// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.
using System;
using System.IO; 
using System.Text;
using UnrealBuildTool;
using System.Diagnostics;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace UnrealBuildTool
{
    public class HTML5SDKInfo
    {
        static string EmscriptenSettingsPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".emscripten");

        static Dictionary<string, string> ReadEmscriptenSettings()
        {
            // Check HTML5ToolChain.cs for duplicate
            if (!System.IO.File.Exists(EmscriptenSettingsPath))
            {
                return new Dictionary<string, string>();
            }

            Dictionary<string, string> Settings = new Dictionary<string, string>();
            System.IO.StreamReader SettingFile = new System.IO.StreamReader(EmscriptenSettingsPath);
            string EMLine = null;
            while ((EMLine = SettingFile.ReadLine()) != null)
            {
                EMLine = EMLine.Split('#')[0];
                string Pattern1 = @"(\w*)\s*=\s*['\[]?([^'\]\r\n]*)['\]]?";
                Regex Rgx = new Regex(Pattern1, RegexOptions.IgnoreCase);
                MatchCollection Matches = Rgx.Matches(EMLine);
                foreach (Match Matched in Matches)
                {
                    if (Matched.Groups.Count == 3 && Matched.Groups[2].ToString() != "")
                    {
                        Settings[Matched.Groups[1].ToString()] = Matched.Groups[2].ToString();
                    }
                }
            }

            return Settings;
        }

        public static string EmscriptenSDKPath()
        {
           var ConfigCache = new ConfigCacheIni(UnrealTargetPlatform.HTML5, "Engine", UnrealBuildTool.GetUProjectPath());
           // always pick from the Engine the root directory and NOT the staged engine directory. 
           string IniFile = Path.GetFullPath(Path.GetDirectoryName(UnrealBuildTool.GetUBTPath()) + "/../../") + "Config/HTML5/HTML5Engine.ini";
           ConfigCache.ParseIniFile(IniFile);

            string PlatformName = "";
            if (!Utils.IsRunningOnMono)
            {
                PlatformName = "Windows";
            }
            else
            {
                PlatformName = "Mac";
            }
            string EMCCPath;
            bool ok = ConfigCache.GetString("HTML5SDKPaths", PlatformName, out EMCCPath);

            if (ok && System.IO.Directory.Exists(EMCCPath))
                return EMCCPath;

            // try to find SDK Location from env.
            if (Environment.GetEnvironmentVariable("EMSCRIPTEN") != null
                && System.IO.Directory.Exists(Environment.GetEnvironmentVariable("EMSCRIPTEN"))
                )
            {
                return Environment.GetEnvironmentVariable("EMSCRIPTEN");
            }

            return ""; 
        }

        public  static string PythonPath()
        {
            // find Python.
            var EmscriptenSettings = ReadEmscriptenSettings();

			// check emscripten generated config file. 
            if (EmscriptenSettings.ContainsKey("PYTHON")
                && System.IO.File.Exists(EmscriptenSettings["PYTHON"])
                )
            {
                return EmscriptenSettings["PYTHON"];
            }

            // It might be setup as a env variable. 
            if (Environment.GetEnvironmentVariable("PYTHON") != null
                &&
                System.IO.File.Exists(Environment.GetEnvironmentVariable("PYTHON"))
                )
            {
                return Environment.GetEnvironmentVariable("PYTHON");
            }

            // it might just be on path. 
            ProcessStartInfo startInfo = new ProcessStartInfo();
            Process PythonProcess = new Process();

            startInfo.CreateNoWindow = true;
            startInfo.RedirectStandardOutput = true;
            startInfo.RedirectStandardInput = true;

            startInfo.Arguments = "python";
			startInfo.UseShellExecute = false;

			if (!Utils.IsRunningOnMono) 
			{
				startInfo.FileName = "C:\\Windows\\System32\\where.exe";
			}
			else 
			{
				startInfo.FileName = "whereis";
			}


			PythonProcess.StartInfo = startInfo;
            PythonProcess.Start();
            PythonProcess.WaitForExit();

            string Apps = PythonProcess.StandardOutput.ReadToEnd();
            Apps = Apps.Replace('\r', '\n');
            string[] locations = Apps.Split('\n');

            return locations[0];
        }

        public static string EmscriptenPackager()
        {
            return Path.Combine(EmscriptenSDKPath(), "tools", "file_packager.py"); 
        }

        public static string EmscriptenCompiler()
        {
            return Path.Combine(EmscriptenSDKPath(), "emcc");
        }

        public static bool IsSDKInstalled()
        {
			return File.Exists(GetVersionInfoPath());
        }

        public static bool IsPythonInstalled()
        {
            if (String.IsNullOrEmpty(PythonPath()))
                return false;
            return true;
        }

        public static string EmscriptenVersion()
        {
            string VersionInfo = File.ReadAllText(GetVersionInfoPath());
            VersionInfo = VersionInfo.Trim();
            return VersionInfo; 
        }

		static string GetVersionInfoPath()
		{
            string BaseSDKPath = HTML5SDKInfo.EmscriptenSDKPath(); 
            return Path.Combine(BaseSDKPath,"emscripten-version.txt");
		}
    }
}