import { Injectable } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import { PassportStrategy } from '@nestjs/passport';
import { Strategy } from 'passport-jwt';
import { Request } from 'express';
import type { AuthUser, JwtPayload } from '../types/auth-user';

/**
 * Custom extractor that reads JWT from the httpOnly "session" cookie.
 */
function cookieExtractor(req: Request): string | null {
  if (req?.cookies) {
    return req.cookies.session || null;
  }
  return null;
}

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {
  constructor(configService: ConfigService) {
    super({
      jwtFromRequest: cookieExtractor,
      ignoreExpiration: false,
      secretOrKey: configService.get<string>('JWT_SECRET', 'fallback-secret'),
    });
  }

  async validate(payload: JwtPayload): Promise<AuthUser> {
    return {
      id: payload.sub,
      username: payload.username,
      role: payload.role,
      tenantId: payload.tenantId,
      // Ein vor dieser Aenderung ausgestelltes Token traegt diesen Anspruch
      // nicht; der strenge Vergleich ergibt dann false, laufende Sitzungen
      // verhalten sich unveraendert (260921-fi3, D-01 — keine Aussperrwelle).
      mustChangePassword: payload.mustChangePassword === true,
    };
  }
}