const LOGIN_RETURN_KEY = 'login_redirect'
const DEFAULT_RETURN_URL = '/pages/toolbox/toolbox'
const LOGIN_ROUTES = ['pages/login/login', 'pages/login/phone']

function routePath(url = '') {
  return String(url).replace(/^\/+/, '').split(/[?#]/)[0]
}

function isLoginRoute(url = '') {
  return LOGIN_ROUTES.includes(routePath(url))
}

function normalizeReturnUrl(value = '') {
  if (!value) return ''
  let url = String(value)
  try {
    if (/%[0-9a-f]{2}/i.test(url)) url = decodeURIComponent(url)
  } catch (e) {}
  if (!url.startsWith('/')) url = `/${url}`
  if (!url.startsWith('/pages/') || isLoginRoute(url)) return ''
  return url
}

function getPageUrl(page) {
  if (!page) return ''
  const fullPath = page.$page && page.$page.fullPath
  const normalizedFullPath = normalizeReturnUrl(fullPath)
  if (normalizedFullPath) return normalizedFullPath

  const route = routePath(page.route || '')
  if (!route || isLoginRoute(route)) return ''
  const options = page.options || (page.$page && page.$page.options) || {}
  const query = Object.keys(options)
    .filter((key) => options[key] !== undefined && options[key] !== null && options[key] !== '')
    .map((key) => `${encodeURIComponent(key)}=${encodeURIComponent(String(options[key]))}`)
    .join('&')
  return normalizeReturnUrl(`/${route}${query ? `?${query}` : ''}`)
}

/**
 * 记录发起登录的页面。普通端返回时优先使用原页面栈；该记录主要用于 H5 微信授权后页面栈丢失的场景。
 */
export function rememberLoginSource(explicitUrl = '') {
  const directUrl = normalizeReturnUrl(explicitUrl)
  if (directUrl) {
    uni.setStorageSync(LOGIN_RETURN_KEY, directUrl)
    return directUrl
  }

  const pages = getCurrentPages()
  for (let index = pages.length - 1; index >= 0; index -= 1) {
    const url = getPageUrl(pages[index])
    if (!url) continue
    uni.setStorageSync(LOGIN_RETURN_KEY, url)
    return url
  }

  return normalizeReturnUrl(uni.getStorageSync(LOGIN_RETURN_KEY))
}

/**
 * 登录成功后回到发起页：
 * - 页面栈仍存在时 navigateBack，保留表单/滚动位置，并触发来源页 onShow；
 * - H5 微信授权导致页面栈丢失时 reLaunch 到已记录路径；
 * - 没有来源页时才回到工具箱首页。
 */
export function returnAfterLogin() {
  const pages = getCurrentPages()
  const firstLoginIndex = pages.findIndex((page) => isLoginRoute(page.route || ''))

  if (firstLoginIndex > 0) {
    uni.removeStorageSync(LOGIN_RETURN_KEY)
    uni.navigateBack({ delta: pages.length - firstLoginIndex })
    return
  }

  const returnUrl = normalizeReturnUrl(uni.getStorageSync(LOGIN_RETURN_KEY))
  uni.removeStorageSync(LOGIN_RETURN_KEY)
  if (returnUrl) {
    uni.reLaunch({ url: returnUrl })
    return
  }

  uni.switchTab({ url: DEFAULT_RETURN_URL })
}