import type { CustomUser } from "@/api/generated/private/models/customUser";
import type { Post } from "@/api/generated/private/models/post";
import type { Chat } from "@/api/generated/private/models/chat";
import type { Message } from "@/api/generated/private/models/message";

/**
 * Frontend permission inference. Mirrors backend permission classes so the UI
 * hides actions the user cannot perform — this is a UX guard, NOT a security
 * boundary. The backend remains the source of truth and will return 403.
 */

function isSuperuser(user: CustomUser | null): boolean {
  // CustomUser shape does not currently expose is_superuser; treat as false.
  // If a role-based check becomes useful, extend here.
  void user;
  return false;
}

export function canEditPost(user: CustomUser | null, post: Post): boolean {
  if (!user) return false;
  return user.id === post.author;
}

export function canDeletePost(
  user: CustomUser | null,
  post: Post,
  ctx?: { hubOwnerId?: number | null; isHubModerator?: boolean },
): boolean {
  if (!user) return false;
  if (user.id === post.author) return true;
  if (isSuperuser(user)) return true;
  if (ctx?.hubOwnerId && ctx.hubOwnerId === user.id) return true;
  if (ctx?.isHubModerator) return true;
  return false;
}

export function canEditMessage(user: CustomUser | null, message: Message): boolean {
  if (!user || message.sender == null) return false;
  return user.id === message.sender;
}

export function canDeleteMessage(
  user: CustomUser | null,
  message: Message,
  chat?: Chat | null,
): boolean {
  if (!user) return false;
  if (message.sender != null && user.id === message.sender) return true;
  if (isSuperuser(user)) return true;
  if (chat?.owner === user.id) return true;
  if (chat?.moderators?.includes(user.id)) return true;
  return false;
}

export function canManageChat(user: CustomUser | null, chat: Chat | null): boolean {
  if (!user || !chat) return false;
  if (chat.owner === user.id) return true;
  if (isSuperuser(user)) return true;
  return chat.moderators?.includes(user.id) ?? false;
}