import {
  Inject,
  Injectable,
  Logger,
  UnauthorizedException,
} from '@nestjs/common';

import { PrismaService } from '../Prisma/prisma.service';
import { Request } from 'express';
import { clerkClient } from '@clerk/express';

import { RedisService } from '../Redis/redis.service';

@Injectable()
export class GraphqlService {
  constructor(
    private readonly prisma: PrismaService,
    @Inject('REDIS_CLIENT') private readonly redis: RedisService,
  ) {}

  async acquireContext(req: Request) {
    // get x-session-id from headers
    let sessionId: string;
    const disableAuth = process.env.DISABLE_AUTH === 'true';
    try {
      sessionId = req.headers['x-session-id'] as string;
    } catch (error) {
      Logger.error('Error acquiring context', error);
      if (disableAuth) {
        return null;
      }
      throw new UnauthorizedException('Must provide a session ID');
    }
    if (disableAuth) {
      return null;
    }
    // redis context cache
    const cachedUser = await this.redis.getUser(sessionId);
    if (cachedUser) {
      return cachedUser;
    }
    // check if the token is valid
    const session = await clerkClient.sessions.getSession(sessionId as string);
    if (!session) {
      throw new UnauthorizedException('Invalid session');
    }
    const user = await this.prisma.user.findUnique({
      where: { id: session.userId },
    });
    if (!user) {
      throw new UnauthorizedException('User not found');
    }
    await this.redis.setUser(sessionId, user, session.expireAt);
    return user;
  }
}