import type { DatabaseSync } from "node:sqlite";
import { up as up0001CommentLikes } from "./migrations/0001_comment_likes.ts";
import { up as up0002DumpThumbnail } from "./migrations/0002_dump_thumbnail.ts";

interface Migration {
  name: string;
  up: (db: DatabaseSync) => void;
}

// Append-only — never edit or reorder a migration once it has shipped.
// Each `up` must be idempotent: it also runs against fresh databases created
// straight from schema.sql, where the change it makes already exists.
const MIGRATIONS: Migration[] = [
  { name: "0001_comment_likes", up: up0001CommentLikes },
  { name: "0002_dump_thumbnail", up: up0002DumpThumbnail },
];

export function runMigrations(db: DatabaseSync): void {
  db.exec(`CREATE TABLE IF NOT EXISTS schema_migrations (
    name       TEXT PRIMARY KEY,
    applied_at TEXT NOT NULL
  );`);

  const applied = new Set(
    (db.prepare(`SELECT name FROM schema_migrations;`).all() as {
      name: string;
    }[]).map((r) => r.name),
  );

  for (const { name, up } of MIGRATIONS) {
    if (applied.has(name)) continue;
    db.exec("BEGIN;");
    try {
      up(db);
      db.prepare(
        `INSERT INTO schema_migrations (name, applied_at) VALUES (?, ?);`,
      ).run(name, new Date().toISOString());
      db.exec("COMMIT;");
      console.log(`[migrate] applied ${name}`);
    } catch (err) {
      db.exec("ROLLBACK;");
      throw err;
    }
  }
}