# -*- encoding: utf-8 -*-
"""
@File    : DynamodbObject.py
@Time    : 2023/8/29 10:05
@Author  : stephen
@Email   : zhangdongming@asj6.wecom.work
@Software: PyCharm
"""

import boto3


class DynamodbObject(object):
    def __init__(self, aws_access_key_id, secret_access_key, region_name):
        self.dynamo = boto3.client(
            'dynamodb',
            aws_access_key_id=aws_access_key_id,
            aws_secret_access_key=secret_access_key,
            region_name=region_name
        )

    def get_item(self, table_name, key_params):
        """
        查询单个项目
        @param table_name: 表名称
        @param key_params: 分区键值、排序键值
        @return: 查询结果
        """
        try:
            response = self.dynamo.get_item(TableName=table_name,
                                            Key=key_params)
        except Exception as err:
            print(repr(err))
            raise
        else:
            return response['Item']

    def put_item(self, table_name, item):
        """
        写入项目
        @param table_name: 表名称
        @param item: 项目键值
        @return: 创建结果
        """
        try:
            response = self.dynamo.put_item(TableName=table_name,
                                            Item=item)
        except Exception as err:
            print(repr(err))
            raise
        else:
            return response

    def query_page(self, table_name, key_condition_expression, expression_attribute_values, exclusive_start_key=None,
                   page_size=10, scan_index_forward=True):
        """
        分页查询
        @param table_name: 表名称
        @param key_condition_expression: 定义键条件表达式以筛选查询结果
        @param expression_attribute_values: 定义表达式中的占位符属性值
        @param exclusive_start_key: 用以分页查询时指定起始键
        @param page_size: 要返回的最大项目数
        @return: 查询结果
        """
        try:
            query_params = {
                'TableName': table_name,
                'KeyConditionExpression': key_condition_expression,
                'ExpressionAttributeValues': expression_attribute_values,
                'Limit': page_size,
                'ScanIndexForward': scan_index_forward
            }
            if exclusive_start_key:
                query_params['ExclusiveStartKey'] = exclusive_start_key

            return self.dynamo.query(**query_params)
        except Exception as err:
            print(repr(err))
            raise

    def query(self, table_name, key_condition_expression, expression_attribute_values, scan_index_forward=True):
        """
        查询项目
        @param table_name: 表名称
        @param key_condition_expression: 定义键条件表达式以筛选查询结果
        @param expression_attribute_values: 定义表达式中的占位符属性值
        @return: 查询结果
        """
        try:
            query_params = {
                'TableName': table_name,
                'KeyConditionExpression': key_condition_expression,
                'ExpressionAttributeValues': expression_attribute_values,
                'ScanIndexForward': scan_index_forward
            }

            return self.dynamo.query(**query_params)
        except Exception as err:
            print(repr(err))
            raise