name: 📝 Update Changelog

# Manual only — automatic triggering is disabled to prevent version mismatches
# between the generated PDF and the GitHub release. Run this manually after
# a release is published and the version is confirmed.
on:
  workflow_dispatch:
    inputs:
      version:
        description: 'Version string (e.g. v1.2.4) — leave blank to auto-increment'
        required: false
        type: string
      dry_run:
        description: 'Dry run — print entry without committing'
        required: false
        default: false
        type: boolean

permissions:
  contents: write  # commit changelog back to main

jobs:
  changelog:
    name: Prepend changelog entry
    runs-on: ubuntu-latest

    steps:
      - name: 🛠️ Checkout
        uses: actions/checkout@v4
        with:
          # Use a PAT so the commit triggers downstream workflows (GITHUB_TOKEN won't)
          token: ${{ secrets.CHANGELOG_PAT || secrets.GITHUB_TOKEN }}
          fetch-depth: 0

      - name: 🐍 Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.13"

      - name: 📝 Generate and prepend changelog entry
        env:
          DRY_RUN:         ${{ inputs.dry_run || 'false' }}
          MANUAL_VERSION:  ${{ inputs.version || '' }}
          GH_SHA:          ${{ github.sha }}
          GH_REF:          ${{ github.ref_name }}
          TRIGGERING_SHA:  ${{ github.event.workflow_run.head_sha || github.sha }}
        run: python scripts/update_changelog.py

      - name: 📤 Commit changelog
        if: ${{ inputs.dry_run != 'true' }}
        run: |
          git config user.name  "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add docs/changelog/index.md
          # Only commit if there's actually a change
          git diff --cached --quiet && echo "No changelog change to commit." || \
            git commit -m "docs: update changelog [skip ci]"
          git push