name: Weekly Flake Update

on:
  schedule:
    - cron: "0 3 * * 1"  # every Monday at 03:00 UTC
  workflow_dispatch:

permissions:
  contents: write
  pull-requests: write

jobs:
  flake_update:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - uses: DeterminateSystems/nix-installer-action@v12

      - name: Set branch name (date)
        id: vars
        run: |
          echo "branch=flake-update/$(date +%Y-%m-%d)" >> $GITHUB_OUTPUT

      - name: Create update branch
        run: |
          git checkout -B ${{ steps.vars.outputs.branch }}

      - name: Update flake inputs
        run: |
          nix flake update

      - name: Commit changes
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add flake.lock
          git commit -m "chore: weekly flake update" || echo "No changes to commit"

      - name: Push branch
        run: |
          git push origin ${{ steps.vars.outputs.branch }} --force

      - name: Install GitHub CLI
        run: |
          sudo apt-get update
          sudo apt-get install -y gh

      - name: Create Pull Request
        run: |
          gh pr create \
            --base main \
            --head ${{ steps.vars.outputs.branch }} \
            --title "[Automated] Weekly flake update $(date +%Y-%m-%d)" \
            --body "Automated weekly update of flake inputs for $(date +%Y-%m-%d)."
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}