/**
 * Adds the `chat_messages` table.
 *
 * Idempotent: safe to run against a fresh db (already created from schema.sql
 * with this table) or an existing one that predates it.
 *
 * @module
 */

import type { DatabaseSync } from "node:sqlite";

/** Applies this migration to `db`. */
export function up(db: DatabaseSync): void {
  db.exec(`CREATE TABLE IF NOT EXISTS chat_messages (
    id         TEXT NOT NULL PRIMARY KEY,
    user_id    TEXT NOT NULL,
    body       TEXT NOT NULL,
    created_at TEXT NOT NULL,
    updated_at TEXT,
    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
  );`);

  db.exec(
    `CREATE INDEX IF NOT EXISTS idx_chat_messages_created ON chat_messages(created_at);`,
  );
}