using System.Runtime.InteropServices;
using MSCO.Server;

// Datenordner (server.json, save/, world.json): Standard = Programmordner,
// unter Linux z.B. "--data /var/lib/msco" oder per Umgebungsvariable MSCO_DATA
string dataDir = ArgValue("--data") ?? Environment.GetEnvironmentVariable("MSCO_DATA") ?? AppContext.BaseDirectory;
dataDir = Path.GetFullPath(dataDir);
Directory.CreateDirectory(dataDir);
// Im Panel installiertes, neueres Update (DATA/app/current)? Dann läuft stattdessen das.
if (Array.IndexOf(args, "--cmd") < 0 && Updater.RunInstalled(args, dataDir) is int updatedExit) return updatedExit;
string configPath = Path.Combine(dataDir, "server.json");
string commandFile = Path.Combine(dataDir, "commands.in");

// --cmd "<befehl>": Befehl an den laufenden Server geben (z.B. docker exec msco-server msco op 1).
// Der Server liest die Datei jede halbe Sekunde; die Antwort steht im Server-Log (docker logs).
if (Array.IndexOf(args, "--cmd") >= 0)
{
    int at = Array.IndexOf(args, "--cmd");
    string command = string.Join(" ", args.Skip(at + 1)).Trim();
    if (command.Length == 0) { Console.WriteLine("Usage: msco <command>   (e.g. msco players, msco op 1, msco say hello)"); return 1; }
    File.AppendAllText(commandFile, command + Environment.NewLine);
    Console.WriteLine("Sent: " + command + "  (output: docker logs --tail 20 msco-server)");
    return 0;
}

try { Console.Title = "MSCO Server"; } catch { } // nicht jedes Terminal unterstützt einen Titel
GameServer.Log("MSCO dedicated server " + Updater.CurrentVersion + " for MSCO mod " + GameServer.ModVersion + " (" + RuntimeInformation.OSDescription + ")");
GameServer.Log("Data folder: " + dataDir);
GameServer.Log("Master server: " + MasterServer.Url);

// Datenordner beschreibbar? (Linux/Docker: gehört er einem anderen Benutzer, gleich klar melden statt abzustürzen)
try
{
    string probe = Path.Combine(dataDir, ".write-test");
    File.WriteAllText(probe, "ok");
    File.Delete(probe);
}
catch (Exception e) when (e is UnauthorizedAccessException or IOException)
{
    GameServer.Log("No write access to the data folder " + dataDir + ": " + e.Message);
    GameServer.Log(GameServer.PermissionHint());
    Pause();
    return 1;
}

ServerConfig config;
bool created;
try
{
    config = ServerConfig.LoadOrCreate(configPath, out created);
}
catch (Exception e) when (e is UnauthorizedAccessException or IOException)
{
    GameServer.Log("Cannot read " + configPath + ": " + e.Message);
    GameServer.Log(GameServer.PermissionHint());
    Pause();
    return 1;
}
var fromEnvironment = config.ApplyEnvironment();
if (fromEnvironment.Count > 0)
    GameServer.Log("Settings overridden by environment (.env): " + string.Join(", ", fromEnvironment));
if (created && string.IsNullOrWhiteSpace(config.LicenseKey))
{
    GameServer.Log("Created " + configPath);
    GameServer.Log("Get a license key at " + MasterServer.Url + "/keys" +
                   (config.PanelEnabled ? " and enter it in the web panel (Settings) - or put it into server.json (\"LicenseKey\")."
                                        : " and put it into server.json (\"LicenseKey\")."));
    if (!config.PanelEnabled) { Pause(); return 1; }
}

