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


using Amazon.DynamoDBv2.Model;
using Amazon.DynamoDBv2;
using Amazon.Runtime.Internal;
using Amazon.DynamoDBv2.DocumentModel;
using NLog.Conditions;


using ServerCore; using ServerBase;


using DYNAMO_DB_TABLE_FULL_NAME = System.String;


namespace ServerBase;

public static class DynamoDbItemRequestHelper
{
    public enum AttribValueAction
    {
        None = 0,

        Increase,       // Atomic 기반 증가
        Decrease,       // Atomic 기반 감소
        Update          // 값의 변경
    }

    public class AttribAction
    {
        public AttribValueAction ValueAction { get; set; } = AttribValueAction.None;
        public AttributeValue Value { get; set; } = new();
    }

    public static (Result, DynamoDbItemRequestQueryContext?) makeUpdateItemRequestWithDoc<TAttrib>( DynamoDbDocBase targetDoc
                                                                                                  , Dictionary<string, AttribAction> toChangeAttibValues
                                                                                                  , DynamoDbQueryExceptionNotifier.ExceptionHandler? exceptionHandler = null )
        where TAttrib : AttribBase
    {
        ConditionValidCheckHelper.throwIfFalseWithCondition(() => 0 < toChangeAttibValues.Count, () => $"Invalid toChangeAttibValues.Count !!! : 0 < {toChangeAttibValues.Count}");

        var server_logic = ServerLogicApp.getServerLogicApp();
        NullReferenceCheckHelper.throwIfNull(server_logic, () => $"server_logic client is null !!! ");
        var db_connector = server_logic.getDynamoDbClient();
        NullReferenceCheckHelper.throwIfNull(db_connector, () => $"db_connector client is null !!! ");

        var result = new Result();

        var primary_key = targetDoc.getPrimaryKey();

        var query_builder = new DynamoDbItemRequestHelper.UpdateItemRequestBuilder(db_connector.getTableFullName(targetDoc.TableName));
        query_builder.withKeys(primary_key.toKeyWithAttributeValue());

        var attrib_path_json_string = targetDoc.toJsonStringOfAttribs();

        var update_expression = "SET ";
        var expression_idx = 0;
        var expression_attribute_names = new Dictionary<string, string>();
        var expression_attribute_values = new Dictionary<string, AttributeValue>();

        var update_item_request = query_builder.getItemRequest();

        foreach (var each in toChangeAttibValues)
        {
            var attrib_key = each.Key;
            var attrib_value = each.Value;

            var target_key = JsonHelper.getJsonPropertyName<TAttrib>(attrib_key);
            (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} - {primary_key.toBasicString()}";
                result.setFail(ServerErrorCode.AttribPathMakeFailed, err_msg);
                Log.getLogger().error(result.toBasicString());

                continue;
            }

            var attribute_names = DynamoDbClientHelper.toExpressionAttributeNamesFromJson(attrib_path_json_string, target_key);
            foreach (var name in attribute_names)
            {
                expression_attribute_names.TryAdd(name.Key, name.Value);
            }

            if (expression_idx > 0) update_expression += ", ";

            var data = attrib_value.Value;
            if (AttribValueAction.Increase == attrib_value.ValueAction)
            {
                var start_key = $":start_{expression_idx}";
                var incr_key = $":incr_{expression_idx}";

                update_expression += $"{attribute_expression} = if_not_exists({attribute_expression}, {start_key}) + {incr_key}";
                expression_attribute_values.Add(incr_key, data);
                expression_attribute_values.TryAdd(start_key, new AttributeValue { N = "0" });
            }
            else if(AttribValueAction.Decrease== attrib_value.ValueAction)
            {
                var start_key = $":start_{expression_idx}";
                var decr_key = $":decr_{expression_idx}";

                update_expression += $"{attribute_expression} = if_not_exists({attribute_expression}, {start_key}) - {decr_key}";
                expression_attribute_values.Add(decr_key, data);
                expression_attribute_values.TryAdd(start_key, new AttributeValue { N = "0" });
            } 
            else if (AttribValueAction.Update == attrib_value.ValueAction)
            {
                var new_value_key = $":newValue_{expression_idx}";

                update_expression += $"{attribute_expression} = {new_value_key}";
                expression_attribute_values.Add(new_value_key, data);
            }

            expression_idx++;
        }

        query_builder.withExpressionAttributeNames(expression_attribute_names);
        query_builder.withUpdateExpression(update_expression);
        query_builder.withExpressionAttributeValues(expression_attribute_values);
        query_builder.withReturnValues(ReturnValue.ALL_NEW);

