name: Update flake lock

on:
  schedule:
    # Gitea cron schedules use UTC. 07:00 UTC is 03:00 EDT.
    - cron: "0 7 * * 0"
  workflow_dispatch:

permissions:
  contents: write

jobs:
  update-flake-lock:
    runs-on: ubuntu-latest

    steps:
      - name: Check out repository
        uses: actions/checkout@v4

      - name: Install upstream Nix
        uses: cachix/install-nix-action@v31

      - name: Update flake lock
        run: nix flake update

      - name: Commit and push changes
        shell: bash
        run: |
          set -euo pipefail

          if git diff --quiet -- flake.lock; then
            echo "flake.lock is already up to date"
            exit 0
          fi

          git config user.name "gitea-actions[bot]"
          git config user.email "gitea-actions[bot]@noreply.localhost"
          git add flake.lock
          git commit -m "chore: update flake lock"
          git push