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

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

// Load confirmation token from env
final confirmationToken = Platform.environment['CONFIRMATION_TOKEN'];
// Load secret key from env
final secretKey = Platform.environment['SECRET_KEY'];

// Configure routes.
final _router = Router()
  ..get('/', _rootHandler)
  ..post('/vk', _vkHandler);

Response _rootHandler(Request req) {
  return Response.ok('Hello, World!\n');
}

Future<Response> _vkHandler(Request req) async {
  // POST request should contain a JSON body.
  // JSON must contain a 'type' field.
  // The value of the 'type' field must be one of the following:
  //   'confirmation'
  //   'wall_post_new'
  // If we recieve a 'confirmation' request, we should respond with a confirmationToken.
  // If we recieve a 'wall_post_new' request, we should validate if 'secret' field equals
  // secretKey and respond with an 'ok' string, printing request in the console.

  final requestBody = await req.readAsString();
  final requestJson = json.decode(requestBody);
  final requestType = requestJson['type'];

  if (requestType == 'confirmation') {
    return Response.ok(confirmationToken);
  } else if (requestType == 'wall_post_new') {
    if (requestJson['secret'] == secretKey) {
      print(requestBody);
      return Response.ok('ok');
    } else {
      return Response.ok('invalid secret');
    }
  } else {
    return Response.ok('invalid request type');
  }
}

// Future<void> _postOnMastodon(reqJson) async {
//   // Called to repost the post on Mastodon on vk.
//   // reqJson contains the 'object' field of the VK post.
//   // This object has the 'text' field with the post text.
//   // Also it contains the 'attachments' field with the attachments.
//   // The attachments field is an array of objects.
// }

void main(List<String> args) async {
  
  // Use any available host or container IP (usually `0.0.0.0`).
  final ip = InternetAddress.anyIPv4;

  // Configure a pipeline that logs requests.
  final _handler = Pipeline().addMiddleware(logRequests()).addHandler(_router);

  // For running in containers, we respect the PORT environment variable.
  final port = int.parse(Platform.environment['PORT'] ?? '8080');
  final server = await serve(_handler, ip, port);
  print('Server listening on port ${server.port}');
}