template-sync.yml

# Inspired by serpro69/claude-starter-kit template-sync approach
name: Template Sync

on:
  workflow_dispatch:
    inputs:
      dry_run:
        description: "Show changes without creating a PR"
        type: boolean
        default: false
      template_repo:
        description: "Upstream template repository (owner/repo)"
        type: string
        default: "stranma/claude-code-python-template"
      template_branch:
        description: "Upstream template branch"
        type: string
        default: "master"
  schedule:
    - cron: "0 9 * * 1" # Weekly on Monday at 09:00 UTC

permissions:
  contents: write
  pull-requests: write

jobs:
  sync:
    name: Sync from upstream template
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

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

      - name: Determine template repo
        id: config
        run: |
          REPO="${{ inputs.template_repo || 'stranma/claude-code-python-template' }}"
          BRANCH="${{ inputs.template_branch || 'master' }}"
          echo "repo=${REPO}" >> "$GITHUB_OUTPUT"
          echo "branch=${BRANCH}" >> "$GITHUB_OUTPUT"
          echo "Syncing from ${REPO}@${BRANCH}"

      - name: Add upstream remote and fetch
        run: |
          git remote add upstream "https://github.com/${{ steps.config.outputs.repo }}.git" || true
          git fetch upstream "${{ steps.config.outputs.branch }}"

      - name: Compute template diff
        id: diff
        env:
          UPSTREAM_BRANCH: ${{ steps.config.outputs.branch }}
        run: |
          # Paths managed by the template (synced from upstream)
          # Defined once here; reused in the apply step via GITHUB_OUTPUT
          TEMPLATE_PATHS=".claude/agents/ .claude/commands/ .claude/hooks/ .claude/rules/ .claude/skills/ .devcontainer/ .github/workflows/ docs/DEVELOPMENT_PROCESS.md"
          echo "template_paths=${TEMPLATE_PATHS}" >> "$GITHUB_OUTPUT"

          # Get changed files between local and upstream
          CHANGED=$(git diff --name-only HEAD "upstream/${UPSTREAM_BRANCH}" -- ${TEMPLATE_PATHS} 2>/dev/null || true)

          if [ -z "$CHANGED" ]; then
            echo "No template changes found"
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            echo "Template changes detected:"
            echo "$CHANGED"
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
            # Store diff summary for PR body
            DIFF_STAT=$(git diff --stat HEAD "upstream/${UPSTREAM_BRANCH}" -- ${TEMPLATE_PATHS} 2>/dev/null || true)
            {
              echo "diff_stat<<EOF"
              echo "$DIFF_STAT"
              echo "EOF"
            } >> "$GITHUB_OUTPUT"
          fi

      - name: Show diff (dry run)
        if: steps.diff.outputs.has_changes == 'true' && (inputs.dry_run == true || inputs.dry_run == 'true')
        run: |
          echo "=== DRY RUN: Changes that would be synced ==="
          echo "${{ steps.diff.outputs.diff_stat }}"

      - name: Apply template changes
        id: apply
        if: steps.diff.outputs.has_changes == 'true' && inputs.dry_run != true && inputs.dry_run != 'true'
        env:
          UPSTREAM_BRANCH: ${{ steps.config.outputs.branch }}
          TEMPLATE_PATHS: ${{ steps.diff.outputs.template_paths }}
        run: |
          SYNC_BRANCH="template-sync/$(date +%Y%m%d)"

          # Check if branch already exists
          if git rev-parse --verify "refs/heads/${SYNC_BRANCH}" > /dev/null 2>&1; then
            echo "Sync branch ${SYNC_BRANCH} already exists, updating"
            git checkout "${SYNC_BRANCH}"
          else
            git checkout -b "${SYNC_BRANCH}"
          fi

          # Checkout template-managed files from upstream
          for path in ${TEMPLATE_PATHS}; do
            git checkout "upstream/${UPSTREAM_BRANCH}" -- "${path}" 2>/dev/null || true
          done

          # Stage and commit
          git add -A
          if git diff --cached --quiet; then
            echo "No changes to commit after checkout"
            echo "changes_applied=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          echo "changes_applied=true" >> "$GITHUB_OUTPUT"

          git commit -m "chore: sync template from upstream

          Source: ${{ steps.config.outputs.repo }}@${{ steps.config.outputs.branch }}"

          git push -u origin "${SYNC_BRANCH}"

          echo "sync_branch=${SYNC_BRANCH}" >> "$GITHUB_ENV"

      - name: Create pull request
        if: steps.apply.outputs.changes_applied == 'true' && inputs.dry_run != true && inputs.dry_run != 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          # Check for existing PR from this branch
          EXISTING_PR=$(gh pr list --head "${{ env.sync_branch }}" --json number --jq '.[0].number' 2>/dev/null || true)

          if [ -n "$EXISTING_PR" ]; then
            echo "PR #${EXISTING_PR} already exists for this sync branch"
            exit 0
          fi

          gh pr create \
            --title "chore: sync upstream template changes" \
            --body "$(cat <<'EOF'
          ## Template Sync

          Automated sync of template-managed files from upstream.

          **Source:** ${{ steps.config.outputs.repo }}@${{ steps.config.outputs.branch }}

          ### Changed files
          ```
          ${{ steps.diff.outputs.diff_stat }}
          ```

          ### What to review
          - Check if any synced files conflict with project-specific customizations
          - Template-managed paths: `.claude/`, `.devcontainer/`, `.github/workflows/`, `docs/DEVELOPMENT_PROCESS.md`
          - Project-specific files (`apps/`, `libs/`, `tests/`, `pyproject.toml`, `README.md`) are NOT touched

          ### How to resolve conflicts
          If a synced file conflicts with local changes, edit the file on this branch to keep your customizations, then merge.
          EOF
          )"

      - name: Summary
        if: steps.diff.outputs.has_changes == 'false'
        run: echo "Already up to date with upstream template. No sync needed."