namespace Uwaa.HTTP.Routing;

/// <summary>
/// Parses a path and generates or acquires a response.
/// </summary>
public abstract class RouterBase
{
    /// <summary>
    /// Which HTTP method the router will respond to.
    /// </summary>
    public abstract HttpMethod Method { get; }

    /// <summary>
    /// The minimum number of path segments required to produce a response.
    /// </summary>
    public abstract int Arguments { get; }

    public Task<HttpResponse?> GetResponse(HttpRequest req, HttpClientInfo info, ArraySegment<string> path)
    {
        HttpMethod method = Method;
        if (method != HttpMethod.Any && req.Method != method)
            return Task.FromResult<HttpResponse?>(null);

        int arguments = Arguments;
        if (path.Count < arguments)
            return Task.FromResult<HttpResponse?>(null);

        return GetResponseInner(req, info, path);
    }

    /// <summary>
    /// Inline method for routing.
    /// </summary>
    /// <param name="req">The request for which the response is being generated.</param>
    /// <param name="info">Information about the client.</param>
    /// <param name="path">The path segments relevant to the router.</param>
    protected abstract Task<HttpResponse?> GetResponseInner(HttpRequest req, HttpClientInfo info, ArraySegment<string> path);
}