using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;



using Amazon.Runtime;
using Amazon.DynamoDBv2.Model;
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.DocumentModel;



using ServerCore; using ServerBase;


namespace ServerBase;

//==============================================================================================
// QueryBatch 클래스의 주요 절차들을 처리해 주는 클래스 이다.
//==============================================================================================
public static class QueryHelper
{
    //==============================================================================================
    // 1. DB 쿼리를 요청한다.
    // 2. 배치쿼리를 요청한다.
    //==============================================================================================
    public static async Task<Result> sendQueryAndBusinessLog(QueryBatchBase batch)
    {
        var result = new Result();
        var err_msg = string.Empty;

        if (batch == null)
        {
            err_msg = $"Failed to DBQuery !!!, QueryBatchBase is null";
            result.setFail(ServerErrorCode.FunctionInvalidParam, err_msg);
            return result;
        }
        
        Stopwatch? stopwatch = null;
        var event_tid = string.Empty;

        var server_logic = ServerLogicApp.getServerLogicApp();
        ArgumentNullException.ThrowIfNull(server_logic);
        var server_config = server_logic.getServerConfig();
        ArgumentNullException.ThrowIfNull(server_config);
        
        if (true == server_config.PerformanceCheckEnable)
        {
            event_tid = string.IsNullOrEmpty(batch.getTransId()) ? System.Guid.NewGuid().ToString("N") : batch.getTransId();
            stopwatch = Stopwatch.StartNew();
        }

        result = await sendQuery(batch);
        if(result.isSuccess())
        {
            batch.sendBusinessLog();
        }
        
        if (null != stopwatch)
        {
            var elapsed_msec = stopwatch.ElapsedMilliseconds;
            stopwatch.Stop();

            if (elapsed_msec > Constant.STOPWATCH_LOG_LIMIT_MSEC)
            {
                Log.getLogger().debug($"QueryBatch - Total Stopwatch Stop : ETID:{event_tid}, ElapsedMSec:{elapsed_msec}, LogAction:{batch.getLogAction().getLogActionType()}");   
            }
        }

        return result;
    }

    //==============================================================================================
    // 1. DB 쿼리를 요청한다.
    // 2. 배치쿼리를 요청한다.
    //==============================================================================================
    private static async Task<Result> sendQuery(QueryBatchBase batch)
    {
        var result = new Result();
        var err_msg = string.Empty;

        if (batch == null)
        {
            err_msg = $"Failed to sendQuery !!!, QueryBatchBase is null";
            result.setFail(ServerErrorCode.FunctionInvalidParam, err_msg);
            return result;
        }

        if (false == batch.hasQuery())
        {
            err_msg = $"Not has DBQuery !!!";
            result.setFail(ServerErrorCode.DynamoDbQueryNoRequested, err_msg);
            return result;
        }

        result = await batch.prepareQueryWithStopwatch();
        if (result.isFail())
        {
            return result;
        }

        result = await batch.doQueryWithStopwatch();
        if (result.isFail())
        {
            return result;
        }

        return result;
    }
}


//==============================================================================================
// 쿼리 관련 확장 함수들을 정의하는 클래스 이다.
//==============================================================================================

public static class QueryExtension
{
    public static bool isSuccess(this CancellationReason reason)
    {
        return true == reason.Code.Equals(DynamoDbQueryExceptionNotifier.Success, StringComparison.OrdinalIgnoreCase);
    }

    public static string toExceptionString(this TransactionCanceledException e)
    {
        return $"[TransactionCanceledException] - exception:{e}";
    }

    public static string toExceptionString(this AmazonDynamoDBException e)
    {
        var err_msg = $"[AmazonDynamoDBException] - occurred:{e.Message}, ";
        err_msg += (e.InnerException != null) ? $" Inner Exception:{e.InnerException.Message}," : "";
        err_msg += $" exception:{e}";

        return err_msg;

    }

    public static string toExceptionString(this AmazonServiceException e)
    {
        return $"[AmazonServiceException] - exception:{e}";
    }

    public static bool isEqualQuery<TDbRequestWithDocument>(this IQueryDbRequester dbRequester)
        where TDbRequestWithDocument : IQueryDbRequester
    {
        if(dbRequester.GetType() == typeof(TDbRequestWithDocument))
        {
            return true;
        }

        return false;
    }
}