        (result, var builded_update_item_request) = query_builder.build();
        if(result.isFail())
        {
            return (result, null);
        }
        NullReferenceCheckHelper.throwIfNull(builded_update_item_request, () => $"builded_update_item_request is null !!! - {primary_key.toBasicString()}");

        var exception_handler = new DynamoDbQueryExceptionNotifier.ExceptionHandler(DynamoDbQueryExceptionNotifier.ConditionalCheckFailed, ServerErrorCode.LackOfTotalCalium);

        return (result, builded_update_item_request.createItemRequestQueryContext(QueryType.Update, exceptionHandler));
    }


    //=========================================================================================
    // UpdateItemRequest Builder
    //=========================================================================================
    public class UpdateItemRequestBuilder
    {
        private readonly UpdateItemRequest m_request;

        private Document? m_document;

        private readonly bool m_is_upsert;

        public UpdateItemRequestBuilder(DYNAMO_DB_TABLE_FULL_NAME tableFullName, bool isUpsert = false)
        {
            ConditionValidCheckHelper.throwIfFalseWithCondition(() => false == tableFullName.isNullOrWhiteSpace(), () => $"Invalid TableFullName !!!, Null or WhiteSpace !!!");

            m_request = new UpdateItemRequest
            {
                TableName = tableFullName,
                Key = new Dictionary<string, AttributeValue>(),
                AttributeUpdates = new Dictionary<string, AttributeValueUpdate>(),
                UpdateExpression = string.Empty,
            };

            m_is_upsert = isUpsert;
        }

        public UpdateItemRequest getItemRequest() => m_request;

        public UpdateItemRequestBuilder withDocument(Document document)
        {
            m_document = document;
            return this;
        }

        public UpdateItemRequestBuilder withReturnValues(ReturnValue returnValue)
        {
            m_request.ReturnValues = returnValue;
            return this;
        }

        public UpdateItemRequestBuilder withConditionExpression(string conditionExpression)
        {
            m_request.ConditionExpression = conditionExpression;
            return this;
        }

        public UpdateItemRequestBuilder withExpressionAttributeNames(Dictionary<string, string> expressionAttributeNames)
        {
            m_request.ExpressionAttributeNames = expressionAttributeNames;
            return this;
        }

        public UpdateItemRequestBuilder withExpressionAttributeValues(Dictionary<string, AttributeValue> expressionAttributeValues)
        {
            m_request.ExpressionAttributeValues = expressionAttributeValues;
            return this;
        }

        public UpdateItemRequestBuilder withKeys(Dictionary<string, AttributeValue> keyValue)
        {
            m_request.Key = keyValue;
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, string keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { S = keyValue };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, int keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, long keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, float keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, double keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, bool keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { BOOL = keyValue };
            return this;
        }

        public UpdateItemRequestBuilder addKey(string keyName, AttributeValue keyValue)
        {
            m_request.Key[keyName] = keyValue;
            return this;
        }

        public UpdateItemRequestBuilder withReturnConsumedCapacity(ReturnConsumedCapacity returnConsumedCapacity)
        {
            m_request.ReturnConsumedCapacity = returnConsumedCapacity;
            return this;
        }

        public UpdateItemRequestBuilder withReturnItemCollectionMetrics(ReturnItemCollectionMetrics returnItemCollectionMetrics)
        {
            m_request.ReturnItemCollectionMetrics = returnItemCollectionMetrics;
            return this;
        }

        public UpdateItemRequestBuilder withUpdateExpression(string updateExpression)
        {
            m_request.UpdateExpression = updateExpression;
            return this;
        }

        public UpdateItemRequestBuilder withConditionCheck(string conditionExpression)
        {
            m_request.ConditionExpression = conditionExpression;
            return this;
        }

