DTLib/DTLib.Web/Routes/SimpleRouter.cs

namespace DTLib.Web.Routes;

public class SimpleRouter : IRouter
{
    /// route for any url that doesn't have its own handler
    public IRouteHandler? DefaultRoute { get; set; }
    
    private readonly Dictionary<string, IRouteHandler> _routes = new();
    private readonly ILogger _logger;

    public SimpleRouter(ILogger logger)
    {
        _logger = new ContextLogger(nameof(SimpleRouter), logger);
    }

    public void MapRoute(string url, HttpMethod method, IRouteHandler route) => _routes.Add($"{url}:{method}", route);

    public void MapRoute(string url, HttpMethod method,
        Func<HttpListenerContext, ContextLogger, Task<HttpStatusCode>> route)
        => MapRoute(url, method, new DelegateRouteHandler(route));
    
    public async Task<HttpStatusCode> Resolve(HttpListenerContext ctx, ContextLogger requestLogger)
    {
        
        string? requestPath = ctx.Request.Url?.AbsolutePath;
        if (string.IsNullOrEmpty(requestPath)) 
            requestPath = "/";
        if (!_routes.TryGetValue($"{requestPath}:{ctx.Request.HttpMethod}", out var route))
            route = DefaultRoute;

        HttpStatusCode status;
        if (route == null)
        {
            _logger.LogWarn(nameof(SimpleRouter), $"couldn't resolve request path {requestPath}");
            status = HttpStatusCode.NotFound;
        }
        else status = await route.HandleRequest(ctx, requestLogger);

        ctx.Response.StatusCode = (int)status;
        await ctx.Response.OutputStream.FlushAsync();
        ctx.Response.OutputStream.Close();
        return status;
    }
}