import { ActionTree, GetterTree, Module, MutationTree } from 'vuex';

import { handleFetch } from '../../api/helpers';
import PermissionStoreModel, { PermissionListModel, PermissionModel, PermissionTypes } from '../types/PermissionStoreModel';
import RootState from '../types/RootStateModel';

const namespaced = true;

const state: PermissionStoreModel = {
  permissions: [],
};

const actions: ActionTree<PermissionStoreModel, RootState> = {
  $init({ dispatch }) {
    dispatch('fetchUserPermissions');
  },
  async fetchUserPermissions({ commit }) {
    const response = await handleFetch('/authorization/permissions');

    commit('userPermissions', await response.json() as PermissionModel[]);
  },
};

const getters: GetterTree<PermissionStoreModel, RootState> = {
  findPermission: (state) => (itemName: string): PermissionModel | undefined => {
    for (const permission of state.permissions) {
      const cmsItemName = permission.cmsItemName.match(/[^.]+$/g);

      if (!cmsItemName) {
        throw new Error('Could not convert permission cmsItemName to entity name');
      }

      if (cmsItemName.toString().toLowerCase() === itemName.toLowerCase()) {
        return permission;
      }
    }
  },
  getPermissions: (state, getters) => (itemName: string): PermissionListModel => {
    return {
      canRead: getters.hasPermission(itemName, PermissionTypes.Read),
      canUpdate: getters.hasPermission(itemName, PermissionTypes.Update),
      canCreate: getters.hasPermission(itemName, PermissionTypes.Create),
      canDelete: getters.hasPermission(itemName, PermissionTypes.Delete),
    };
  },
  hasPermission: (state, getters) => (itemName: string, permission: PermissionTypes): boolean => {
    const permissionEntity = getters.findPermission(itemName);

    // If no permission was found, default to having no permissions.
    if (!permissionEntity) {
      return false;
    }

    return permissionEntity.permission >= permission;
  },
  canRead: (state, getters) => (itemName: string): boolean => {
    return getters.hasPermission(itemName, PermissionTypes.Read);
  },
  canUpdate: (state, getters) => (itemName: string): boolean => {
    return getters.hasPermission(itemName, PermissionTypes.Update);
  },
  canCreate: (state, getters) => (itemName: string): boolean => {
    return getters.hasPermission(itemName, PermissionTypes.Create);
  },
  canDelete: (state, getters) => (itemName: string): boolean => {
    return getters.hasPermission(itemName, PermissionTypes.Delete);
  },
};

const mutations: MutationTree<PermissionStoreModel> = {
  userPermissions(state, permissions: PermissionModel[]) {
    state.permissions = permissions;
  },
};

export const permissionStore: Module<PermissionStoreModel, RootState> = {
  namespaced,
  state,
  getters,
  actions,
  mutations,
};