import 'dart:convert';
import 'dart:io';

import 'package:shelf/shelf.dart';
import 'package:shelf_router/shelf_router.dart';

import '../cors_headers.dart';
import '../firebase_auth.dart';
import '../trading/trading_dev_actions.dart';

const String tradingDevBasePath = '/v1/me/trading/dev';

/// Dev-only HTTP endpoints to exercise the trading flow without waiting for
/// real market conditions. Mounted only when `TRADING_DEV_ENDPOINTS_ENABLED=true`.
///
/// Endpoints:
///   * `POST /v1/me/trading/dev/force-fire` — seeds dipped snapshots for the
///     caller and runs one [TradingPipeline.evaluate] cycle. The next worker
///     tick (or an immediate SignalR push from `createAndDeliverQuestion`)
///     surfaces the question in the Flutter UI.
Handler tradingDevHandler({
  required FirebaseAuthVerifier auth,
  required TradingDevActions devActions,
}) {
  final Router router = Router();

  router.post('$tradingDevBasePath/force-fire', (Request request) async {
    final String? firebaseUid = await _verify(auth, request);
    if (firebaseUid == null) {
      return _jsonResponse(401, <String, dynamic>{'error': 'Unauthorized'});
    }
    try {
      final ForceFireResult result = await devActions.forceFireDip(firebaseUid);
      return _jsonResponse(200, result.toJson());
    } catch (e, st) {
      stderr.writeln('trading dev force-fire failed for $firebaseUid: $e\n$st');
      return _jsonResponse(500, <String, dynamic>{'error': 'Internal error'});
    }
  });

  return (Request request) async {
    if (request.method == 'OPTIONS') {
      return Response.ok('', headers: apiCorsHeaders());
    }
    return router.call(request);
  };
}

Future<String?> _verify(FirebaseAuthVerifier auth, Request request) {
  return auth.verifyBearerToken(
    request.headers['Authorization'] ?? request.headers['authorization'],
  );
}

Response _jsonResponse(int status, Map<String, dynamic> body) {
  return Response(
    status,
    body: jsonEncode(body),
    headers: <String, String>{
      ...apiCorsHeaders(),
      'Content-Type': 'application/json',
    },
  );
}