download

browser.ts

@@ -1,3 +1,5 @@
-import { type Browser, chromium } from "playwright";
+import type { Browser, BrowserContext } from "playwright";
+import { chromium, devices } from "playwright";
 
-export { Browser, chromium };
+export { Browser, BrowserContext, chromium };
+export const { userAgent } = devices["Desktop Chrome"];

main.ts

@@ -21,7 +21,7 @@ const options = {
     async run() {
       const db = await createDatabase(args.values.db!);
       const browser = await chromium.launch({ headless: false });
-      const platform = createPlatform(db, browser);
+      const platform = createPlatform({ db, browser });
       await platform.login();
     },
   },
@@ -30,7 +30,7 @@ const options = {
     async run() {
       const db = await createDatabase(args.values.db!);
       const browser = await chromium.launch();
-      const platform = createPlatform(db, browser);
+      const platform = createPlatform({ db, browser });
       await platform.logout();
     },
   },
@@ -52,6 +52,17 @@ const options = {
       console.dir(books, { depth: null });
     },
   },
+  download: {
+    type: "string",
+    async run() {
+      const db = await createDatabase(args.values.db!);
+      const library = createLibrary(db);
+      const books = await library.getBooks();
+      const browser = await chromium.launch();
+      const platform = createPlatform({ db, browser });
+      await platform.download(args.values.download!, books);
+    },
+  },
   help: {
     type: "boolean",
     short: "h",

platform.ts

@@ -2,15 +2,7 @@ import type { Database } from "./database";
 import type { Browser } from "./browser";
 import { DmmBooks } from "./platforms/dmm-books";
 
-export function createPlatform(db: Database, browser: Browser) {
-  const platform = DmmBooks(db, browser);
-
-  return {
-    async login() {
-      await platform.login();
-    },
-    async logout() {
-      await platform.logout();
-    },
-  };
+export function createPlatform(opt: { db: Database; browser: Browser }) {
+  const platform = DmmBooks(opt);
+  return platform;
 }

platforms/dmm-books.ts

@@ -1,7 +1,129 @@
+import fs from "node:fs/promises";
+import type { Book } from "../library";
+import { userAgent, type Browser, type BrowserContext } from "../browser";
 import type { Database } from "../database";
-import type { Browser } from "../browser";
 
