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 ServerCore; using ServerBase;
using ServerCommon;
using ServerCommon.BusinessLogDomain;


using SESSION_ID = System.Int32;
using WORLD_META_ID = System.UInt32;
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;
using Pipelines.Sockets.Unofficial.Buffers;


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

        private string m_pk = string.Empty;

        private readonly List<CharacterBaseDoc> m_to_read_character_base_docs = new();

        public DBQCharacterReadAll(string combinationKeyForPK)
            : base(typeof(DBQCharacterReadAll).Name)
        {
            m_combination_key_for_pk = combinationKeyForPK;
        }

        //=====================================================================================
        // 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 CharacterBaseDoc();
            doc.setCombinationKeyForPK(m_combination_key_for_pk);
            
            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();

            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() as Player;
            NullReferenceCheckHelper.throwIfNull(owner, () => "owner is null !!!");

            var query_batch = getQueryBatch();
            NullReferenceCheckHelper.throwIfNull(query_batch, () => "query_batch is null !!!");

            var db_connector = query_batch.getDynamoDbConnector();
            var query_config = db_connector.makeQueryConfigForReadByPKOnly(m_pk);

            (result, var read_docs) = await db_connector.simpleQueryDocTypesWithQueryOperationConfig<CharacterBaseDoc>(query_config, eventTid: query_batch.getTransId());
            if(result.isFail())
            {
                return result;
            }

            var character_max_create_count = MetaHelper.GameConfigMeta.CharacterCreateMaxCount;
            if (read_docs.Count > character_max_create_count)
            {
                err_msg = $"Character Max Count Exceeded !!! : loadedCount:{read_docs.Count} <= CharacterMaxCount:{character_max_create_count} - {toBasicString()}, {owner.toBasicString()}";
                Log.getLogger().error(err_msg);
            }

            // 1. 기본 캐릭터가 선택 되어 있는지 체크 한다.
            var user_attribute = owner.getEntityAttribute<UserAttribute>();
            NullReferenceCheckHelper.throwIfNull(user_attribute, () => "user_attribute is null !!!");

            var selected_character_guid = user_attribute.SelectedCharacterGuid;
            if(true == selected_character_guid.isNullOrWhiteSpace())
            {
                err_msg = $"Not selected Character !!! : loadedCharacterCount:{read_docs.Count}, CharacterMaxCount:{character_max_create_count} - {toBasicString()}, {owner.toBasicString()}";
                result.setFail(ServerErrorCode.CharacterNotSelected, err_msg);
                Log.getLogger().error(result.toBasicString());
                return result;
            }

            // 2. 선택된 캐릭터가 존재하는지 체크 한다.
            var found_selected_character_base_doc = read_docs.Find(x => x.getAttrib<CharacterBaseAttrib>()?.CharacterGuid == selected_character_guid);
            if (null == found_selected_character_base_doc)
            {
                err_msg = $"Not found Character !!! : selectedCharacterGuid:{selected_character_guid}, loadedCharacterCount:{read_docs.Count}, CharacterMaxCount:{MetaHelper.GameConfigMeta.CharacterCreateMaxCount} - {toBasicString()}, {owner.toBasicString()}";
                result.setFail(ServerErrorCode.CharacterNotFound, err_msg);
                Log.getLogger().error(result.toBasicString());
                return result;
            }

            // 3. 선택된 캐릭터를 먼저 로딩 한다.
            var user_create_or_load_action = owner.getEntityAction<UserCreateOrLoadAction>();
            NullReferenceCheckHelper.throwIfNull(user_attribute, () => "user_attribute is null !!!");

            result = await user_create_or_load_action.tryLoadCharacterByChracterBaseDoc(found_selected_character_base_doc);
            if(result.isFail())
            {
                return result;
            }

            m_to_read_character_base_docs.Add(found_selected_character_base_doc);
            read_docs.Remove(found_selected_character_base_doc);
            character_max_create_count -= 1;

            // 4. 나머지 캐릭터를 로딩 한다.
            for(var i = 0; i < character_max_create_count; i++)
            {
                var remain_character_base_doc = read_docs[i];
                result = await user_create_or_load_action.tryLoadCharacterByChracterBaseDoc(remain_character_base_doc);
                if (result.isFail())
                {
                    return result;
                }

                m_to_read_character_base_docs.Add(remain_character_base_doc);
            }

            return result;
        }

        public List<CharacterBaseDoc> getToReadCharacterBaseDocs() => m_to_read_character_base_docs;

        //=====================================================================================
        // 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 new Player? getOwner() => getQueryBatch()?.getLogActor() as Player;
    }
}