Source

// What this browser remembers: boards it manages (with their admin keys), boards it opened, and the name
// it posts under. Lives only in this browser; the admin link carries a key to another device.
export interface MyBoard { id: string; title: string; key?: string; at: number }

const BOARDS = "feedback:boards";
const VISITED = "feedback:visited";
const NAME = "feedback:name";

function read<T>(key: string, fallback: T): T {
  try {
    const v = JSON.parse(localStorage.getItem(key) || "null");
    return v ?? fallback;
  } catch {
    return fallback;
  }
}

export function myBoards(): MyBoard[] {
  const list = read<MyBoard[]>(BOARDS, []);
  return Array.isArray(list) ? list.filter((b) => b && typeof b.id === "string" && b.key) : [];
}

export function rememberBoard(board: Partial<MyBoard> & { id: string }) {
  const list = read<MyBoard[]>(BOARDS, []).filter((b) => b && typeof b.id === "string");
  const prev = list.find((b) => b.id === board.id);
  const next = { title: "", at: Date.now(), ...prev, ...board };
  localStorage.setItem(BOARDS, JSON.stringify([next, ...list.filter((b) => b.id !== board.id)].slice(0, 200)));
}

export function forgetBoard(id: string) {
  localStorage.setItem(BOARDS, JSON.stringify(read<MyBoard[]>(BOARDS, []).filter((b) => b.id !== id)));
}

export const adminKey = (id: string) => myBoards().find((b) => b.id === id)?.key;

/** Boards this browser opened, newest first, so votes can come along when the person signs in. */
export function visitedBoards(): string[] {
  const list = read<string[]>(VISITED, []);
  return Array.isArray(list) ? list.filter((x) => typeof x === "string") : [];
}

export function rememberVisit(id: string) {
  localStorage.setItem(VISITED, JSON.stringify([id, ...visitedBoards().filter((x) => x !== id)].slice(0, 50)));
}

export const savedName = () => localStorage.getItem(NAME) || "";
export const saveName = (name: string) => localStorage.setItem(NAME, name.trim());