using System;
using System.IO;
using webapi.Infrastructure.Model;
using NVelocity.App;
using Commons.Collections;
using NVelocity.Runtime.Resource;
using NVelocity.Runtime.Resource.Loader;
using NVelocity.Runtime.Directive;
using NVelocity;

namespace webapi.Infractructure.Helpers
{
    public static class TemplateHelper
    {
        public static string Generate(Letter letter, string template)
        {
            //try
            {
                return generateImpl(letter, template);
            }
            //catch (Exception)
            //{
            //    // todo: log
            //    return string.Empty;
            //}
        }

        private static string generateImpl(Letter letter, string templateName)
        {
            var velocity = new VelocityEngine();
            var props = new ExtendedProperties();
            
            string templateFolderAbsolutePath = System.Web.Hosting.HostingEnvironment.MapPath("~\\bin\\Templates");
            // workaround for using NVelocity from GAC, not from bin folder
            props.AddProperty("file.resource.loader.path", templateFolderAbsolutePath);
            props.AddProperty("resource.manager.class", typeof(ResourceManagerImpl).AssemblyQualifiedName);
            props.AddProperty("file.resource.loader.class", typeof(FileResourceLoader).AssemblyQualifiedName);
            props.AddProperty("directive.manager", typeof(DirectiveManager).AssemblyQualifiedName);

            velocity.Init(props);

            var template = velocity.GetTemplate(templateName);
            var context = new VelocityContext();
            context.Put("letter", letter);

            using (var writer = new StringWriter())
            {
                template.Merge(context, writer);
                var result = writer.GetStringBuilder().ToString();
                return result;
            }
        }
    }
}