Tukukkk

I Want to write clean and easy to maintainable code. What can I improve on below code?

Below is example of my masterdata service, which receive master data as json input, after some validation I need to create/update/delete master data into Cosmos DB.

public class MasterService : IMasterService

{

    private readonly IMasterDao masterDataService;

    private readonly ILog log;



    public MasterService(IMasterDao masterDataService, ILog log)

    {

        this.log = log;

        this.masterDataService = masterDataService;

    }



    public async Task<bool> UpdateMasterData(string message, string windowsZonesFilePath)

    {

        this.ValidateArgument<ArgumentException>(() => string.IsNullOrWhiteSpace(message), "Invalid MasterData Message");

        Dictionary<string, object> json = JsonConvert.DeserializeObject<Dictionary<string, object>>(message);

        this.ValidateArgument<ArgumentException>(() => !json.ContainsKey("OperationType"), "OperationType doesn't exist");

        this.ValidateArgument<ArgumentException>(() => !json.ContainsKey("AssetType"), "AssetType doesn't exist");

        this.ValidateArgument<ArgumentException>(() => !json.ContainsKey("AssetId"), "AssetId doesn't exist");



        string operationType = json["OperationType"].ToString().ToUpper();

        string assetType = json["AssetType"].ToString();

        string assetId = json["AssetId"].ToString();

        //TimeZone only mandatory for Plant asset

        if (assetType.Equals("Plant", StringComparison.InvariantCultureIgnoreCase) && json.ContainsKey("PlantAffiliationType")

            && json["PlantAffiliationType"].ToString().Equals("owner", StringComparison.InvariantCultureIgnoreCase))

        {

            this.ValidateArgument<ArgumentException>(() => !json.ContainsKey("TimeZone"), "TimeZone doesn't exist");

            string timeZone = json["TimeZone"].ToString();

            string newTimeZone = GetTimeZone(windowsZonesFilePath, timeZone);

            json["TimeZone"] = newTimeZone;

        }



        log.Info($"DATA received for AssetType : {assetType} with AssetId : {assetId} and operationType : {operationType}");



        if (!json.Keys.Contains("ApplicationName"))

            json.Add("ApplicationName", AMSConstraints.ApplicationName);



        JObject newMessage = JObject.Parse(JsonConvert.SerializeObject(json));



        if (operationType.Equals(OperationType.New.ToString(), StringComparison.InvariantCultureIgnoreCase))

        {

            log.Info($"Adding in database");

            await this.masterDataService.CreateAsync(newMessage);

            return true;

        }

        else if (operationType.Equals(OperationType.Update.ToString(), StringComparison.InvariantCultureIgnoreCase))

        {

            log.Info($"Replacing in database");

            return await this.masterDataService.UpdateDocumentByAsset(assetId, assetType, newMessage);

        }

        else if (operationType.Equals(OperationType.Delete.ToString(), StringComparison.InvariantCultureIgnoreCase))

        {

            log.Info($"Deleting Document");

            return await this.masterDataService.DeleteAsset(assetId, assetType);

        }

        return false;

    }



    private string GetTimeZone(string filePath, string timeZone)

    {

        XDocument xdoc = XDocument.Load(filePath);

        return xdoc.Descendants("mapZone")

                    .Where(x => x.Attribute("other").Value.Equals(timeZone, StringComparison.InvariantCultureIgnoreCase))

                    .Select(x => (string)x.Attribute("type"))

                    .FirstOrDefault();

    }



    private void ValidateArgument<exType>(Func<bool> validation, string errorMessage) where exType : Exception

    {

        if (validation())

        {

            throw Activator.CreateInstance(typeof(exType), errorMessage) as exType;

        }

    }

}