using System;
using ln.http;
using ln.http.exceptions;
using ln.http.router;
using ln.templates.html;

namespace ln.templates.http
{
    public delegate void PrepareRenderContext(TemplateRouter templateRouter,TemplateDocument templateDocument, RenderContext renderContext);
    public class TemplateRouter : IHttpRouter
    {
        public ITemplateSource TemplateSource { get; }
        public String DefaultTemplatePath { get; set; }

        public event PrepareRenderContext OnPrepareRenderContext;

        public TemplateRouter(ITemplateSource templateSource)
        {
            TemplateSource = templateSource;
        }

        public HttpResponse Route(HttpRoutingContext routingContext, HttpRequest httpRequest)
        {
            string lookupPath = routingContext.Path.Length > 0 ? routingContext.Path.Substring(1) : DefaultTemplatePath;
            Console.WriteLine("... {0}", lookupPath);

            TemplateDocument document = TemplateSource.GetTemplateByPath(lookupPath);
            if ((DefaultTemplatePath != null) && (document != null))
                document = TemplateSource.GetTemplateByPath(DefaultTemplatePath);

            if (document != null)
            {
                HttpResponse response = new HttpResponse(httpRequest);
                RenderContext renderContext = new RenderContext(response.ContentWriter, TemplateSource);
                renderContext.SetScriptObject("request", httpRequest);
                renderContext.SetScriptObject("response", response);
                OnPrepareRenderContext?.Invoke(this, document, renderContext);
                document.RenderTemplate(renderContext);

                return response;
            }
            return null;
        }
    }
}