import {
  CanActivate,
  ExecutionContext,
  ForbiddenException,
  Injectable,
} from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { Request } from 'express';
import { PERMISSIONS_KEY } from '../decorators/permissions.decorator';
import { AuthenticatedUser } from '../decorators/current-user.decorator';

@Injectable()
export class PermissionsGuard implements CanActivate {
  constructor(private readonly reflector: Reflector) {}

  canActivate(context: ExecutionContext): boolean {
    const required = this.reflector.getAllAndOverride<string[]>(
      PERMISSIONS_KEY,
      [context.getHandler(), context.getClass()],
    );
    if (!required || required.length === 0) return true;

    const request = context
      .switchToHttp()
      .getRequest<Request & { user?: AuthenticatedUser }>();
    const user = request.user;
    if (!user) throw new ForbiddenException('Not authenticated');

    const has =
      user.permissions.includes('*') ||
      required.every((p) => user.permissions.includes(p));
    if (!has) {
      throw new ForbiddenException(
        `Missing required permissions: ${required.join(', ')}`,
      );
    }
    return true;
  }
}