import { CanActivate, ExecutionContext, Injectable, UnauthorizedException } from "@nestjs/common";
import { Reflector } from "@nestjs/core";
import { JwtService } from "@nestjs/jwt";
import { Request } from 'express';
import { IS_PUBLIC_KEY } from "../decorators/public.decorator";
import { ConfigService } from "@nestjs/config";

@Injectable()
export class AuthGuard implements CanActivate {
  constructor(
    private readonly jwtService: JwtService,
    private readonly reflector: Reflector,
    private readonly configService: ConfigService,
  ) {}

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

    const request = context.switchToHttp().getRequest<Request>();
    if (request.path.startsWith('/api-docs')) {
      return true;
    }

    const authHeader = request.headers['authorization'] as string | undefined;
    if (!authHeader || !authHeader.startsWith('Bearer ')) {
      throw new UnauthorizedException('Token manquant ou invalide');
    }

    const token = authHeader.split(' ')[1];
    try {
      const payload = await this.jwtService.verifyAsync(token, {
        secret: this.configService.get<string>('jwt.accessSecret'),
      });

      request.user = {
        ...payload,
        id: payload.sub,
      };

      return true;
    } catch (error) {
      throw new UnauthorizedException('Token invalide ou expiré');
    }
  }
}