-export function DmmBooks(db: Database, browser: Browser) {
+var NFBR: any;
+
+async function getFiles() {
+  const params = new URLSearchParams(location.search);
+  const model = new NFBR.a6G.Model({
+    settings: new NFBR.Settings("NFBR.SettingData"),
+    viewerFontSize: NFBR.a0X.a3K,
+    viewerFontFace: NFBR.a0X.a3k,
+    viewerSpreadDouble: true,
+    viewerSpread: {},
+  });
+  const a6l = new NFBR.a6G.a6L(model);
+  const a2f = new NFBR.a2F();
+  const a5w = await a2f.a5W({
+    contentId: params.get(NFBR.a5q.Key.CONTENT_ID),
+    a6m: params.get(NFBR.a5q.Key.a6M),
+    preview:
+      params.get(NFBR.a5q.Key.LOOK_INSIDE) !== NFBR.a5q.LookInsideType.DISABLED,
+    previewType:
+      params.get(NFBR.a5q.Key.LOOK_INSIDE) ?? NFBR.a5q.LookInsideType.DISABLED,
+    contentType: a6l.getContentType(),
+    title: true,
+  });
+  const content = new NFBR.a6i.Content(a5w.url);
+  const a5n = new NFBR.a5n();
+  await a5n.a5s(content, "configuration", a6l);
+
+  const files: Array<{
+    url: string;
+    blocks: [];
+    width: number;
+    height: number;
+  }> = [];
+
+  for (const index of Object.keys(content.files)) {
+    const file = content.files[index];
+    const conf = content.configuration.contents[index];
+    const {
+      No,
+      Size: { Width, Height },
+    } = file.FileLinkInfo.PageLinkInfoList[0].Page;
+
+    const page = new NFBR.a6i.Page(
+      `${conf.file}/${No}.jpeg`,
+      index,
+      `${conf["original-file-path"]}#-acs-position-${file.PageToBookmark[0][0]}-${file.PageToBookmark[0][1]}`,
+    );
+
+    const w = [...page.url]
+      .map((c) => c.charCodeAt())
+      .reduce((a, cc) => a + cc, 0);
+
+    const pattern = (w % NFBR.a0X.a3h) + 1;
+    const blocks = NFBR.a3E.a3f(
+      Width,
+      Height,
+      NFBR.a0X.a3g,
+      NFBR.a0X.a3G,
+      pattern,
+    );
+
+    const url = `${a5w.url}${page.url}`;
+
+    files.push({ url, blocks, width: Width, height: Height });
+  }
+
+  return files;
+}
+
+async function drawImage(file: {
+  url: string;
+  blocks: Array<Record<string, number>>;
+  width: number;
+  height: number;
+}) {
+  const canvas = Object.assign(document.createElement("canvas"), {
+    width: file.width,
+    height: file.height,
+  });
+
+  const image = (await new Promise((resolve) => {
+    Object.assign(new Image(), {
+      crossOrigin: "use-credentials",
+      src: file.url,
+      onload() {
+        resolve(this);
+      },
+    });
+  })) as HTMLImageElement;
+
+  const ctx = canvas.getContext("2d")!;
+
+  for (const q of file.blocks) {
+    ctx.drawImage(
+      image,
+      q.destX,
+      q.destY,
+      q.width,
+      q.height,
+      q.srcX,
+      q.srcY,
+      q.width,
+      q.height,
+    );
+  }
+
+  const dataUrl = canvas.toDataURL();
+  return dataUrl;
+}
+
+export function DmmBooks({ db, browser }: { db: Database; browser: Browser }) {
+  async function loadBrowserContext(): Promise<BrowserContext> {
+    const { secrets } = await db.get(
+      `select secrets from platforms where name = 'dmm-books'`,
+    );
+
+    const storageState = JSON.parse(secrets) ?? undefined;
+    const ctx = await browser.newContext({ storageState, userAgent });
+    return ctx;
+  }
+
   return {
     async login() {
       const ctx = await browser.newContext();
@@ -9,16 +131,58 @@ export function DmmBooks(db: Database, browser: Browser) {
       await page.goto("https://accounts.dmm.com/service/login/password");
       await page.waitForURL("https://www.dmm.com/", { timeout: 0 });
       const secrets = await ctx.storageState();
-      await ctx.close();
+      await browser.close();
       await db.run(
         `update platforms set secrets = ? where name = 'dmm-books'`,
         JSON.stringify(secrets),
       );
     },
     async logout() {
+      await browser.close();
       await db.run(
         `update platforms set secrets = 'null' where name = 'dmm-books'`,
       );
     },
+    async download(dir: string, books: Array<Book>) {
+      await fs.mkdir(dir);
+
+      const ctx = await loadBrowserContext();
+      const page = await ctx.newPage();
+
+      // TODO: 複数ブックのサポート
+      const book = books[0];
+
+      // TODO: downloadBook() にまとめる
+      await page.goto(book.readerUrl);
+
+      const files = await page.evaluate(getFiles);
+      const digits = String(files.length).length;
+
+      function pad(n: string) {
+        return n.padStart(digits, "0");
+      }
+
+      for (const [n, file] of Object.entries(files)) {
+        const dataUrl = await page.evaluate(drawImage, file);
+        const [prefix, base64] = dataUrl.split(",", 2);
+
+        if (!prefix.startsWith("data:image/png;")) {
+          throw new Error("Only image/png is supported.");
+        }
+
+        if (!prefix.endsWith(";base64")) {
+          throw new Error("Only base64 is supported.");
+        }
+
+        const buffer = Buffer.from(base64, "base64");
+        await fs.writeFile(`${dir}/${pad(n)}.png`, buffer);
+
+        process.stderr.write(".");
+      }
+
+      process.stderr.write(`\n`);
+
+      await browser.close();
+    },
   };
 }