<template>
    <div class="app-container">
      <el-button type="primary" @click="handleAddRole">
        {{ $t('permission.addRole') }}
      </el-button>
  
      <el-table :data="rolesList" style="width: 100%;margin-top:30px;" border>
        <el-table-column align="center" label="Role Key" width="220">
          <template slot-scope="scope">
            {{ scope.row.key }}
          </template>
        </el-table-column>
        <el-table-column align="center" label="Role Name" width="220">
          <template slot-scope="scope">
            {{ scope.row.name }}
          </template>
        </el-table-column>
        <el-table-column align="header-center" label="Description">
          <template slot-scope="scope">
            {{ scope.row.description }}
          </template>
        </el-table-column>
        <el-table-column align="center" label="Operations">
          <template slot-scope="scope">
            <el-button type="primary" size="small" @click="handleEdit(scope)">
              {{ $t('permission.editPermission') }}
            </el-button>
            <el-button type="danger" size="small" @click="handleDelete(scope)">
              {{ $t('permission.delete') }}
            </el-button>
          </template>
        </el-table-column>
      </el-table>
  
      <el-dialog :visible.sync="dialogVisible" :title="dialogType==='edit'?'Edit Role':'New Role'">
        <el-form :model="role" label-width="80px" label-position="left">
          <el-form-item label="Name">
            <el-input v-model="role.name" placeholder="Role Name" />
          </el-form-item>
          <el-form-item label="Desc">
            <el-input
              v-model="role.description"
              :autosize="{ minRows: 2, maxRows: 4}"
              type="textarea"
              placeholder="Role Description"
            />
          </el-form-item>
          <el-form-item label="Menus">
            <el-tree ref="tree" :check-strictly="checkStrictly" :data="routesData" :props="defaultProps" show-checkbox node-key="path" class="permission-tree" />
          </el-form-item>
        </el-form>
        <div style="text-align:right;">
          <el-button type="danger" @click="dialogVisible=false">
            {{ $t('permission.cancel') }}
          </el-button>
          <el-button type="primary" @click="confirmRole">
            {{ $t('permission.confirm') }}
          </el-button>
        </div>
      </el-dialog>
    </div>
  </template>
  
  <script>
  import path from 'path'
  import { deepClone } from '@/utils'
  import { getRoutes, getRoles, addRole, deleteRole, updateRole } from '@/api/role'
  import i18n from '@/lang'
  
  const defaultRole = {
    key: '',
    name: '',
    description: '',
    routes: []
  }
  
  export default {
    data() {
      return {
        role: Object.assign({}, defaultRole),
        routes: [],
        rolesList: [],
        dialogVisible: false,
        dialogType: 'new',
        checkStrictly: false,
        defaultProps: {
          children: 'children',
          label: 'title'
        }
      }
    },
    computed: {
      routesData() {
        return this.routes
      }
    },
    created() {
      // Mock: get all routes and roles list from server
      this.getRoutes()
      this.getRoles()
    },
    methods: {
      async getRoutes() {
        const res = await getRoutes()
        this.serviceRoutes = res.data
        const routes = this.generateRoutes(res.data)
        this.routes = this.i18n(routes)
      },
      async getRoles() {
        const res = await getRoles()
        this.rolesList = res.data
      },
      i18n(routes) {
        const app = routes.map(route => {
          route.title = i18n.t(`route.${route.title}`)
          if (route.children) {
            route.children = this.i18n(route.children)
          }
          return route
        })
        return app
      },
      // Reshape the routes structure so that it looks the same as the sidebar
      generateRoutes(routes, basePath = '/') {
        const res = []
  
        for (let route of routes) {
          // skip some route
          if (route.hidden) { continue }
  
          const onlyOneShowingChild = this.onlyOneShowingChild(route.children, route)
  
          if (route.children && onlyOneShowingChild && !route.alwaysShow) {
            route = onlyOneShowingChild
          }
  
          const data = {
            path: path.resolve(basePath, route.path),
            title: route.meta && route.meta.title
  
