/**
 * Lets a chat message reply to another, through `chat_messages.reply_to_id`.
 * The column has no foreign key on purpose: when the replied-to message is
 * deleted, the id stays and chat-service's join reads null, so the chat shows
 * "deleted message" where the quote was.
 *
 * @module
 */

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

/**
 * Run once by `runMigrations`. Existing messages reply to nothing, and a
 * database made from schema.sql already has the column.
 */
export function up(db: DatabaseSync): void {
  const cols = db.prepare(`PRAGMA table_info(chat_messages);`).all() as {
    name: string;
  }[];
  if (!cols.some((c) => c.name === "reply_to_id")) {
    db.exec(`ALTER TABLE chat_messages ADD COLUMN reply_to_id TEXT;`);
  }
}