import { HttpException } from "@nestjs/common";
import { Injectable, Scope } from "@nestjs/common";
import type { NestInterceptor } from "@nestjs/common";
import type { ExecutionContext } from "@nestjs/common";
import type { CallHandler } from "@nestjs/common";
import { from, throwError } from "rxjs";
import { catchError, tap } from "rxjs/operators";
import { SystemLogService } from "../../services/system-log.service";

/**
 * Stamps `status_code` into system_log rows created during the request.
 *
 * Why: `SystemLogService` writes the row early (inside service methods),
 * before the HTTP framework finalizes the response status.
 * This interceptor runs after the handler so we can persist the response status.
 */
@Injectable({ scope: Scope.REQUEST })
export class SystemLogStatusCodeInterceptor implements NestInterceptor {
  constructor(private readonly systemLogService: SystemLogService) {}

  intercept(context: ExecutionContext, next: CallHandler) {
    const http = context.switchToHttp();
    const res = http.getResponse<any>();
    const start = Date.now();

    return next.handle().pipe(
      tap(() => {
        const statusCode = typeof res?.statusCode === "number" ? res.statusCode : 200;
        void this.systemLogService.applyResponseStatusToPendingLogs(statusCode, Date.now() - start);
      }),
      catchError((err) => {
        const statusCode =
          err instanceof HttpException ? err.getStatus() : typeof res?.statusCode === "number" ? res.statusCode : 500;
        void this.systemLogService.applyResponseStatusToPendingLogs(statusCode, Date.now() - start);
        return throwError(() => err);
      }),
    );
  }
}