        public (Result, UpdateItemRequest?) build()
        {
            var result = new Result();

            if(null != m_document)
            {
                result = m_document.tryFillupUpdateItemRequest(m_request, m_is_upsert);
                if(result.isFail())
                {
                    return (result, null);
                }
            }
            else
            {
                if (    false == m_is_upsert
                     && null != m_request.ConditionExpression 
                     && m_request.ConditionExpression.isNullOrWhiteSpace() )
                {
                    m_request.ConditionExpression = $"attribute_exists({PrimaryKey.PK_Define}) AND attribute_exists({PrimaryKey.SK_Define})";
                }
            }

            return (result, m_request);
        }
    }

    //=========================================================================================
    // GetItemRequest Builder
    //=========================================================================================
    public class GetItemRequestBuilder
    {
        private readonly GetItemRequest m_request;
        public GetItemRequestBuilder(string tableName)
        {
            m_request = new GetItemRequest
            {
                TableName = tableName,
                Key = new Dictionary<string, AttributeValue>(),
                ExpressionAttributeNames = new Dictionary<string, string>()
            };
        }

        public GetItemRequestBuilder withKeys(Dictionary<string, AttributeValue> keyValue)
        {
            m_request.Key = keyValue;
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, string keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { S = keyValue };
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, int keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, long keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, double keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, float keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public GetItemRequestBuilder addKey(string keyName, bool keyValue)
        {
            m_request.Key[keyName] = new AttributeValue { BOOL = keyValue };
            return this;
        }

        public GetItemRequestBuilder withConsistentRead(bool isConsistentRead)
        {
            m_request.ConsistentRead = isConsistentRead;
            return this;
        }

        public GetItemRequestBuilder withProjectionExpression(string projectExpression)
        {
            m_request.ProjectionExpression = projectExpression;
            return this;
        }

        public GetItemRequestBuilder withExpressionAttributeNames(Dictionary<string, string> expressionAttributeNames)
        {
            m_request.ExpressionAttributeNames = expressionAttributeNames;
            return this;
        }

        public GetItemRequestBuilder withReturnConsumedCapacity(ReturnConsumedCapacity returnConsumedCapacity)
        {
            m_request.ReturnConsumedCapacity = returnConsumedCapacity;
            return this;
        }

        public GetItemRequest build()
        {
            return m_request;
        }
    }

    //=========================================================================================
    // PutItemRequest Builder
    //=========================================================================================
    public class PutItemRequestBuilder
    {
        private readonly PutItemRequest m_request;

        public PutItemRequestBuilder(string tableName)
        {
            m_request = new PutItemRequest
            {
                TableName = tableName,
                Item = new Dictionary<string, AttributeValue>(),
                ExpressionAttributeNames = new Dictionary<string, string>(),
                ExpressionAttributeValues = new Dictionary<string, AttributeValue>()
            };
        }

        public PutItemRequestBuilder withItem(Dictionary<string, AttributeValue> attributeValues)
        {
            m_request.Item = attributeValues;
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, string keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { S = keyValue };
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, int keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, long keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, double keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, float keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { N = keyValue.ToString() };
            return this;
        }

        public PutItemRequestBuilder addItem(string keyName, bool keyValue)
        {
            m_request.Item[keyName] = new AttributeValue { BOOL = keyValue };
            return this;
        }

        public PutItemRequestBuilder withConditionalOperator(ConditionalOperator conditionalOperator)
        {
            m_request.ConditionalOperator = conditionalOperator;
            return this;
        }

        public PutItemRequestBuilder withConditionalCapacity(ReturnConsumedCapacity returnConsumedCapacity)
        {
            m_request.ReturnConsumedCapacity = returnConsumedCapacity;
            return this;
        }

        public PutItemRequestBuilder withConditionExpression(string conditionExpression)
        {
            m_request.ConditionExpression = conditionExpression;
            return this;
        }

        public PutItemRequestBuilder withExpressionAttributeNames(Dictionary<string, string> expressAttributeNames)
        {
            m_request.ExpressionAttributeNames = expressAttributeNames;
            return this;
        }

