import {
  CallHandler,
  ExecutionContext,
  Injectable,
  NestInterceptor,
} from '@nestjs/common';
import type { Request } from 'express';
import { Observable, tap } from 'rxjs';
import { auditStory } from './audit-detail';
import { AuditLogsService } from './audit-logs.service';

const SKIP_PREFIXES = [
  '/api/health',
  '/api/auth/login',
  '/api/auth/register',
  '/api/auth/otp',
  '/api/auth/refresh',
  '/api/portal',
  '/api/public',
  '/api/platform',
  '/api/audit-logs',
];

type AuthedRequest = Request & {
  user?: {
    userId?: string;
    id?: string;
    organizationId?: string;
  };
};

function inferEntity(path: string): { entityType: string | null; entityId: string | null } {
  const clean = path.replace(/^\/api\/?/, '').split('?')[0] ?? '';
  const parts = clean.split('/').filter(Boolean);
  if (!parts.length) return { entityType: null, entityId: null };
  const entityType = parts[0] ?? null;
  const maybeId = parts[1];
  const entityId =
    maybeId && !['new', 'me', 'summary', 'dashboard', 'board'].includes(maybeId)
      ? maybeId
      : null;
  return { entityType, entityId };
}

function actionLabel(method: string, path: string): string {
  const m = method.toUpperCase();
  if (m === 'POST') return 'ایجاد';
  if (m === 'PATCH' || m === 'PUT') return 'ویرایش';
  if (m === 'DELETE') return 'حذف';
  return m;
  void path;
}

@Injectable()
export class AuditLogsInterceptor implements NestInterceptor {
  constructor(private readonly audit: AuditLogsService) {}

  intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
    const http = context.switchToHttp();
    const req = http.getRequest<AuthedRequest>();
    const method = (req.method ?? 'GET').toUpperCase();
    if (!['POST', 'PATCH', 'PUT', 'DELETE'].includes(method)) {
      return next.handle();
    }

    const path = req.originalUrl || req.url || '';
    if (SKIP_PREFIXES.some((p) => path.startsWith(p))) {
      return next.handle();
    }

    const organizationId = req.user?.organizationId;
    if (!organizationId) return next.handle();

    const actorUserId = req.user?.userId ?? req.user?.id ?? null;
    const { entityType, entityId } = inferEntity(path);
    const action = actionLabel(method, path);
    const ip =
      (req.headers['x-forwarded-for'] as string | undefined)?.split(',')[0]?.trim() ||
      req.ip ||
      null;

    return next.handle().pipe(
      tap({
        next: (response) => {
          const story = auditStory(method, req.body, response);
          const summary =
            story.summary ||
            `${action} ${entityType ?? 'منبع'} از مسیر ${path.split('?')[0]}`;
          void this.audit.write({
            organizationId,
            actorUserId,
            action,
            method,
            path: path.split('?')[0] ?? path,
            entityType,
            entityId,
            summary,
            meta: story.label || story.detail ? { label: story.label, detail: story.detail } : null,
            ip,
          });
        },
      }),
    );
  }
}