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

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

import requests
import torch


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 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
    file = Path(file)
    assert_msg = f"Downloaded file '{file}' does not exist or size is < min_bytes={min_bytes}"
    try:  # url1
        print(f'Downloading {url} to {file}...')
        torch.hub.download_url_to_file(url, str(file))
        assert file.exists() and file.stat().st_size > min_bytes, assert_msg  # check
    except Exception as e:  # url2
        file.unlink(missing_ok=True)  # remove partial downloads
        print(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
            file.unlink(missing_ok=True)  # remove partial downloads
            print(f"ERROR: {assert_msg}\n{error_msg}")
        print('')


def attempt_download(file, repo='ultralytics/yolov5'): # 检查模型文件是否存在，如果不存在就重新下载。 # from utils.downloads import *; attempt_download()
    # Attempt file download if does not exist
    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():
                print(f'Found {url} locally at {file}')  # file already exists
            else:
                safe_download(file=file, url=url, min_bytes=1E5)
            return file

        # GitHub assets
        file.parent.mkdir(parents=True, exist_ok=True)  # make parent dir (if required)
        try:
            response = requests.get(f'https://api.github.com/repos/{repo}/releases/latest').json()  # github api
            assets = [x['name'] for x in response['assets']]  # release assets, i.e. ['yolov5s.pt', 'yolov5m.pt', ...]
            tag = response['tag_name']  # i.e. 'v1.0'
        except Exception:  # fallback plan
            assets = [
                'yolov5n.pt', 'yolov5s.pt', 'yolov5m.pt', 'yolov5l.pt', 'yolov5x.pt', 'yolov5n6.pt', 'yolov5s6.pt',
                'yolov5m6.pt', 'yolov5l6.pt', 'yolov5x6.pt']
            try:
                tag = subprocess.check_output('git tag', shell=True, stderr=subprocess.STDOUT).decode().split()[-1]
            except Exception:
                tag = 'v6.1'  # current release

        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}',
                url2=f'https://storage.googleapis.com/{repo}/{tag}/{name}',  # backup url (optional)
                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='')
    file.unlink(missing_ok=True)  # remove existing file
    cookie.unlink(missing_ok=True)  # 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
    cookie.unlink(missing_ok=True)  # remove existing cookie

    # Error check
    if r != 0:
        file.unlink(missing_ok=True)  # 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))