/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

function getHeader (weex) {
  const { extractComponentStyle } = weex
  const { supportSticky } = weex.utils

  return {
    data () {
      return {
        sticky: false,
        initTop: 0,
        placeholder: null,
        supportSticky: supportSticky()
      }
    },

    mounted () {
      this.initTop = this.$el.offsetTop
      this.placeholder = window.document.createElement('header')
    },

    updated () {
      if (!this.sticky) {
        this.initTop = this.$el.offsetTop
      }
    },

    methods: {
      addSticky () {
        this.sticky = true
        this.placeholder.style.display = 'block'
        this.placeholder.style.width = this.$el.offsetWidth + 'px'
        this.placeholder.style.height = this.$el.offsetHeight + 'px'
        this.$el.parentNode.insertBefore(this.placeholder, this.$el)
      },

      removeSticky () {
        this.sticky = false
        try {
          this.$el.parentNode.removeChild(this.placeholder)
        }
        catch (e) {
        }
      }
    },

    render (createElement) {
      /* istanbul ignore next */
      // if (process.env.NODE_ENV === 'development') {
      //   validateStyles('header', this.$vnode.data && this.$vnode.data.staticStyle)
      // }
      return createElement('html:header', {
        attrs: { 'weex-type': 'header' },
        ref: 'header',
        staticClass: 'weex-header weex-ct',
        class: { 'weex-sticky': this.sticky, 'weex-ios-sticky': this.supportSticky },
        staticStyle: extractComponentStyle(this)
      }, this.$slots.default)
    }
  }
}

export default {
  init (weex) {
    weex.registerComponent('header', getHeader(weex))
  }
}