feat: parse magnet links

packages/app/package.json

@@ -21,6 +21,7 @@
     "@types/uuid": "^9.0.0",
     "@types/webscopeio__react-textarea-autocomplete": "^4.7.2",
     "@webscopeio/react-textarea-autocomplete": "^4.9.2",
+    "base32-decode": "^1.0.0",
     "bech32": "^2.0.0",
     "dexie": "^3.2.2",
     "dexie-react-hooks": "^1.1.1",

packages/app/src/Const.ts

@@ -44,6 +44,7 @@ export const DefaultRelays = new Map<string, RelaySettings>([
   ["wss://eden.nostr.land", { read: true, write: false }],
   ["wss://atlas.nostr.land", { read: true, write: false }],
   ["wss://relay.orangepill.dev", { read: true, write: false }],
+  ["wss://nos.lol", { read: true, write: false }],
 ]);
 
 /**
@@ -152,3 +153,8 @@ export const AppleMusicRegex =
  * Nostr Nests embed regex
  */
 export const NostrNestsRegex = /nostrnests\.com\/[a-zA-Z0-9]+/i;
+
+/*
+ * Magnet link parser
+ */
+export const MagnetRegex = /(magnet:[\S]+)/i; 

packages/app/src/Element/Magnet.tsx

@@ -0,0 +1,18 @@
+import { Magnet } from "Util";
+
+interface MagnetLinkProps {
+  magnet: Magnet;
+}
+
+const MagnetLink = ({ magnet }: MagnetLinkProps) => {
+  return (
+    <div className="note-invoice">
+      <h4>Magnet Link</h4>
+      <a href={magnet.raw} rel="noreferrer">
+        {magnet.dn ?? magnet.infoHash}
+      </a>
+    </div>
+  );
+};
+
+export default MagnetLink;

packages/app/src/Element/Text.tsx

@@ -3,17 +3,16 @@ import { useMemo, useCallback } from "react";
 import { Link } from "react-router-dom";
 import ReactMarkdown from "react-markdown";
 import { visit, SKIP } from "unist-util-visit";
+import * as unist from "unist";
+import { HexKey, Tag } from "@snort/nostr";
 
-import { MentionRegex, InvoiceRegex, HashtagRegex } from "Const";
-import { eventLink, hexToBech32, splitByUrl, unwrap } from "Util";
+import { MentionRegex, InvoiceRegex, HashtagRegex, MagnetRegex } from "Const";
+import { eventLink, hexToBech32, magnetURIDecode, splitByUrl, unwrap } from "Util";
 import Invoice from "Element/Invoice";
 import Hashtag from "Element/Hashtag";
-
-import { Tag } from "@snort/nostr";
 import Mention from "Element/Mention";
 import HyperText from "Element/HyperText";
-import { HexKey } from "@snort/nostr";
-import * as unist from "unist";
+import MagnetLink from "Element/Magnet";
 
 export type Fragment = string | React.ReactNode;
 
@@ -45,6 +44,25 @@ export default function Text({ content, tags, creator }: TextProps) {
       .flat();
   }
 
+  function extractMagnetLinks(fragments: Fragment[]) {
+    return fragments
+      .map(f => {
+        if (typeof f === "string") {
+          return f.split(MagnetRegex).map(a => {
+            if (a.startsWith("magnet:")) {
+              const parsed = magnetURIDecode(a);
+              if (parsed) {
+                return <MagnetLink magnet={parsed} />;
+              }
+            }
+            return a;
+          });
+        }
+        return f;
+      })
+      .flat();
+  }
+
   function extractMentions(frag: TextFragment) {
     return frag.body
       .map(f => {
@@ -135,6 +153,7 @@ export default function Text({ content, tags, creator }: TextProps) {
     fragments = extractLinks(fragments);
     fragments = extractInvoices(fragments);
     fragments = extractHashtags(fragments);
+    fragments = extractMagnetLinks(fragments);
     return fragments;
   }
 

packages/app/src/Util.test.ts

@@ -1,4 +1,4 @@
-import { splitByUrl } from "./Util";
+import { splitByUrl, magnetURIDecode } from "./Util";
 
 describe("splitByUrl", () => {
   it("should split a string by URLs", () => {
@@ -38,3 +38,21 @@ describe("splitByUrl", () => {
     expect(splitByUrl(inputStr)).toEqual(expectedOutput);
   });
 });
+
+describe("magnet", () => {
+  it("should parse magnet link", () => {
+    const book =
+      "magnet:?xt=urn:btih:d2474e86c95b19b8bcfdb92bc12c9d44667cfa36&xt=urn:btmh:1220d2474e86c95b19b8bcfdb92bc12c9d44667cfa36d2474e86c95b19b8bcfdb92b&dn=Leaves+of+Grass+by+Walt+Whitman.epub&tr=udp%3A%2F%2Ftracker.example4.com%3A80&tr=udp%3A%2F%2Ftracker.example5.com%3A80&tr=udp%3A%2F%2Ftracker.example3.com%3A6969&tr=udp%3A%2F%2Ftracker.example2.com%3A80&tr=udp%3A%2F%2Ftracker.example1.com%3A1337";
+    const output = magnetURIDecode(book);
+    expect(output).not.toBeUndefined();
+    expect(output!.dn).toEqual("Leaves of Grass by Walt Whitman.epub");
+    expect(output!.infoHash).toEqual("d2474e86c95b19b8bcfdb92bc12c9d44667cfa36");
+    expect(output!.tr).toEqual([
+      "udp://tracker.example4.com:80",
+      "udp://tracker.example5.com:80",
+      "udp://tracker.example3.com:6969",
+      "udp://tracker.example2.com:80",
+      "udp://tracker.example1.com:1337",
+    ]);
+  });
+});

