Initial commit

src/services/cache.ts

@@ -0,0 +1,81 @@
+import { existsSync, mkdirSync, readFileSync, writeFileSync } from 'fs';
+import path from 'path';
+import os from 'os';
+import type { ChapterFile, ChapterView, TextFragment } from '../types.ts';
+
+const TOC_FILENAME = 'toc.links';
+
+function looksLikeFragments(content: string): boolean {
+  try {
+    const parsed = JSON.parse(content);
+    return (
+      Array.isArray(parsed) &&
+      parsed.length > 0 &&
+      typeof parsed[0] === 'object' &&
+      parsed[0] !== null &&
+      'body' in (parsed[0] as object)
+    );
+  } catch {
+    return false;
+  }
+}
+
+export class Cache {
+  private readonly base: string;
+
+  constructor(basePath: string) {
+    this.base = basePath.replace(/^~/, os.homedir());
+  }
+
+  private chapterPath(id: number, index: number): string {
+    return path.join(this.base, String(id), String(index));
+  }
+
+  private tocPath(id: number): string {
+    return path.join(this.base, String(id), TOC_FILENAME);
+  }
+
+  private ensureDir(id: number): void {
+    const dir = path.join(this.base, String(id));
+    if (!existsSync(dir)) mkdirSync(dir, { recursive: true });
+  }
+
+  tryGetChapters(id: number, from: number, to: number): ChapterView | null {
+    if (from > to) return null;
+
+    const chapters: ChapterFile[] = [];
+    for (let i = from; i <= to; i++) {
+      const p = this.chapterPath(id, i);
+      if (!existsSync(p)) return null;
+      const content = readFileSync(p, 'utf-8');
+      if (content.length < 10) return null;
+      chapters.push({ path: p, hasStyle: looksLikeFragments(content) });
+    }
+    return { id, min: from, max: to, chapters };
+  }
+
+  tryGetToc(id: number): string[] | null {
+    const p = this.tocPath(id);
+    if (!existsSync(p)) return null;
+    const lines = readFileSync(p, 'utf-8')
+      .split('\n')
+      .map(l => l.trim())
+      .filter(Boolean);
+    if (lines.length === 0) return null;
+    return lines;
+  }
+
+  saveChapters(id: number, chapters: { index: number; content: string }[]): ChapterFile[] {
+    this.ensureDir(id);
+    return chapters.map(({ index, content }) => {
+      const p = this.chapterPath(id, index);
+      writeFileSync(p, content, 'utf-8');
+      return { path: p, hasStyle: looksLikeFragments(content) };
+    });
+  }
+
+  saveToc(id: number, urls: string[]): void {
+    this.ensureDir(id);
+    writeFileSync(this.tocPath(id), urls.join('\n'), 'utf-8');
+  }
+}