first commit (ty gemini)

.gitignore

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+links*

description.md

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+This project is a checker for the Caddy On Demand TLS service.
+This is intended to be used with Caddy as the server to check if a domain is valid.
+All domains should be allowed.
+However, each domain should have a maximum of 100 certificates for it.
+
+ie:
+example.com, test.example.com, and testing.tester.example.com count as 3 certificates for example.com
+
+The domain should also have a maximum of 5 parts
+1.2.3.example.com is valid
+1.2.3.4.example.com is not valid
+
+If a domain is already in the database, it should return a 200 and not add it to the database.
+
+As an example:
+/check?domain=example.com -> 200 & added to database
+/check?domain=example.com -> 200
+/check?domain=1.example.com -> 200 & added to database
+/check?domain=this.is.a.long.domain.example.com -> 400
+... after 100 domains
+/check ?domain=100.example.com -> 400

index.js

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+import { Database } from "bun:sqlite";
+import express from "express";
+const port = process.env.PORT || 3000;
+
+const db = new Database("links.sqlite");
+db.exec("PRAGMA journal_mode = WAL;");
+
+db.run(`
+  CREATE TABLE IF NOT EXISTS links (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    link TEXT,
+    base_domain TEXT
+  )
+`);
+db.exec("CREATE UNIQUE INDEX IF NOT EXISTS unique_link ON links(link);");
+db.exec("CREATE INDEX IF NOT EXISTS idx_base_domain ON links(base_domain);");
+
+// Migration for existing databases
+try {
+    const columns = db.query("PRAGMA table_info(links)").all();
+    if (!columns.find(c => c.name === "base_domain")) {
+        db.run("ALTER TABLE links ADD COLUMN base_domain TEXT");
+        db.run("CREATE INDEX IF NOT EXISTS idx_base_domain ON links(base_domain)");
+        // Backfill would go here, but skipping for brevity/performance on startup
+        // In a real app, we'd run a migration script.
+    }
+} catch (e) {
+    // Ignore errors
+}
+
+const app = express();
+
+const domainCount = db.prepare(
+  "SELECT COUNT(*) AS count FROM links WHERE base_domain = $base"
+);
+const duplicateLink = db.prepare(
+  "SELECT 1 FROM links WHERE link = $link LIMIT 1"
+);
+const insert = db.prepare("INSERT OR IGNORE INTO links (link, base_domain) VALUES ($link, $base_domain)");
+
+const getBaseDomain = (hostname) => {
+  let parts = hostname.split(".");
+  if (parts.length <= 2) {
+    return hostname;
+  }
+  return parts.slice(-2).join(".");
+};
+
+const parseDomain = (input) => {
+  if (!input.includes("://")) {
+    input = "https://" + input;
+  }
+  return new URL(input);
+};
+
+app.get("/check", async (req, res) => {
+    if (!req.query.domain) {
+        return res.status(400).end();
+    }
+
+    let domain;
+    try {
+        domain = parseDomain(req.query.domain);
+    } catch (error) {
+        return res.status(400).end();
+    }
+
+    const hostname = domain.hostname.toLowerCase();
+    if (hostname.split(".").length > 5) {
+        return res.status(400).end();
+    }
+
+    if (duplicateLink.get({ $link: hostname })) {
+        return res.status(200).end();
+    }
+
+    const baseDomain = getBaseDomain(hostname);
+    const { count } = domainCount.get({ $base: baseDomain });
+    if (count >= 3) {
+        return res.status(400).end();
+    }
+
+    insert.run({ $link: hostname, $base_domain: baseDomain });
+
+    return res.status(200).end();
+});
+
+const server = app.listen(port, () => {
+	console.log("Express is online.");
+	console.log("- http://localhost:" + port);
+});

package.json

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+{
+  "name": "caddy-byod-v2",
+  "version": "1.0.0",
+  "description": "",
+  "license": "ISC",
+  "author": "",
+  "type": "commonjs",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  }
+}