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


using Newtonsoft.Json;
using Amazon.DynamoDBv2;
using Amazon.DynamoDBv2.Model;
using Amazon.DynamoDBv2.DocumentModel;
using Amazon.Runtime;
using StackExchange.Redis;



using ServerCore; using ServerBase;
using ServerCommon.BusinessLogDomain;


using DYNAMO_DB_TABLE_NAME = System.String;
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 ITEM_GUID = System.String;



namespace ServerCommon
{
    public class DBQEntityDeleteAfterReadAll<TDoc> : QueryExecutorBase
        where TDoc : DynamoDbDocBase, new()
    {
        private string m_combination_key_for_pk = string.Empty;
        private string m_combination_key_for_sk = string.Empty;

        private string m_pk = string.Empty;
        private string m_sk = string.Empty;

        private List<Amazon.DynamoDBv2.DocumentModel.Document>? m_read_documents_nullable;

        public DBQEntityDeleteAfterReadAll(string combinationKeyForPK, string combinationKeyForSK = "")
            : base(typeof(DBQEntityDeleteAfterReadAll<TDoc>).Name)
        {
            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()
        {
            await Task.CompletedTask;

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

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

            var doc = new TDoc();

            doc.setCombinationKeyForPKSK(m_combination_key_for_pk, m_combination_key_for_sk);

            var error_code = doc.onApplyPKSK();
            if (error_code.isFail())
            {
                err_msg = $"Failed to onApplyPKSK() !!! : {error_code.toBasicString()} - {toBasicString()}, {owner.toBasicString()}";
                result.setFail(error_code, err_msg);
                Log.getLogger().error(result.toBasicString());
                return result;
            }

            m_pk = doc.getPK();
            m_sk = doc.getSK();

            return result;
        }

        //=====================================================================================
        // onPrepareQuery()를 성공할 경우 호출된다.
        //=====================================================================================
        public override async Task<Result> onQuery()
        {
            var result = new Result();
            var err_msg = string.Empty;

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

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

            var server_logic = ServerLogicApp.getServerLogicApp();
            var dynamo_db_connector = query_batch.getDynamoDbConnector();

            var table = dynamo_db_connector.getTableByDoc<TDoc>();
            var query_config = dynamo_db_connector.makeQueryConfigForReadByPKOnly(m_pk);

            (result, var read_documents) = await table.simpleQueryWithQueryOperationConfig(query_config, query_batch.getTransId());
            if(result.isFail())
            {
                return result;
            }
            m_read_documents_nullable = read_documents;

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

            foreach (var document in m_read_documents_nullable)
            {
                var to_delete_doc = document.createDocumentQueryContext(table.TableName, QueryType.Delete);

                result = await query_runner.tryRegisterQueryContext(to_delete_doc);
                if (result.isFail())
                {
                    return result;
                }
            }

            var msg = $"{this.getTypeName()} : tryDeleteCount:{m_read_documents_nullable.Count}, isUseTransact:{query_batch.isUseTransact()} - TransId:{query_batch.getTransId()}";
            Log.getLogger().info(msg);

            return result;
        }

        public List<Amazon.DynamoDBv2.DocumentModel.Document>? getReadDocuments() => m_read_documents_nullable;

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