public bool TryLoadConfig()

in src/Config/FileSystemRuntimeConfigLoader.cs [190:289]
79 lines of code
17 McCabe index (conditional complexity)

    public bool TryLoadConfig(
        string path,
        [NotNullWhen(true)] out RuntimeConfig? outConfig,
        bool replaceEnvVar = false,
        ILogger? logger = null,
        bool? isDevMode = null)
    {
        if (_fileSystem.File.Exists(path))
        {
            Console.WriteLine($"Loading config file from {_fileSystem.Path.GetFullPath(path)}.");

            // Use File.ReadAllText because DAB doesn't need write access to the file
            // and ensures the file handle is released immediately after reading.
            // Previous usage of File.Open may cause file locking issues when
            // actively using hot-reload and modifying the config file in a text editor.
            // Includes an exponential back-off retry mechanism to accommodate
            // circumstances where the file may be in use by another process.
            int runCount = 1;
            string json = string.Empty;
            while (runCount <= FileUtilities.RunLimit)
            {
                try
                {
                    json = _fileSystem.File.ReadAllText(path);
                    break;
                }
                catch (IOException ex)
                {
                    Console.WriteLine($"IO Exception, retrying due to {ex.Message}");
                    if (runCount == FileUtilities.RunLimit)
                    {
                        throw;
                    }

                    Thread.Sleep(TimeSpan.FromSeconds(Math.Pow(FileUtilities.ExponentialRetryBase, runCount)));
                    runCount++;
                }
            }

            if (!string.IsNullOrEmpty(json) && TryParseConfig(json, out RuntimeConfig, connectionString: _connectionString, replaceEnvVar: replaceEnvVar))
            {
                if (TrySetupConfigFileWatcher())
                {
                    Console.WriteLine("Monitoring config: {0} for hot-reloading.", ConfigFilePath);
                    logger?.LogInformation("Monitoring config: {ConfigFilePath} for hot-reloading.", ConfigFilePath);
                }

                // When isDevMode is not null it means we are in a hot-reload scenario, and need to save the previous
                // mode in the new RuntimeConfig since we do not support hot-reload of the mode.
                if (isDevMode is not null && RuntimeConfig.Runtime is not null && RuntimeConfig.Runtime.Host is not null)
                {
                    // Log error when the mode is changed during hot-reload. 
                    if (isDevMode != this.RuntimeConfig.IsDevelopmentMode())
                    {
                        if (logger is null)
                        {
                            Console.WriteLine("Hot-reload doesn't support switching mode. Please restart the service to switch the mode.");
                        }
                        else
                        {
                            logger.LogError("Hot-reload doesn't support switching mode. Please restart the service to switch the mode.");
                        }
                    }

                    RuntimeConfig.Runtime.Host.Mode = (bool)isDevMode ? HostMode.Development : HostMode.Production;
                }

                outConfig = RuntimeConfig;

                if (LastValidRuntimeConfig is null)
                {
                    LastValidRuntimeConfig = RuntimeConfig;
                }

                return true;
            }

            if (LastValidRuntimeConfig is not null)
            {
                RuntimeConfig = LastValidRuntimeConfig;
            }

            outConfig = null;
            return false;
        }

        if (logger is null)
        {
            string errorMessage = $"Unable to find config file: {path} does not exist.";
            Console.Error.WriteLine(errorMessage);
        }
        else
        {
            string errorMessage = "Unable to find config file: {path} does not exist.";
            logger.LogError(message: errorMessage, path);
        }

        outConfig = null;
        return false;
    }