<template>
  <div class="fixed-header" :style="headerStyle">
    <LayoutHeader ref="header" theme="transparent">
      <template>
        <div ref="titleBlock" class="title-block" :style="`transform: translate3d(0, ${blockTranslateY}, 0)`">
          <slot></slot>
        </div>
      </template>
      <template v-slot:opts>
        <WidgetShare v-if="!share" class="article-share" :option="shareOption" @click.native="onShare"></WidgetShare>
      </template>
    </LayoutHeader>
  </div>
</template>

<script>
import ArticleItemHeader from '../article/article-item-header';
import {getDetailShareData} from 'utils/share-handler';

export default {
  name: 'ArticleDetailHeader',
  data() {
    return {
      shareOption: {
        color: '#fff',
        iconBold: true
      }
    };
  },
  props: [
    'data',
    'step',
    'titleStep',
    'share'
  ],
  computed: {
    stepPercent() {
      return parseInt(this.step, 10) / 100;
    },
    headerStyle() {
      let style = {};

      this.setIconColor(Math.floor((255 - 68) * (1 - this.stepPercent) + 68));
      style.background = `rgba(255,255,255,${this.stepPercent})`;

      if (this.stepPercent > 0.98) {
        style.borderBottom = '1px solid #efefef';
      }

      return style;
    },
    blockTranslateY() {
      return '-' + parseInt(`0${this.titleStep}`, 10) + '%';
    }
  },
  mounted() {
    this._iconColor && this.setIconColor(this._iconColor);
  },
  methods: {
    setIconColor(color) {
      if (!this.$el) {
        this._iconColor = color;
        return;
      }

      if (!this.icons) {
        this.icons = [...this.$el.querySelectorAll('.back .iconfont'), ...this.$el.querySelectorAll('.opts .iconfont')];
      }

      if (this.icons && this.icons.length) {
        this.icons.forEach(dom => {
          dom.style.color = `rgb(${color},${color},${color})`;
        });
      }
    },
    onShare() {
      this.$yoho.share(getDetailShareData(this.data));
    },
    onFollow() {
      return parseInt(this.step, 10) / 100;
    },
    onBack() {
      this.$refs.header.onBack();
    }
  },
  components: {
    ArticleItemHeader,
  }
};
</script>

<style scoped>
.fixed-header {
  position: fixed;
  width: 100%;
  z-index: 10;
  transition: all 100ms;

  /deep/ .title {
    overflow: visible!important;
  }

  .title-block {
    height: 100%;
    position: absolute;
    top: 100%;
    left: -60px;
    right: -60px;
  }

  .article-share {
    margin-right: 26px;
  }
}
</style>