// OpenTween - Client of Twitter
// Copyright (c) 2007-2012 kiri_feather (@kiri_feather) <kiri.feather@gmail.com>
//           (c) 2008-2012 Moz (@syo68k)
//           (c) 2008-2012 takeshik (@takeshik) <http://www.takeshik.org/>
//           (c) 2010-2012 anis774 (@anis774) <http://d.hatena.ne.jp/anis774/>
//           (c) 2010-2012 fantasticswallow (@f_swallow) <http://twitter.com/f_swallow>
//           (c) 2012      Egtra (@egtra) <http://dev.activebasic.com/egtra/>
//           (c) 2012      kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
// All rights reserved.
// 
// This file is part of OpenTween.
// 
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General public License as published by the Free
// Software Foundation; either version 3 of the License, or (at your option)
// any later version.
// 
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General public License
// for more details.
// 
// You should have received a copy of the GNU General public License along
// with this program. If not, see <http://www.gnu.org/licenses/>, or write to
// the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
// Boston, MA 02110-1301, USA.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Diagnostics;
using System.Windows.Forms;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;
using System.Globalization;
using System.Reflection;
using Microsoft.Win32;

namespace OpenTween
{
    internal class MyApplication
    {
        /// <summary>
        /// 起動時に指定されたオプションを取得します
        /// </summary>
        public static IDictionary<string, string> StartupOptions { get; private set; }

        /// <summary>
        /// アプリケーションのメイン エントリ ポイントです。
        /// </summary>
        [STAThread]
        static int Main(string[] args)
        {
            if (!CheckRuntimeVersion())
            {
                var message = string.Format(Properties.Resources.CheckRuntimeVersion_Error, ".NET Framework 4.5.1");
                MessageBox.Show(message, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
                return 1;
            }

            StartupOptions = ParseArguments(args);

            if (!SetConfigDirectoryPath())
                return 1;

            InitCulture();

            // 同じ設定ファイルを使用する OpenTween プロセスの二重起動を防止する
            string pt = MyCommon.settingPath.Replace("\\", "/") + "/" + Application.ProductName;
            using (Mutex mt = new Mutex(false, pt))
            {
                if (!mt.WaitOne(0, false))
                {
                    var text = string.Format(MyCommon.ReplaceAppName(Properties.Resources.StartupText1), MyCommon.GetAssemblyName());
                    MessageBox.Show(text, MyCommon.ReplaceAppName(Properties.Resources.StartupText2), MessageBoxButtons.OK, MessageBoxIcon.Information);

                    TryActivatePreviousWindow();
                    return 1;
                }

                TaskScheduler.UnobservedTaskException += (s, e) =>
                {
                    e.SetObserved();
                    OnUnhandledException(e.Exception.Flatten());
                };
                Application.ThreadException += (s, e) => OnUnhandledException(e.Exception);
                AppDomain.CurrentDomain.UnhandledException += (s, e) => OnUnhandledException((Exception)e.ExceptionObject);

                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(new TweenMain());

                mt.ReleaseMutex();

                return 0;
            }
        }

        /// <summary>
        /// 動作中の .NET Framework のバージョンが適切かチェックします
        /// </summary>
        private static bool CheckRuntimeVersion()
        {
            // Mono 上で動作している場合はバージョンチェックを無視します
            if (Type.GetType("Mono.Runtime", false) != null)
                return true;

            // .NET Framework 4.5.1 以降で動作しているかチェックする
            // 参照: http://msdn.microsoft.com/en-us/library/hh925568%28v=vs.110%29.aspx

            using (var lmKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry32))
            using (var ndpKey = lmKey.OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\"))
            {
                var releaseKey = (int)ndpKey.GetValue("Release");
                return releaseKey >= 378675;
            }
        }

        /// <summary>
        /// “/key:value”形式の起動オプションを解釈し IDictionary に変換する
        /// </summary>
        /// <remarks>
        /// 不正な形式のオプションは除外されます。
        /// また、重複したキーのオプションが入力された場合は末尾に書かれたオプションが採用されます。
        /// </remarks>
        internal static IDictionary<string, string> ParseArguments(IEnumerable<string> arguments)
        {
            var optionPattern = new Regex(@"^/(.+?)(?::(.*))?$");

            return arguments.Select(x => optionPattern.Match(x))
                .Where(x => x.Success)
                .GroupBy(x => x.Groups[1].Value)
                .ToDictionary(x => x.Key, x => x.Last().Groups[2].Value);
        }

        private static void TryActivatePreviousWindow()
        {
            // 実行中の同じアプリケーションのウィンドウ・ハンドルの取得
            var prevProcess = GetPreviousProcess();
            if (prevProcess == null || prevProcess.MainWindowHandle == IntPtr.Zero)
            {
                return;
            }

            var form = Control.FromHandle(prevProcess.MainWindowHandle) as Form;
            if (form != null)
            {
                if (form.WindowState == FormWindowState.Minimized)
                {
                    NativeMethods.RestoreWindow(form);
                }
                form.Activate();
            }
        }

        private static Process GetPreviousProcess()
        {
            var currentProcess = Process.GetCurrentProcess();
            try
            {
                return Process.GetProcessesByName(currentProcess.ProcessName)
                    .Where(p => p.Id != currentProcess.Id)
                    .FirstOrDefault(p => p.MainModule.FileName.Equals(currentProcess.MainModule.FileName, StringComparison.OrdinalIgnoreCase));
            }
            catch
            {
                return null;
            }
        }

        private static void OnUnhandledException(Exception ex)
        {
            if (MyCommon.ExceptionOut(ex))
            {
                Application.Exit();
            }
        }

        private static bool IsEqualCurrentCulture(string CultureName)
        {
            return Thread.CurrentThread.CurrentUICulture.Name.StartsWith(CultureName, StringComparison.Ordinal);
        }

        public static string CultureCode
        {
            get
            {
                if (MyCommon.cultureStr == null)
                {
                    var cfgCommon = SettingCommon.Load();
                    MyCommon.cultureStr = cfgCommon.Language;
                    if (MyCommon.cultureStr == "OS")
                    {
                        if (!IsEqualCurrentCulture("ja") &&
                           !IsEqualCurrentCulture("en") &&
                           !IsEqualCurrentCulture("zh-CN"))
                        {
                            MyCommon.cultureStr = "en";
                        }
                    }
                }
                return MyCommon.cultureStr;
            }
        }

        public static void InitCulture()
        {
            try
            {
                var culture = CultureInfo.CurrentCulture;
                if (CultureCode != "OS")
                    culture = new CultureInfo(CultureCode);

                CultureInfo.DefaultThreadCurrentUICulture = culture;
                Thread.CurrentThread.CurrentUICulture = culture;
            }
            catch (Exception)
            {
            }
        }

        private static bool SetConfigDirectoryPath()
        {
            string configDir;
            if (StartupOptions.TryGetValue("configDir", out configDir) && !string.IsNullOrEmpty(configDir))
            {
                // 起動オプション /configDir で設定ファイルの参照先を変更できます
                if (!Directory.Exists(configDir))
                {
                    var text = string.Format(Properties.Resources.ConfigDirectoryNotExist, configDir);
                    MessageBox.Show(text, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return false;
                }

                MyCommon.settingPath = Path.GetFullPath(configDir);
            }
            else
            {
                if (File.Exists(Path.Combine(Application.StartupPath, "roaming")))
                {
                    MyCommon.settingPath = MySpecialPath.UserAppDataPath();
                }
                else
                {
                    MyCommon.settingPath = Application.StartupPath;
                }
            }

            return true;
        }
    }
}
