export interface RecentLocation {
  mapId: number
  x: number
  y: number
  zoom?: number
  label?: string
  at: number
}

const STORAGE_KEY = 'hnh-map-recent-locations'
const MAX_RECENT = 10

function loadRecent(): RecentLocation[] {
  if (import.meta.server) return []
  try {
    const raw = localStorage.getItem(STORAGE_KEY)
    if (!raw) return []
    const parsed = JSON.parse(raw) as RecentLocation[]
    return Array.isArray(parsed) ? parsed.slice(0, MAX_RECENT) : []
  } catch {
    return []
  }
}

function saveRecent(list: RecentLocation[]) {
  if (import.meta.server) return
  try {
    localStorage.setItem(STORAGE_KEY, JSON.stringify(list.slice(0, MAX_RECENT)))
  } catch (_) {}
}

export function useRecentLocations() {
  const recent = ref<RecentLocation[]>([])

  function refresh() {
    recent.value = loadRecent()
  }

  function push(entry: Omit<RecentLocation, 'at'>) {
    const list = loadRecent()
    const at = Date.now()
    const filtered = list.filter(
      (r) => !(r.mapId === entry.mapId && r.x === entry.x && r.y === entry.y)
    )
    filtered.unshift({ ...entry, at })
    saveRecent(filtered)
    refresh()
  }

  function clear() {
    saveRecent([])
    refresh()
  }

  onMounted(refresh)

  return {
    recent: readonly(recent),
    refresh,
    push,
    clear,
  }
}