import { promises as fs } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { type Kysely, sql } from "kysely";
import { FileMigrationProvider, type MigrationResultSet, Migrator } from "kysely/migration";

/** 迁移目录:packages/db/migrations,文件名 NNNN_name.ts,导出 up/down */
export const MIGRATIONS_DIR = fileURLToPath(new URL("../migrations", import.meta.url));

export interface MigratorOptions {
  /**
   * kysely_migration 表所在 schema。默认不指定(走 search_path)。
   * 在非 public schema 里迁移(如测试隔离 schema)时必须显式指定,
   * 否则 Kysely 会把 public 下已存在的迁移表当成当前库的迁移记录。
   */
  migrationTableSchema?: string;
}

// biome-ignore lint/suspicious/noExplicitAny: 迁移器不关心具体表类型
export function createMigrator(db: Kysely<any>, opts: MigratorOptions = {}): Migrator {
  return new Migrator({
    db,
    provider: new FileMigrationProvider({ fs, path, migrationFolder: MIGRATIONS_DIR }),
    ...(opts.migrationTableSchema ? { migrationTableSchema: opts.migrationTableSchema } : {}),
  });
}

/** 迁移到最新;失败时抛出 */
// biome-ignore lint/suspicious/noExplicitAny: 同上
export async function migrateToLatest(db: Kysely<any>, opts: MigratorOptions = {}): Promise<MigrationResultSet> {
  const result = await createMigrator(db, opts).migrateToLatest();
  if (result.error) throw result.error;
  return result;
}

/** 清空 public schema(仅开发/测试用) */
// biome-ignore lint/suspicious/noExplicitAny: 同上
export async function resetSchema(db: Kysely<any>): Promise<void> {
  await sql`drop schema if exists public cascade`.execute(db);
  await sql`create schema public`.execute(db);
}