import boto3
import os
import tempfile

from utility import aws_access_key_id, aws_secret_access_key,terminal_print

s3 = boto3.client(
    's3', 
    aws_access_key_id=aws_access_key_id,
    aws_secret_access_key=aws_secret_access_key
    )

# post or update a file to s3
@terminal_print
def upload_file(path, bucket, object_name=None):
    """Upload a file to an S3 bucket

    :param path: path to file for upload
    :param bucket: Bucket to upload to
    :param object_name: S3 object name. 
        If not specified then file_name is used
    :return: True if file was uploaded, else False
    """
    file_name = os.path.basename(path)

    if object_name is None:
        object_name = file_name

    try:

        res = s3.upload_file(path, bucket, object_name)
    except Exception as e:
        print(e)
        return False
    return res

@terminal_print
def upload_fileobj(file_obj, bucket, object_name=None):
    '''
    Upload a file object to an S3 bucket
    
    :param file_obj: File object to upload
    :param bucket: Bucket to upload to
    :param object_name: S3 object name.
        If not specified then file_name is used
        
    :return: True if file was uploaded, else False
    '''
    if object_name is None:
        object_name = file_obj.name

    try:
        res = s3.upload_fileobj(file_obj, bucket, object_name)
    except Exception as e:
        print(e)
        return e
    return res

# get a file from s3
@terminal_print
def download_file(bucket, object_name, file_name=None):
    """Download a file from an S3 bucket

    :param bucket: Bucket to download from
    :param file_name: File to download
    :param object_name: S3 object name. 
        If not specified then file_name is used
    :return: True if file was downloaded, else False
    """
    if file_name is None:
        file_name = object_name

    try:
        s3.download_file(bucket, object_name, file_name)
    except Exception as e:
        print(e)
        return False
    return True

# download a file object from s3
@terminal_print
def download_fileobj(bucket, object_name, temp_obj=None):
    '''
    Download a file object from an S3 bucket
    
    :param file_name: File to download
    :param bucket: Bucket to download from
    :param object_name: S3 object name.
        If not specified then file_name is used
        
    :return: True if file was downloaded, else False
    '''
    if temp_obj is None:
        temp_obj = tempfile.TemporaryFile()

    try:
        s3.download_fileobj(bucket, object_name, temp_obj)
    except Exception as e:
        print(e)
        return False
    return temp_obj

# delete a file from s3
@terminal_print
def delete_file(bucket, object_name):
    """Delete a file from an S3 bucket

    :param bucket: Bucket to delete from
    :param object_name: S3 object name. 
    :return: True if file was deleted, else False
    """
    try:
        response = s3.delete_object(Bucket=bucket, Key=object_name)
    except Exception as e:
        print(e)
        return False
    return response

# list all files in a bucket
@terminal_print
def list_files(bucket):
    """List files in a bucket

    :param bucket: Bucket to list from
    :return: List of files in bucket
    """
    try:
        response = s3.list_objects_v2(Bucket=bucket)
    except Exception as e:
        print(e)
        return False
    return response['Contents']