import requests
import subprocess
import gzip
import urllib.request
import sys
import base64

# Variables of the needed elements
extract_id = sys.argv[2]
# auth_token = sys.argv[3]
base_url = "https://analytics.northpass.io/extracts"
encryption_key = sys.argv[3]
current_dir = "./"

# Set the API endpoint, authentication headers, and other parameters
headers = {
    "accept": "application/json",
    "X-Api-Key": sys.argv[1],
}


# This first call provides you with the fileID and IV value to download the encrypted file
def get_extract_id(base_url, headers, extract_id, encryption_key):
    url = f"{base_url}/{extract_id}/files/latest/"
    response = requests.get(url, headers=headers)
    data = response.json()
    file_id = data["fileId"]
    iv = data["initializationVector"]
    download_file(base_url, headers, extract_id, file_id, encryption_key, iv)


# This function downloads the file, changes the IV and EK from base64 to Hex, and then decrypts it.
# It then opens and prints the results for verification that the data is human readable.
def download_file(base_url, headers, extract_id, file_id, encryption_key, iv):
    url = f"{base_url}/{extract_id}/files/{file_id}/download"
    response = requests.get(url, headers=headers)
    data = response.json()
    download_url = data["url"]

    # Downloads the file to the cwd
    url_resp = urllib.request.urlretrieve(download_url, "Client_API_Extract.csv.gz")
    file_name = url_resp[0]
    decrypted_file = "Client_File.csv.gz"

    # Base64 > Hex
    encryption_key = base64.b64decode(encryption_key).hex()
    print(encryption_key)
    iv = base64.b64decode(iv).hex()
    print(iv)

    # Decryption Command as provided in Northpass Documentation
    resp = subprocess.run(
        [
            "openssl",
            "enc",
            "-aes-256-cbc",
            "-d",
            "-nosalt",
            "-in",
            file_name,
            "-out",
            decrypted_file,
            "-K",
            encryption_key,
            "-iv",
            iv,
        ]
    )
    print(resp)

    # Print data in CSV to ensure it is human readable
    with gzip.open(decrypted_file, "rb") as uncompressed:
        file = uncompressed.read()
        print(file)


if __name__ == "__main__":
    get_extract_id(base_url, headers, extract_id, encryption_key)