Kavita/Kavita.Common/Configuration.cs

using System;
using System.IO;
using System.Text.Json;
using Kavita.Common.EnvironmentInfo;
using Microsoft.Extensions.Hosting;

namespace Kavita.Common;

public static class Configuration
{
    public static readonly string AppSettingsFilename = Path.Join("config", GetAppSettingFilename());

    public static int Port
    {
        get => GetPort(GetAppSettingFilename());
        set => SetPort(GetAppSettingFilename(), value);
    }

    public static string JwtToken
    {
        get => GetJwtToken(GetAppSettingFilename());
        set => SetJwtToken(GetAppSettingFilename(), value);
    }

    private static string GetAppSettingFilename()
    {
        if (!string.IsNullOrEmpty(AppSettingsFilename))
        {
            return AppSettingsFilename;
        }

        var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
        var isDevelopment = environment == Environments.Development;
        return "appsettings" + (isDevelopment ? ".Development" : string.Empty) + ".json";
    }

    #region JWT Token

    private static string GetJwtToken(string filePath)
    {
        try
        {
            var json = File.ReadAllText(filePath);
            var jsonObj = JsonSerializer.Deserialize<dynamic>(json);
            const string key = "TokenKey";

            if (jsonObj.TryGetProperty(key, out JsonElement tokenElement))
            {
                return tokenElement.GetString();
            }

            return string.Empty;
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error reading app settings: " + ex.Message);
        }

        return string.Empty;
    }

    private static void SetJwtToken(string filePath, string token)
    {
        try
        {
            var currentToken = GetJwtToken(filePath);
            var json = File.ReadAllText(filePath)
                .Replace("\"TokenKey\": \"" + currentToken, "\"TokenKey\": \"" + token);
            File.WriteAllText(filePath, json);
        }
        catch (Exception)
        {
            /* Swallow exception */
        }
    }

    public static bool CheckIfJwtTokenSet()
    {
        try
        {
            return GetJwtToken(GetAppSettingFilename()) != "super secret unguessable key";
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error writing app settings: " + ex.Message);
        }

        return false;
    }

    #endregion

    #region Port

    private static void SetPort(string filePath, int port)
    {
        if (new OsInfo(Array.Empty<IOsVersionAdapter>()).IsDocker)
        {
            return;
        }

        try
        {
            var currentPort = GetPort(filePath);
            var json = File.ReadAllText(filePath).Replace("\"Port\": " + currentPort, "\"Port\": " + port);
            File.WriteAllText(filePath, json);
        }
        catch (Exception)
        {
            /* Swallow Exception */
        }
    }

    private static int GetPort(string filePath)
    {
        const int defaultPort = 5000;
        if (new OsInfo(Array.Empty<IOsVersionAdapter>()).IsDocker)
        {
            return defaultPort;
        }

        try
        {
            var json = File.ReadAllText(filePath);
            var jsonObj = JsonSerializer.Deserialize<dynamic>(json);
            const string key = "Port";

            if (jsonObj.TryGetProperty(key, out JsonElement tokenElement))
            {
                return tokenElement.GetInt32();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error writing app settings: " + ex.Message);
        }

        return defaultPort;
    }

    #endregion
}