"""Downloads and extract the Visual C++ Redistributables.

This is useful when working with minidump files as the user may be running
with a new different version of the runtime. This script aims to maintain 
a copy of the various versions.

Versions are normally added once I encoourter them.

This requires dark.exe from Wix (http://wixtoolset.org/releases/) and
expand.exe (File Expansion Utility - this comes with Microsoft Windows).
"""
from __future__ import print_function

import os
import requests
import subprocess
import tempfile
import zipfile

def download_file(uri, dest):
    """Download the uri to dest."""
    if os.path.isfile(dest):
        # Skipping, already downloaded.
        return dest
    r = requests.get(uri, stream=True)
    with open(dest, 'wb') as f:
        for chunk in r.iter_content(chunk_size=1024): 
            if chunk: # filter out keep-alive new chunks
                f.write(chunk)
    return dest

def fetch_runtimes(download_directory):
    """Fetches the Visual C++ x64 Redistributable from Microsoft.

    download_directory: The directory to write the resulting files in.

    Return the (version, runtime_file) for each known runtime.
    """
    # Some of these packages came from:
    # https://blogs.technet.microsoft.com/jagbal/2017/09/04/where-can-i-download-the-old-visual-c-redistributables/
    # Others came from Choclately (https://chocolatey.org/)
    runtime_downloads = [
        (
            '14.0.23026.0',
            'https://download.microsoft.com/download/9/3/F/93FCF1E7-E6A4-478B-96E7-D4B285925B00/vc_redist.x64.exe',
            # This next one seems to be the same version.
            #'https://download.microsoft.com/download/4/7/a/47a9d485-9e3a-4707-be1d-26011ff15f42/vc_redist.x64.exe',
        ),
        (
            '14.0.25325.0',
            'https://download.visualstudio.microsoft.com/download/pr/11100230/15ccb3f02745c7b206ad10373cbca89b/VC_redist.x64.exe',
        ),
        (
            '14.10.25017',
            'https://download.microsoft.com/download/3/b/f/3bf6e759-c555-4595-8973-86b7b4312927/vc_redist.x64.exe',
        ),
        (
            '14.10.25008.0',
            'https://download.microsoft.com/download/8/9/d/89d195e1-1901-4036-9a75-fbe46443fc5a/vc_redist.x64.exe',
        ),
        (
            '14.10.25017.0',
            'https://download.microsoft.com/download/3/b/f/3bf6e759-c555-4595-8973-86b7b4312927/vc_redist.x64.exe',
        ),
        (
            '14.11.25325.0',
            'https://download.visualstudio.microsoft.com/download/pr/11100230/15ccb3f02745c7b206ad10373cbca89b/VC_redist.x64.exe',
        ),
        (
            '14.12.25810',
            'https://download.visualstudio.microsoft.com/download/pr/100349091/2cd2dba5748dc95950a5c42c2d2d78e4/VC_redist.x64.exe',
        ),
        (
            '14.12.2581',
            'https://download.visualstudio.microsoft.com/download/pr/100349091/2cd2dba5748dc95950a5c42c2d2d78e4/VC_redist.x64.exe',
        ),
    ]

    for version, download_uri in runtime_downloads:
        filename = version + '_' + os.path.basename(download_uri)
        destination = download_file(download_uri, os.path.join(download_directory, filename))
        yield version, destination
    
def fetch_wix(download_directory):
    """Downloads the WiX toolset.

    This is used to extract the runtime packages.
    """
    zip_path = os.path.join(download_directory, '__wix.zip')
    if not os.path.isfile(zip_path):
        wix = 'https://github.com/wixtoolset/wix3/releases/download/' + \
            'wix3111rtm/wix311-binaries.zip'
        download_file(wix, zip_path)

    with zipfile.ZipFile(zip_path, 'r') as zip_file:
        zip_file.extractall(os.path.join(download_directory, '__wix'))

    return os.path.join(download_directory, '__wix')

def extract_burn_bundle(wix_tool_location, bundle_exe):
    """Extracts a burn bundle to a temporary directory.
    
    bundle_exe: The bundle executable to extract.
    """
    dark_exe = os.path.join(wix_tool_location, 'dark.exe')
    output_directory = tempfile.mkdtemp()
    subprocess.call([dark_exe, "-nologo", "-x", output_directory, bundle_exe])
    return output_directory

def find_cabs(directory):
    base_path = os.path.join(directory, 'AttachedContainer', 'packages')
    for name in os.listdir(base_path):
        if name.endswith('_amd64'):
            yield os.path.join(base_path, name, 'cab1.cab')

def extract_cab(cab_source, destination):
    subprocess.call(['expand.exe', "-F:*", cab_source, destination])

def fetch_all(base_directory):
    download_directory = os.path.join(base_directory, 'Downloads')
    wix_tool_location = fetch_wix(download_directory)
    for ver, installer in fetch_runtimes(download_directory):
        output_directory = os.path.join(base_directory, 'vcruntime_' + ver)
        if not os.path.isdir(output_directory):
            os.makedirs(output_directory)

        if os.listdir(output_directory):
            print('Already have ' + ver)
            continue
        
        for cab in find_cabs(extract_burn_bundle(wix_tool_location, installer)):
            extract_cab(cab, output_directory)

if __name__ == '__main__':
    fetch_all(r'd:\Microsoft\Runtimes')