Refactors

Dobby233Liu · Sep 16, 2024 · da80d24 · da80d24
1 parent 5c9dae8
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Showing 8 changed files with 221 additions and 151 deletions.
diff --git a/.eslintrc.cjs b/.eslintrc.cjs
diff --git a/.markdownlint.json b/.markdownlint.json
@@ -0,0 +1,30 @@
+{
+    "blanks-around-fences": false,
+    "blanks-around-headings": false,
+    "blanks-around-lists": false,
+    "code-fence-style": false,
+    "emphasis-style": false,
+    "heading-start-left": false,
+    "heading-style": false,
+    "hr-style": false,
+    "line-length": false,
+    "list-indent": false,
+    "no-blanks-blockquote": false,
+    "no-hard-tabs": false,
+    "no-missing-space-atx": false,
+    "no-missing-space-closed-atx": false,
+    "no-multiple-blanks": false,
+    "no-multiple-space-atx": false,
+    "no-multiple-space-blockquote": false,
+    "no-multiple-space-closed-atx": false,
+    "no-trailing-spaces": false,
+    "ol-prefix": false,
+    "strong-style": false,
+    "list-marker-space": {
+        "ul_multi": 3,
+        "ul_single": 3
+    },
+    "ul-indent": {
+        "indent": 4
+    }
+}
diff --git a/README.md b/README.md
@@ -26,7 +26,9 @@ bembedfix 目前提供三种元数据：
 -   [Twitter Cards](https://developer.x.com/en/docs/twitter-for-websites/cards/overview/abouts-cards)
 
 > [!WARNING]
-> 如果用户代理为 Discordbot，Twitter Cards 元数据中提供的 player MIME 类型会被谎报为 video/mp4，表现为客户端里视频封面上有播放按钮但是不能直接播放。详情见 [#26][issue-26]
+> 如果用户代理为 Discordbot，Twitter Cards 元数据中提供的 player MIME 类型会被谎报为 video/mp4。
+> 表现为客户端里视频封面上有播放按钮但是不能直接播放。
+> 详情见 [#26][issue-26]
 
 值得注意的是，本服务目前只在 Discord 和 Twitter 上正式受测试过。
 

diff --git a/eslint.config.mjs b/eslint.config.mjs
@@ -0,0 +1,16 @@
+import globals from "globals";
+import js from "@eslint/js";
+
+export default [
+    js.configs.recommended,
+    {
+        languageOptions: {
+            globals: {
+                ...globals.node,
+            },
+
+            ecmaVersion: "latest",
+            sourceType: "module",
+        },
+    },
+];
diff --git a/src/index.js b/src/index.js
@@ -10,6 +10,7 @@ import {
     shouldNotAddRedirectMetaprop,
     oembedAddExtraMetadata,
     isUserAStupidKidAndTryingToAccessAWordpressApi,
+    applySearchParams,
 } from "./utils.js";
 import {
     getRequestedInfo,
@@ -108,13 +109,14 @@ export default async function handler(req, res) {
 
         data.provider = PROVIDER_NAME;
         // FIXME: preferredly do this in some other way or somewhere else
-        let oembedJson = new URL("oembed.json", getMyBaseURL(req));
-        let oembedXml = new URL("oembed.xml", getMyBaseURL(req));
-        for (let [k, v] of Object.entries(data.oembedAPIQueries)) {
-            if (v == null) continue;
-            oembedJson.searchParams.set(k, v);
-            oembedXml.searchParams.set(k, v);
-        }
+        let oembedJson = applySearchParams(
+            new URL("oembed.json", getMyBaseURL(req)),
+            data.oembedAPIQueries,
+        );
+        let oembedXml = applySearchParams(
+            new URL("oembed.xml", getMyBaseURL(req)),
+            data.oembedAPIQueries,
+        );
         data.oembed_json = oembedJson;
         data.oembed_xml = oembedXml;
         data.lie_about_embed_player = !html5EmbedWorks;

