One VC bot, one C # and an orange

Continuing my experiments with a “smart” home, for fun, I decided to add a group to VK to control some of its characteristics. For this article, we specify the task: we will try to write in the language of a simple bot, which will respond on behalf of the community in VK, and consider how quickly it can be run on arm32 (in my case, orange pi zero).

Thought about the warmth

There are many other options (for example, runtime), this is one of them

So, decompose on shelves.

Create an application in VC

Here is the detailed documentation.

To create a bot go here
Click "create application" and select "Standalone Application".
Now we are moving to the management and in the Application Id tab we remember its Id. It is useful to us further.

We get a token for working with groups

We send the request by simply inserting into the browser string:
```
https://oauth.vk.com/authorize?client_id=YOURAPPID&group_ids=YOURGROUPID6&display=page&scope=messages,wall,manage&response_type=token&v=5.92 
```
where YOURAPPID is the application id that we found in the previous spoiler, and YOURGROUPID id is your community.
We give access to the application
And we get this answer
```
 https://oauth.vk.com/blank.html#expires_in=0&access_token_YOURGROUPID=YOURTOKEN 
```
Where the token will be a very long combination of Latin letters and numbers

Easier we get the token

Go to the community management

Set up a community to work with long poll

Go to the management tab of our community.
Api Usage and LongPoll Api
Event types (events), we mark the necessary ones in them, for tests I would note everything.

Go to the main part:
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We start favorite ide, we create the console application on net core

Add VkNet

spoiler

Unfortunately on the wiki, the documentation is a bit outdated. One of the reasons for creating this guide.
But there is great support here.

 var api = new VkApi(); api.Authorize(new ApiAuthParams(){AccessToken =MyAppToken });

And in an endless loop we will receive updates.

  while (true) { var s = api.Groups.GetLongPollServer(MyGroupId); var poll = api.Groups.GetBotsLongPollHistory( new BotsLongPollHistoryParams() {Server = s.Server, Ts = s.Ts, Key = s.Key, Wait = 1}); }

Check if something has come to us

 if(poll?.Updates== null) continue;

For all received data, we will find out if any of this is a message, if so, then we will print its contents.

  foreach (var a in poll.Updates) { if (a.Type == GroupUpdateType.MessageNew) { Console.WriteLine(a.Message.Body); } }

And answer the user with the same text

  api.Messages.Send(new MessagesSendParams() { UserId = a.Message.UserId, Message = a.Message.Body });

Received code

 class Program { public static string MyAppToken => "f6bf5e26*************************************************************"; public static ulong MyGroupId => 10******; static void Main(string[] args) { var api = new VkApi(); api.Authorize(new ApiAuthParams(){AccessToken =MyAppToken }); while (true) { var s = api.Groups.GetLongPollServer(MyGroupId); var poll = api.Groups.GetBotsLongPollHistory( new BotsLongPollHistoryParams() {Server = s.Server, Ts = s.Ts, Key = s.Key, Wait = 1}); if(poll?.Updates== null) continue; foreach (var a in poll.Updates) { if (a.Type == GroupUpdateType.MessageNew) { Console.WriteLine(a.Message.Body); api.Messages.Send(new MessagesSendParams() { UserId = a.Message.UserId, Message = a.Message.Body }); } } } } }