From 80b231d5ec1675dc8a4eaba7a021e757230ff796 Mon Sep 17 00:00:00 2001
From: Wenzhuo Liu <mgt@oi-wiki.org>
Date: Sat, 9 Dec 2023 17:40:16 +0800
Subject: [PATCH] feat(rehype-typst): add font caching (#436)

---
 .../lib/cached-font-middleware.js             | 53 +++++++++++++++++++
 projects/rehype-typst/lib/index.js            |  4 +-
 projects/rehype-typst/package.json            |  1 +
 projects/rehype-typst/test.js                 |  1 +
 yarn.lock                                     | 15 ++++++
 5 files changed, 72 insertions(+), 2 deletions(-)
 create mode 100644 projects/rehype-typst/lib/cached-font-middleware.js

diff --git a/projects/rehype-typst/lib/cached-font-middleware.js b/projects/rehype-typst/lib/cached-font-middleware.js
new file mode 100644
index 00000000..fbbb3f70
--- /dev/null
+++ b/projects/rehype-typst/lib/cached-font-middleware.js
@@ -0,0 +1,53 @@
+import { preloadFontAssets } from '@myriaddreamin/typst.ts/dist/esm/options.init.mjs';
+import * as fs from 'fs';
+import * as path from 'path';
+import { HttpsProxyAgent } from 'https-proxy-agent';
+
+export async function cachedFontInitOptions() {
+  const { existsSync, mkdirSync, readFileSync, writeFileSync } = fs;
+  const fetcher = (await import('node-fetch')).default;
+  const dataDir =
+    process.env.APPDATA ||
+    (process.platform == 'darwin'
+      ? process.env.HOME + '/Library/Preferences'
+      : process.env.HOME + '/.local/share');
+
+  const cacheDir = path.join(dataDir, 'typst/fonts');
+
+  return {
+    beforeBuild: [
+      preloadFontAssets({
+        assets: ['text', 'cjk', 'emoji'],
+        fetcher: async (url, init) => {
+          const cachePath = path.join(cacheDir, url.toString().replace(/[^a-zA-Z0-9]/g, '_'));
+          if (existsSync(cachePath)) {
+            const font_res = {
+              arrayBuffer: async () => {
+                return readFileSync(cachePath).buffer;
+              },
+            };
+
+            return font_res;
+          }
+
+          console.log('loading remote font:', url);
+          const proxyOption = process.env.HTTPS_PROXY
+            ? { agent: new HttpsProxyAgent(process.env.HTTPS_PROXY) }
+            : {};
+
+          const font_res = await fetcher(url, {
+            ...proxyOption,
+            ...((init) || {}),
+          });
+          const buffer = await font_res.arrayBuffer();
+          mkdirSync(path.dirname(cachePath), { recursive: true });
+          writeFileSync(cachePath, Buffer.from(buffer));
+          font_res.arrayBuffer = async () => {
+            return buffer;
+          };
+          return font_res;
+        },
+      }),
+    ],
+  };
+}
diff --git a/projects/rehype-typst/lib/index.js b/projects/rehype-typst/lib/index.js
index 19f3402a..1a3ffdc9 100644
--- a/projects/rehype-typst/lib/index.js
+++ b/projects/rehype-typst/lib/index.js
@@ -8,13 +8,13 @@
 import { fromHtmlIsomorphic } from 'hast-util-from-html-isomorphic'
 import { toText } from 'hast-util-to-text'
 import { $typst } from '@myriaddreamin/typst.ts/dist/esm/contrib/snippet.mjs'
-
 import { SKIP, visitParents } from 'unist-util-visit-parents'
-
+import { cachedFontInitOptions } from './cached-font-middleware.js'
 /** @type {Readonly<Options>} */
 const emptyOptions = {}
 /** @type {ReadonlyArray<unknown>} */
 const emptyClasses = []
+$typst.setCompilerInitOptions(await cachedFontInitOptions());
 await $typst.svg({
   mainContent: ''
 })
diff --git a/projects/rehype-typst/package.json b/projects/rehype-typst/package.json
index e3a329ec..f0747c45 100644
--- a/projects/rehype-typst/package.json
+++ b/projects/rehype-typst/package.json
@@ -19,6 +19,7 @@
     "@types/katex": "^0.16.0",
     "hast-util-from-html-isomorphic": "^2.0.0",
     "hast-util-to-text": "^4.0.0",
+    "https-proxy-agent": "^7.0.2",
     "unist-util-visit-parents": "^6.0.0",
     "vfile": "^6.0.0"
   },
diff --git a/projects/rehype-typst/test.js b/projects/rehype-typst/test.js
index ba57f3cd..143def16 100644
--- a/projects/rehype-typst/test.js
+++ b/projects/rehype-typst/test.js
@@ -32,5 +32,6 @@ unified()
   .use(rehypeTypst)
   .use(rehypeStringify)
   .process(test_code, (err, file) => {
+    if (err) throw err
     console.log(String(file))
   })
diff --git a/yarn.lock b/yarn.lock
index 3bdafec9..e13727f7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3324,6 +3324,13 @@ agent-base@6, agent-base@^6.0.2:
   dependencies:
     debug "4"
 
+agent-base@^7.0.2:
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-7.1.0.tgz#536802b76bc0b34aa50195eb2442276d613e3434"
+  integrity sha512-o/zjMZRhJxny7OyEF+Op8X+efiELC7k7yOjMzgfzVqOzXqkBkWI79YoTdOtsuWd5BWhAGAuOY/Xa6xpiaWXiNg==
+  dependencies:
+    debug "^4.3.4"
+
 agentkeepalive@^4.2.1:
   version "4.5.0"
   resolved "https://registry.yarnpkg.com/agentkeepalive/-/agentkeepalive-4.5.0.tgz#2673ad1389b3c418c5a20c5d7364f93ca04be923"
@@ -6420,6 +6427,14 @@ https-proxy-agent@5.0.1, https-proxy-agent@^5.0.0:
     agent-base "6"
     debug "4"
 
+https-proxy-agent@^7.0.2:
+  version "7.0.2"
+  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-7.0.2.tgz#e2645b846b90e96c6e6f347fb5b2e41f1590b09b"
+  integrity sha512-NmLNjm6ucYwtcUmL7JQC1ZQ57LmHP4lT15FQ8D61nak1rO6DH+fz5qNK2Ap5UN4ZapYICE3/0KodcLYSPsPbaA==
+  dependencies:
+    agent-base "^7.0.2"
+    debug "4"
+
 human-signals@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/human-signals/-/human-signals-2.1.0.tgz#dc91fcba42e4d06e4abaed33b3e7a3c02f514ea0"