/*

  This Source Code Form is subject to the terms of the Mozilla Public

  License, v. 2.0. If a copy of the MPL was not distributed with this

  file, You can obtain one at http://mozilla.org/MPL/2.0/.

	Copyright (C) 2012 Prince Samuel <prince.samuel@gmail.com>

*/

using System;

using System.Collections.Generic;

using System.Text;

using System.Net;

using System.Threading;

using System.IO;

using OpenHardwareMonitor.GUI;

using OpenHardwareMonitor.Hardware;

using System.Reflection;

using System.Drawing;

using System.Drawing.Imaging;

namespace OpenHardwareMonitor.Utilities

{

    public class HttpServer

    {

        private HttpListener listener;

        private int listenerPort, nodeCount;

        private Thread listenerThread;

        private Node root;

        public HttpServer(Node r, int p)

        {

            root = r;

            listenerPort = p;

            //JSON node count. 

            nodeCount = 0;

            listener = new HttpListener();

        }

        public Boolean startHTTPListener()

        {

            try

            {

                if (listener.IsListening)

                    return true;

                string prefix = "http://+:" + listenerPort + "/";

                listener.Prefixes.Clear();

                listener.Prefixes.Add(prefix);

                listener.Start();

                if (listenerThread == null)

                {

                    listenerThread = new Thread(HandleRequests);

                    listenerThread.Start();

                }

            }

            catch (Exception e)

            {

                return false;

            }

            return true;

        }

        public Boolean stopHTTPListener()

        {

            try

            {

                listenerThread.Abort();

                listener.Stop();

                listenerThread = null;

            }

            catch (System.Net.HttpListenerException e)

            {

            }

            catch (System.Threading.ThreadAbortException e)

            {

            }

            catch (System.NullReferenceException e)

            {

            }

            catch (Exception e)

            {

            }

            return true;

        }

        public void HandleRequests()

        {

            while (listener.IsListening)

            {

                var context = listener.BeginGetContext(new AsyncCallback(ListenerCallback), listener);

                context.AsyncWaitHandle.WaitOne();

            }

        }

        public void ListenerCallback(IAsyncResult result)

        {

            HttpListener listener = (HttpListener)result.AsyncState;

            if (listener == null || !listener.IsListening)

                return;

            // Call EndGetContext to complete the asynchronous operation.

            HttpListenerContext context = listener.EndGetContext(result);

            HttpListenerRequest request = context.Request;

            var requestedFile = request.RawUrl.Substring(1);

            if (requestedFile == "data.json")

            {

                sendJSON(context);

                return;

            }

            if (requestedFile.Contains("images_icon"))

            {

                serveResourceImage(context, requestedFile.Replace("images_icon/", ""));

                return;

            }

            //default file to be served

            if (string.IsNullOrEmpty(requestedFile))

                requestedFile = "index.html";

            string[] splits = requestedFile.Split('.');

            string ext = splits[splits.Length - 1];

            serveResourceFile(context, "Web." + requestedFile.Replace('/', '.'), ext);

        }

        private void serveResourceFile(HttpListenerContext context ,string name, string ext) {

          //hack! resource names do not support the hyphen

          name = "OpenHardwareMonitor.Resources." + name.Replace("custom-theme", "custom_theme");

          string[] names = 

            Assembly.GetExecutingAssembly().GetManifestResourceNames();

          for (int i = 0; i < names.Length; i++) {

            if (names[i].Replace('\\', '.') == name) {

              using (Stream stream = Assembly.GetExecutingAssembly().

                GetManifestResourceStream(names[i])) {

                    context.Response.ContentType = getcontentType("." + ext);

                    context.Response.ContentLength64 = stream.Length;

                    byte[] buffer = new byte[512 * 1024];

                    int len;

                    while ((len = stream.Read(buffer, 0, buffer.Length)) > 0)

                    {

                        context.Response.OutputStream.Write(buffer, 0, len);

                    }

                    context.Response.OutputStream.Close();

                }

              return;

            }

          }

          context.Response.OutputStream.Close();

          context.Response.StatusCode = 404;

          context.Response.Close();

        }

        private void serveResourceImage(HttpListenerContext context ,string name) {

          name = "OpenHardwareMonitor.Resources." + name;

          string[] names = 

            Assembly.GetExecutingAssembly().GetManifestResourceNames();

          for (int i = 0; i < names.Length; i++) {

            if (names[i].Replace('\\', '.') == name) {

              using (Stream stream = Assembly.GetExecutingAssembly().

