import { Database } from 'bun:sqlite';
import type { NonceStore } from './types';

export class MemoryNonceStore implements NonceStore {
  private seen = new Map<string, number>();

  consume(nonce: string, expiresAt: number): boolean {
    const now = Date.now();
    // Prune inline instead of on a timer — tokens expire in minutes and this
    // map only grows one entry per successful send, so the scan stays tiny.
    for (const [key, exp] of this.seen) {
      if (exp < now) {
        this.seen.delete(key);
      }
    }
    if (this.seen.has(nonce)) {
      return false;
    }
    this.seen.set(nonce, expiresAt);
    return true;
  }
}

export class SqliteNonceStore implements NonceStore {
  private db: Database;

  constructor(path: string) {
    this.db = new Database(path, { create: true });
    this.db.run('CREATE TABLE IF NOT EXISTS nonces (nonce TEXT PRIMARY KEY, expires_at INTEGER NOT NULL)');
    // Without this the prune below is a full table scan on every consume — the
    // primary key indexes `nonce`, not `expires_at`.
    this.db.run('CREATE INDEX IF NOT EXISTS nonces_expires_at ON nonces (expires_at)');
  }

  consume(nonce: string, expiresAt: number): boolean {
    // Pruning rides on consume rather than a background sweeper: a row is only
    // ever added by a consume, so the table can't grow while nothing is calling
    // this. That makes it self-limiting — no timer to own or shut down.
    this.db.run('DELETE FROM nonces WHERE expires_at < ?', [Date.now()]);
    const result = this.db.run('INSERT OR IGNORE INTO nonces (nonce, expires_at) VALUES (?, ?)', [nonce, expiresAt]);
    return result.changes === 1;
  }

  // Release the underlying SQLite handle. Optional in production (the store lives
  // for the process), but Windows won't delete the DB file while a handle is open,
  // so tests must close before removing their temp dir.
  close(): void {
    this.db.close();
  }
}