import { GuildMember, Permissions } from 'discord.js';
import { Config } from './structures';
import $ from './lib';

export enum PERMISSIONS {
  NONE,
  MOD,
  ADMIN,
  OWNER,
  BOT_SUPPORT,
  BOT_ADMIN,
  BOT_OWNER,
}
export const PermissionNames = [
  'User',
  'Moderator',
  'Administrator',
  'Server Owner',
  'Bot Support',
  'Bot Admin',
  'Bot Owner',
];

// Here is where you enter in the functions that check for permissions.
const PermissionChecker: ((member: GuildMember) => boolean)[] = [
  // NONE //
  () => true,

  // MOD //
  (member) =>
    member.hasPermission(Permissions.FLAGS.MANAGE_ROLES) ||
    member.hasPermission(Permissions.FLAGS.MANAGE_MESSAGES) ||
    member.hasPermission(Permissions.FLAGS.KICK_MEMBERS) ||
    member.hasPermission(Permissions.FLAGS.BAN_MEMBERS),

  // ADMIN //
  (member) => member.hasPermission(Permissions.FLAGS.ADMINISTRATOR),

  // OWNER //
  (member) => member.guild.ownerID === member.id,

  // BOT_SUPPORT //
  (member) => Config.support.includes(member.id),

  // BOT_ADMIN //
  (member) => Config.admins.includes(member.id),

  // BOT_OWNER //
  (member) => Config.owner === member.id,
];

// After checking the lengths of these three objects, use this as the length for consistency.
const length = Object.keys(PERMISSIONS).length / 2;

export function hasPermission(
  member: GuildMember,
  permission: PERMISSIONS,
): boolean {
  for (let i = length - 1; i >= permission; i--)
    if (PermissionChecker[i](member)) return true;
  return false;
}

export function getPermissionLevel(member: GuildMember): number {
  for (let i = length - 1; i >= 0; i--)
    if (PermissionChecker[i](member)) return i;
  return 0;
}

// Length Checking
(() => {
  const lenNames = PermissionNames.length;
  const lenChecker = PermissionChecker.length;

  // By transitive property, lenNames and lenChecker have to be equal to each other as well.
  if (length !== lenNames || length !== lenChecker)
    $.error(
      `Permission object lengths aren't equal! Enum Length (${length}), Names Length (${lenNames}), and Functions Length (${lenChecker}). This WILL cause problems!`,
    );
})();