namespace MSCO.Server;

/// <summary>
/// server.json im Web-Panel lesen und ändern - bei laufendem Server (dann sofort wirksam) und wenn er aus ist
/// (z.B. Lizenzschlüssel eintragen, damit er überhaupt starten kann).
/// </summary>
public static class ConfigEditor
{
    public static object Build(ServerConfig config) => new
    {
        name = config.Name,
        description = config.Description,
        maxPlayers = config.MaxPlayers,
        isPublic = config.Public,
        requireSteam = config.RequireSteam,
        publicAddress = config.PublicAddress,
        saveSyncMinutes = config.SaveSyncMinutes,
        licenseGraceHours = config.LicenseGraceHours,
        autosaveSeconds = config.AutosaveSeconds,
        port = config.Port,
        panelEnabled = config.PanelEnabled,
        panelPort = config.PanelPort,
        panelBindAddress = config.PanelBindAddress,
        panelTrustProxy = config.PanelTrustProxy,
        panelBasePath = config.PanelBasePath,
        licenseKeySet = !string.IsNullOrWhiteSpace(config.LicenseKey),
        steamWebApiKeySet = !string.IsNullOrWhiteSpace(config.SteamWebApiKey),
        environmentOverrides = config.EnvironmentOverrides,
        // In Docker muss ein anderer Port zusätzlich in docker-compose.yml freigegeben werden (Warnung im Panel)
        inDocker = Environment.GetEnvironmentVariable("DOTNET_RUNNING_IN_CONTAINER") == "true"
    };

    /// <summary>Einstellungen ändern. Schlüssel (Lizenz, Steam Web API) nur als Owner; leer = unverändert.</summary>
    public static string Apply(ServerConfig config, string configPath, System.Text.Json.JsonElement b, bool owner, string by)
    {
        if (b.ValueKind != System.Text.Json.JsonValueKind.Object) return "Invalid settings";
        var changed = new List<string>();
        bool restartNeeded = false;

        string Text(string name, string current, int max)
        {
            if (!b.TryGetProperty(name, out var v) || v.ValueKind != System.Text.Json.JsonValueKind.String) return current;
            string s = v.GetString().Trim();
            if (s.Length > max) s = s[..max];
            if (s != current) changed.Add(name);
            return s;
        }
        int Number(string name, int current, int min, int max)
        {
            if (!b.TryGetProperty(name, out var v) || !v.TryGetInt32(out int n)) return current;
            n = Math.Clamp(n, min, max);
            if (n != current) changed.Add(name);
            return n;
        }
        bool Flag(string name, bool current)
        {
            if (!b.TryGetProperty(name, out var v) || (v.ValueKind != System.Text.Json.JsonValueKind.True && v.ValueKind != System.Text.Json.JsonValueKind.False)) return current;
            bool f = v.GetBoolean();
            if (f != current) changed.Add(name);
            return f;
        }

        string name = Text("name", config.Name, 60);
        if (name.Length == 0) return "The server name cannot be empty";
        config.Name = name;
        config.Description = Text("description", config.Description, 300);
        config.MaxPlayers = Number("maxPlayers", config.MaxPlayers, 1, 64);
        config.Public = Flag("isPublic", config.Public);
        config.RequireSteam = Flag("requireSteam", config.RequireSteam);
        config.PublicAddress = Text("publicAddress", config.PublicAddress, 200);
        config.SaveSyncMinutes = Number("saveSyncMinutes", config.SaveSyncMinutes, 0, 240);
        config.AutosaveSeconds = Number("autosaveSeconds", config.AutosaveSeconds, 10, 3600);
        config.LicenseGraceHours = Number("licenseGraceHours", config.LicenseGraceHours, 1, 720);

        int before = changed.Count;
        int oldPort = config.Port, oldPanelPort = config.PanelPort;
        config.Port = Number("port", config.Port, 1, 65535);
        config.PanelEnabled = Flag("panelEnabled", config.PanelEnabled);
        config.PanelPort = Number("panelPort", config.PanelPort, 0, 65535);
        config.PanelBindAddress = Text("panelBindAddress", config.PanelBindAddress, 60);
        config.PanelTrustProxy = Flag("panelTrustProxy", config.PanelTrustProxy);
        config.PanelBasePath = Text("panelBasePath", config.PanelBasePath, 60);
        if (changed.Count > before) restartNeeded = true;
        // Ports gehören dem Programm, nicht dem Gameserver: "Restart" im Panel reicht dafür nicht
        bool portChanged = config.Port != oldPort || config.PanelPort != oldPanelPort;

        foreach (string secret in new[] { "licenseKey", "steamWebApiKey" })
        {
            if (!b.TryGetProperty(secret, out var v) || v.ValueKind != System.Text.Json.JsonValueKind.String || v.GetString().Trim().Length == 0) continue;
            if (!owner) return "Only the owner can change keys";
            string value = v.GetString().Trim();
            if (value.Length > 200) return "Key too long";
            if (secret == "licenseKey") config.LicenseKey = value; else config.SteamWebApiKey = value;
            changed.Add(secret);
            restartNeeded = true;
        }

        if (changed.Count == 0) return "Nothing changed";
        try { config.Save(configPath); }
        catch (Exception e) { return "Could not save server.json: " + e.Message; }
        GameServer.Log($"Settings changed by {by}: {string.Join(", ", changed)}");
        var overridden = changed.Where(c => config.EnvironmentOverrides.Any(e => e.Replace("_", "").Contains(c.ToUpperInvariant().Replace("ISPUBLIC", "PUBLIC")))).ToList();
        return "Settings saved" +
               (portChanged ? " - the new port only applies after the whole program restarts (docker compose restart); in Docker publish it in docker-compose.yml first"
                : restartNeeded ? " - some changes need a restart" : "") +
               (overridden.Count > 0 ? " (note: " + string.Join(", ", overridden) + " is also set by an environment variable, which wins on restart)" : "");
    }
}