length === 0) {
+    return {};
+  }
+
+  if (scopedFilters.length === 1) {
+    return scopedFilters[0];
+  }
+
+  return { $and: scopedFilters };
+}
+
+export function canAccessPost() {
+  return true;
+}
+
+export function canEditPost(doc: any, session?: SessionPayload | null) {
+  return isPostOwner(doc, session);
+}
+
+export function canDeletePost(doc: any, session?: SessionPayload | null) {
+  return Boolean(doc && isAdminSession(session));
+}
+
+export function serializePost(doc: any): Post {
+  return {
+    _id: doc._id?.toString(),
+    title: doc.title ?? "",
+    slug: doc.slug ?? "",
+    markdown: doc.markdown ?? "",
+    cover: doc.cover,
+    tags: doc.tags ?? [],
+    signal: doc.signal ?? DEFAULT_OPC_SIGNAL,
+    author: doc.author ?? "匿名",
+    ownerId: doc.ownerId,
+    createdAt: doc.createdAt ?? new Date().toISOString(),
+    updatedAt: doc.updatedAt ?? doc.createdAt ?? new Date().toISOString(),
+    views: doc.views ?? 0
+  };
+}