import os
import glob
import xattr
import pathlib
import time
import hashlib

from decouple import config
from etcd3_wrapper import Etcd3Wrapper
from uuid import uuid4


def getxattr(f, attr, symlink=False):
    try:
        return xattr.getxattr(f, attr, symlink).decode("utf-8")
    except OSError as _:
        return None


def sha512sum(filename):
    _sum = hashlib.sha512()
    buffer_size = 2**16

    with open(filename, "rb") as f:
        while True:
            data = f.read(buffer_size)
            if not data:
                break
            _sum.update(data)

    return _sum.hexdigest()


BASE_DIR = config("BASE_DIR")

FILE_PREFIX = config("FILE_PREFIX")

etcd_client = Etcd3Wrapper()

# Recursively Get All Files and Folder below BASE_DIR
files = glob.glob(f"{BASE_DIR}/**", recursive=True)

# Retain only Files
files = list(filter(lambda f: os.path.isfile(f), files))

untracked_files = list(
    filter(lambda f: not bool(getxattr(f, "user.utracked")), files)
)

tracked_files = list(
    filter(lambda f: f not in untracked_files, files)
)
for file in untracked_files:
    file_id = uuid4()

    # Get Username
    owner = pathlib.Path(file).parts[2]

    # Get Creation Date of File
    # Here, we are assuming that ctime is creation time
    # which is mostly not true.
    creation_date = time.ctime(os.stat(file).st_ctime)

    # Get File Size
    size = os.path.getsize(file)

    # Compute sha512 sum
    sha_sum = sha512sum(file)

    # File Path excluding base and username
    file_path = pathlib.Path(file).parts[3:]
    file_path = os.path.join(*file_path)

    # Create Entry
    entry_key = f"{FILE_PREFIX}/{file_id}"
    entry_value = {"filename": file_path,
                   "owner": owner,
                   "sha512sum": sha_sum,
                   "creation_date": creation_date,
                   "size": size
                   }

    print(f"Tracking {file}")

    # Insert Entry
    etcd_client.put(entry_key, entry_value, value_in_json=True)
    xattr.setxattr(file, b"user.utracked", b"True")