namespace Uwaa.HTTP.Routing;

/// <summary>
/// Selects one of multiple possible routers.
/// </summary>
public class Router : RouterBase
{
    public record Route(string? Key, RouterBase Router);

    public readonly List<Route> Routes = new List<Route>();

    public override HttpMethod Method => HttpMethod.Any;

    public override int Arguments => 0;

    protected override async Task<HttpResponse?> GetResponseInner(HttpRequest req, HttpClientInfo info, ArraySegment<string> path)
    {
        string next = path.Count == 0 ? string.Empty : path[0];
        foreach (Route route in Routes)
        {
            if (route.Key == next || route.Key == null)
            {
                HttpResponse? resp = await route.Router.GetResponse(req, info, route.Key == null || path.Count == 0 ? path : path[1..]);
                if (resp != null)
                    return resp;
            }
        }
        return null;
    }

    /// <summary>
    /// Adds a route to the router on the given sub path.
    /// </summary>
    public void Add(string? key, RouterBase router) => Routes.Add(new Route(key, router));

    /// <summary>
    /// Adds a route to the router.
    /// </summary>
    public void Add(RouterBase router) => Add(null, router);

    /// <summary>
    /// Adds an endpoint to the router on the given sub path.
    /// </summary>
    public void Add(string? key, FuncEndpointDelegateAsync func) => Routes.Add(new Route(key, new FuncEndpoint(func)));

    /// <summary>
    /// Adds a wildcard endpoint to the router.
    /// </summary>
    public void Add(FuncEndpointDelegateAsync func) => Add(null, func);

    /// <summary>
    /// Adds an endpoint to the router on the given sub path.
    /// </summary>
    public void Add(string? key, FuncEndpointDelegate func) => Add(key, (req, info) => Task.FromResult(func(req, info)));

    /// <summary>
    /// Adds a wildcard endpoint to the router.
    /// </summary>
    public void Add(FuncEndpointDelegate func) => Add(null, func);

    /// <summary>
    /// Adds a static response to the router on the given sub path.
    /// </summary>
    public void Add(string? key, HttpResponse response) => Routes.Add(new Route(key, new StaticEndpoint(response)));

    /// <summary>
    /// Adds a wildcard static response to the router.
    /// </summary>
    public void Add(HttpResponse response) => Add(null, response);
}