using System.Threading.Tasks;

public class Query
{
	public static async Task<string> Get(string urlPath, bool withAuth, Dictionary<string,string> extraParameters = null)
	{
		return await Call("GET", urlPath, withAuth, extraParameters);
	}

	public static async Task<string> Post(string urlPath, bool withAuth, string postData, Dictionary<string,string> extraParameters = null)
	{
		return await Call("POST", urlPath, withAuth, extraParameters, postData);
	}

	public static async Task<string> Call(string method, string urlPath, bool withAuth, 
		Dictionary<string,string> extraParameters = null, string postData = null)
	{
		string finalPath = LocalConfig.homeserver + urlPath;

		for (int i=0; i<10; i++)
		{
			using (var client = new HttpClient())
			{
				if (withAuth)
					client.DefaultRequestHeaders.Add("Authorization", "Bearer " + LocalConfig.authToken);

				if (extraParameters != null)
				{
					foreach ((string key, string value) in extraParameters)
					{
						client.DefaultRequestHeaders.Add(key, value);
					}
				}
				
				HttpResponseMessage response;
				if (method == "POST")
				{
					response = await client.PostAsync(finalPath, new StringContent(postData));
				} else {
					response = await client.GetAsync(finalPath);
				}

				if (response.IsSuccessStatusCode)
					return await response.Content.ReadAsStringAsync();

				// Retry logic
				// ex: https://spec.matrix.org/v1.14/client-server-api/#rate-limiting
				if (response.StatusCode == System.Net.HttpStatusCode.TooManyRequests)
				{
					if (i != 9)
						await Task.Delay(i*1000 + 100);
					else
						Console.WriteLine("FATAL - too many requests even though we delayed");					
				} else 
				{
					Console.WriteLine("Problem with API request:" + response.StatusCode);

					if ((int) response.StatusCode >= 400 && (int) response.StatusCode < 500)
					{
						Console.WriteLine("Giving up on this one due to status code.");
						return null;
					}

					if (i != 9)
						Console.WriteLine("Retry...");
					else
						Console.WriteLine("FATAL");
				}
				
			}
		}

		return null;
	}
}