const STAR_KEY = 'jinrong.analyst.starredQuestions'
const RECENT_KEY = 'jinrong.analyst.recentQuestions'
const MAX_RECENT = 8

export type RecentQuestion = { question: string; at: number }

function readJson<T>(key: string, fallback: T): T {
  try {
    const raw = localStorage.getItem(key)
    if (!raw) return fallback
    return JSON.parse(raw) as T
  } catch {
    return fallback
  }
}

export function loadStarredQuestions(): string[] {
  const list = readJson<string[]>(STAR_KEY, [])
  return Array.isArray(list) ? list : []
}

export function saveStarredQuestions(questions: string[]): void {
  localStorage.setItem(STAR_KEY, JSON.stringify(questions.slice(0, 30)))
}

export function toggleStarredQuestion(question: string): string[] {
  const q = question.trim()
  if (!q) return loadStarredQuestions()
  const set = new Set(loadStarredQuestions())
  if (set.has(q)) set.delete(q)
  else set.add(q)
  const next = [...set]
  saveStarredQuestions(next)
  return next
}

export function loadRecentQuestions(): RecentQuestion[] {
  const list = readJson<RecentQuestion[]>(RECENT_KEY, [])
  return Array.isArray(list) ? list : []
}

export function pushRecentQuestion(question: string): RecentQuestion[] {
  const q = question.trim()
  if (!q) return loadRecentQuestions()
  const now = Date.now()
  const rest = loadRecentQuestions().filter((r) => r.question !== q)
  const next = [{ question: q, at: now }, ...rest].slice(0, MAX_RECENT)
  localStorage.setItem(RECENT_KEY, JSON.stringify(next))
  return next
}