From 78cf47df192318caf3d01a3ac57382e6dece9240 Mon Sep 17 00:00:00 2001
From: Adrian Moennich <adrian.moennich@cern.ch>
Date: Tue, 10 Oct 2023 16:55:30 +0200
Subject: [PATCH] ci: Use referenced core PR to install Indico

---
 .github/utils/get_core_repo.py | 99 ++++++++++++++++++++++++++++++++++
 .github/workflows/ci.yml       | 45 +++-------------
 2 files changed, 107 insertions(+), 37 deletions(-)
 create mode 100644 .github/utils/get_core_repo.py

diff --git a/.github/utils/get_core_repo.py b/.github/utils/get_core_repo.py
new file mode 100644
index 0000000..0c97007
--- /dev/null
+++ b/.github/utils/get_core_repo.py
@@ -0,0 +1,99 @@
+# This file is part of the Indico plugins.
+# Copyright (C) 2002 - 2023 CERN
+#
+# The Indico plugins are free software; you can redistribute
+# them and/or modify them under the terms of the MIT License;
+# see the LICENSE file for more details.
+
+import itertools
+import json
+import os
+import re
+import subprocess
+import sys
+
+
+CORE = sys.argv[1]
+SCOPE = sys.argv[2]
+CORE_USER, CORE_REPO = CORE.split('/')
+
+def lookup_via_referenced_prs():
+    this_pr_body = os.environ['PR_BODY']
+    this_base_ref = os.environ['PR_BASE_REF']
+
+    referenced_prs = set()
+    for match in itertools.chain(
+        re.finditer(r'(?:(?<![/\w.-])(\w[\w.-]+)/(\w[\w.-]+)|\B)#([1-9]\d*)\b', this_pr_body),
+        re.finditer(r'\bhttps://github\.com/([^/]+)/([^/]+)/pull/([1-9]\d*)\b', this_pr_body)
+    ):
+        user, repo, num = match.groups()
+        if user != CORE_USER or repo != CORE_REPO:
+            continue
+        referenced_prs.add(int(num))
+
+    print(f'Referenced core PRs: {referenced_prs or "none"}')
+    if not referenced_prs:
+        return None
+
+    candidates = {}
+    for num in referenced_prs:
+        try:
+            resp = subprocess.check_output(['gh', 'api', f'repos/{CORE}/pulls/{num}'], encoding='utf-8')
+        except subprocess.CalledProcessError:
+            print(f'Discarding {num}: not found (probably an issue and not a PR)')
+            continue
+        pr_data = json.loads(resp)
+        if pr_data['state'] != 'open':
+            print(f'Discarding {num}: not open')
+            continue
+        head_ref = pr_data['head']['ref']
+        head_repo = pr_data['head']['repo']['full_name']
+        base_ref = pr_data['base']['ref']
+        if base_ref != this_base_ref:
+            print(f'Discarding {num}: different base branches ({base_ref} != {this_base_ref})')
+            continue
+        candidates[num] = (head_repo, head_ref)
+
+    print(f'Viable core PRs: {",".join(map(str, candidates)) or "none"}')
+    if len(candidates) > 1:
+        print('Found multiple PRs, not guessing which one to use')
+        # Fail the CI run - if this ever happens, we may be able to come up with suitable logic to pick one
+        sys.exit(1)
+    elif not candidates:
+        print('Found no suitable PRs')
+        return None
+    return candidates.popitem()[1]
+
+
+def main():
+    gh_event = os.environ['GITHUB_EVENT_NAME']
+    check_common_branch = True
+    if gh_event == 'push':
+        full_repo = CORE
+        branch = os.environ['GITHUB_REF'].removeprefix('refs/heads/')
+        print(f'Using current branch: {branch}')
+    elif gh_event == 'pull_request':
+        if res := lookup_via_referenced_prs():
+            full_repo, branch = res
+            check_common_branch = False
+            print(f'Using branch from referenced core PR: {full_repo}:{branch}')
+        else:
+            full_repo = CORE
+            branch = os.environ['GITHUB_BASE_REF'].removeprefix('refs/heads/')
+            print(f'Using branch from PR target: {branch}')
+    else:
+        print(f'Unsupported event: {gh_event}')
+        return 1
+
+    if check_common_branch and branch != 'master' and not branch.endswith('.x'):
+        print(f'Uncommon branch {branch}; defaulting to master')
+        branch = 'master'
+
+    with open(os.environ['GITHUB_ENV'], 'a') as f:
+        f.write(f'{SCOPE}_REPO={full_repo}\n')
+        f.write(f'{SCOPE}_BRANCH={branch}\n')
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6400dcd..fbf6783 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,29 +23,18 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - name: Get upstream branch name
-        run: |
-          if [[ $GITHUB_EVENT_NAME == push ]]; then
-            upstream_branch="${GITHUB_REF#refs/heads/}"
-          elif [[ $GITHUB_EVENT_NAME == pull_request ]]; then
-            upstream_branch="${GITHUB_BASE_REF#refs/heads/}"
-          else
-            echo "unsupported event: $GITHUB_EVENT_NAME"
-            exit 1
-          fi
-          if [[ $upstream_branch != master && $upstream_branch != *.x ]]; then
-            echo "assuming there is no branch named ${upstream_branch} in indico; defaulting to master"
-            upstream_branch=master
-          else
-            echo "using indico upstream branch ${upstream_branch}"
-          fi
-          echo "INDICO_BRANCH=${upstream_branch}" >> "$GITHUB_ENV"
-
       - name: Setup Python
         uses: actions/setup-python@v4
         with:
           python-version: ${{ env.PYTHON_VERSION }}
 
+      - name: Pick Indico core repo
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR_BODY: ${{ github.event_name == 'pull_request' && github.event.pull_request.body }}
+          PR_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.ref }}
+        run: python .github/utils/get_core_repo.py indico/indico INDICO
+
       - name: Install system dependencies
         run: sudo apt-get install postgresql-client libpq-dev
 
@@ -86,7 +75,7 @@ jobs:
       - name: Install Indico
         run: |
           pip install Babel
-          pip install git+https://github.com/indico/indico.git@${INDICO_BRANCH}#egg=indico[dev]
+          pip install "indico[dev] @ git+https://github.com/${INDICO_REPO}.git@${INDICO_BRANCH}"
 
       - name: Install node dependencies
         if: steps.cache-npm.outputs.cache-hit != 'true'
@@ -113,24 +102,6 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - name: Get upstream branch name
-        run: |
-          if [[ $GITHUB_EVENT_NAME == push ]]; then
-            upstream_branch="${GITHUB_REF#refs/heads/}"
-          elif [[ $GITHUB_EVENT_NAME == pull_request ]]; then
-            upstream_branch="${GITHUB_BASE_REF#refs/heads/}"
-          else
-            echo "unsupported event: $GITHUB_EVENT_NAME"
-            exit 1
-          fi
-          if [[ $upstream_branch != master && $upstream_branch != *.x ]]; then
-            echo "assuming there is no branch named ${upstream_branch} in indico; defaulting to master"
-            upstream_branch=master
-          else
-            echo "using indico upstream branch ${upstream_branch}"
-          fi
-          echo "INDICO_BRANCH=${upstream_branch}" >> "$GITHUB_ENV"
-
       - name: Setup Python
         uses: actions/setup-python@v4
         with: