// Author: fruit.com.cn

const SEEN_KEY = 'transcode-notice-seen'

export const TRANSCODE_NOTICE_SEEN = 'transcode-notice-seen'

export interface NoticeCounts {
  running: number
  success: number
  failed: number
}

/** 上次打开通知页时已经看过的数量。 */
export function readSeen(): NoticeCounts {
  try {
    const raw = localStorage.getItem(SEEN_KEY)
    if (!raw) return { running: 0, success: 0, failed: 0 }
    const data = JSON.parse(raw) as NoticeCounts
    return {
      running: Number(data.running || 0),
      success: Number(data.success || 0),
      failed: Number(data.failed || 0)
    }
  } catch {
    return { running: 0, success: 0, failed: 0 }
  }
}

/** 比上次查看多出来的数量，看过的不再计入角标。 */
export function unreadCounts(current: NoticeCounts): NoticeCounts {
  const seen = readSeen()
  return {
    running: Math.max(0, current.running - seen.running),
    success: Math.max(0, current.success - seen.success),
    failed: Math.max(0, current.failed - seen.failed)
  }
}

/** 把当前数量记为已读，并通知顶栏收起角标。 */
export function markTranscodeNoticeSeen(current: NoticeCounts) {
  const seen = readSeen()
  localStorage.setItem(
    SEEN_KEY,
    JSON.stringify({
      running: Math.max(seen.running, current.running),
      success: Math.max(seen.success, current.success),
      failed: Math.max(seen.failed, current.failed)
    })
  )
  window.dispatchEvent(new Event(TRANSCODE_NOTICE_SEEN))
}