name: Sync fork with upstream

on:
  schedule:
    - cron: "15 3 * * *"   # runs daily at 03:15 UTC
  workflow_dispatch: {}     # allow manual run

permissions:
  contents: write

env:
  UPSTREAM: deepbeepmeep/Wan2GP
  UPSTREAM_BRANCH: main
  TARGET_BRANCH: main

jobs:
  sync:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout fork
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Add upstream remote
        run: |
          git remote add upstream https://github.com/${UPSTREAM}.git
          git fetch upstream ${UPSTREAM_BRANCH}

      - name: Fast-forward fork
        run: |
          git checkout ${TARGET_BRANCH}
          # Try a strict fast-forward; fail if conflicts or diverged history.
          git merge --ff-only upstream/${UPSTREAM_BRANCH}
          git push origin ${TARGET_BRANCH}