using System.Net;
using System.Security.Cryptography;

namespace Test
{
    public class Program
    {
        private const string SECRET_KEY = "arsuwuxsy2lesiq7a835gdttu39";

        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            var app = builder.Build();

            app.UseHttpsRedirection();

            app.MapPost("/mywebhookurl", async (HttpContext context) =>
            {
                try
                {
                    string senderUrl = context.Request.Headers["X-Telligent-Webhook-Sender"].FirstOrDefault();
                    string hashSignature = context.Request.Headers["X-Telligent-Webhook-Signature"].FirstOrDefault();

                    string rawPostData;
                    using (var reader = new System.IO.StreamReader(context.Request.Body))
                    {
                        rawPostData = await reader.ReadToEndAsync();
                    }

                    // Validate the posted data's authenticity
                    string calculatedSignature = CalculateSignature(rawPostData, SECRET_KEY);
                    if (!hashSignature.Equals(calculatedSignature))
                    {
                        // The signatures do mot match only if the wrong secret is used, 
                        // or the data is not from the community site.
                        context.Response.StatusCode = (int)HttpStatusCode.BadRequest;
                        System.Console.WriteLine("Signature validation failed.");
                    }
                    var webhookEvents = System.Text.Json.JsonSerializer.Deserialize<WebhookEvents>(rawPostData);

                    foreach (var webhookEvent in webhookEvents.events)
                    {
                        // Ensure that the event type is the one you want to handle
                        if (webhookEvent.TypeId == "98b84792-bbcc-4c27-8df3-f594322b5087")   // Blog Post Created
                        {
                            var userId = Int32.Parse(webhookEvent.EventData["ActorUserId"].ToString());
                            var contentId = Guid.Parse(webhookEvent.EventData["ContentId"].ToString());
                            var blogPostId = Int32.Parse(webhookEvent.EventData["BlogPostId"].ToString());

                            // TODO: do something with the data
                            System.Console.WriteLine($"Blog Post Created: userId: {userId}, contentId: {contentId}, blogPostId: {blogPostId}");

                        }
                    }

                    context.Response.StatusCode = (int)HttpStatusCode.OK;
                }
                catch (Exception ex)
                {
                    System.Console.WriteLine(ex.ToString());
                    context.Response.StatusCode = (int)HttpStatusCode.Conflict;
                }
            });

            app.Run();
        }

        private static string CalculateSignature(string data, string secret)
        {
            var encoding = new System.Text.UTF8Encoding();
            byte[] secretByte = encoding.GetBytes(secret);
            HMACSHA256 hmacsha256 = new HMACSHA256(secretByte);

            byte[] dataBytes = encoding.GetBytes(data);
            byte[] dataHash = hmacsha256.ComputeHash(dataBytes);

            return Convert.ToBase64String(dataHash);
        }
    }

    public class WebhookEvents
    {
        public List<WebhookEvent> events { get; set; }
    }

    public class WebhookEvent
    {
        public string TypeId { get; set; }
        public string DateOccurred { get; set; }
        public Dictionary<string, object> EventData { get; set; }
    }
}