        public PutItemRequestBuilder withExpressionAttributeValues(Dictionary<string, AttributeValue> expressAttributeValues)
        {
            m_request.ExpressionAttributeValues = expressAttributeValues;
            return this;
        }

        public PutItemRequestBuilder withReturnConsumedCapacity(ReturnConsumedCapacity retrunConsumedCapacity)
        {
            m_request.ReturnConsumedCapacity = retrunConsumedCapacity;
            return this;
        }

        public PutItemRequestBuilder withReturnItemCollectionMetrics(ReturnItemCollectionMetrics returnItemCollectionMetrics)
        {
            m_request.ReturnItemCollectionMetrics = returnItemCollectionMetrics;
            return this;
        }

        public PutItemRequest build()
        {
            return m_request;
        }
    }

    //=========================================================================================
    // DeleteItemRequest Builder
    //=========================================================================================
    public class DeleteItemRequestBuilder
    {
        private readonly DeleteItemRequest m_request;

        public DeleteItemRequestBuilder(string tableName)
        {
            m_request = new DeleteItemRequest
            {
                TableName = tableName,
                Key = new Dictionary<string, AttributeValue>(),
                ExpressionAttributeNames = new Dictionary<string, string>(),
                ExpressionAttributeValues = new Dictionary<string, AttributeValue>()
            };
        }

        public DeleteItemRequestBuilder withKeys(Dictionary<string, AttributeValue> keys)
        {
            m_request.Key = keys;
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, string attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { S = attributeValue };
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, int attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { N = attributeValue.ToString() };
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, long attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { N = attributeValue.ToString() };
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, double attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { N = attributeValue.ToString() };
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, float attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { N = attributeValue.ToString() };
            return this;
        }

        public DeleteItemRequestBuilder addKey(string attributeName, bool attributeValue)
        {
            m_request.Key[attributeName] = new AttributeValue { BOOL = attributeValue };
            return this;
        }

        public DeleteItemRequestBuilder withConditionalOperator(ConditionalOperator conditionalOperator)
        {
            m_request.ConditionalOperator = conditionalOperator;
            return this;
        }

        public DeleteItemRequestBuilder withReturnValues(ReturnValue returnValue)
        {
            m_request.ReturnValues = returnValue;
            return this;
        }

        public DeleteItemRequestBuilder withConditionExpression(string conditionExpression)
        {
            m_request.ConditionExpression = conditionExpression;
            return this;
        }

        public DeleteItemRequestBuilder withExpressionAttributeNames(Dictionary<string, string> expressionAttributeNames)
        {
            m_request.ExpressionAttributeNames = expressionAttributeNames;
            return this;
        }

        public DeleteItemRequestBuilder withExpressionAttributeValues(Dictionary<string, AttributeValue> expressionAttributeValues)
        {
            m_request.ExpressionAttributeValues = expressionAttributeValues;
            return this;
        }

        public DeleteItemRequestBuilder withReturnConsumedCapacity(ReturnConsumedCapacity returnConsumedCapacity)
        {
            m_request.ReturnConsumedCapacity = returnConsumedCapacity;
            return this;
        }

        public DeleteItemRequestBuilder withReturnItemCollectionMetrics(ReturnItemCollectionMetrics returnItemCollectionMetrics)
        {
            m_request.ReturnItemCollectionMetrics = returnItemCollectionMetrics;
            return this;
        }

        public DeleteItemRequest build()
        {
            return m_request;
        }
    }

    public static DynamoDbItemRequestQueryContext createItemRequestQueryContext( this AmazonDynamoDBRequest itemRequest
                                                                               , QueryType queryType
                                                                               , DynamoDbQueryExceptionNotifier.ExceptionHandler? exceptionHandler = null)
    {
        return new DynamoDbItemRequestQueryContext(itemRequest, queryType, exceptionHandler);
    }

    public static bool isValid(this AmazonDynamoDBRequest itemRequest)
    {
        //if (document.getPK() == string.Empty || document.getSK() == string.Empty || document.getDocType() == string.Empty)
        //{
        //    Log.getLogger().error($"PK or SK or DocType is empty !!! : {document.toBasicString()}");
        //    return false;
        //}

        return true;
    }
}