chore: more refactorings

src/main/engine/GenerationPostIndexService.ts

@@ -0,0 +1,129 @@
+import type { PostData } from './PostEngine';
+import type { GenerationPostIndexLike } from './GenerationSitemapFeedService';
+
+export type GenerationSection = 'core' | 'single' | 'category' | 'tag' | 'date';
+
+export type GenerationPostIndex = GenerationPostIndexLike;
+
+function resolvePostCreatedAt(post: { createdAt: Date | string }): Date {
+  if (post.createdAt instanceof Date) {
+    return post.createdAt;
+  }
+
+  const parsed = new Date(post.createdAt);
+  return Number.isNaN(parsed.getTime()) ? new Date() : parsed;
+}
+
+export function buildGenerationPostIndex(posts: PostData[]): GenerationPostIndex {
+  const postsByCategory = new Map<string, PostData[]>();
+  const postsByTag = new Map<string, PostData[]>();
+  const postsByYear = new Map<number, PostData[]>();
+  const postsByYearMonth = new Map<string, PostData[]>();
+  const postsByYearMonthDay = new Map<string, PostData[]>();
+
+  const append = <TKey extends string | number>(target: Map<TKey, PostData[]>, key: TKey, post: PostData) => {
+    const existing = target.get(key);
+    if (existing) {
+      existing.push(post);
+      return;
+    }
+    target.set(key, [post]);
+  };
+
+  for (const post of posts) {
+    for (const category of post.categories || []) {
+      append(postsByCategory, category, post);
+    }
+
+    for (const tag of post.tags || []) {
+      append(postsByTag, tag, post);
+    }
+
+    const createdAt = resolvePostCreatedAt(post);
+    const year = createdAt.getFullYear();
+    const month = String(createdAt.getMonth() + 1).padStart(2, '0');
+    const day = String(createdAt.getDate()).padStart(2, '0');
+    const ym = `${year}/${month}`;
+    const ymd = `${year}/${month}/${day}`;
+
+    append(postsByYear, year, post);
+    append(postsByYearMonth, ym, post);
+    append(postsByYearMonthDay, ymd, post);
+  }
+
+  return {
+    postsByCategory,
+    postsByTag,
+    postsByYear,
+    postsByYearMonth,
+    postsByYearMonthDay,
+  };
+}
+
+function countPaginatedPages(totalPosts: number, maxPostsPerPage: number): number {
+  if (totalPosts <= 0) {
+    return 0;
+  }
+  return Math.max(1, Math.ceil(totalPosts / maxPostsPerPage));
+}
+
+export function estimateGenerationUnitsBySection(params: {
+  posts: PostData[];
+  allCategories: Set<string>;
+  allTags: Set<string>;
+  yearsMap: Map<number, Date>;
+  yearMonthsMap: Map<string, Date>;
+  yearMonthDaysMap: Map<string, Date>;
+  maxPostsPerPage: number;
+  postIndex?: GenerationPostIndex;
+}): Record<GenerationSection, number> {
+  const {
+    posts,
+    allCategories,
+    allTags,
+    yearsMap,
+    yearMonthsMap,
+    yearMonthDaysMap,
+    maxPostsPerPage,
+    postIndex,
+  } = params;
+
+  const index = postIndex ?? buildGenerationPostIndex(posts);
+  const rootPages = countPaginatedPages(posts.length, maxPostsPerPage);
+  const pageRoutes = index.postsByCategory.get('page')?.length ?? 0;
+
+  const categoryPages = Array.from(allCategories).reduce((sum, category) => {
+    const count = index.postsByCategory.get(category)?.length ?? 0;
+    return sum + countPaginatedPages(count, maxPostsPerPage);
+  }, 0);
+
+  const tagPages = Array.from(allTags).reduce((sum, tag) => {
+    const count = index.postsByTag.get(tag)?.length ?? 0;
+    return sum + countPaginatedPages(count, maxPostsPerPage);
+  }, 0);
+
+  let datePages = 0;
+
+  for (const [year] of yearsMap) {
+    const count = index.postsByYear.get(year)?.length ?? 0;
+    datePages += countPaginatedPages(count, maxPostsPerPage);
+  }
+
+  for (const [ym] of yearMonthsMap) {
+    const count = index.postsByYearMonth.get(ym)?.length ?? 0;
+    datePages += countPaginatedPages(count, maxPostsPerPage);
+  }
+
+  for (const [ymd] of yearMonthDaysMap) {
+    const count = index.postsByYearMonthDay.get(ymd)?.length ?? 0;
+    datePages += countPaginatedPages(count, maxPostsPerPage);
+  }
+
+  return {
+    core: 4 + rootPages + pageRoutes,
+    single: posts.length,
+    category: categoryPages,
+    tag: tagPages,
+    date: datePages,
+  };
+}