import { type Kysely, sql } from "kysely";
import { execDdl, oneOf } from "../src/migration-helpers.ts";

// IA-2 站点类型:site.kind(pt / public_bt / rss_feed / torznab),各类型声明支持的获取方式(contracts SITE_KINDS)。
// - 存量:adapter = generic_rss 的站点(旧"自定义 RSS 站点:只抓 RSS,不登录")→ rss_feed;其余 → pt。
// - RSS 归属站点:不属于任何站点的 feed_source 按地址主机名归入「自定义 RSS 源」站点(同主机一个站点,
//   key = rss-<主机>,重名加序号);清掉这些 Feed 的游标窗口与条件请求头,下次抓取把窗口里的条目重新写成资源
//   (之前无站点时观察记录被标 ignored/no_site,没有进 source_release)。
// down 只删列;迁移建的站点与 Feed 归属保留(对旧版本就是普通的 generic_rss 站点)。

export const SITE_KINDS = ["pt", "public_bt", "rss_feed", "torznab"] as const;

/** 主机名 → 站点 key 片段:小写,非字母数字换成 -,首尾去 -;空则 feed */
export function hostSlug(host: string): string {
  const s = host
    .toLowerCase()
    .replace(/^www\./, "")
    .replace(/[^a-z0-9]+/g, "-")
    .replace(/^-+|-+$/g, "")
    .slice(0, 40)
    .replace(/-+$/, "");
  return s || "feed";
}

function hostOf(urlDisplay: string): string | null {
  try {
    return new URL(urlDisplay).host || null;
  } catch {
    return null;
  }
}

// biome-ignore lint/suspicious/noExplicitAny: 迁移不依赖应用表类型
export async function up(db: Kysely<any>): Promise<void> {
  await execDdl(
    db,
    `alter table site add column kind text not null default 'pt' ${oneOf("kind", SITE_KINDS)};
     update site set kind = 'rss_feed' where adapter = 'generic_rss';
     create index site_kind_idx on site (kind) where deleted_at is null;`,
  );

  const orphans = await db
    .selectFrom("feed_source")
    .select(["id", "url_display", "name"])
    .where("site_id", "is", null)
    .orderBy("created_at")
    .execute();
  if (!orphans.length) return;

  const taken = new Set((await db.selectFrom("site").select("key").execute()).map((r) => r.key as string));
  const byHost = new Map<string, { id: string; name: string }[]>();
  for (const f of orphans) {
    const host = hostOf(f.url_display as string) ?? "unknown";
    const list = byHost.get(host) ?? [];
    list.push({ id: f.id as string, name: f.name as string });
    byHost.set(host, list);
  }
  for (const [host, feeds] of byHost) {
    const base = `rss-${hostSlug(host === "unknown" ? "" : host)}`;
    let key = base;
    for (let n = 2; taken.has(key); n++) key = `${base}-${n}`;
    taken.add(key);
    const site = await db
      .insertInto("site")
      .values({
        key,
        name: host === "unknown" ? (feeds[0]?.name ?? "自定义 RSS 源") : host,
        kind: "rss_feed",
        adapter: "generic_rss",
        base_url: host === "unknown" ? "https://invalid.local" : `https://${host}`,
        snapshot_enabled: false,
        search_default: false,
      })
      .returning("id")
      .executeTakeFirstOrThrow();
    await db
      .updateTable("feed_source")
      .set({
        site_id: site.id,
        etag: null,
        last_modified: null,
        cursor: sql`cursor - 'window'`,
      })
      .where(
        "id",
        "in",
        feeds.map((f) => f.id),
      )
      .execute();
  }
}

// biome-ignore lint/suspicious/noExplicitAny: 同上
export async function down(db: Kysely<any>): Promise<void> {
  await execDdl(
    db,
    `drop index if exists site_kind_idx;
     alter table site drop column if exists kind;`,
  );
}