using System.Globalization;


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


using ServerCore; using ServerBase;
using ServerCommon;



namespace GameServer;

public class DBQBeaconShopItemUpdate : QueryExecutorBase
{
    private string m_combination_key_for_pk = string.Empty;

    private string m_combination_key_for_sk = string.Empty;
    private double m_delta { get; set; }
    
    private PrimaryKey m_primary_key = new();
    
    //=====================================================================================
    // 0 < deltaCount => 증가
    // 0 > deltaCount => 감소
    //=====================================================================================

    public DBQBeaconShopItemUpdate(string combinationKeyForPK, string combinationKeyForSK, double delta) : base(nameof(DBQBeaconShopItemUpdate))
    {
        m_delta = delta;
        m_combination_key_for_pk = combinationKeyForPK;
        m_combination_key_for_sk = combinationKeyForSK;
    }
    
    //=====================================================================================
    // DB 쿼리 직전에 준비해야 할 로직들을 작성한다.
    //=====================================================================================
    public override async Task<Result> onPrepareQuery()
    {
        var owner = getOwner();

        var (result, make_primary_key) = await DynamoDBDocBaseHelper.makePrimaryKey<BeaconShopItemDoc>(m_combination_key_for_pk, m_combination_key_for_sk);
        if (result.isFail())
        {
            return result;
        }
        NullReferenceCheckHelper.throwIfNull(make_primary_key, () => $"make_primary_key is null !!! - {owner.toBasicString()}");

        m_primary_key = make_primary_key;

        return result;
    }
    
    //=====================================================================================
    // onPrepareQuery()를 성공할 경우 호출된다.
    //=====================================================================================
    public override async Task<Result> onQuery()
    {
        var owner = getOwner();

        var query_batch = getQueryBatch() as QueryBatch<QueryRunnerWithItemRequest>;
        NullReferenceCheckHelper.throwIfNull(query_batch, () => $"query_batch is null !!! - {owner.toBasicString()}");

        var query_runner_with_item_request = query_batch.getQueryRunner();
        NullReferenceCheckHelper.throwIfNull(query_runner_with_item_request, () => $"query_runner_with_item_request is null !!! - {owner.toBasicString()}");

        var db_connector = query_batch.getDynamoDbConnector();

        var table = db_connector.getTableByDoc<BeaconShopItemDoc>();
        var update = makeUpdateItemRequestUpdateBeaconShopItemCount(table, m_primary_key.toKeyWithAttributeValue(), JsonHelper.getJsonPropertyName<BeaconShopItemAttrib>(nameof(BeaconShopItemAttrib.ItemStackCount)));
        if (update.result.isFail()) return update.result;
        NullReferenceCheckHelper.throwIfNull(update.updateRequest, () => $"update_request is null !!! - {owner.toBasicString()}");

        var exception_handler = new DynamoDbQueryExceptionNotifier.ExceptionHandler(DynamoDbQueryExceptionNotifier.ConditionalCheckFailed, ServerErrorCode.BeaconShopUpdateNewData);
        
        var query_context = update.updateRequest.createItemRequestQueryContext(QueryType.Update, exception_handler);
        var result = await query_runner_with_item_request.tryRegisterQueryContext(query_context);

        return result;
    }
    
    //=====================================================================================
    // DB 쿼리를 성공하고, doFnCommit()가 QueryResultType.NotCalledQueryFunc를 반환할 경우 호출된다.
    //=====================================================================================
    public override async Task onQueryResponseCommit()
    {
        await Task.CompletedTask;
        return;
    }

    //=====================================================================================
    // DB 쿼리를 실패하고, doFnRollback()가 QueryResultType.NotCalledQueryFunc를 반환할 경우 호출된다.
    //=====================================================================================
    public override async Task onQueryResponseRollback(Result errorResult)
    {
        await Task.CompletedTask;
        return;
    }
        
    private (Result result, UpdateItemRequest? updateRequest) makeUpdateItemRequestUpdateBeaconShopItemCount( Table table
                                                                                                            , Dictionary<string, AttributeValue> attributeValueWithPrimaryKey
                                                                                                            , string targetAttribName )
    {
        var result = new Result();
        string err_msg;

        if (string.IsNullOrEmpty(targetAttribName))
        {
            err_msg = $"Failed to DynamoDbClientHelper.toAttributeExpressionFromJson() !!! : targetAttribName - {targetAttribName}";
            result.setFail(ServerErrorCode.AttribPathMakeFailed, err_msg);
            Log.getLogger().error(result.toBasicString());

            return (result, null);
        }

        var query_builder = new DynamoDbItemRequestHelper.UpdateItemRequestBuilder(table.TableName);
        query_builder.withKeys(attributeValueWithPrimaryKey);

        var target_doc = new BeaconShopItemDoc();
        var attrib_path_json_string = target_doc.toJsonStringOfAttribs();
        (var is_success, var attribute_expression) = DynamoDbClientHelper.toAttributeExpressionFromJson(attrib_path_json_string, targetAttribName);
        if (false == is_success)
        {
            err_msg = $"Failed to DynamoDbClientHelper.toAttributeExpressionFromJson() !!! : attribPath:{attrib_path_json_string}, targetKey:{targetAttribName}";
            result.setFail(ServerErrorCode.AttribPathMakeFailed, err_msg);
            Log.getLogger().error(result.toBasicString());

            return (result, null);
        }

        var attribute_names = DynamoDbClientHelper.toExpressionAttributeNamesFromJson(attrib_path_json_string, targetAttribName);
        query_builder.withExpressionAttributeNames(attribute_names);

        var update_expression = (m_delta >= 0)
            ? $"SET {attribute_expression} = if_not_exists({attribute_expression}, :start) + :changeValue"
            : $"SET {attribute_expression} = if_not_exists({attribute_expression}, :start) - :changeValue";

        query_builder.withUpdateExpression(update_expression);
        
        if (m_delta < 0)
        {
            query_builder.withConditionExpression($"{attribute_expression} >= :changeValue");
        }

        var expression_attribute_values = new Dictionary<string, AttributeValue>
        {
            { ":changeValue", new AttributeValue { N = Math.Abs(m_delta).ToString(CultureInfo.InvariantCulture) } },
            { ":start", new AttributeValue { N = "0" } }
        };
        query_builder.withExpressionAttributeValues(expression_attribute_values);

        query_builder.withReturnValues(ReturnValue.ALL_NEW);

        return query_builder.build();
    }
}