import intersection from 'lodash/intersection';

// =========================================================================
// BASIC PERMISSIONS
// =========================================================================

const basicPerms = {
  'INTERACT_WITH_COMMUNITY': (user) => {
    const banned = user.status.banned.status;
    const suspended = user.status.suspension.until && new Date(user.status.suspension.until) > new Date();

    return !banned && !suspended;
  },
  'EDIT_NAME': (user) => {
    const usernameStatus = user.status.username.status;
    return usernameStatus === 'UNSET' || usernameStatus === 'REJECTED';
  }
};

// =========================================================================
// PERMISSIONS BY ROLE
// =========================================================================

const basicRoles = {
  HAS_STAFF_TAG: ['ADMIN', 'MODERATOR', 'STAFF']
};

const queryRoles = {
  UPDATE_CONFIG: ['ADMIN'],
  ACCESS_ADMIN: ['ADMIN', 'MODERATOR'],
  VIEW_USER_EMAILS: ['ADMIN']
};

const mutationRoles = {
  CHANGE_ROLES: ['ADMIN'],
  MODERATE_COMMENTS: ['ADMIN', 'MODERATOR']
};

const roles = {...basicRoles, ...queryRoles, ...mutationRoles};

export const can = (user, ...perms) => {

  if (!user) {
    return false;
  }

  return perms.every((perm) => {

    // Basic Permissions
    const permAction = basicPerms[perm];
    if (typeof permAction !== 'undefined') {
      return permAction(user);
    }

    // Permissions by Role
    const role = roles[perm];
    if (typeof role === 'undefined') {
      throw new Error(`${perm} is not a valid role or permission`);
    }

    return intersection(role, user.roles).length > 0;
  });
};