diff --git a/src/utils.js b/src/utils.js
@@ -256,3 +256,22 @@ export async function obtainVideoStreamFromCobalt(videoPageURL, page = 1) {
         return item.url;
     }
 }
+
+// This lets nullish operators work
+export function parseIntSafe(value, radix) {
+    let ret = parseInt(value, radix);
+    if (isNaN(ret)) return null;
+    return ret;
+}
+
+export function applySearchParams(url, newParams) {
+    if (!newParams) return url;
+    // I hate my job
+    for (const [k, v] of newParams instanceof URLSearchParams
+        ? newParams.entries()
+        : Object.entries(newParams)) {
+        if (v === null || v === undefined) continue;
+        url.searchParams.set(k, v);
+    }
+    return url;
+}
diff --git a/src/utils_bilibili.js b/src/utils_bilibili.js
@@ -8,10 +8,12 @@ import {
     DEFAULT_WIDTH,
     DEFAULT_HEIGHT,
     obtainVideoStreamFromCobalt,
+    parseIntSafe,
+    applySearchParams,
 } from "./utils.js";
 import { FAKE_CLIENT_UA_HEADERS, COBALT_API_INSTANCE } from "./constants.js";
 import makeFetchCookie from "fetch-cookie";
-import * as crypto from "node:crypto";
+import { wbiGetKeys, wbiSignURLSearchParams } from "./utils_bilibili_crypto.js";
 
 // Group 4 is the ID of the video
 const MAIN_SITE_VIDEO_PAGE_PATHNAME_REGEX =
@@ -27,23 +29,16 @@ export const isURLBilibiliVideo = (u) =>
 export const getVideoIdByPath = (p) =>
     MAIN_SITE_VIDEO_PAGE_PATHNAME_REGEX.exec(stripTrailingSlashes(p))[1];
 
-// I hate my job
-const searchParamEntries = (searchParams) =>
-    searchParams instanceof URLSearchParams
-        ? searchParams.entries()
-        : Object.entries(searchParams);
-
 export function makeVideoPage(vid, page = 1, searchParams) {
+    assert(vid);
     const ret = new URL(vid, "https://www.bilibili.com/video/");
     if (page != 1) ret.searchParams.set("p", page);
-    if (searchParams) {
-        for (const [k, v] of searchParamEntries(searchParams))
-            ret.searchParams.set(k, v);
-    }
+    applySearchParams(ret, searchParams);
     return ret.href;
 }
 
 export function makeEmbedPlayerURL(vid, cid, page = 1, searchParams) {
+    assert(vid && cid);
     // //player.bilibili.com/player.html?aid=429619610&bvid=BV1GG411b7sc&cid=805522554&page=1
     const ret = new URL("https://player.bilibili.com/player.html");
     if (vid.startsWith("BV")) {
@@ -53,10 +48,7 @@ export function makeEmbedPlayerURL(vid, cid, page = 1, searchParams) {
     }
     ret.searchParams.set("cid", cid);
     ret.searchParams.set("page", page);
-    if (searchParams) {
-        for (const [k, v] of searchParamEntries(searchParams))
-            ret.searchParams.set(k, v);
-    }
+    applySearchParams(ret, searchParams);
     return ret.href;
 }
 
@@ -142,113 +134,6 @@ function genSpoofHeaders(referer = null, destOrigin) {
     };
 }
 
