name: Deploy nightly build

on:
  schedule:
    - cron: '0 2 * * *' # Run at 2 AM UTC every day
  push:
    branches:
      - main
  workflow_dispatch: # Manual trigger

jobs:
  deploy-nightly:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        # We intentionally don't set `persist-credentials` to `false` because we
        # want to push to the nightly branch. This is safe because we only use
        # our own commands and there are no external actions beyond this point.

      - name: Configure git
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

      - name: Update heroku.yml
        run: |
          sed -i 's/NIGHTLY: 0/NIGHTLY: 1/' heroku.yml

      - name: Create and push commit to nightly branch
        run: |
          TIMESTAMP=$(date -u +"%Y-%m-%d %H:%M:%S UTC")
          git checkout -B nightly
          git add heroku.yml
          git commit -m "deploy: $TIMESTAMP"
          git push --force origin nightly