/*Relyence API Retry Example - C#

This file contains C# sample code demonstrating how to handle HTTP 429
(Too Many Requests) responses from the Relyence API.

This example is provided as a .txt file for email compatibility. You may
copy the applicable code into a .cs file in your project and adapt it to
your integration.

The example:
- Retries requests that receive HTTP 429
- Uses the Retry-After response header when available
- Falls back to exponential backoff with jitter
- Stops retrying after a defined number of attempts

This is reference code and may require modification for your application's
framework, API client, error handling, and concurrency model.*/

using System;
using RestSharp;
using System.Linq;
using System.Threading;
using System.Diagnostics;

public class ApiExample
{
    const int TooManyRequestsStatusCode = 429;

    public static RestResponse ExecuteWithRetry(Func<RestResponse> apiCall, int maxRetries = 6)
    {
        for (int attempt = 1; attempt <= maxRetries; attempt++)
        {
            RestResponse response = apiCall();

            if ((int)response.StatusCode != TooManyRequestsStatusCode)
            {
                return response;
            }
            if (attempt == maxRetries)
            {
                return response;
            }

            //get retry-after from header if it exists otherwise use exponential backoff
            var retryAfter = response.Headers?.FirstOrDefault(h => h.Name.Equals("Retry-After", StringComparison.OrdinalIgnoreCase))?.Value?.ToString();

            int delayMs;

            if (int.TryParse(retryAfter, out int seconds))
            {
                delayMs = seconds * 1000;
            }
            else
            {
                var exponential = Math.Pow(2, attempt) * 1000;
                var jitter = new Random().Next(0, 500);
                delayMs = (int)exponential + jitter;
            }

            Thread.Sleep(delayMs);
        }
        throw new Exception("Retry loop failed unexpectedly.");
    }

    public static bool DeleteFunction(string address, BearerToken token, int functionId)
    {
        try
        {
            var client = new RestClient(address);
            var request = new RestRequest($"/v1/function");
            request.AddHeader("Authorization", $"Bearer {token.AccessToken}");
            request.AddQueryParameter("id", functionId);

            RestResponse response = ExecuteWithRetry(() => client.ExecuteDelete(request));

            if (response.IsSuccessful)
            {
                return true;
            }
            else return false;
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex.Message);
            return false;
        }
    }
}