#!/usr/bin/env python
"""
Download SciPy wheels from Anaconda staging area.

"""
import sys
import os
import re
import shutil
import argparse
import urllib
import urllib.request

import urllib3
from bs4 import BeautifulSoup

__version__ = '0.1'

# Edit these for other projects.
STAGING_URL = 'https://anaconda.org/multibuild-wheels-staging/scipy'
PREFIX = 'scipy'

def http_manager():
    """
    Return a urllib3 http request manager, leveraging
    proxy settings when available.
    """
    proxy_dict = urllib.request.getproxies()
    if 'http' in proxy_dict:
        http = urllib3.ProxyManager(proxy_dict['http'])
    elif 'all' in proxy_dict:
        http = urllib3.ProxyManager(proxy_dict['all'])
    else:
        http = urllib3.PoolManager(cert_reqs='CERT_REQUIRED')
    return http

def get_wheel_names(version):
    """ Get wheel names from Anaconda HTML directory.

    This looks in the Anaconda multibuild-wheels-staging page and
    parses the HTML to get all the wheel names for a release version.

    Parameters
    ----------
    version : str
        The release version. For instance, "1.5.0".

    """
    http = http_manager()
    tmpl = re.compile(rf"^.*{PREFIX}-{version}-.*\.whl$")
    index_url = f"{STAGING_URL}/files"
    index_html = http.request('GET', index_url)
    soup = BeautifulSoup(index_html.data, 'html.parser')
    return soup.findAll(text=tmpl)


def download_wheels(version, wheelhouse):
    """Download release wheels.

    The release wheels for the given SciPy version are downloaded
    into the given directory.

    Parameters
    ----------
    version : str
        The release version. For instance, "1.5.0".
    wheelhouse : str
        Directory in which to download the wheels.

    """
    http = http_manager()
    wheel_names = get_wheel_names(version)

    for i, wheel_name in enumerate(wheel_names):
        wheel_url = f"{STAGING_URL}/{version}/download/{wheel_name}"
        wheel_path = os.path.join(wheelhouse, wheel_name)
        with open(wheel_path, 'wb') as f:
            with http.request('GET', wheel_url, preload_content=False,) as r:
                print(f"{i + 1:<4}{wheel_name}")
                shutil.copyfileobj(r, f)
    print(f"\nTotal files downloaded: {len(wheel_names)}")


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "version",
        help="SciPy version to download.")
    parser.add_argument(
        "-w", "--wheelhouse",
        default=os.path.join(os.getcwd(), "release", "installers"),
        help="Directory in which to store downloaded wheels\n"
             "[defaults to <cwd>/release/installers]")

    args = parser.parse_args()

    wheelhouse = os.path.expanduser(args.wheelhouse)
    if not os.path.isdir(wheelhouse):
        raise RuntimeError(
            f"{wheelhouse} wheelhouse directory is not present."
            " Perhaps you need to use the '-w' flag to specify one.")

    download_wheels(args.version, wheelhouse)