import VueRouter from 'vue-router'

import {
  isFn
} from 'uni-shared'

import {
  isPage
} from 'uni-helpers'

import {
  createAppMixin
} from './app'

import {
  createPageMixin
} from './page'

function getMinId (routes) {
  let minId = 0
  routes.forEach(route => {
    if (route.meta.id) {
      minId++
    }
  })
  return minId
}

function getHash () {
  const href = window.location.href
  const index = href.indexOf('#')
  return index === -1 ? '' : decodeURI(href.slice(index + 1))
}

function getLocation (base = '/') {
  let path = decodeURI(window.location.pathname)
  if (base && path.indexOf(base) === 0) {
    path = path.slice(base.length)
  }
  return (path || '/') + window.location.search + window.location.hash
}

/**
 * Service 层 Vue 插件
 * 1.init keepAliveInclude?
 * 2.init router
 * 3.init entryRoute
 * 4.hack vue _init (app)
 * 5.use router
 */
export default {
  install (Vue, {
    routes
  } = {}) {
    const minId = getMinId(routes)
    const router = new VueRouter({
      id: minId,
      mode: __uniConfig.router.mode,
      base: __uniConfig.router.base,
      routes,
      scrollBehavior (to, from, savedPosition) {
        if (savedPosition) {
          return savedPosition
        } else {
          return {
            x: 0,
            y: 0
          }
        }
      }
    })
    const keepAliveInclude = []

    // 需跨平台，根据用户配置 hash 或 history 来调用
    const entryRoute = router.match(__uniConfig.router.mode === 'history' ? getLocation(__uniConfig.router.base)
      : getHash())
    if (entryRoute.meta.name) {
      if (entryRoute.meta.id) {
        keepAliveInclude.push(entryRoute.meta.name + '-' + entryRoute.meta.id)
      } else {
        keepAliveInclude.push(entryRoute.meta.name + '-' + (minId + 1))
      }
    }

    /* eslint-disable no-undef */
    if (__PLATFORM__ === 'h5') {
      if (entryRoute.meta && entryRoute.meta.name) {
        document.body.className = 'uni-body ' + entryRoute.meta.name
      }
    }

    Vue.mixin({
      beforeCreate () {
        const options = this.$options
        if (options.mpType === 'app') {
          options.data = function () {
            return {
              keepAliveInclude
            }
          }
          const appMixin = createAppMixin(routes, entryRoute)
          // mixin app hooks
          Object.keys(appMixin).forEach(hook => {
            options[hook] = options[hook] ? [].concat(appMixin[hook], options[hook]) : [appMixin[hook]]
          })

          // router
          options.router = router

          // onError
          if (!isFn(options.onError)) {
            options.onError = function (err) {
              console.error(err)
            }
          }
        } else if (isPage(this)) {
          const pageMixin = createPageMixin()
          // mixin page hooks
          Object.keys(pageMixin).forEach(hook => {
            options[hook] = options[hook] ? [].concat(pageMixin[hook], options[hook]) : [pageMixin[hook]]
          })
        } else {
          if (this.$parent && this.$parent.__page__) {
            this.__page__ = this.$parent.__page__
          }
        }
      }
    })

    Object.defineProperty(Vue.prototype, '$page', {
      get () {
        return this.__page__
      }
    })

    Vue.use(VueRouter)
  }

}