From c91675647e42f5e1f7607ca5718e2b7052de8946 Mon Sep 17 00:00:00 2001
From: Jack Lloyd <jack@randombit.net>
Date: Mon, 10 Jul 2023 08:14:49 -0400
Subject: [PATCH] ok

---
 .github/workflows/ci.yml               |  7 +--
 src/scripts/ci/gh_get_changes_in_pr.py | 80 ++++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 5 deletions(-)
 create mode 100755 src/scripts/ci/gh_get_changes_in_pr.py

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ca5ee118000..645a1784b09 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -132,11 +132,8 @@ jobs:
       - name: Configure Build
         run: python3 ./configure.py --cc=clang
 
-      - name: Does this work?
-        run: echo ${{ github.event.after }} ${{ github.event.before }}
-
-      - name: Does this work?
-        run: cat ${{ github.event_path }}
+      - name: Get the changed file list
+        run: ./src/scripts/ci/gh_get_changes_in_pr.py ${{ github.event.after }} --api-token=${{ secrets.GITHUB_TOKEN }}
 
       - name: Run Clang Tidy
         run: python3 ./src/scripts/dev_tools/run_clang_tidy.py --verbose --only-changed-files --fast-checks-only
diff --git a/src/scripts/ci/gh_get_changes_in_pr.py b/src/scripts/ci/gh_get_changes_in_pr.py
new file mode 100755
index 00000000000..8728392977c
--- /dev/null
+++ b/src/scripts/ci/gh_get_changes_in_pr.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+
+import argparse
+import gzip
+import http.client
+import json
+import re
+import sys
+
+def main(args = None):
+    if args is None:
+        args = sys.argv
+
+    re_git_sha = re.compile('[0-9A-Fa-f]{20}')
+
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument('--base-commit', default='master', metavar='BRANCH')
+    parser.add_argument('--api-host', default='api.github.com', metavar='HOST')
+    parser.add_argument('--api-token', default=None)
+    parser.add_argument('this_commit')
+
+    args = vars(parser.parse_args())
+
+    gh_api = args['api_host']
+    this_commit = args['this_commit']
+    base_commit = args['base_commit']
+
+    if re_git_sha.match(this_commit) is None:
+        print("The argument '%s' does not look like a git commit id" % (this_commit))
+        return 1
+
+    headers = {
+        "Accept": "application/vnd.github+json",
+        "Accept-Encoding": "gzip",
+        "X-GitHub-Api-Version": "2022-11-28",
+        "Host": gh_api,
+        "User-Agent": "Botan gh_get_changes_in_pr.py",
+    }
+
+    if args.get('api_token'):
+        headers['Authorization'] = 'Bearer %s' % (args['api_token'])
+
+    api_req = "/repos/randombit/botan/compare/%s...%s?per_page=0" % (base_commit, this_commit)
+
+    gh = http.client.HTTPSConnection(gh_api)
+    gh.request('GET', api_req, headers=headers)
+    resp = gh.getresponse()
+
+    if resp.status != 200:
+        print("GH API call returned unexpected status %d" % (resp.status))
+        return 1
+
+    is_gzip = False
+    content_encoding = resp.getheader('Content-Encoding')
+    if content_encoding:
+        if content_encoding == 'gzip':
+            is_gzip = True
+        else:
+            print("Unexpected Content-Encoding %s" % (content_encoding))
+            return 1
+
+    body = resp.read()
+
+    if is_gzip:
+        body = gzip.decompress(body)
+
+    j = json.loads(body)
+
+    if 'files' not in j:
+        return 0
+
+    for f in j['files']:
+        print(f['filename'])
+
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main())
+