using GCMM.Properties;
using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GCMM
{
    partial class MainForm
    {
        public void UpdateButton(Button button, bool enabled)
        {
            if (enabled)
            {
                button.ForeColor = Color.Lime;
                button.FlatAppearance.MouseOverBackColor = Color.FromArgb(0, 40, 0);
                button.FlatAppearance.MouseDownBackColor = Color.Green;
            }
            else
            {
                button.ForeColor = Color.Green;
                button.FlatAppearance.MouseOverBackColor = Color.Black;
                button.FlatAppearance.MouseDownBackColor = Color.Black;
            }
        }

        public string GetGameFolder()
        {
            string libs;
            if (Environment.OSVersion.Platform == PlatformID.Win32NT)
                libs = steamPath + @"\steamapps\libraryfolders.vdf";
            else
                return null;
            foreach (var line in File.ReadAllLines(libs).Concat(new[] { "\t\"19\"\t\t\"" + steamPath + "\"" }))
            {
                var regex = new Regex("\\t\"\\d+\"\\t\\t\"(.+)\"");
                var match = regex.Match(line);
                if (!match.Success)
                    continue;
                string library = match.Groups[1].Value.Replace("\\\\", "\\");
                library += @"\steamapps\common\";
                if (GetExe(library + "Gamecraft") != null)
                    return library + "Gamecraft";
                if (GetExe(library + "RobocraftX") != null)
                    return library + "RobocraftX";
            }
            return null;
        }

        public string SelectGameFolder()
        {
            var ofd = new OpenFileDialog();
            ofd.Filter = "Gamecraft executable|Gamecraft.exe|Gamecraft Preview executable|GamecraftPreview.exe";
            ofd.Title = "Game location";
            ofd.InitialDirectory = steamPath + @"\steamapps\common\";
            ofd.CheckFileExists = true;
            ofd.ShowDialog();
            if (string.IsNullOrWhiteSpace(ofd.FileName))
                return null;
            return Directory.GetParent(ofd.FileName).FullName;
        }

        public (string, int) AskForSteamLogin()
        {
            while (MessageBox.Show("Couid not find your Steam configuration to set launch options.\n\n" +
                "Please make sure you are logged into Steam and click Retry or click Cancel to skip setting this up.",
                "Steam config not found", MessageBoxButtons.RetryCancel) != DialogResult.Cancel)
            {
                var ret = GetSteamLocationAndUser();
                if (ret != (null, 0))
                    return ret;
            }
            return (null, 0);
        }

        /// <summary>
        /// Does not return the current value if setting it is not possible because Steam is running.
        /// </summary>
        /// <param name="autoLaunch">The value to set or null to keep as is</param>
        /// <returns>The current value, unless setting it while Steam is running</returns>
        public bool UpdateOrGetSteamConfigToAutoStart(bool? autoLaunch)
        {
            string commandToUse = Application.ExecutablePath + " -start %command%";
            if (autoLaunch.HasValue && Process.GetProcessesByName("steam").Length > 0)
            { //Setting it while Steam is running
                if (MessageBox.Show("Cannot set launch options while Steam is running." +
                    (autoLaunch.Value
                    ? " Do you want to do it manually? If so, it will be copied on your clipboard." +
                    " Right click the game, select Properties and paste it in the launch options field."
                    : " Do you want to do it manually?" +
                    " If so, right click the game, select Properties and remove the text from the launch options field."),
                    "Launch options in Steam", MessageBoxButtons.YesNo) == DialogResult.Yes && autoLaunch.Value)
                    Clipboard.SetText(commandToUse);
                return false;
            }
            var regex = new Regex(@"(\t{6}""LaunchOptions""\t+"")(.*)("")");
            string path = steamPath + @"\userdata\" + Settings.Default.SteamUserID + @"\config\localconfig.vdf";
            var lines = File.ReadAllLines(path);
            bool shouldMatch = false;
            bool ret = false;
            for (int i = 0; i < lines.Length; i++)
            {
                if (lines[i] == "\t\t\t\t\t\"1078000\"")
                    shouldMatch = true; //Found the game
                else if(shouldMatch)
                {
                    var match = regex.Match(lines[i]);
                    if (!match.Success)
                        continue;
                    ret = match.Groups[2].Value.Contains("GCMM.exe");
                    string enabledCommand = match.Groups[1].Value + commandToUse.Replace("\\", "\\\\") + match.Groups[3].Value;
                    if (autoLaunch.HasValue)
                    {
                        if (autoLaunch.Value)
                            lines[i] = enabledCommand;
                        else
                            lines[i] = match.Groups[1].Value + match.Groups[3].Value;
                        File.WriteAllLines(path, lines);
                    }
                    else if (ret && lines[i] != enabledCommand) //GCMM got moved or something and it's only queried, not set
                    {
                        lines[i] = enabledCommand;
                        File.WriteAllLines(path, lines);
                    }
                    break;
                }
            }
            return ret;
        }

        public (string, int) GetSteamLocationAndUser()
        {
            if (Environment.OSVersion.Platform != PlatformID.Win32NT) return (null, 0);
            using (var key = Registry.CurrentUser.OpenSubKey(@"Software\Valve\Steam\ActiveProcess"))
            {
                string path = (string)key?.GetValue("SteamClientDll");
                path = path != null ? Directory.GetParent(path).FullName : null;
                return (path, (int)(key?.GetValue("ActiveUser") ?? 0));
            }
        }

