import {
  CanActivate,
  ExecutionContext,
  ForbiddenException,
  Injectable,
  SetMetadata,
  createParamDecorator,
} from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';
import { Reflector } from '@nestjs/core';
import type { AuthenticatedAdmin } from './jwt.strategy';

/** Marks a route as reachable without a token (login, health checks). */
export const IS_PUBLIC_KEY = 'isPublic';
export const Public = () => SetMetadata(IS_PUBLIC_KEY, true);

/** Requires the caller to hold this rid (ancestors count — see expandWithParents). */
export const REQUIRED_RID_KEY = 'requiredRid';
export const RequirePermission = (rid: string) => SetMetadata(REQUIRED_RID_KEY, rid);

/** Injects the authenticated admin: `@CurrentAdmin() admin: AuthenticatedAdmin`. */
export const CurrentAdmin = createParamDecorator(
  (_data: unknown, ctx: ExecutionContext): AuthenticatedAdmin =>
    ctx.switchToHttp().getRequest().user,
);

/**
 * JWT guard that honours @Public().
 *
 * Registered globally in AuthModule, so every route is authenticated by default
 * and opting out is explicit. The legacy app had the inverse default — its router
 * guard skipped a hardcoded `noneAuthUrl` list — which meant any route added
 * without a `meta.role` was silently unprotected.
 */
@Injectable()
export class JwtAuthGuard extends AuthGuard('jwt') {
  constructor(private readonly reflector: Reflector) {
    super();
  }

  canActivate(context: ExecutionContext) {
    const isPublic = this.reflector.getAllAndOverride<boolean>(IS_PUBLIC_KEY, [
      context.getHandler(),
      context.getClass(),
    ]);
    if (isPublic) return true;
    return super.canActivate(context);
  }
}

/** Enforces @RequirePermission(rid) against the expanded permission list. */
@Injectable()
export class PermissionsGuard implements CanActivate {
  constructor(private readonly reflector: Reflector) {}

  canActivate(context: ExecutionContext): boolean {
    const requiredRid = this.reflector.getAllAndOverride<string>(REQUIRED_RID_KEY, [
      context.getHandler(),
      context.getClass(),
    ]);
    if (!requiredRid) return true;

    const user: AuthenticatedAdmin | undefined = context.switchToHttp().getRequest().user;
    if (!user) throw new ForbiddenException();

    if (!user.permissions.includes(requiredRid)) {
      throw new ForbiddenException(`Missing permission: ${requiredRid}`);
    }
    return true;
  }
}