import 'dart:io';
import 'dart:convert';
import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as io;
import 'package:shelf_router/shelf_router.dart';
import 'package:tracker_backend/database.dart';

void main(List<String> args) async {
  // Use port 8090 as requested
  final port = 8090;
  final db = TrackerDatabase();

  final app = Router();

  app.get('/', (Request request) {
    return Response.ok('Tracker Sync Server Running');
  });

  // Simple Sync Endpoint (Push)
  // Expects JSON: { "userId": "...", "entries": [ ... ] }
  app.post('/sync/push', (Request request) async {
    try {
      final payload = await request.readAsString();
      final data = jsonDecode(payload);
      final userId = data['userId'];
      final entries = data['entries'] as List;

      print('Received sync push for $userId with ${entries.length} entries');

      for (var entry in entries) {
        // Basic upsert handling
        db.upsertCycleEntry(userId, entry);
      }

      return Response.ok(
          jsonEncode({'status': 'success', 'synced': entries.length}));
    } catch (e) {
      print('Sync Error: $e');
      return Response.internalServerError(body: 'Sync Failed: $e');
    }
  });

  // Pull Endpoint
  // GET /sync/pull?userId=...
  app.get('/sync/pull', (Request request) {
    final userId = request.url.queryParameters['userId'];
    if (userId == null) return Response.badRequest(body: 'Missing userId');

    final entries = db.getCycleEntries(userId);
    return Response.ok(jsonEncode({'entries': entries}));
  });

  // Enable CORS
  final handler = Pipeline().addMiddleware((innerHandler) {
    return (request) async {
      final response = await innerHandler(request);
      return response.change(headers: {
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
        'Access-Control-Allow-Headers': 'Origin, Content-Type',
      });
    };
  }).addHandler(app);

  final server = await io.serve(handler, InternetAddress.anyIPv4, port);
  print('Server running on localhost:${server.port}');
}