/**
 * 顶栏长连接通知：共享状态 + 只绑定一次 appWs:notice
 * 多页各挂 AppTopPushNotice 时，仅「页面栈顶」的实例展示（用 $root 与栈顶 $vm 比较）
 */
import Vue from 'vue'
import { parseAppWsNoticeDisplay, formatNoticeTimeForBanner } from '@/common/utils/parseAppWsNotice.js'

const HIDE_MS = 3000

function _fingerprint(item) {
	if (item && item.id) return 'id:' + item.id
	return 't:' + (item.time || '') + '|' + (item.text || '')
}

function _createState() {
	// 非 H5/非 Vue2 时降级为普通对象
	if (typeof Vue !== 'undefined' && Vue.observable) {
		return Vue.observable({
			visible: false,
			enterActive: false,
			displayTime: '',
			displayText: '',
			displayPicture: '',
			gnpLastKey: '',
			gnpLastKeyAt: 0,
			gnpNoticeSeen: {},
			gnpHideTimer: null,
		})
	}
	return {
		visible: false,
		enterActive: false,
		displayTime: '',
		displayText: '',
		displayPicture: '',
		gnpLastKey: '',
		gnpLastKeyAt: 0,
		gnpNoticeSeen: {},
		gnpHideTimer: null,
	}
}

export const noticeTopState = _createState()

let _bound = false
function _onMsg(msg) {
	const item = parseAppWsNoticeDisplay(msg)
	if (!item || !String(item.text).trim()) return
	const key = _fingerprint(item)
	const now = Date.now()
	if (key === noticeTopState.gnpLastKey && now - (noticeTopState.gnpLastKeyAt || 0) < 2000) return
	if (item.id && noticeTopState.gnpNoticeSeen[item.id]) return
	if (item.id) {
		noticeTopState.gnpNoticeSeen = { ...noticeTopState.gnpNoticeSeen, [item.id]: 1 }
	}
	noticeTopState.gnpLastKey = key
	noticeTopState.gnpLastKeyAt = now
	noticeTopState.displayTime = formatNoticeTimeForBanner(item.time) || '—'
	noticeTopState.displayText = item.text
	noticeTopState.displayPicture = item.picture || ''
	if (noticeTopState.gnpHideTimer) {
		clearTimeout(noticeTopState.gnpHideTimer)
		noticeTopState.gnpHideTimer = null
	}
	noticeTopState.visible = true
	noticeTopState.enterActive = false
	// 与 index 内联版一致，下一帧后触发入场动画
	setTimeout(() => {
		noticeTopState.enterActive = true
	}, 30)
	noticeTopState.gnpHideTimer = setTimeout(() => {
		hideTopNotice()
	}, HIDE_MS)
}

export function hideTopNotice() {
	if (noticeTopState.gnpHideTimer) {
		clearTimeout(noticeTopState.gnpHideTimer)
		noticeTopState.gnpHideTimer = null
	}
	noticeTopState.enterActive = false
	setTimeout(() => {
		noticeTopState.visible = false
		noticeTopState.displayPicture = ''
	}, 220)
}

/** 在 App onLaunch 或首屏调用一次 */
export function bindAppWsTopNoticeListenerOnce() {
	if (_bound) return
	_bound = true
	uni.$off('appWs:notice', _onMsg)
	uni.$on('appWs:notice', _onMsg)
}