                GetManifestResourceStream(names[i])) {

                Image image = Image.FromStream(stream);

                context.Response.ContentType = "image/png";

                using (MemoryStream ms = new MemoryStream())

                {

                    image.Save(ms, ImageFormat.Png);

                    ms.WriteTo(context.Response.OutputStream);

                }

                context.Response.OutputStream.Close();

                image.Dispose();

                return;

              }

            }

          } 

          context.Response.OutputStream.Close();

          context.Response.StatusCode = 404;

          context.Response.Close();

        }

        private void sendJSON(HttpListenerContext context)

        {

            string JSON = "{\"id\": 0, \"Text\": \"Sensor\", \"Children\": [";

            nodeCount = 1;

            JSON += generateJSON(root);

            JSON += "]";

            JSON += ", \"Min\": \"Min\"";

            JSON += ", \"Value\": \"Value\"";

            JSON += ", \"Max\": \"Max\"";

            JSON += ", \"ImageURL\": \"\"";

            JSON += "}";

            var responseContent = JSON;

            byte[] buffer = Encoding.UTF8.GetBytes(responseContent);

            context.Response.ContentLength64 = buffer.Length;

            context.Response.ContentType = "application/json";

            Stream outputStream = context.Response.OutputStream;

            outputStream.Write(buffer, 0, buffer.Length);

            outputStream.Close();

        }

        private string generateJSON(Node n)

        {

            string JSON = "{\"id\": " + nodeCount + ", \"Text\": \"" + n.Text + "\", \"Children\": [";

            nodeCount++;

            foreach (Node child in n.Nodes)

                JSON += generateJSON(child) + ", ";

            if (JSON.EndsWith(", "))

                JSON = JSON.Remove(JSON.LastIndexOf(","));

            JSON += "]";

            if (n is SensorNode)

            {

                JSON += ", \"Min\": \"" + ((SensorNode)n).Min + "\"";

                JSON += ", \"Value\": \"" + ((SensorNode)n).Value + "\"";

                JSON += ", \"Max\": \"" + ((SensorNode)n).Max + "\"";

                JSON += ", \"ImageURL\": \"images/transparent.png\"";

            }

            else if (n is HardwareNode)

            {

                JSON += ", \"Min\": \"\"";

                JSON += ", \"Value\": \"\"";

                JSON += ", \"Max\": \"\"";

                JSON += ", \"ImageURL\": \"images_icon/" + getHardwareImageFile((HardwareNode)n) + "\"";

            }

            else if (n is TypeNode)

            {

                JSON += ", \"Min\": \"\"";

                JSON += ", \"Value\": \"\"";

                JSON += ", \"Max\": \"\"";

                JSON += ", \"ImageURL\": \"images_icon/" + getTypeImageFile((TypeNode)n) + "\"";

            }

            else

            {

                JSON += ", \"Min\": \"\"";

                JSON += ", \"Value\": \"\"";

                JSON += ", \"Max\": \"\"";

                JSON += ", \"ImageURL\": \"images_icon/computer.png\"";

            }

            JSON += "}";

            return JSON;

        }

        private static void returnFile(HttpListenerContext context, string filePath)

        {

            context.Response.ContentType = getcontentType(Path.GetExtension(filePath));

            const int bufferSize = 1024 * 512; //512KB

            var buffer = new byte[bufferSize];

            using (var fs = File.OpenRead(filePath))

            {

                context.Response.ContentLength64 = fs.Length;

                int read;

                while ((read = fs.Read(buffer, 0, buffer.Length)) > 0)

                    context.Response.OutputStream.Write(buffer, 0, read);

            }

            context.Response.OutputStream.Close();

        }

        private static string getcontentType(string extension)

        {

            switch (extension)

            {

                case ".avi": return "video/x-msvideo";

                case ".css": return "text/css";

                case ".doc": return "application/msword";

                case ".gif": return "image/gif";

                case ".htm":

                case ".html": return "text/html";

                case ".jpg":

                case ".jpeg": return "image/jpeg";

                case ".js": return "application/x-javascript";

                case ".mp3": return "audio/mpeg";

                case ".png": return "image/png";

                case ".pdf": return "application/pdf";

                case ".ppt": return "application/vnd.ms-powerpoint";

                case ".zip": return "application/zip";

                case ".txt": return "text/plain";

                default: return "application/octet-stream";

            }

        }

        private static string getHardwareImageFile(HardwareNode hn)

        {

            switch (hn.Hardware.HardwareType)

            {

                case HardwareType.CPU:

                    return "cpu.png";

                case HardwareType.GpuNvidia:

                    return "nvidia.png";

                case HardwareType.GpuAti:

                    return "ati.png";

                case HardwareType.HDD:

                    return "hdd.png";

                case HardwareType.Heatmaster:

                    return "bigng.png";

                case HardwareType.Mainboard:

                    return "mainboard.png";

                case HardwareType.SuperIO:

                    return "chip.png";

                case HardwareType.TBalancer:

                    return "bigng.png";

                case HardwareType.RAM:

                    return "chip.png";

                default:

                    return "cpu.png";

            }

        }

        private static string getTypeImageFile(TypeNode tn)

        {

            switch (tn.SensorType)

            {

                case SensorType.Voltage:

                    return "voltage.png";

                case SensorType.Clock:

                    return "clock.png";

                case SensorType.Load:

                    return "load.png";

                case SensorType.Temperature:

                    return "temperature.png";

                case SensorType.Fan:

                    return "fan.png";

                case SensorType.Flow:

                    return "flow.png";

                case SensorType.Control:

                    return "control.png";

                case SensorType.Level:

                    return "level.png";

                case SensorType.Power:

                    return "power.png";

                default:

                    return "power.png";

            }

        }

        public int ListenerPort

        {

            get { return listenerPort; }

            set { listenerPort = value; }

        }

        ~HttpServer()

        {

            stopHTTPListener();

            listener.Abort();

        }

        public void Quit()

        {

            stopHTTPListener();

            listener.Abort();

        }

    }

}