template-init.yml

name: Template initialisation

on:
  push:
    branches:
      - main  # runs after the very first push that creates the repo

jobs:
  init:
    # Do not run in the original template repository itself
    if: github.event.repository.name != 'python-template'
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
      issues: write

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Derive project‑specific names
        id: names
        run: |
          echo "repo_slug=${{ github.event.repository.name }}" >> "$GITHUB_OUTPUT"
          snake=$(echo "${{ github.event.repository.name }}" | tr '-' '_')
          echo "repo_snake=$snake" >> "$GITHUB_OUTPUT"
          echo "repo_owner=${{ github.event.repository.owner.login }}" >> "$GITHUB_OUTPUT"

      - name: Create working branch
        run: git switch -c template-init

      - name: Replace repo owner
        # The previous form `${{ ... }} != marksverdhei` pre-substituted only the
        # left side, leaving GHA to evaluate `<owner_login> != marksverdhei` as
        # an expression — both unquoted identifiers resolved to null context
        # refs, so `null != null` was always false and this step was *always
        # skipped*. New repos kept marksverdhei references unreplaced. The
        # comparison has to live entirely inside one expression scope.
        if: github.event.repository.owner.login != 'marksverdhei'
        run: |
          repo_owner="${{ steps.names.outputs.repo_owner }}"
          # replace repo owner placeholder
          grep -lr --exclude-dir=.git 'marksverdhei' . | xargs -r sed -i "s/marksverdhei/${repo_owner}/g"

      - name: Replace placeholders inside files
        env:
          REPO_DESC: ${{ github.event.repository.description }}
        run: |
          repo_slug="${{ steps.names.outputs.repo_slug }}"
          repo_snake="${{ steps.names.outputs.repo_snake }}"

          # replace dash-style placeholder
          grep -lr --exclude-dir=.git 'python-template' . | xargs -r sed -i "s/python-template/${repo_slug}/g"
          # replace snake_case placeholder
          grep -lr --exclude-dir=.git 'python_template' . | xargs -r sed -i "s/python_template/${repo_snake}/g"
          # replace pyproject.toml description placeholder
          # Done in Python so arbitrary characters in the description (slashes,
          # quotes, shell metachars) can't break sed parsing or shell parsing.
          python3 - <<'PY'
          import os, pathlib
          path = pathlib.Path("pyproject.toml")
          text = path.read_text()
          desc = os.environ.get("REPO_DESC", "")
          if desc:
              text = text.replace("Add your description here", desc, 1)
          else:
              text = "\n".join(
                  line for line in text.splitlines()
                  if line.strip() != 'description = "Add your description here"'
              ) + "\n"
          path.write_text(text)
          PY

      - name: Rename files and directories
        run: |
          repo_slug="${{ steps.names.outputs.repo_slug }}"
          repo_snake="${{ steps.names.outputs.repo_snake }}"

          # function to rename safely preserving path depth
          rename_path() {
            old_path="$1"; new_path="$2";
            mkdir -p "$(dirname "$new_path")"
            git mv "$old_path" "$new_path"
          }

          export -f rename_path

          # dash‑style paths
          find . -depth -name '*python-template*' -print0 | while IFS= read -r -d '' f; do
            rename_path "$f" "${f//python-template/$repo_slug}";
          done

          # snake_case paths
          find . -depth -name '*python_template*' -print0 | while IFS= read -r -d '' f; do
            rename_path "$f" "${f//python_template/$repo_snake}";
          done

      - name: Remove this workflow so it never runs again
        run: git rm -f .github/workflows/template-init.yml

      - name: Commit changes
        run: |
          git config --global user.name 'github-actions[bot]'
          git config --global user.email 'github-actions[bot]@users.noreply.github.com'
          git add -u
          git commit -m "chore: initialize project from template" || echo "Nothing to commit"

      - name: Push branch
        run: git push -f origin template-init

      - name: Create pull request
        id: create_pr
        continue-on-error: true
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          issue_title="Grant GitHub Actions permission to create pull requests"
          # look for an open issue with that exact title
          issue_num=$(gh issue list --state open --search "in:title \"$issue_title\"" --json number --jq '.[0].number')

          # Base PR body text
          pr_body=$'Automated placeholder replacement, path renames, and self‑cleanup.'

          # Append closing reference if the issue exists
          if [ -n "$issue_num" ]; then
            pr_body+=$' Fixes #'"$issue_num"
          fi

          # Create the PR
          gh pr create \
            --title "Initialize project from template" \
            --body "$pr_body" \
            --base ${{ github.ref }} \
            --head template-init

      - name: Create issue to grant PR permissions (if missing)
        if: steps.create_pr.outcome == 'failure'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          set -e
          issue_title="Grant GitHub Actions permission to create pull requests"
          # Does an open issue with this exact title already exist?
          existing=$(gh issue list --state open --search "in:title \"$issue_title\"" --json number --jq '.[0].number')
          if [ -z "$existing" ]; then
            echo "Creating new issue: $issue_title"
            gh issue create \
              --title "$issue_title" \
              --body $'The workflow attempted to create a pull request but failed with the following error:\n\n```\npull request create failed: GraphQL: GitHub Actions is not permitted to create or approve pull requests (createPullRequest)\n```\n\nPlease grant the required permission by visiting the following link:\n\nhttps://github.com/${{ github.repository }}/settings/actions\n\nThen, in **Actions → General → Workflow permissions**, choose **Read and write permissions** (and optionally **Allow GitHub Actions to create and approve pull requests**).\n![Screenshot of checkbox](https://github.com/user-attachments/assets/cac2626e-bace-4f97-99b4-529331218ee6)\nAfter updating the setting, re‑run the workflow to complete the project initialisation.'
          else
            echo "Issue #$existing already exists – skipping creation."
          fi

      - name: Fail workflow because PR could not be created
        if: steps.create_pr.outcome == 'failure'
        run: |
          echo "Failing workflow due to failed PR creation. Please grant the required permissions and re-run." >&2
          exit 1