<template>
  <div class="layout-tabs">
    <el-tabs
      type="border-card"
      v-model="curTabKey"
      closable
      @tab-click="clickTab"
      @tab-remove="removeTab"
    >
      <el-tab-pane
        v-for="item in tabs"
        :label="item.title"
        :name="item.tabKey"
        :key="item.tabKey"
      >
        <template slot="label"
          >{{ item.title }}
          <i
            v-if="curTabKey === item.tabKey"
            class="el-icon-refresh"
            @click="refreshTab(item)"
          ></i
        ></template>
      </el-tab-pane>
    </el-tabs>
    <div class="close-tabs" @click="closeOtherTabs">关闭其他</div>
  </div>
</template>

<script>
import { mapMutations, mapActions } from "vuex";
import EventBus from "@/utils/event-bus";

export default {
  name: "LayoutTabs",
  props: {
    // 【根据项目修改】tab页面在路由的第几层，或者说第几层的 router-view 组件（当前项目为第二层）
    tabRouteViewDepth: {
      type: Number,
      default: 2,
    },
    // tab页面的key值，从route对象中取，一个key值对应一个tab页面
    // 默认为matchRoute.path值
    getTabKey: {
      type: Function,
      default: function (routeMatch /* , route */) {
        return routeMatch.path;
      },
    },
    // tab页签的标题，默认从路由meta.title中获取
    tabTitleKey: {
      type: String,
      default: "title",
    },
  },
  data() {
    return {
      tabs: [],
      curTabKey: "",
    };
  },
  methods: {
    ...mapActions("cache", ["addCache", "removeCache", "removeCacheEntry"]),
    ...mapMutations(["setIsRenderTab"]),
    // 切换tab
    changeCurTab() {
      // 当前路由信息
      const { path, query, params, hash, matched } = this.$route;
      // tab标签页路由信息：meta、componentName
      const routeMatch = matched[this.tabRouteViewDepth - 1];
      const meta = routeMatch.meta;
      const componentName = routeMatch.components?.default?.name;
      // 获取tab标签页信息：tabKey标签页key值；title-标签页标题；tab-存在的标签页
      const tabKey = this.getTabKey(routeMatch, this.$route);
      const title = String(meta[this.tabTitleKey] || "");
      const tab = this.tabs.find((tab) => tab.tabKey === tabKey);

      if (!tabKey) {
        // tabKey默认为路由的name值
        console.warn(
          `LayoutTabs组件：${path} 路由没有匹配的tab标签页，如有需要请配置tab标签页的key值`
        );
        return;
      }

      // 同一个路由，但是新旧路径不同时，需要清除路由缓存。例如route.path配置为 '/detail/:id'时路径会不同
      // 这里判断 props.tabRouteViewDepth === matched.length 必须是跟tab同级路由，否则会影响多级路由缓存
      if (
        tab &&
        tab.path !== path &&
        this.tabRouteViewDepth === matched.length
      ) {
        this.removeCacheEntry(componentName || "");
        tab.title = "";
      }

      const newTab = {
        tabKey,
        title: tab?.title || title,
        path,
        params,
        query,
        hash,
        componentName,
      };
      tab ? Object.assign(tab, newTab) : this.tabs.push(newTab);
      this.curTabKey = tabKey;
    },
    // 点击tab
    clickTab(pane) {
      if (!pane.index) return;

      const tab = this.tabs[Number(pane.index)];
      if (tab.path !== this.$route.path) {
        this.gotoTab(tab);
      }
    },
    // 移除tab
    async removeTab(tabKey) {
      // 剩下一个时不能删
      if (this.tabs.length === 1) return;

      const index = this.tabs.findIndex((tab) => tab.tabKey === tabKey);
      if (index < -1) return;

      const tab = this.tabs[index];
      this.tabs.splice(index, 1);

      // 如果删除的是当前tab，则切换到最后一个tab
      if (tab.tabKey === this.curTabKey) {
        const lastTab = this.tabs[this.tabs.length - 1];
        lastTab && this.gotoTab(lastTab);
      }
      this.removeCache(tab.componentName || "");
    },
    // 跳转tab页面
    async gotoTab(tab) {
      await this.$router.push({
        path: tab.path,
        query: tab.query,
        hash: tab.hash,
      });
    },
    // 关闭非当前页的所有tab页签
    closeOtherTabs() {
      this.tabs
        .filter((tab) => tab.tabKey !== this.curTabKey)
        .forEach((tab) => {
          this.removeCache(tab.componentName || "");
        });
      this.tabs = this.tabs.filter((tab) => tab.tabKey === this.curTabKey);
    },
    // 刷新当前tab页面
    async refreshTab(tab) {
      this.setIsRenderTab(false);
      await this.removeCacheEntry(tab.componentName);
      this.setIsRenderTab(true);
    },
    // 关闭tab页面，默认关闭当前页
    async closeLayoutTab(tabKey = this.curTabKey) {
      const index = this.tabs.findIndex((tab) => tab.tabKey === tabKey);
      if (index > -1) {
        this.removeCache(this.tabs[index].componentName);
        this.tabs.splice(index, 1);
      }
    },
    // 设置当前tab的标题
    setCurTabTitle(title) {
      const curTab = this.tabs.find((tab) => tab.tabKey === this.curTabKey);
      if (curTab) {
        curTab.title = title;
      }
    },
  },
  watch: {
    "$route.path": {
      handler() {
        this.changeCurTab();
      },
      immediate: true,
    },
  },
  created() {
    // 对外提供的事件：关闭弹窗；设置tab标题
    EventBus.$on("LayoutTabs:closeTab", (tabKey) => {
      this.closeLayoutTab(tabKey);
    });
    EventBus.$on("LayoutTabs:setTabTitle", (title) => {
      this.setCurTabTitle(title);
    });
  },
};
</script>

<style lang="less">
.layout-tabs {
  position: relative;
  height: 32px;
  line-height: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #f5f7fa;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.12), 0 0 6px 0 rgba(0, 0, 0, 0.04);
  //background-color: #fcc;
  .close-tabs {
    padding-right: 12px;
    cursor: pointer;
    color: #999;
    height: 32px;
    line-height: 32px;
    font-size: 12px;
    &:hover {
      color: #169e8c;
    }
  }
  .el-tabs--border-card {
    height: 30px;
    flex: 1;
    margin-right: 12px;
    border: 1px solid #dcdfe6;
    box-shadow: none;
  }

  .el-tabs__item {
    height: 30px;
    line-height: 30px;
    font-size: 12px;
  }
  .el-tabs__content {
    display: none;
  }
}
</style>
