export type YoutubeProChannel = {
  id: string;
  name: string;
  /** 备忘尾码（旧版） */
  streamKeySuffix?: string;
  /** 完整串流密钥或 rtmp(s) URL */
  streamKey?: string;
  /** 本线路 URL_config 草稿（多路本地编排） */
  urlLines?: string;
  /** 建议 PM2 名，如 youtube2__xxx */
  pm2Name?: string;
  notes?: string;
};

const STORAGE_KEY = "live-hub-youtube-pro-v2";
const PM2_SANITIZE_RE = /[^a-zA-Z0-9_.-]+/g;

export function sanitizeYoutubePm2Name(value: string): string {
  return (value || "").trim().replace(PM2_SANITIZE_RE, "_");
}

export function resolveYoutubeProChannelPm2(channel: Pick<YoutubeProChannel, "id" | "pm2Name">): string {
  const raw = sanitizeYoutubePm2Name(String(channel.pm2Name || ""));
  return raw || defaultPm2NameForChannel(String(channel.id || ""));
}

export function parseYoutubeProChannelList(raw: unknown): YoutubeProChannel[] {
  if (!Array.isArray(raw)) return [];
  return raw
    .map((x) => migrateRow(x as Record<string, unknown>))
    .filter((c): c is YoutubeProChannel => c !== null);
}

function migrateRow(x: Record<string, unknown>): YoutubeProChannel | null {
  if (!x || typeof x !== "object") return null;
  const id = String(x.id || "").trim();
  if (!id) return null;
  const name = String(x.name || "").trim() || id;
  return {
    id,
    name,
    streamKeySuffix: typeof x.streamKeySuffix === "string" ? x.streamKeySuffix : undefined,
    streamKey: typeof x.streamKey === "string" ? x.streamKey : undefined,
    urlLines: typeof x.urlLines === "string" ? x.urlLines : undefined,
    pm2Name: typeof x.pm2Name === "string" ? x.pm2Name : undefined,
    notes: typeof x.notes === "string" ? x.notes : undefined,
  };
}

function safeParse(raw: string | null): YoutubeProChannel[] {
  if (!raw) return [];
  try {
    const v = JSON.parse(raw) as unknown;
    if (!Array.isArray(v)) return [];
    return v.map((x) => migrateRow(x as Record<string, unknown>)).filter((c): c is YoutubeProChannel => c !== null);
  } catch {
    return [];
  }
}

export function loadYoutubeProChannels(): YoutubeProChannel[] {
  if (typeof window === "undefined") return [];
  let raw = window.localStorage.getItem(STORAGE_KEY);
  if (!raw) {
    raw = window.localStorage.getItem("live-hub-youtube-pro-v1");
    if (raw) {
      const legacy = safeParse(raw);
      if (legacy.length) {
        window.localStorage.setItem(STORAGE_KEY, JSON.stringify(legacy));
        return legacy;
      }
    }
  }
  return safeParse(raw);
}

export function saveYoutubeProChannels(channels: YoutubeProChannel[]): void {
  if (typeof window === "undefined") return;
  window.localStorage.setItem(STORAGE_KEY, JSON.stringify(channels));
}

const YOUTUBE_PRO_SYNC_PATHS = ["/hub/youtube_pro_channels", "/youtube_pro_channels"] as const;

export type YoutubeProChannelsRemoteResult = {
  fetched: boolean;
  channels: YoutubeProChannel[];
};

/** 从服务器拉多频道列表（依次尝试 /hub 与根路径，兼容反代未转发 /hub 的情况） */
export async function fetchYoutubeProChannelsRemote(
  fetchJson: <T,>(path: string, init?: RequestInit) => Promise<T>,
): Promise<YoutubeProChannelsRemoteResult> {
  for (const path of YOUTUBE_PRO_SYNC_PATHS) {
    try {
      const data = await fetchJson<{ channels?: unknown }>(path);
      return { fetched: true, channels: parseYoutubeProChannelList(data.channels) };
    } catch {
      /* try next */
    }
  }
  return { fetched: false, channels: [] };
}

export async function pushYoutubeProChannelsRemote(
  fetchJson: <T,>(path: string, init?: RequestInit) => Promise<T>,
  channels: YoutubeProChannel[],
): Promise<void> {
  let last: Error | null = null;
  for (const path of YOUTUBE_PRO_SYNC_PATHS) {
    try {
      await fetchJson(path, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ channels }),
      });
      return;
    } catch (e) {
      last = e instanceof Error ? e : new Error(String(e));
    }
  }
  throw last ?? new Error("youtube_pro_channels sync failed");
}

export function newChannelId(): string {
  return `ch_${Date.now().toString(36)}_${Math.random().toString(36).slice(2, 7)}`;
}

export function defaultPm2NameForChannel(channelId: string): string {
  return `youtube2__${sanitizeYoutubePm2Name(channelId) || "channel"}`;
}