// /**
//  * File: FileSystemRouter.cs
//  * Author: haraldwolff
//  *
//  * This file and it's content is copyrighted by the Author and / or copyright holder.
//  * Any use wihtout proper permission is illegal and may lead to legal actions.
//  *
//  *
//  **/
using System;
using System.IO;
using System.Collections.Generic;
using ln.http.route;
using ln.mime;

namespace ln.http
{
    public class FileSystemRouter : HttpRoute
    {
        private string _rootPath;
        public String RootPath
        {
            get => _rootPath;
            private set
            {
                _rootPath = Path.GetFullPath(value);
            }
        }

        List<string> indexNames = new List<string>();
        public String[] IndexNames => indexNames.ToArray();
        
        private HttpRouter _parentRouter;
        private MimeTypes _mimeTypes;

        public FileSystemRouter(HttpRouter parentRouter, string mapPath, MimeTypes mimeTypes, string fileSystemPath)
        :base(HttpMethod.GET, mapPath)
        {
            _parentRouter = parentRouter;
            _parentRouter?.Map(this);

            _mimeTypes = mimeTypes;
            
            if (!Directory.Exists(fileSystemPath))
                throw new FileNotFoundException();

            RootPath = fileSystemPath;
            Console.Error.WriteLine("FileSystemRouter created ({0})", RootPath);

            AddIndex("index.html");
            AddIndex("index.htm");

            _routerDelegate = RouteToFileSystem;
        }
        
        public FileSystemRouter(string mapPath, MimeTypes mimeTypes, string fileSystemPath)
            :this(null, mapPath, mimeTypes, fileSystemPath){}

        public FileSystemRouter(string mapPath, string fileSystemPath)
            :this(null, mapPath, null, fileSystemPath){}
        
        public FileSystemRouter(MimeTypes mimeTypes, string fileSystemPath)
            :this(null, null, mimeTypes, fileSystemPath)
        {
        }
        public FileSystemRouter(string fileSystemPath)
            :this(null, null, null, fileSystemPath)
        {
        }
        
        public void AddIndex(string indexName) => indexNames.Add(indexName);
        public void RemoveIndex(string indexName) => indexNames.Remove(indexName);

        public bool RouteToFileSystem(HttpRequestContext requestContext, string routePath)
        {
            string filename = ChooseFile(routePath);

            if (filename is null)
                return false;

            requestContext.Response =
                HttpResponse
                    .OK()
                    .Content(new FileStream(filename, FileMode.Open, FileAccess.Read));
            
            if (_mimeTypes?.TryGetMimeTypeByExtension(Path.GetExtension(filename), out MimeType mimeType) ?? false)
                requestContext.Response.ContentType(mimeType.ToString());
                
            return true;
        }

        string ChooseFile(string path)
        {
            string finalPath = Path.Join(_rootPath, path);

            if (File.Exists(finalPath))
                return finalPath;
            
            if (Directory.Exists(finalPath))
            {
                foreach (string indexName in indexNames)
                {
                    string indexFileName = Path.Combine(finalPath, indexName);
                    if (File.Exists(indexFileName))
                        return indexFileName;
                }
            }

            return null;
        }

        public void Dispose()
        {
            _parentRouter?.UnMap(this);
            _parentRouter = null;
        }
    }

}