import { Injectable } from '@nestjs/common';
import { PassportStrategy } from '@nestjs/passport';
import { Strategy, ExtractJwt } from 'passport-jwt';
import { ConfigService } from '@nestjs/config';
import { passportJwtSecret } from 'jwks-rsa';
import { mapGroupsToPermissions } from './permissions.enum';
import type { AuthenticatedUser } from './authenticated-request';

interface JwtPayload {
  sub: string;
  email: string;
  name?: string;
  preferred_username?: string;
  groups?: string[];
}

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy, 'jwt') {
  constructor(configService: ConfigService) {
    const issuer = configService.get<string>('OIDC_ISSUER', '');

    super({
      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
      ignoreExpiration: false,
      issuer,
      algorithms: ['RS256'],
      secretOrKeyProvider: passportJwtSecret({
        cache: true,
        rateLimit: true,
        jwksRequestsPerMinute: 5,
        jwksUri: `${issuer.endsWith('/') ? issuer.slice(0, -1) : issuer}/jwks/`,
      }),
    });
  }

  validate(payload: JwtPayload): AuthenticatedUser {
    const groups = payload.groups ?? [];
    return {
      userId: payload.sub,
      email: payload.email,
      name: payload.name || payload.preferred_username || '',
      preferredUsername: payload.preferred_username ?? null,
      groups: groups,
      permissions: mapGroupsToPermissions(groups),
    };
  }
}