<template>
  <div :class="classes">
    <slot name="tabs">
      <div :class="[prefixCls + '-bar']">
        <span class="back" @click="onBackClick">
          <i class="iconfont fontcls">&#xe763;</i>
        </span>
        <span class="help" @click="onHelpClick">
          <i class="iconfont fontcls">&#xe630;</i>
        </span>
        <div>
          <div
            :class="tabCls(item)"
            v-for="(item, index) in navList"
            @click="handleChange(index)"
            :key="index"
          >{{item.label}}</div>
        </div>
      </div>
    </slot>
    <div :class="contentClasses" :style="contentStyle" ref="panes">
      <slot name="panes"></slot>
    </div>
  </div>
</template>

<script>
export default {
  name: 'Tabs',
  props: {
    value: {
      type: [String, Number]
    }
  },
  data() {
    return {
      prefixCls: 'yoho-tabs',
      navList: [{
        label: '有货优惠券',
        name: 0
      }, {
        label: 'UFO优惠券',
        name: 1
      }],
      activeKey: this.value
    };
  },
  computed: {
    classes() {
      return [`${this.prefixCls}`];
    },
    contentClasses() {
      return ['yoho-tabs-pane'];
    },
    contentStyle() {
      return [];
    }
  },
  methods: {
    updateNav() {
      this.getTabs().forEach((pane, index) => {
        if (!pane.currentName) {
          pane.currentName = index;
        }

        if (index === 0) {
          if (!this.activeKey) {
            this.activeKey = pane.currentName || index;
          }
        }
      });

      this.updateStatus();
    },
    getTabs() {
      return this.$children.filter(item => item.$options.name === 'TabPane');
    },
    updateStatus() {
      const tabs = this.getTabs();

      tabs.forEach(tab => (tab.show = tab.currentName === this.activeKey));
    },
    handleChange(index) {
      const nav = this.navList[index];

      this.activeKey = nav.name;
      this.$emit('input', nav.name);
    },
    tabCls(item) {
      return [
        'yoho-tab',
        {
          ['yoho-tab-active']: item.name === this.activeKey
        }
      ];
    },
    onBackClick() {
      this.$yoho.finishPage({});
    },
    onHelpClick() {
      this.$yoho.goNewPage({
        url: window.location.protocol + '//m.yohobuy.com/service/qaDetail?keyword=%E4%BC%98%E6%83%A0%E5%88%B8&sonId=181'
      });
    }
  },
  watch: {
    activeKey() {
      this.updateStatus();
    },
    value(val) {
      this.activeKey = val;
    }
  },
  created() {
    this.updateNav();
  }
};
</script>

<style lang="scss" scoped>
$yoho-tab: yoho-tab;

.#{$yoho-tab}s {
  width: 100%;
  height: 100%;
}

.#{$yoho-tab} {
  display: inline-block;
  width: 200px;
  height: 56px;
  font-size: 24px;
  color: white;
  border: 1px solid white;
  box-sizing: border-box;
  background: #3a3a3a;
  text-align: center;
  line-height: 56px;
}

.#{$yoho-tab} + .#{$yoho-tab} {
  border-left: none;
}

.#{$yoho-tab}s-bar {
  width: 100%;
  height: 90px;
  display: flex;
  background: #3a3a3a;
  justify-content: center;
  align-items: center;
  z-index: 4;
}

.#{$yoho-tab}-active {
  color: #444;
  background-color: white;
}

.#{$yoho-tab}s-pane {
  width: 100%;
  height: 100%;
}

.fontcls {
  color: white;
  font-size: 45px;
}

.back {
  display: inline-block;
  width: 90px;
  height: 90px;
  line-height: 90px;
  position: absolute;
  left: 0;
  text-align: center;
}

.help {
  display: inline-block;
  width: 90px;
  height: 90px;
  line-height: 90px;
  position: absolute;
  right: 0;
  text-align: center;
}
</style>