import os.path
import boto3
from botocore.config import Config

class S3Loader:
    def __init__(self, bucket_name):
        self.bucket_name = bucket_name
        endpoint = None
        if "AWS_ENDPOINT_S3" in os.environ:
            s3_config = Config(
                s3={'addressing_style': 'virtual',
                'payload_signing_enabled': False},
                # Disable chunked encoding which causes issues with OSS
                signature_version='s3v4'
            )
            endpoint = os.environ["AWS_ENDPOINT_S3"]
            self.s3 = boto3.resource('s3', endpoint_url=endpoint, config=s3_config)
        else:
            self.s3 = boto3.resource('s3')

    def get_file(self, filename):
        key = filename
        return self.s3.Object(self.bucket_name, key).get()['Body'].read()

    def get_file_list(self, path):
        bucket = self.s3.Bucket(self.bucket_name)
        prefix = path
        return [obj.key for obj in bucket.objects.filter(Prefix=prefix)]

    def file_exists(self, path):
        bucket = self.s3.Bucket(self.bucket_name)
        prefix = path
        return any([obj.key == path for obj in bucket.objects.filter(Prefix=prefix)])

    def save_file(self, filename, content):
        raise Exception("s3 loader does not support save file")

    def upload_file(self, filename, s3_key):
        key = s3_key
        self.s3.Object(self.bucket_name, key).upload_file(filename)