jobs:
  deploy:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout repository
        uses: actions/checkout@v3
        with:
          # Fetch all history so we can diff the 'before' and 'after' SHAs
          fetch-depth: 0 

      - name: Detect changed files
        id: detect
        run: |
          echo "🔍 Checking which files changed..."
          FRONTEND_CHANGED=false
          BACKEND_CHANGED=false

          # 1. Handle MANUAL RUN (workflow_dispatch)
          # If triggered manually, assume we want to deploy everything.
          if [ "${{ github.event_name }}" == "workflow_dispatch" ]; then
            echo " MANUAL RUN: Forcing deployment for both frontend and backend."
            FRONTEND_CHANGED=true
            BACKEND_CHANGED=true

          # 2. Handle FIRST PUSH (before SHA is all zeros)
          # If this is the first push to a new branch, deploy everything.
          elif [ "${{ github.event.before }}" == "0000000000000000000000000000000000000000" ]; then
            echo " NEW BRANCH/FIRST PUSH: Forcing deployment for both."
            FRONTEND_CHANGED=true
            BACKEND_CHANGED=true
          
          # 3. Handle a normal PUSH event
          # Reliably diff between the two SHAs of the push.
          else
            echo " PUSH EVENT: Diffing from ${{ github.event.before }} to ${{ github.event.after }}"
            CHANGED=$(git diff --name-only ${{ github.event.before }} ${{ github.event.after }})
            
            echo "--- Changed Files ---"
            echo "$CHANGED"
            echo "---------------------"

            echo "$CHANGED" | grep -q '^sgeUpdated/sge-frontend/' && FRONTEND_CHANGED=true || true
            echo "$CHANGED" | grep -q '^sgeUpdated/sge-backend/' && BACKEND_CHANGED=true || true
          fi

          # 4. Set outputs
          echo "frontend=$FRONTEND_CHANGED" >> $GITHUB_OUTPUT
          echo "backend=$BACKEND_CHANGED" >> $GITHUB_OUTPUT

          echo "✅ Frontend changed: $FRONTEND_CHANGED"
          echo "✅ Backend changed:  $BACKEND_CHANGED"

      # ... your Deploy Baackend and Deploy Frontend steps remain the same ...
      
      - name: Deploy Backend
        if: ${{ steps.detect.outputs.backend == 'true' }}
        # ... (rest of your step) ...

      - name: Deploy Frontend
        if: ${{ steps.detect.outputs.frontend == 'true' }}
        # ... (rest of your step) ...