1 files changed, 101 insertions, 0 deletions
diff --git a/packaging/windows/fetch-msys2-installer.py b/packaging/windows/fetch-msys2-installer.py
new file mode 100755
index 000000000..e30e7205c
--- /dev/null
+++ b/packaging/windows/fetch-msys2-installer.py
@@ -0,0 +1,101 @@
+#!/usr/bin/env python
+
+'''Fetch the MSYS2 installer.'''
+
+from __future__ import annotations
+
+import hashlib
+import json
+import shutil
+import sys
+
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from typing import Final
+from urllib.request import Request, urlopen
+
+REPO: Final = 'msys2/msys2-installer'
+
+
+def get_latest_release() -> tuple[str, str]:
+    '''Get the latest release for the repo.'''
+    REQUEST: Final = Request(
+        url=f'https://api.github.com/repos/{REPO}/releases',
+        headers={
+            'Accept': 'application/vnd.github+json',
+            'X-GitHub-API-Version': '2022-11-28',
+        },
+        method='GET',
+    )
+
+    print('>>> Fetching release list')
+
+    with urlopen(REQUEST, timeout=15) as response:
+        if response.status != 200:
+            print(f'!!! Failed to fetch release list, status={response.status}')
+            sys.exit(1)
+
+        data = json.load(response)
+
+    data = list(filter(lambda x: x['name'] != 'Nightly Installer Build', data))
+
+    name = data[0]['name']
+    version = data[0]['tag_name'].replace('-', '')
+
+    return name, version
+
+
+def fetch_release_asset(tmpdir: Path, name: str, file: str) -> Path:
+    '''Fetch a specific release asset.'''
+    REQUEST: Final = Request(
+        url=f'https://github.com/{REPO}/releases/download/{name}/{file}',
+        method='GET',
+    )
+    TARGET: Final = tmpdir / file
+
+    print(f'>>> Downloading {file}')
+
+    with urlopen(REQUEST, timeout=15) as response:
+        if response.status != 200:
+            print(f'!!! Failed to fetch {file}, status={response.status}')
+            sys.exit(1)
+
+        TARGET.write_bytes(response.read())
+
+    return TARGET
+
+
+def main() -> None:
+    '''Core program logic.'''
+    if len(sys.argv) != 2:
+        print(f'{__file__} must be run with exactly one argument.')
+
+    target = Path(sys.argv[1])
+    tmp_target = target.with_name(f'.{target.name}.tmp')
+
+    name, version = get_latest_release()
+
+    with TemporaryDirectory() as tmpdir:
+        tmppath = Path(tmpdir)
+
+        installer = fetch_release_asset(tmppath, name, f'msys2-base-x86_64-{version}.tar.zst')
+        checksums = fetch_release_asset(tmppath, name, f'msys2-base-x86_64-{version}.tar.zst.sha256')
+
+        print('>>> Verifying SHA256 checksum')
+        expected_checksum = checksums.read_text().partition(' ')[0].casefold()
+        actual_checksum = hashlib.sha256(installer.read_bytes()).hexdigest().casefold()
+
+        if expected_checksum != actual_checksum:
+            print('!!! Checksum mismatch')
+            print(f'!!! Expected: {expected_checksum}')
+            print(f'!!! Actual:   {actual_checksum}')
+            sys.exit(1)
+
+        print(f'>>> Copying to {target}')
+
+        shutil.copy(installer, tmp_target)
+        tmp_target.replace(target)
+
+
+if __name__ == '__main__':
+    main()