name: PR Preview
on:
  pull_request:
    types: [opened, synchronize, reopened, closed]

env:
  REGISTRY: registry.oci.euphon.net
  BASE_DOMAIN: oil.oci.euphon.net

jobs:
  deploy-preview:
    if: github.event.action != 'closed'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Unit tests
        run: cd frontend && npm ci && npm run test:unit

      - name: Deploy Preview Environment
        run: |
          PR_ID="${{ github.event.pull_request.number }}"
          NS="oil-pr-${PR_ID}"
          HOST="pr-${PR_ID}.${BASE_DOMAIN}"
          IMAGE="${REGISTRY}/oil-calculator:pr-${PR_ID}"

          # Sync source to oci build server
          rsync -az --exclude node_modules --exclude .git --exclude .venv \
            . oci:/tmp/oil-pr-${PR_ID}-build/

          ssh oci bash -s "${PR_ID}" "${NS}" "${HOST}" "${IMAGE}" << 'DEPLOY_SCRIPT'
            set -e
            PR_ID="$1"; NS="$2"; HOST="$3"; IMAGE="$4"

            cd /tmp/oil-pr-${PR_ID}-build

            # Copy production DB into build context so it's baked into image
            PROD_POD=$(sudo k3s kubectl get pods -n oil-calculator -l app=oil-calculator \
              --field-selector=status.phase=Running -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || echo "")
            if [ -n "$PROD_POD" ]; then
              sudo k3s kubectl cp "oil-calculator/${PROD_POD}:/data/oil_calculator.db" /tmp/pr-${PR_ID}.db
              mkdir -p data
              cp /tmp/pr-${PR_ID}.db data/oil_calculator.db
            fi

            # Build image (with DB baked in)
            cat > Dockerfile.preview << 'DEOF'
            FROM node:20-slim AS frontend-build
            WORKDIR /build
            COPY frontend/package.json frontend/package-lock.json ./
            RUN npm ci
            COPY frontend/ ./
            RUN npm run build

            FROM python:3.12-slim
            WORKDIR /app
            COPY backend/requirements.txt .
            RUN pip install --no-cache-dir -r requirements.txt
            COPY backend/ ./backend/
            COPY --from=frontend-build /build/dist ./frontend/
            # Bake production DB copy into image
            COPY data/oil_calculator.db /data/oil_calculator.db
            ENV DB_PATH=/data/oil_calculator.db
            ENV FRONTEND_DIR=/app/frontend
            EXPOSE 8000
            CMD ["uvicorn", "backend.main:app", "--host", "0.0.0.0", "--port", "8000"]
            DEOF

            docker build -f Dockerfile.preview -t "${IMAGE}" .
            docker push "${IMAGE}"

            # Create namespace
            sudo k3s kubectl create namespace "${NS}" --dry-run=client -o yaml | sudo k3s kubectl apply -f -

            # Copy regcred from production namespace
            sudo k3s kubectl get secret regcred -n oil-calculator -o json | \
              sed "s/\"namespace\":\"oil-calculator\"/\"namespace\":\"${NS}\"/" | \
              sudo k3s kubectl apply -f -

            # Deploy pod + service + ingress (no PVC needed, DB is in image)
            cat << EOYAML | sudo k3s kubectl apply -f -
          apiVersion: apps/v1
          kind: Deployment
          metadata:
            name: oil-calculator
            namespace: ${NS}
          spec:
            replicas: 1
            selector:
              matchLabels:
                app: oil-calculator
            template:
              metadata:
                labels:
                  app: oil-calculator
              spec:
                imagePullSecrets:
                  - name: regcred
                containers:
                  - name: app
                    image: ${IMAGE}
                    ports:
                      - containerPort: 8000
                    resources:
                      requests:
                        cpu: 50m
                        memory: 64Mi
                      limits:
                        cpu: 500m
                        memory: 256Mi
          ---
          apiVersion: v1
          kind: Service
          metadata:
            name: oil-calculator
            namespace: ${NS}
          spec:
            selector:
              app: oil-calculator
            ports:
              - port: 80
                targetPort: 8000
          ---
          apiVersion: networking.k8s.io/v1
          kind: Ingress
          metadata:
            name: oil-calculator
            namespace: ${NS}
            annotations:
              traefik.ingress.kubernetes.io/router.tls.certresolver: le
          spec:
            ingressClassName: traefik
            tls:
              - hosts:
                  - ${HOST}
            rules:
              - host: ${HOST}
                http:
                  paths:
                    - path: /
                      pathType: Prefix
                      backend:
                        service:
                          name: oil-calculator
                          port:
                            number: 80
          EOYAML

            # Wait for rollout
            sudo k3s kubectl rollout status deploy/oil-calculator -n "${NS}" --timeout=120s

            # Cleanup build dir
            rm -rf /tmp/oil-pr-${PR_ID}-build /tmp/pr-${PR_ID}.db

            echo "Preview deployed: https://${HOST}"
          DEPLOY_SCRIPT

      - name: Comment PR with preview URL
        run: |
          PR_ID="${{ github.event.pull_request.number }}"
          HOST="pr-${PR_ID}.${BASE_DOMAIN}"
          curl -s -X POST \
            "https://git.euphon.cloud/api/v1/repos/${{ github.repository }}/issues/${PR_ID}/comments" \
            -H "Authorization: token ${{ secrets.GIT_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d "{\"body\": \"🚀 Preview deployed: https://${HOST}\n\nDB is a copy of production. Changes here won't affect prod.\"}"

  teardown-preview:
    if: github.event.action == 'closed'
    runs-on: ubuntu-latest
    steps:
      - name: Teardown Preview Environment
        run: |
          PR_ID="${{ github.event.pull_request.number }}"
          NS="oil-pr-${PR_ID}"
          IMAGE="${REGISTRY}/oil-calculator:pr-${PR_ID}"

          ssh oci "
            sudo k3s kubectl delete namespace ${NS} --ignore-not-found
            docker rmi ${IMAGE} 2>/dev/null || true
          "

      - name: Comment PR
        run: |
          PR_ID="${{ github.event.pull_request.number }}"
          curl -s -X POST \
            "https://git.euphon.cloud/api/v1/repos/${{ github.repository }}/issues/${PR_ID}/comments" \
            -H "Authorization: token ${{ secrets.GIT_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d "{\"body\": \"🗑️ Preview environment torn down.\"}"