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


using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Amazon.DynamoDBv2.Model;


using ServerCore; using ServerBase;
using ServerCommon;


using DYNAMO_DB_TABLE_FULL_NAME = System.String;
using SESSION_ID = System.Int32;
using META_ID = System.UInt32;
using ENTITY_GUID = System.String;
using ACCOUNT_ID = System.String;
using OWNER_GUID = System.String;
using USER_GUID = System.String;
using CHARACTER_GUID = System.String;
using UGC_NPC_META_GUID = System.String;
using ITEM_GUID = System.String;


namespace GameServer
{
    public class DBQUgcNpcLikeSelecteeCountUpdate : QueryExecutorBase
    {
        private string m_combination_key_for_pk = string.Empty;

        private Int32 m_delta_count = 0;

        private PrimaryKey m_primary_key = new();

        //=====================================================================================
        // 0 < deltaCount => 증가
        // 0 > deltaCount => 감소
        //=====================================================================================

        public DBQUgcNpcLikeSelecteeCountUpdate( string combinationKeyForPK
                                               , Int32 deltaCount )
            : base(typeof(DBQUgcNpcLikeSelecteeCountUpdate).Name)
        {
            m_combination_key_for_pk = combinationKeyForPK;

            m_delta_count = deltaCount;
        }

        //=====================================================================================
        // DB 쿼리 직전에 준비해야 할 로직들을 작성한다.
        //=====================================================================================
        public override async Task<Result> onPrepareQuery()
        {
            await Task.CompletedTask;

            var result = new Result();
            var err_msg = string.Empty;

            var owner = getOwner();
            NullReferenceCheckHelper.throwIfNull(owner, () => $"owner is null !!!");

            (result, var make_primary_key) = await DynamoDBDocBaseHelper.makePrimaryKey<UgcNpcLikeSelecteeCountDoc>(m_combination_key_for_pk);
            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()
        {
            await Task.CompletedTask;

            var result = new Result();
            var err_msg = string.Empty;

            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<UgcNpcLikeSelecteeCountDoc>();

            var delta_count = m_delta_count;
            (result, var update_item_request) = makeUpdateItemRequest( db_connector
                                                                     , table.TableName
                                                                     , m_primary_key.toKeyWithAttributeValue()
                                                                     , nameof(UgcNpcLikeSelecteeCountAttrib.LikeCount)
                                                                     , delta_count );
            if (result.isFail())
            {
                return result;
            }
            NullReferenceCheckHelper.throwIfNull(update_item_request, () => $"update_item_request is null !!! - {owner.toBasicString()}");

            var query_context = update_item_request.createItemRequestQueryContext(QueryType.Upsert);
            result = await query_runner_with_item_request.tryRegisterQueryContext(query_context);

            return result;
        }

        private (Result, UpdateItemRequest?) makeUpdateItemRequest( DynamoDbClient dbClient, DYNAMO_DB_TABLE_FULL_NAME tableFullName
                                                                  , Dictionary<string, AttributeValue> attributeValueWithPrimaryKey
                                                                  , string targetAttribName
                                                                  , Int32 deltaCount )
        {
            var result = new Result();

            var owner = getOwner();

            var update_item_request = new UpdateItemRequest();
            update_item_request.TableName = tableFullName;
            update_item_request.Key = attributeValueWithPrimaryKey;

            var target_doc = new UgcNpcLikeSelecteeCountDoc();
            var attrib_path_json_string = target_doc.toJsonStringOfAttribs();
            var target_key = JsonHelper.getJsonPropertyName<UgcNpcLikeSelecteeCountAttrib>(targetAttribName);

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

                return (result, null);
            }

            // ExpressionAttributeNames를 설정 한다.
            update_item_request.ExpressionAttributeNames = DynamoDbClientHelper.toExpressionAttributeNamesFromJson(attrib_path_json_string, target_key);

            var update_expression = $"SET {attribute_expression} = if_not_exists({attribute_expression}, :start) + :incr";
            update_item_request.UpdateExpression = update_expression;

            var expressionAttributeValues = new Dictionary<string, AttributeValue>
            {
                { ":incr", new AttributeValue { N = deltaCount.ToString() } },
                { ":start", new AttributeValue { N = "0" } }
            };
            update_item_request.ExpressionAttributeValues = expressionAttributeValues;
            update_item_request.ReturnValues = "ALL_NEW";


            return (result, update_item_request);
        }

        //=====================================================================================
        // 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;
        }

        public override Player getOwner()
        {
            var owner = base.getOwner() as Player;
            NullReferenceCheckHelper.throwIfNull(owner, () => $"owner is null !!!");

            return owner;
        }
    }
}