# YOLOv5 🚀 by Ultralytics, GPL-3.0 license
"""
Download utils
"""

import logging
import os
import platform
import subprocess
import time
import urllib
from pathlib import Path
from zipfile import ZipFile

import requests
import torch


def is_url(url, check=True):
    # Check if string is URL and check if URL exists
    try:
        url = str(url)
        result = urllib.parse.urlparse(url)
        assert all([result.scheme, result.netloc])  # check if is url
        return (urllib.request.urlopen(url).getcode() == 200) if check else True  # check if exists online
    except (AssertionError, urllib.request.HTTPError):
        return False


def gsutil_getsize(url=''):
    # gs://bucket/file size https://cloud.google.com/storage/docs/gsutil/commands/du
    s = subprocess.check_output(f'gsutil du {url}', shell=True).decode('utf-8')
    return eval(s.split(' ')[0]) if len(s) else 0  # bytes


def url_getsize(url='https://ultralytics.com/images/bus.jpg'):
    # Return downloadable file size in bytes
    response = requests.head(url, allow_redirects=True)
    return int(response.headers.get('content-length', -1))


def safe_download(file, url, url2=None, min_bytes=1E0, error_msg=''):
    # Attempts to download file from url or url2, checks and removes incomplete downloads < min_bytes
    from utils.general import LOGGER

    file = Path(file)
    assert_msg = f"Downloaded file '{file}' does not exist or size is < min_bytes={min_bytes}"
    try:  # url1
        LOGGER.info(f'Downloading {url} to {file}...')
        torch.hub.download_url_to_file(url, str(file), progress=LOGGER.level <= logging.INFO)
        assert file.exists() and file.stat().st_size > min_bytes, assert_msg  # check
    except Exception as e:  # url2
        if file.exists():
            file.unlink()  # remove partial downloads
        LOGGER.info(f'ERROR: {e}\nRe-attempting {url2 or url} to {file}...')
        os.system(f"curl -# -L '{url2 or url}' -o '{file}' --retry 3 -C -")  # curl download, retry and resume on fail
    finally:
        if not file.exists() or file.stat().st_size < min_bytes:  # check
            if file.exists():
                file.unlink()  # remove partial downloads
            LOGGER.info(f"ERROR: {assert_msg}\n{error_msg}")
        LOGGER.info('')


def attempt_download(file, repo='ultralytics/yolov5', release='v6.2'):
    # Attempt file download from GitHub release assets if not found locally. release = 'latest', 'v6.2', etc.
    from utils.general import LOGGER

    def github_assets(repository, version='latest'):
        # Return GitHub repo tag (i.e. 'v6.2') and assets (i.e. ['yolov5s.pt', 'yolov5m.pt', ...])
        if version != 'latest':
            version = f'tags/{version}'  # i.e. tags/v6.2
        response = requests.get(f'https://api.github.com/repos/{repository}/releases/{version}').json()  # github api
        return response['tag_name'], [x['name'] for x in response['assets']]  # tag, assets

    file = Path(str(file).strip().replace("'", ''))
    if not file.exists():
        # URL specified
        name = Path(urllib.parse.unquote(str(file))).name  # decode '%2F' to '/' etc.
        if str(file).startswith(('http:/', 'https:/')):  # download
            url = str(file).replace(':/', '://')  # Pathlib turns :// -> :/
            file = name.split('?')[0]  # parse authentication https://url.com/file.txt?auth...
            if Path(file).is_file():
                LOGGER.info(f'Found {url} locally at {file}')  # file already exists
            else:
                safe_download(file=file, url=url, min_bytes=1E5)
            return file

        # GitHub assets
        assets = [f'yolov5{size}{suffix}.pt' for size in 'nsmlx' for suffix in ('', '6', '-cls', '-seg')]  # default
        try:
            tag, assets = github_assets(repo, release)
        except Exception:
            try:
                tag, assets = github_assets(repo)  # latest release
            except Exception:
                try:
                    tag = subprocess.check_output('git tag', shell=True, stderr=subprocess.STDOUT).decode().split()[-1]
                except Exception:
                    tag = release

        file.parent.mkdir(parents=True, exist_ok=True)  # make parent dir (if required)
        if name in assets:
            url3 = 'https://drive.google.com/drive/folders/1EFQTEUeXWSFww0luse2jB9M1QNZQGwNl'  # backup gdrive mirror
            safe_download(
                file,
                url=f'https://github.com/{repo}/releases/download/{tag}/{name}',
                min_bytes=1E5,
                error_msg=f'{file} missing, try downloading from https://github.com/{repo}/releases/{tag} or {url3}')

    return str(file)


def gdrive_download(id='16TiPfZj7htmTyhntwcZyEEAejOUxuT6m', file='tmp.zip'):
    # Downloads a file from Google Drive. from yolov5.utils.downloads import *; gdrive_download()
    t = time.time()
    file = Path(file)
    cookie = Path('cookie')  # gdrive cookie
    print(f'Downloading https://drive.google.com/uc?export=download&id={id} as {file}... ', end='')
    if file.exists():
        file.unlink()  # remove existing file
    if cookie.exists():
        cookie.unlink()  # remove existing cookie

    # Attempt file download
    out = "NUL" if platform.system() == "Windows" else "/dev/null"
    os.system(f'curl -c ./cookie -s -L "drive.google.com/uc?export=download&id={id}" > {out}')
    if os.path.exists('cookie'):  # large file
        s = f'curl -Lb ./cookie "drive.google.com/uc?export=download&confirm={get_token()}&id={id}" -o {file}'
    else:  # small file
        s = f'curl -s -L -o {file} "drive.google.com/uc?export=download&id={id}"'
    r = os.system(s)  # execute, capture return
    if cookie.exists():
        cookie.unlink()  # remove existing cookie

    # Error check
    if r != 0:
        if file.exists():
            file.unlink()  # remove partial
        print('Download error ')  # raise Exception('Download error')
        return r

    # Unzip if archive
    if file.suffix == '.zip':
        print('unzipping... ', end='')
        ZipFile(file).extractall(path=file.parent)  # unzip
        file.unlink()  # remove zip

    print(f'Done ({time.time() - t:.1f}s)')
    return r


def get_token(cookie="./cookie"):
    with open(cookie) as f:
        for line in f:
            if "download" in line:
                return line.split()[-1]
    return ""


# Google utils: https://cloud.google.com/storage/docs/reference/libraries ----------------------------------------------
#
#
# def upload_blob(bucket_name, source_file_name, destination_blob_name):
#     # Uploads a file to a bucket
#     # https://cloud.google.com/storage/docs/uploading-objects#storage-upload-object-python
#
#     storage_client = storage.Client()
#     bucket = storage_client.get_bucket(bucket_name)
#     blob = bucket.blob(destination_blob_name)
#
#     blob.upload_from_filename(source_file_name)
#
#     print('File {} uploaded to {}.'.format(
#         source_file_name,
#         destination_blob_name))
#
#
# def download_blob(bucket_name, source_blob_name, destination_file_name):
#     # Uploads a blob from a bucket
#     storage_client = storage.Client()
#     bucket = storage_client.get_bucket(bucket_name)
#     blob = bucket.blob(source_blob_name)
#
#     blob.download_to_filename(destination_file_name)
#
#     print('Blob {} downloaded to {}.'.format(
#         source_blob_name,
#         destination_file_name))