        public void DetectConfigLocationAndAutoStart(string steamPath, ref int user)
        {
            string path = steamPath + @"\userdata";
            if (user == 0)
            {
                var dirs = Directory.GetDirectories(path);
                var goodPaths = (from dir in dirs
                                 where File.Exists(dir + @"\config\localconfig.vdf")
                                 select dir).ToArray();
                if (goodPaths.Length != 1)
                {
                    (_, user) = AskForSteamLogin();
                    path += user;
                }
                else
                {
                    path = goodPaths[0];
                    user = int.Parse(Path.GetFileName(path));
                }
            }
            else
                path += "\\" + user;
            path += @"\config\localconfig.vdf";
            if (path != null && user != 0 && File.Exists(path))
            {
                Settings.Default.SteamUserID = user;
                UpdateOrGetSteamConfigToAutoStart(true);
            }
            else
                Settings.Default.AutoLaunch = false;
        }

        private (EventHandler, Task) CheckStartGame(string command)
        {
            var tcs = new TaskCompletionSource<object>();
            return ((sender, e) =>
            {
                Action act = async () =>
                {
                    if (((sender as Process)?.ExitCode ?? 0) != 0)
                    {
                        status.Text = "Status: Patching failed";
                        return;
                    }
                    if (CheckIfPatched() == GameState.Patched || unpatched.Checked)
                        if (command != null)
                        {
                            if (sender is Process) //Patched just now
                                CheckCompatibilityAndDisableMods();
                            await CheckModUpdatesAsync();
                            Process.Start(command);
                        }
                        else if (Environment.OSVersion.Platform == PlatformID.Win32NT)
                            Process.Start("steam://run/1078000/");
                        else
                            Process.Start("xdg-open", "steam://run/1078000/");
                    EndWork(false);
                    tcs.SetResult(null);
                };
                if (InvokeRequired)
                    Invoke(act);
                else
                    act();
            }, tcs.Task);
        }

        private void CheckCompatibilityAndDisableMods()
        {
            if (!unpatched.Checked && MessageBox.Show("If the game updated just now, some mods may be incompatible or they may work just fine." +
                " Do you want to try running with mods?" +
                "\n\nClick Yes to start the game with mods (after a small update or if you just installed GCMM)" +
                "\nClick No to disable mods before starting the game (after a major update)" +
                "\n\nYou can always enable/disable mods by launching GCMM.",
                "Possible incompatibility warning", MessageBoxButtons.YesNo) == DialogResult.No)
                unpatched.Checked = true;
        }

        private async Task CheckModUpdatesAsync()
        {
            var updatable = mods.Values.Where(mod => mod.Updatable).ToArray();
            if (updatable.Length == 0)
                return;
            if (MessageBox.Show("Mod update(s) available!\n\n"
                + updatable.Select(mod => mod.Name + " " + mod.LatestVersion).Aggregate((a, b) => a + "\n")
                + "\n\nDo you want to update them now? You can also update later by opening GCMM.",
                "Update(s) available", MessageBoxButtons.YesNo) == DialogResult.No)
                return;
            foreach (var mod in updatable)
                await InstallMod(mod);
            MessageBox.Show("Mods updated");
        }

        public WebClient GetClient()
        {
            var client = new WebClient();
            if (!Settings.Default.UseProxy)
                client.Proxy = null;
            client.Headers.Clear();
            client.Headers[HttpRequestHeader.Accept] = "application/json";
            client.BaseAddress = "https://git.exmods.org";
            return client;
        }

        private bool working = false;
        /// <summary>
        /// Some simple "locking", only allow one operation at a time
        /// </summary>
        /// <returns>Whether the work can begin</returns>
        public bool BeginWork()
        {
            if (working) return false;
            working = true;
            UpdateButton(playbtn, false);
            UpdateButton(installbtn, false);
            UpdateButton(uninstallbtn, false);
            UpdateButton(settingsbtn, false);
            unpatched.Enabled = false;
            return true;
        }

        public void EndWork(bool desc = true)
        {
            working = false;
            UpdateButton(playbtn, true);
            UpdateButton(settingsbtn, true);
            if (desc)
                modlist_SelectedIndexChanged(modlist, null);
            unpatched.Enabled = true;
        }

        /// <summary>
        /// Path must start with \
        /// </summary>
        /// <param name="path"></param>
        /// <param name="gamepath"></param>
        /// <returns></returns>
        public string GamePath(string path, string gamepath = null)
        {
            return ((gamepath ?? Settings.Default.GamePath) + path).Replace('\\', Path.DirectorySeparatorChar);
        }

        public string GetExe(string path = null)
        {
            if (File.Exists(GamePath("\\Gamecraft.exe", path)))
                return "Gamecraft.exe";
            if (File.Exists(GamePath("\\GamecraftPreview.exe", path)))
                return "GamecraftPreview.exe";
            return null;
        }

        private bool CheckNoExe()
        {
            return CheckNoExe(out _);
        }

        private bool CheckNoExe(out string path)
        {
            path = GetExe();
            if (path == null)
            {
                MessageBox.Show("Gamecraft not found! Set the correct path in Settings.");
                return true;
            }
            return false;
        }

        public async Task<DateTime> GetLastGameUpdateTime()
        {
            /*using (var client = GetClient())
            {
                string html = await client.DownloadStringTaskAsync("https://api.steamcmd.net/v1/info/1078000");
                var regex = new Regex("<i>timeupdated:</i>[^<]*<b>([^<]*)</b>");
                var match = regex.Match(html);
                if (!match.Success)
                    return default;
                return new DateTime(1970, 1, 1).AddSeconds(long.Parse(match.Groups[1].Value));
            }*/
            //return new DateTime(2020, 12, 28);
            return default;
        }
    }
}