// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
/**
 * Before running this C++ code example, set up your development environment, including your credentials.
 *
 * For more information, see the following documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/getting-started.html
 *
 * For information on the structure of the code examples and how to build and run the examples, see
 * https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/getting-started-code-examples.html.
 *
 **/

// snippet-start:[dynamodb.cpp.update_item.inc]
#include <aws/core/Aws.h>
#include <aws/dynamodb/DynamoDBClient.h>
#include <aws/dynamodb/model/UpdateItemRequest.h>
#include <aws/dynamodb/model/UpdateItemResult.h>
#include <iostream>
// snippet-end:[dynamodb.cpp.update_item.inc]
#include "dynamodb_samples.h"

// snippet-start:[dynamodb.cpp.update_item.code]
//! Update an Amazon DynamoDB table item.
/*!
  \sa updateItem()
  \param tableName: The table name.
  \param partitionKey: The partition key.
  \param partitionValue: The value for the partition key.
  \param attributeKey: The key for the attribute to be updated.
  \param attributeValue: The value for the attribute to be updated.
  \param clientConfiguration: AWS client configuration.
  \return bool: Function succeeded.
  */

/*
 *  The example code only sets/updates an attribute value. It processes
 *  the attribute value as a string, even if the value could be interpreted
 *  as a number. Also, the example code does not remove an existing attribute
 *  from the key value.
 */

bool AwsDoc::DynamoDB::updateItem(const Aws::String &tableName,
                                  const Aws::String &partitionKey,
                                  const Aws::String &partitionValue,
                                  const Aws::String &attributeKey,
                                  const Aws::String &attributeValue,
                                  const Aws::Client::ClientConfiguration &clientConfiguration) {
    Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);

    // *** Define UpdateItem request arguments.
    // Define TableName argument.
    Aws::DynamoDB::Model::UpdateItemRequest request;
    request.SetTableName(tableName);

    // Define KeyName argument.
    Aws::DynamoDB::Model::AttributeValue attribValue;
    attribValue.SetS(partitionValue);
    request.AddKey(partitionKey, attribValue);

    // Construct the SET update expression argument.
    Aws::String update_expression("SET #a = :valueA");
    request.SetUpdateExpression(update_expression);

    // Construct attribute name argument.
    Aws::Map<Aws::String, Aws::String> expressionAttributeNames;
    expressionAttributeNames["#a"] = attributeKey;
    request.SetExpressionAttributeNames(expressionAttributeNames);

    // Construct attribute value argument.
    Aws::DynamoDB::Model::AttributeValue attributeUpdatedValue;
    attributeUpdatedValue.SetS(attributeValue);
    Aws::Map<Aws::String, Aws::DynamoDB::Model::AttributeValue> expressionAttributeValues;
    expressionAttributeValues[":valueA"] = attributeUpdatedValue;
    request.SetExpressionAttributeValues(expressionAttributeValues);

    // Update the item.
    const Aws::DynamoDB::Model::UpdateItemOutcome &outcome = dynamoClient.UpdateItem(
            request);
    if (outcome.IsSuccess()) {
        std::cout << "Item was updated" << std::endl;
    } else {
        std::cerr << outcome.GetError().GetMessage() << std::endl;
        return false;
    }

    return waitTableActive(tableName, dynamoClient);
}
// snippet-end:[dynamodb.cpp.update_item.code]

/*
 *  main function
 *
 *  Usage: 'run_update_item <table_name> <partition_key> <partition_value> <attribute_key>
 *         <attribute_value>'
 *
 *  Prerequisites: Create a pre-populated DynamoDB table.
 *
 *  For instructions on populating a table with sample data, see
 *  https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/SampleData.html.
 *
 */

#ifndef TESTING_BUILD

int main(int argc, char **argv) {
    if (argc < 6) {
        std::cout << R"(
Usage:
    run_update_item <table_name> <partition_key> <partition_value> <attribute_key>
          <attribute_value>
Where:
    table_name        - Name of the table to put the item in.
    partition_key     - The partition key.
    partition_value   - The value of the partition key.
    attribute_key     - The attribute key.
    attribute_value   - The attribute value.
)";
        return 1;
    }

    Aws::SDKOptions options;
    Aws::InitAPI(options);
    {
        const Aws::String tableName(argv[1]);
        const Aws::String partitionKey(argv[2]);
        const Aws::String partitionValue(argv[3]);
        const Aws::String attributeKey(argv[4]);
        const Aws::String attributeValue(argv[5]);

        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region (overrides config file).
        // clientConfig.region = "us-east-1";

        AwsDoc::DynamoDB::updateItem(tableName, partitionKey, partitionValue,
                                     attributeKey,
                                     attributeValue, clientConfig);
    }
    Aws::ShutdownAPI(options);
    return 0;
}

#endif //  TESTING_BUILD