export type Channel = {
  id: string;
  name: string;
  memberIds: string[];
};

const KEY = "lazyboy.channels";

export function readChannels(): Channel[] {
  try {
    const parsed = JSON.parse(localStorage.getItem(KEY) || "[]") as unknown;
    if (!Array.isArray(parsed)) return [];
    return parsed.flatMap((row) => {
      if (!row || typeof row !== "object") return [];
      const item = row as Partial<Channel>;
      if (typeof item.id !== "string" || typeof item.name !== "string" || !Array.isArray(item.memberIds)) return [];
      return [{ id: item.id, name: item.name, memberIds: item.memberIds.filter((id) => typeof id === "string") }];
    });
  } catch {
    return [];
  }
}

export function writeChannels(channels: Channel[]): void {
  localStorage.setItem(KEY, JSON.stringify(channels));
}