// --import-save [Pfad]: Spielstand aus My Summer Car übernehmen
if (Array.IndexOf(args, "--import-save") >= 0)
{
    string source = ArgValue("--import-save") ?? DefaultSaveFolder();
    if (source == null || !Directory.Exists(source))
    {
        GameServer.Log("Save folder not found" + (source != null ? ": " + source : "") +
                       ". Use --import-save \"/path/to/My Summer Car\" (the folder containing defaultES2File.txt).");
        Pause();
        return 1;
    }
    string target = Path.Combine(dataDir, "save");
    Directory.CreateDirectory(target);
    int copied = 0;
    foreach (string name in new[] { "defaultES2File.txt", "items.txt", "meshsave.txt", "graveyard.txt", "notepad.txt" })
    {
        string file = Path.Combine(source, name);
        if (!File.Exists(file)) continue;
        File.Copy(file, Path.Combine(target, name), true);
        copied++;
    }
    GameServer.Log($"Imported {copied} save files from {source}");
    // Neuer Spielstand = alte Änderungen passen nicht mehr dazu, und er ist der neue Reset-Punkt
    string world = Path.Combine(dataDir, "world.json");
    if (File.Exists(world)) File.Delete(world);
    string original = Path.Combine(dataDir, "save_original");
    if (Directory.Exists(original)) Directory.Delete(original, true);
}

// Der Host läuft die ganze Zeit (Port + Web-Panel) und startet/stoppt den Gameserver - auch wenn der nicht starten
// kann (Lizenz, Spielstand ...), bleibt das Panel erreichbar. Konsole, "msco <befehl>" und Signale gehen an den Host.
var host = new ServerHost(config, dataDir, configPath);

// Konsolenbefehle in eigenem Thread lesen, ausgeführt werden sie in der Server-Schleife.
// Als Dienst (systemd/Docker ohne Terminal) gibt es keine Eingabe - dann einfach ohne Konsole laufen.
var input = new Thread(() =>
{
    try
    {
        string line;
        while ((line = Console.ReadLine()) != null) host.Command(line);
    }
    catch { }
}) { IsBackground = true };
input.Start();

// Befehle von "msco <befehl>" (docker exec) aus der Datei commands.in übernehmen
var commandWatcher = new Thread(() =>
{
    string processing = commandFile + ".processing";
    while (true)
    {
        Thread.Sleep(500);
        try
        {
            if (!File.Exists(commandFile)) continue;
            File.Move(commandFile, processing, true);
            foreach (string line in File.ReadAllLines(processing))
                if (line.Trim().Length > 0) { GameServer.Log("> " + line.Trim()); host.Command(line.Trim()); }
            File.Delete(processing);
        }
        catch { }
    }
}) { IsBackground = true };
commandWatcher.Start();

// Sauber beenden (Weltzustand speichern) bei Strg+C, systemctl stop / docker stop (SIGTERM) und SIGQUIT
Console.CancelKeyPress += (_, e) => { e.Cancel = true; host.RequestExit(); };
using var sigterm = PosixSignalRegistration.Create(PosixSignal.SIGTERM, ctx => { ctx.Cancel = true; host.RequestExit(); });
using var sigquit = PosixSignalRegistration.Create(PosixSignal.SIGQUIT, ctx => { ctx.Cancel = true; host.RequestExit(); });

int exitCode = host.Run();
if (exitCode == Updater.RestartExitCode) Updater.Relaunch(args);
else if (exitCode != 0) Pause();
return exitCode;

string ArgValue(string name)
{
    int i = Array.IndexOf(args, name);
    return i >= 0 && i + 1 < args.Length && !args[i + 1].StartsWith("--") ? args[i + 1] : null;
}

// Spielstand dieses Rechners: Windows direkt, Linux über Steam Proton
static string DefaultSaveFolder()
{
    string home = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
    const string relative = "AppData/LocalLow/Amistech/My Summer Car";
    if (OperatingSystem.IsWindows()) return Path.Combine(home, relative);

    foreach (string steamRoot in new[] { ".steam/steam", ".local/share/Steam", ".var/app/com.valvesoftware.Steam/.local/share/Steam" })
    {
        string proton = Path.Combine(home, steamRoot, "steamapps/compatdata/516750/pfx/drive_c/users/steamuser", relative);
        if (Directory.Exists(proton)) return proton;
    }
    return null;
}

static void Pause()
{
    // In Docker nicht auf Enter warten: sonst sieht der Container wie "läuft" aus, obwohl der Server beendet ist
    if (Console.IsInputRedirected || Environment.GetEnvironmentVariable("DOTNET_RUNNING_IN_CONTAINER") == "true") return;
    Console.WriteLine("Press Enter to exit.");
    Console.ReadLine();
}