-// XREF: https://socialsisteryi.github.io/bilibili-API-collect/docs/misc/sign/wbi.html#javascript
-
-/**
- * @param {import("fetch-cookie").FetchCookieImpl} fetchCookie
- */
-// FIXME: We'd want to cache this somehow
-async function getWbiKeys(fetchCookie, referer) {
-    const response = await fetchCookie(
-        "https://api.bilibili.com/x/web-interface/nav",
-        {
-            headers: genSpoofHeaders(referer, "api.bilibili.com"),
-            referrerPolicy: "strict-origin-when-cross-origin",
-        },
-    );
-
-    let responseDataRaw;
-    try {
-        responseDataRaw = await response.text();
-    } catch (e) {
-        e.message =
-            `请求 WBI 签名口令失败。（HTTP 状态码为 ${response.status}）` +
-            "\n" +
-            e.message;
-        throw e;
-    }
-
-    let responseData = {};
-    try {
-        responseData = JSON.parse(responseDataRaw);
-    } catch (_) {
-        // pass
-    }
-    if (
-        !response.ok ||
-        (responseData.code && ![0, -101].includes(responseData.code))
-    ) {
-        throw errorFromBilibili(
-            new Error(
-                `请求 WBI 签名口令失败。（HTTP 状态码为 ${response.status}）` +
-                    "\n" +
-                    responseDataRaw,
-            ),
-            responseData,
-        );
-    }
-
-    function getKeyFromFakeBfsPath(path) {
-        // Future-proof
-        let paramLoc = path.indexOf("@");
-        path = path.slice(
-            path.lastIndexOf("/") + 1,
-            paramLoc >= 0 ? paramLoc : path.length,
-        );
-        path = path.slice(0, path.lastIndexOf("."));
-        assert(path.length >= 32);
-        return path;
-    }
-
-    return {
-        img: getKeyFromFakeBfsPath(
-            new URL(responseData.data.wbi_img.img_url).pathname,
-        ),
-        sub: getKeyFromFakeBfsPath(
-            new URL(responseData.data.wbi_img.sub_url).pathname,
-        ),
-    };
-}
-
-const WBI_MIXIN_KEY_SHUFFLE_ORDER = [
-    46, 47, 18, 2, 53, 8, 23, 32, 15, 50, 10, 31, 58, 3, 45, 35, 27, 43, 5, 49,
-    33, 9, 42, 19, 29, 28, 14, 39, 12, 38, 41, 13, 37, 48, 7, 16, 24, 55, 40,
-    61, 26, 17, 0, 1, 60, 51, 30, 4, 22, 25, 54, 21, 56, 59, 6, 63, 57, 62, 11,
-    36, 20, 34, 44, 52,
-];
-
-const WBI_SIGN_CHAR_FILTER_REGEX = /[!'()*]/g;
-
-/**
- * @param {URL} url
- */
-function wbiSignURLSearchParams(url, img, sub) {
-    const fullKey = img + sub;
-    const mixinKey = WBI_MIXIN_KEY_SHUFFLE_ORDER.map((i) => fullKey.charAt(i))
-        .join("")
-        .slice(0, 32);
-    const timestamp = Math.round(Date.now() / 1000);
-
-    url.searchParams.set("wts", timestamp);
-    url.searchParams.sort();
-    url.searchParams.forEach((value, key) => {
-        url.searchParams.set(
-            key,
-            value.replace(WBI_SIGN_CHAR_FILTER_REGEX, ""),
-        );
-    });
-    let query = "?" + url.searchParams.toString();
-
-    const signature = crypto
-        .createHash("md5")
-        .update(query + mixinKey)
-        .digest("hex");
-    query += `&w_rid=${signature}`;
-
-    url.search = query;
-    return url;
-}
-
 /**
  * @param {import("fetch-cookie").FetchCookieImpl} fetchCookie
  */
@@ -309,8 +194,8 @@ export async function getRequestedInfo(path, search) {
         id: null,
         page: null,
         searchParams: {
-            videoPage: {},
-            embedPlayer: {},
+            videoPage: new URLSearchParams(),
+            embedPlayer: new URLSearchParams(),
         },
     };
 
@@ -346,7 +231,7 @@ export async function getRequestedInfo(path, search) {
 
     ret.id = getVideoIdByPath(url.pathname);
     assert(ret.id, "无法从 URL 中提取视频 ID");
-    ret.page = parseInt(search.get("p") ?? "1") ?? 1;
+    ret.page = parseIntSafe(search.get("p")) ?? 1;
 
     const fakeReferer = makeVideoPage(
         ret.id,
@@ -370,14 +255,15 @@ export async function getRequestedInfo(path, search) {
 
     // web / b23.tv
     let startProgress =
-        parseInt(search.get("t")) || parseInt(search.get("start_progress"));
+        parseIntSafe(search.get("t")) ??
+        parseIntSafe(search.get("start_progress"));
     if (startProgress) {
-        ret.searchParams.videoPage["t"] = startProgress;
+        ret.searchParams.videoPage.set("t", startProgress);
         // this has to be t for the embed player, start_progress will not work
-        ret.searchParams.embedPlayer["t"] = startProgress;
+        ret.searchParams.embedPlayer.set("t", startProgress);
     }
 
-    ret.wbiKeys = await getWbiKeys(fetchCookie, fakeReferer);
+    ret.wbiKeys = await wbiGetKeys(fetchCookie, fakeReferer);
     // TODO: buvid4; bili_ticket (for space). Doesn't seem so important right now
 
     return ret;
@@ -420,7 +306,11 @@ export async function getVideoData(info, getVideoURL, dropCobaltErrs) {
     const resInfo = res.data;
 
     page = page <= resInfo.pages.length ? page : 1;
-    videoPageURL = makeVideoPage(resInfo.id, page, info.searchParams.videoPage);
+    videoPageURL = makeVideoPage(
+        resInfo.bvid,
+        page,
+        info.searchParams.videoPage,
+    );
     let cid = resInfo.pages[page - 1].cid ?? resInfo.cid;
     let title = resInfo.title;
     // TODO