#!/usr/bin/env python

import os

import boto3
import botocore
import json
import swiftclient
from botocore.utils import fix_s3_host
from botocore.client import Config
from oauth2client.service_account import ServiceAccountCredentials
from gcloud.storage.client import Client
from gcloud import exceptions
from azure.storage.blob import BlockBlobService

bucket_name = os.getenv('BUCKET_NAME')

if os.getenv('DATABASE_STORAGE') == "s3":
    conn = boto3.resource('s3')
    exists = True
    try:
        conn.meta.client.head_bucket(Bucket=bucket_name)
    except botocore.exceptions.ClientError as e:
        # If a client error is thrown, then check that it was a 404 error.
        # If it was a 404 error, then the bucket does not exist.
        error_code = int(e.response['Error']['Code'])
        if error_code == 404:
            exists = False
        else:
            raise

    if not exists:
        conn.create_bucket(Bucket=bucket_name)

elif os.getenv('DATABASE_STORAGE') == "gcs":
    scopes = ['https://www.googleapis.com/auth/devstorage.full_control']
    credentials = ServiceAccountCredentials.from_json_keyfile_name(os.getenv('GS_APPLICATION_CREDS'), scopes=scopes)
    with open(os.getenv('GS_APPLICATION_CREDS')) as data_file:
        data = json.load(data_file)
    client = Client(credentials=credentials, project=data['project_id'])
    exists = True
    try:
        client.get_bucket(bucket_name)
    except exceptions.NotFound:
        exists = False
    except:
        raise
    if not exists:
        client.create_bucket(bucket_name)

elif os.getenv('DATABASE_STORAGE') == "azure":
    block_blob_service = BlockBlobService(account_name=os.getenv('WABS_ACCOUNT_NAME'), account_key=os.getenv('WABS_ACCESS_KEY'))
    #It doesn't throw an exception if the container exists by default(https://github.com/Azure/azure-storage-python/blob/master/azure/storage/blob/baseblobservice.py#L504).
    block_blob_service.create_container(bucket_name)

elif os.getenv('DATABASE_STORAGE') == "swift":
    conn = swiftclient.Connection(
        user=os.getenv('SWIFT_USER'),
        key=os.getenv('SWIFT_PASSWORD'),
        authurl=os.getenv('SWIFT_AUTHURL'),
        auth_version=os.getenv('SWIFT_AUTH_VERSION'),
        tenant_name=os.getenv('SWIFT_TENANT')
    )
    # swift also does not throw exception if container already exists.
    conn.put_container(os.getenv('BUCKET_NAME'))

else:
    conn = boto3.resource('s3', endpoint_url=os.getenv('S3_URL'), config=Config(signature_version='s3v4'))
    # stop boto3 from automatically changing the endpoint
    conn.meta.client.meta.events.unregister('before-sign.s3', fix_s3_host)
    exists = True
    try:
        conn.meta.client.head_bucket(Bucket=bucket_name)
    except botocore.exceptions.ClientError as e:
        # If a client error is thrown, then check that it was a 404 error.
        # If it was a 404 error, then the bucket does not exist.
        error_code = int(e.response['Error']['Code'])
        if error_code == 404:
            exists = False
        else:
            raise

    if not exists:
        conn.create_bucket(Bucket=bucket_name)