import boto3

from utility import *

# initialize dynamodb instance
db_client = boto3.client(
    "dynamodb",
    aws_access_key_id = aws_access_key_id,
    aws_secret_access_key = aws_secret_access_key,
    region_name = "us-east-1"
    )

'''
dynamodb data operations
'''

# get the list of articles from articles table in dynamodb
@terminal_print
def get_table(table_name:str):
    result = db_client.scan(TableName = table_name)
    items = result["Items"]
    while "LastEvaluatedKey" in result:
        result = db_client.scan(TableName = table_name,ExclusiveStartKey = result["LastEvaluatedKey"])
        items.extend(result["Items"])
    return [db_map_to_py_dict(r) for r in items]

# add a new article to table articles in dynamodb, return error if failed
def post_item(table_name:str,item:dict):
    try:
        res = db_client.put_item(
            TableName = table_name,
            Item = py_dict_to_db_map(item)
        )
    except Exception as e:
        return {"Error":e}
    return res

# update an article in table articles in dynamodb, return error if failed
@terminal_print
def put_item(table_name:str,item:dict):
    try:
        res = db_client.put_item(
            TableName = table_name,
            Item = py_dict_to_db_map(item)
        )
    except Exception as e:
        return {"Error":e}
    return res

# delete an article in table articles in dynamodb, return error if not found.
@terminal_print
def delete_item(table_name:str,key:dict):
    try:
        res = db_client.delete_item(
            TableName = table_name,
            Key = py_dict_to_db_map(key)
        )
    except Exception as e:
        return {"Error":e}
    return res


'''
'''
@terminal_print
def get_item(table_name:str,key:dict):
    try:
        res = db_client.get_item(
            TableName = table_name,
            Key = py_dict_to_db_map(key)
        )
    except Exception as e:
        return {"Error":e}
    return res

'''
dynamodb structure management
'''
@terminal_print
def get_structure(table_name:str):
    result = db_client.describe_table(TableName = table_name)
    return result["Table"]["AttributeDefinitions"]