using Newtonsoft.Json;
using System;
using System.Collections.Specialized;
using System.Net;
using System.Text;

//A simple C# class to post messages to a Slack channel
//Note: This class uses the Newtonsoft Json.NET serializer available via NuGet
public class SlackClient
{
	private readonly Uri _uri;
	private readonly Encoding _encoding = new UTF8Encoding();
	
	public SlackClient(string urlWithAccessToken)
	{
		_uri = new Uri(urlWithAccessToken);
	}
	
	//Post a message using simple strings
	public void PostMessage(string text, string username = null, string channel = null)
	{
		Payload payload = new Payload()
		{
			Channel = channel,
			Username = username,
			Text = text
		};
		
		PostMessage(payload);
	}
	
	//Post a message using a Payload object
	public void PostMessage(Payload payload)
	{
		string payloadJson = JsonConvert.SerializeObject(payload);
		
		using (WebClient client = new WebClient())
		{
			NameValueCollection data = new NameValueCollection();
			data["payload"] = payloadJson;
	
			var response = client.UploadValues(_uri, "POST", data);
			
			//The response text is usually "ok"
			string responseText = _encoding.GetString(response);
		}
	}
}

//This class serializes into the Json payload required by Slack Incoming WebHooks
public class Payload
{
	[JsonProperty("channel")]
	public string Channel { get; set; }
	
	[JsonProperty("username")]
	public string Username { get; set; }
	
	[JsonProperty("text")]
	public string Text { get; set; }
}