          }
  
          // recursive child routes
          if (route.children) {
            data.children = this.generateRoutes(route.children, data.path)
          }
          res.push(data)
        }
        return res
      },
      generateArr(routes) {
        let data = []
        routes.forEach(route => {
          data.push(route)
          if (route.children) {
            const temp = this.generateArr(route.children)
            if (temp.length > 0) {
              data = [...data, ...temp]
            }
          }
        })
        return data
      },
      handleAddRole() {
        this.role = Object.assign({}, defaultRole)
        if (this.$refs.tree) {
          this.$refs.tree.setCheckedNodes([])
        }
        this.dialogType = 'new'
        this.dialogVisible = true
      },
      handleEdit(scope) {
        this.dialogType = 'edit'
        this.dialogVisible = true
        this.checkStrictly = true
        this.role = deepClone(scope.row)
        this.$nextTick(() => {
          const routes = this.generateRoutes(this.role.routes)
          this.$refs.tree.setCheckedNodes(this.generateArr(routes))
          // set checked state of a node not affects its father and child nodes
          this.checkStrictly = false
        })
      },
      handleDelete({ $index, row }) {
        this.$confirm('Confirm to remove the role?', 'Warning', {
          confirmButtonText: 'Confirm',
          cancelButtonText: 'Cancel',
          type: 'warning'
        })
          .then(async() => {
            await deleteRole(row.key)
            this.rolesList.splice($index, 1)
            this.$message({
              type: 'success',
              message: 'Delete succed!'
            })
          })
          .catch(err => { console.error(err) })
      },
      generateTree(routes, basePath = '/', checkedKeys) {
        const res = []
  
        for (const route of routes) {
          const routePath = path.resolve(basePath, route.path)
  
          // recursive child routes
          if (route.children) {
            route.children = this.generateTree(route.children, routePath, checkedKeys)
          }
  
          if (checkedKeys.includes(routePath) || (route.children && route.children.length >= 1)) {
            res.push(route)
          }
        }
        return res
      },
      async confirmRole() {
        const isEdit = this.dialogType === 'edit'
  
        const checkedKeys = this.$refs.tree.getCheckedKeys()
        this.role.routes = this.generateTree(deepClone(this.serviceRoutes), '/', checkedKeys)
  
        if (isEdit) {
          await updateRole(this.role.key, this.role)
          for (let index = 0; index < this.rolesList.length; index++) {
            if (this.rolesList[index].key === this.role.key) {
              this.rolesList.splice(index, 1, Object.assign({}, this.role))
              break
            }
          }
        } else {
          const { data } = await addRole(this.role)
          this.role.key = data.key
          this.rolesList.push(this.role)
        }
  
        const { description, key, name } = this.role
        this.dialogVisible = false
        this.$notify({
          title: 'Success',
          dangerouslyUseHTMLString: true,
          message: `
              <div>Role Key: ${key}</div>
              <div>Role Name: ${name}</div>
              <div>Description: ${description}</div>
            `,
          type: 'success'
        })
      },
      // reference: src/view/layout/components/Sidebar/SidebarItem.vue
      onlyOneShowingChild(children = [], parent) {
        let onlyOneChild = null
        const showingChildren = children.filter(item => !item.hidden)
  
        // When there is only one child route, the child route is displayed by default
        if (showingChildren.length === 1) {
          onlyOneChild = showingChildren[0]
          onlyOneChild.path = path.resolve(parent.path, onlyOneChild.path)
          return onlyOneChild
        }
  
        // Show parent if there are no child route to display
        if (showingChildren.length === 0) {
          onlyOneChild = { ... parent, path: '', noShowingChildren: true }
          return onlyOneChild
        }
  
        return false
      }
    }
  }
  </script>
  
  <style lang="scss" scoped>
  .app-container {
    .roles-table {
      margin-top: 30px;
    }
    .permission-tree {
      margin-bottom: 30px;
    }
  }
  </style>