initial commit - read-only DiscDag integration

1 files changed, 159 insertions, 0 deletions

diff --git a/main.ts b/main.ts
new file mode 100644
index 0000000..d8767b0
--- /dev/null
+++ b/main.ts
@@ -0,0 +1,159 @@
+import { URLSearchParams } from "url";
+import express from "express";
+import cors from "cors";
+import fetch from "node-fetch";
+import cookieParser from "cookie-parser";
+import * as cheerio from "cheerio";
+
+import { wrap } from "./async";
+
+const PORT = 3000;
+const DISCDAG_URL = 'http://solipsys.co.uk/cgi-bin/DiscDAG.py';
+const PUBLIC_URL = 'http://localhost:3000';
+
+const app = express();
+
+app.use(cors({ origin: 'http://localhost:8080' }));
+app.use(express.json());
+app.use(cookieParser());
+
+const discdag = express()
+  .post('/login', wrap(async ($req, $res) => {
+    const { username, password } = $req.body;
+
+    const res = await fetch(DISCDAG_URL, {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'application/x-www-form-urlencoded',
+      },
+      body: new URLSearchParams({
+        Action: 'Login',
+        Username: username,
+        Password: password,
+      }).toString(),
+    });
+
+    if (res.status !== 200)
+      throw new Error("bad response");
+
+    const cookies = (res.headers.get('set-cookie') ?? '').split(' ');
+    let digest: string | null = null;
+    for (const cookiestr of cookies) {
+      if (!cookiestr.startsWith('digest=')) continue;
+
+      digest = cookiestr.split('=')[1];
+      break;
+    }
+
+    if (!digest)
+      throw new Error("no digest cookie");
+
+    const body = await res.text();
+    const discussions = [...body.matchAll(/"\/cgi-bin\/DiscDAG.py\?DiscussionID=(.+?)"/g)].map(m => m[1]);
+    
+    return $res
+      .cookie('digest', digest)
+      .json({ discussions });
+  }))
+
+  .get('/user/:name', wrap(async ($req, $res) => {
+    const { name } = $req.params;
+
+    return $res.json({
+      '@context': 'https://www.w3.org/ns/activitystreams',
+      id: `${PUBLIC_URL}/discdag/user/${name}`,
+      type: 'User',
+      name,
+    });
+  }))
+
+  .get('/:discussion', wrap(async ($req, $res) => {
+    const { discussion } = $req.params;
+    const { digest } = $req.cookies;
+
+    const res = await fetch(DISCDAG_URL, {
+      headers: {
+        'Cookie': `DiscussionID=${discussion}; digest=${digest}`,
+      }
+    });
+
+    if (res.status !== 200)
+      throw new Error("bad response");
+
+    const doc = cheerio.load(await res.text());
+
+    type Note = {
+      type: 'Note';
+      published: string;
+      attributedTo: string | {
+        id: string;
+        type: 'Person',
+        name: string;
+      };
+      inReplyTo: string[];
+      replies: string[];
+      content: string;
+    };
+
+    let first = null;
+    const items: Record<string, Note> = {};
+    for (const node of doc('g.node', 'svg')) {
+      const nodeId = doc('title', node).text();
+      const [_, time, author] = nodeId.split('_');
+
+      const id = `${PUBLIC_URL}/discdag/${discussion}/${nodeId}`;
+      first = first ?? id;
+
+      const content = doc('g:first text', node)
+        .slice(3)
+        .map(function(this: any) { return doc(this).text(); })
+        .toArray()
+        .join(' ').trim();
+
+      items[id] = {
+        type: 'Note',
+        published: time.replace(/^(\d{4})(\d\d)(\d\d)(\d\d)(\d\d)(\d\d)[a-z]+/, '$1-$2-$3T$4:$5:$6Z'),
+        attributedTo: `${PUBLIC_URL}/discdag/user/${author}`,
+        inReplyTo: [],
+        replies: [],
+        content,
+      };
+    }
+
+    for (const node of doc('g.edge', 'svg')) {
+      let [frm, to] = doc('title', node).text().split('->');
+      frm = `${PUBLIC_URL}/discdag/${discussion}/${frm}`;
+      to = `${PUBLIC_URL}/discdag/${discussion}/${to}`;
+
+      items[frm].replies.push(to);
+      items[to].inReplyTo.push(frm);
+    }
+    
+    return $res.json({
+      '@context': [
+        'https://www.w3.org/ns/activitystreams',
+        {
+          items: {
+            '@id': 'as:items',
+            '@type': '@id',
+            '@container': '@id'
+          },
+        },
+      ],
+      id: `${PUBLIC_URL}/discdag/${discussion}`,
+      type: 'Document',
+      name: discussion,
+      first,
+      items,
+    });
+  }));
+
+app.use('/discdag', discdag)
+
+try {
+  app.listen(PORT, (): void => {
+  console.log(`Connected successfully on port ${PORT}`);
+  });
+} catch (error) {
+  console.error(`Error occured: ${error}`);
+}