ln.templates/ln.templates/FileSystemTemplateResolver.cs

using System;
using System.Collections.Generic;
using System.IO;
using ln.templates.html;

namespace ln.templates
{
    public class FileSystemTemplateSource : ITemplateResolver
    {
        public String BasePath { get; }
        public bool Throws { get; }

        Dictionary<string, Template> _templates = new Dictionary<string, Template>();

        public FileSystemTemplateSource(String path,bool throws)
            :this(path)
        {
            Throws = throws;
        }
        public FileSystemTemplateSource(String path)
        {
            path = Path.GetFullPath(path);
            
            if (!Directory.Exists(path))
                throw new FileNotFoundException();
            BasePath = path;
        }

        public Template GetTemplateByPath(string path) => GetTemplateByPath(path, Throws);
        public Template GetTemplateByPath(string path,bool _throw)
        {
            string templatePath = Path.Combine(BasePath, path);
            if (!File.Exists(templatePath))
            {
                if (_templates.ContainsKey(path))
                    _templates.Remove(path);

                if (_throw)
                    throw new FileNotFoundException();
                return null;
            }

            if (!_templates.TryGetValue(path,out Template template))
            {
                template = new Template(templatePath, this);
                _templates[path] = template;
            }

            return template;
        }
    }
}