name: Update Nix Flake

on:
  schedule:
    - cron: "30 0 * * *" # daily run
  workflow_dispatch: {}

jobs:
  update-flake:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          token: "${{ gitea.token }}"
          fetch-depth: 0
          ref: flake-updates

      - name: Git config
        shell: bash
        run: |
          git config user.name "Gitea Actions"
          git config user.email "actions@gitea.local"

      - name: Merge main branch
        run: |
          git merge --squash origin/main
          # solve merge conflict by taking flake.lock from main
          git checkout origin/main -- flake.lock
          git commit -m "Merge main branch squashed $(date -I)"

      - name: Set up Nix
        uses: cachix/install-nix-action@v31

      - name: Update Flake
        run: nix flake update

      - name: Commit and push changes
        shell: bash
        run: |
          git add flake.lock
          if git diff --cached --quiet; then
            echo "No changes to commit."
          else
            git commit -m "Update flake.lock $(date -I)"
            git push origin flake-updates
          fi