// SQLite storage for waitlist signups. One row per unique email — dedup is
// enforced by the DB itself (UNIQUE, case-insensitive), so a repeat signup is a
// no-op rather than a duplicate row.

import Database from "better-sqlite3";
import path from "node:path";
import fs from "node:fs";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const DATA_DIR = path.join(__dirname, "..", "data");
const DB_PATH = process.env.DB_PATH || path.join(DATA_DIR, "waitlist.db");

fs.mkdirSync(path.dirname(DB_PATH), { recursive: true });

const db = new Database(DB_PATH);
db.pragma("journal_mode = WAL");
db.exec(`
  CREATE TABLE IF NOT EXISTS signups (
    id         INTEGER PRIMARY KEY AUTOINCREMENT,
    email      TEXT NOT NULL UNIQUE COLLATE NOCASE,
    source     TEXT,
    ip         TEXT,
    user_agent TEXT,
    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now'))
  );
`);

const insertStmt = db.prepare(
  `INSERT INTO signups (email, source, ip, user_agent)
   VALUES (@email, @source, @ip, @user_agent)
   ON CONFLICT(email) DO NOTHING`
);
const countStmt = db.prepare(`SELECT COUNT(*) AS n FROM signups`);
const listStmt = db.prepare(
  `SELECT id, email, source, ip, created_at FROM signups ORDER BY created_at DESC, id DESC`
);

/**
 * Add an email. Returns { added: true } on a new signup, { added: false } if the
 * email was already on the list (deduped — no duplicate stored).
 */
export function addEmail({ email, source = null, ip = null, userAgent = null }) {
  const info = insertStmt.run({ email, source, ip, user_agent: userAgent });
  return { added: info.changes > 0 };
}

export function countEmails() {
  return countStmt.get().n;
}

export function listEmails() {
  return listStmt.all();
}

export default db;