DTLib/DTLib.Web/Routes/SimpleRouter.cs

namespace DTLib.Web.Routes;

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

    public SimpleRouter(ILogger logger)
    {
        _logger = logger;
    }

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

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

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