import {
  CallHandler,
  ExecutionContext,
  Injectable,
  Logger,
  NestInterceptor,
} from '@nestjs/common';
import type { Request, Response } from 'express';
import { Observable, tap } from 'rxjs';

@Injectable()
export class LoggingInterceptor implements NestInterceptor {
  private readonly logger = new Logger(LoggingInterceptor.name);

  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
    const http = context.switchToHttp();
    const req = http.getRequest<Request>();
    const res = http.getResponse<Response>();
    const { method, url, body } = req;
    const start = Date.now();

    this.logger.debug(`→ ${method} ${url} ${JSON.stringify(body)}`);

    return next.handle().pipe(
      tap((responseBody) => {
        const ms = Date.now() - start;
        this.logger.debug(`← ${method} ${url} ${res.statusCode} (${ms}ms) ${JSON.stringify(responseBody)}`);
      }),
    );
  }
}