sync-upstream.yml

name: Sync with upstream

# Opens a PR in this repo whenever the upstream AIM template has new commits.
# Merge the PR to pull the updates in; Netlify will auto-rebuild.
#
# === Prerequisite (one-time, per repo) ===
# GitHub disables Actions-created PRs by default. To let this workflow open
# PRs automatically, go to:
#   Settings → Actions → General → Workflow permissions
#   ✅ Allow GitHub Actions to create and approve pull requests
#   (then click Save)
#
# Without that toggle, the workflow still pushes the sync branch and prints a
# clickable compare URL — you just have to open the PR yourself from the UI.
#
# To disable: delete this file.
# To customize: change UPSTREAM_REPO below.

on:
  schedule:
    # Daily at 06:00 UTC. Adjust if you want a different cadence.
    - cron: "0 6 * * *"
  workflow_dispatch: {}

permissions:
  contents: write
  pull-requests: write

env:
  UPSTREAM_REPO: kitty4D/aim
  UPSTREAM_BRANCH: main
  SYNC_BRANCH: sync/upstream

jobs:
  sync:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout this repo
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Configure git identity
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"

      - name: Add upstream remote and fetch
        run: |
          git remote add upstream "https://github.com/${UPSTREAM_REPO}.git"
          git fetch upstream "${UPSTREAM_BRANCH}"

      - name: Compute divergence
        id: diff
        run: |
          BEHIND=$(git rev-list --count HEAD.."upstream/${UPSTREAM_BRANCH}")
          AHEAD=$(git rev-list --count "upstream/${UPSTREAM_BRANCH}"..HEAD)
          echo "behind=$BEHIND" >> "$GITHUB_OUTPUT"
          echo "ahead=$AHEAD" >> "$GITHUB_OUTPUT"
          echo "Behind upstream by $BEHIND, ahead by $AHEAD."

      - name: Already up to date — nothing to do
        if: steps.diff.outputs.behind == '0'
        run: echo "::notice::Already up to date with ${UPSTREAM_REPO}@${UPSTREAM_BRANCH}"

      - name: Update sync branch from upstream
        if: steps.diff.outputs.behind != '0'
        run: |
          git checkout -B "${SYNC_BRANCH}" "upstream/${UPSTREAM_BRANCH}"
          git push origin "${SYNC_BRANCH}" --force

      - name: Open or update sync PR
        if: steps.diff.outputs.behind != '0'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          BEHIND: ${{ steps.diff.outputs.behind }}
          AHEAD: ${{ steps.diff.outputs.ahead }}
        run: |
          TITLE="Sync with upstream ${UPSTREAM_REPO} (${BEHIND} new commit(s))"

          BODY_FILE="$(mktemp)"
          {
            echo "## 🔄 Upstream sync"
            echo
            echo "Your repo is **${BEHIND} commit(s) behind** [\`${UPSTREAM_REPO}@${UPSTREAM_BRANCH}\`](https://github.com/${UPSTREAM_REPO}/tree/${UPSTREAM_BRANCH})."
            echo
            if [ "${AHEAD}" != "0" ]; then
              echo "> ⚠️ You also have **${AHEAD} local commit(s)** that aren't in upstream."
              echo "> This sync branch is reset to the upstream state, so merging will overwrite those local commits with the upstream version. Review the diff carefully before merging."
              echo
            fi
            echo "### What this PR does"
            echo
            echo "Brings your repo up to date with the latest [\`${UPSTREAM_REPO}\`](https://github.com/${UPSTREAM_REPO}) template."
            echo
            echo "### How to apply"
            echo
            echo "Use **Squash and merge** or **Create a merge commit** below. Netlify will auto-rebuild your site within ~1 minute."
            echo
            echo "---"
            echo
            echo "_This PR was opened automatically by the \`.github/workflows/sync-upstream.yml\` workflow. Delete that file to disable auto-syncing._"
          } > "${BODY_FILE}"

          COMPARE_URL="https://github.com/${GITHUB_REPOSITORY}/compare/${UPSTREAM_BRANCH}...${SYNC_BRANCH}"

          EXISTING=$(gh pr list --head "${SYNC_BRANCH}" --state open --json number --jq '.[0].number // empty' || echo "")
          if [ -n "${EXISTING}" ]; then
            if gh pr edit "${EXISTING}" --title "${TITLE}" --body-file "${BODY_FILE}"; then
              echo "::notice::Updated existing PR #${EXISTING}"
            else
              echo "::warning::Couldn't update PR #${EXISTING} via API — see compare URL: ${COMPARE_URL}"
            fi
          else
            if gh pr create \
              --base "${UPSTREAM_BRANCH}" \
              --head "${SYNC_BRANCH}" \
              --title "${TITLE}" \
              --body-file "${BODY_FILE}"; then
              echo "::notice::Opened sync PR"
            else
              echo "::warning::PR API rejected (likely 'Resource not accessible by integration')."
              echo "::warning::Fix: Settings → Actions → General → Workflow permissions → enable 'Allow GitHub Actions to create and approve pull requests'."
              echo "::notice::Sync branch is pushed; open the PR manually here:"
              echo "::notice::${COMPARE_URL}"
            fi
          fi