packages/app/src/Util.ts

@@ -3,6 +3,7 @@ import { sha256 as hash } from "@noble/hashes/sha256";
 import { bytesToHex } from "@noble/hashes/utils";
 import { decode as invoiceDecode } from "light-bolt11-decoder";
 import { bech32 } from "bech32";
+import base32Decode from "base32-decode";
 import { HexKey, TaggedRawEvent, u256, EventKind, encodeTLV, NostrPrefix } from "@snort/nostr";
 
 import { MetadataCache } from "State/Users";
@@ -271,3 +272,110 @@ export function decodeInvoice(pr: string) {
     console.error(e);
   }
 }
+
+export interface Magnet {
+  dn?: string | string[];
+  tr?: string | string[];
+  xs?: string | string[];
+  as?: string | string[];
+  ws?: string | string[];
+  kt?: string[];
+  ix?: number | number[];
+  xt?: string | string[];
+  infoHash?: string;
+  raw?: string;
+}
+
+/**
+ * Parse a magnet URI and return an object of keys/values
+ */
+export function magnetURIDecode(uri: string): Magnet | undefined {
+  try {
+    const result: Record<string, string | number | number[] | string[] | undefined> = {
+      raw: uri,
+    };
+
+    // Support 'magnet:' and 'stream-magnet:' uris
+    const data = uri.trim().split("magnet:?")[1];
+
+    const params = data && data.length > 0 ? data.split("&") : [];
+
+    params.forEach(param => {
+      const split = param.split("=");
+      const key = split[0];
+      const val = decodeURIComponent(split[1]);
+
+      if (!result[key]) {
+        result[key] = [];
+      }
+
+      switch (key) {
+        case "dn": {
+          (result[key] as string[]).push(val.replace(/\+/g, " "));
+          break;
+        }
+        case "kt": {
+          val.split("+").forEach(e => {
+            (result[key] as string[]).push(e);
+          });
+          break;
+        }
+        case "ix": {
+          (result[key] as number[]).push(Number(val));
+          break;
+        }
+        case "so": {
+          // todo: not implemented yet
+          break;
+        }
+        default: {
+          (result[key] as string[]).push(val);
+          break;
+        }
+      }
+    });
+
+    // Convenience properties for parity with `parse-torrent-file` module
+    let m;
+    if (result.xt) {
+      const xts = Array.isArray(result.xt) ? result.xt : [result.xt];
+      xts.forEach(xt => {
+        if (typeof xt === "string") {
+          if ((m = xt.match(/^urn:btih:(.{40})/))) {
+            result.infoHash = [m[1].toLowerCase()];
+          } else if ((m = xt.match(/^urn:btih:(.{32})/))) {
+            const decodedStr = base32Decode(m[1], "RFC4648-HEX");
+            result.infoHash = [bytesToHex(new Uint8Array(decodedStr))];
+          } else if ((m = xt.match(/^urn:btmh:1220(.{64})/))) {
+            result.infoHashV2 = [m[1].toLowerCase()];
+          }
+        }
+      });
+    }
+
+    if (result.xs) {
+      const xss = Array.isArray(result.xs) ? result.xs : [result.xs];
+      xss.forEach(xs => {
+        if (typeof xs === "string" && (m = xs.match(/^urn:btpk:(.{64})/))) {
+          if (!result.publicKey) {
+            result.publicKey = [];
+          }
+          (result.publicKey as string[]).push(m[1].toLowerCase());
+        }
+      });
+    }
+
+    for (const [k, v] of Object.entries(result)) {
+      if (Array.isArray(v)) {
+        if (v.length === 1) {
+          result[k] = v[0];
+        } else if (v.length === 0) {
+          result[k] = undefined;
+        }
+      }
+    }
+    return result;
+  } catch (e) {
+    console.warn("Failed to parse magnet link", e);
+  }
+}

yarn.lock

@@ -3168,6 +3168,18 @@ balanced-match@^1.0.0:
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.2.tgz#e83e3a7e3f300b34cb9d87f615fa0cbf357690ee"
   integrity sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==
 
+base32-decode@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/base32-decode/-/base32-decode-1.0.0.tgz#2a821d6a664890c872f20aa9aca95a4b4b80e2a7"
+  integrity sha512-KNWUX/R7wKenwE/G/qFMzGScOgVntOmbE27vvc6GrniDGYb6a5+qWcuoXl8WIOQL7q0TpK7nZDm1Y04Yi3Yn5g==
+
+base32@^0.0.7:
+  version "0.0.7"
+  resolved "https://registry.yarnpkg.com/base32/-/base32-0.0.7.tgz#9d3c21de7efde73086fa0164d57ffcb1120c68ea"
+  integrity sha512-ire9Jmh+BsUk4Idu0wu6aKeJJr/2j28Mlu0qqJBd1SyOGxW/VRotkfwAv3/KE/entVlNwCefs9bxi7kBeCIxTQ==
+  dependencies:
+    minimist "^1.2.6"
+
 base64-js@^1.3.1:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/base64-js/-/base64-js-1.5.1.tgz#1b1b440160a5bf7ad40b650f095963481903930a"