name: Update Nix flakes and commit changes

on:
  schedule:
    - cron: "0 2/5 * * * *" # not to frequent, GitHub only allows a few pulls per hour

jobs:
  update-and-commit:
    runs-on: native

    steps:


      - name: checkout repository
        uses: actions/checkout@v2
        with:
          ref: "update"
          depth: 0

      - name: setup git
        run: |
          git config --local user.email "action@git.ingolf-wagner.de"
          git config --local user.name "Forgejo Action"

      # fixme: not working for some reason
      #- name: rebase with main branch
      #  run: |
      #    git fetch origin main
      #    git rebase origin/main

      - name: setup ssh
        run: |
          cat <<EOF > .id_rsa
          ${{ secrets.SSH_KEY }}
          EOF
          chmod 600 .id_rsa

          eval $(ssh-agent)
          ssh-add .id_rsa

          cat <<EOF > "$GITHUB_ENV"
          SSH_AUTH_SOCK="$SSH_AUTH_SOCK"
          SSH_AGENT_PID=$SSH_AGENT_PID
          EOF

      - name: update nix flakes
        run: nix flake update

        # we need the ssh-agent here, otherwise git push would use the GITHUB_TOKEN
        # which prevents other workflows to be triggered
      - name: commit and push changes
        run: |
          git diff --quiet && \
          git diff --staged --quiet || \
          (git commit -am "Update Nix flakes" && git push)

      - name: teardown ssh
        if: always()
        run: |
          echo $SSH_AGENT_PID
          kill $SSH_AGENT_PID