pipeline {
    agent any

    environment {
        HARBOR_URL     = '192.168.108.200:80'
        HARBOR_PROJECT = 'library'
        IMAGE_TAG      = "${env.BUILD_NUMBER}"
        K8S_CRED_ID    = 'k8s-config'

        FRONTEND_IMAGE = '192.168.108.200:80/library/scrum-frontend'
        BACKEND_IMAGE  = '192.168.108.200:80/library/scrum-backend'

        // Workspace root IS the project root — no subdirectory needed
        K8S_OVERLAY    = 'k8s/overlays/on-premise'
    }

    options {
        buildDiscarder(logRotator(numToKeepStr: '10'))
        timeout(time: 30, unit: 'MINUTES')
        disableConcurrentBuilds()
    }

    stages {

        stage('Checkout') {
            steps {
                checkout scm
                echo "Workspace: ${env.WORKSPACE}"
                sh 'ls -la'   // quick sanity check — confirm Dockerfile is here
            }
        }

        stage('Test') {
            parallel {
                stage('Backend Tests') {
                    steps {
                        dir('server') {          // server/ relative to workspace root
                            sh 'npm ci && npm test -- --reporter=verbose 2>&1 || true'
                        }
                    }
                }
                stage('Frontend Tests') {
                    steps {
                        // frontend lives at workspace root
                        sh 'npm ci && npm test -- --reporter=verbose 2>&1 || true'
                    }
                }
            }
        }

        stage('Build Images') {
            parallel {
                stage('Build Frontend') {
                    steps {
                        // Dockerfile is at workspace root
                        sh """
                            docker build \
                                -f Dockerfile \
                                -t ${FRONTEND_IMAGE}:${IMAGE_TAG} \
                                -t ${FRONTEND_IMAGE}:latest \
                                .
                        """
                    }
                }
                stage('Build Backend') {
                    steps {
                        dir('server') {          // server/Dockerfile
                            sh """
                                docker build \
                                    -f Dockerfile \
                                    -t ${BACKEND_IMAGE}:${IMAGE_TAG} \
                                    -t ${BACKEND_IMAGE}:latest \
                                    .
                            """
                        }
                    }
                }
            }
        }

        stage('Push to Harbor') {
            steps {
                withCredentials([usernamePassword(
                    credentialsId: 'harbor-creds',
                    usernameVariable: 'HARBOR_USER',
                    passwordVariable: 'HARBOR_PASS'
                )]) {
                    sh """
                        echo \$HARBOR_PASS | docker login ${HARBOR_URL} -u \$HARBOR_USER --password-stdin

                        docker push ${FRONTEND_IMAGE}:${IMAGE_TAG}
                        docker push ${FRONTEND_IMAGE}:latest

                        docker push ${BACKEND_IMAGE}:${IMAGE_TAG}
                        docker push ${BACKEND_IMAGE}:latest
                    """
                }
            }
        }

        stage('Patch Image Tags') {
            steps {
                dir("${K8S_OVERLAY}") {
                    sh """
                        kustomize edit set image \
                            scrum-frontend=${FRONTEND_IMAGE}:${IMAGE_TAG} \
                            scrum-backend=${BACKEND_IMAGE}:${IMAGE_TAG}
                    """
                }
            }
        }

        stage('Setup MetalLB') {
            steps {
                withKubeConfig([credentialsId: "${K8S_CRED_ID}"]) {
                    sh """
                        # Install MetalLB if not already present (idempotent)
                        kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.8/config/manifests/metallb-native.yaml

                        # Controller must be ready before applying CRDs
                        kubectl rollout status deployment/controller -n metallb-system --timeout=120s

                        # Speaker runs on every node as a DaemonSet.
                        # On CPU-constrained clusters it may be slow — don't fail the
                        # pipeline, just print status so we can diagnose if needed.
                        kubectl rollout status daemonset/speaker -n metallb-system --timeout=180s || {
                            echo "WARNING: MetalLB speaker rollout not complete — printing diagnostics"
                            kubectl get pods -n metallb-system -o wide
                            kubectl describe pods -l component=speaker -n metallb-system | grep -A 10 Events
                        }

                        # Apply IP pool and L2Advertisement (idempotent)
                        kubectl apply -f k8s/overlays/on-premise/metallb/

                        echo "MetalLB setup done. Current pod state:"
                        kubectl get pods -n metallb-system -o wide
                    """
                }
            }
        }

        stage('Deploy to K8s') {
            steps {
                withKubeConfig([credentialsId: "${K8S_CRED_ID}"]) {
                    sh "kubectl apply -k ${K8S_OVERLAY}"

                    // Show pod state immediately after apply so we can see pull/init status in logs
                    sh "kubectl get pods -n scrum-manager -o wide"

                    // MySQL uses Recreate strategy: old pod terminates then new starts.
                    sh "kubectl rollout status deployment/mysql   -n scrum-manager --timeout=300s"

                    // maxSurge=0: old pod terminates first, new pod starts after.
                    // CPU-constrained nodes may delay scheduling — 600s covers this.
                    sh "kubectl rollout status deployment/backend  -n scrum-manager --timeout=600s"

                    sh "kubectl rollout status deployment/frontend -n scrum-manager --timeout=600s"

                    echo "All deployments rolled out."
                }
            }
        }

        stage('Smoke Test') {
            steps {
                withKubeConfig([credentialsId: "${K8S_CRED_ID}"]) {
                    // Run a curl pod inside the cluster to hit the backend health endpoint.
                    // Uses FQDN (backend.scrum-manager.svc.cluster.local) to be explicit.
                    sh """
                        kubectl run smoke-${BUILD_NUMBER} \
                            --image=curlimages/curl:8.5.0 \
                            --restart=Never \
                            --rm \
                            --attach \
                            --timeout=30s \
                            -n scrum-manager \
                            -- curl -sf --max-time 10 \
                               http://backend.scrum-manager.svc.cluster.local:3001/api/health \
                        && echo "Health check PASSED" \
                        || echo "Health check FAILED (non-blocking)"
                    """
                }
            }
        }

        stage('Clean Up') {
            steps {
                sh """
                    docker rmi ${FRONTEND_IMAGE}:${IMAGE_TAG} || true
                    docker rmi ${FRONTEND_IMAGE}:latest       || true
                    docker rmi ${BACKEND_IMAGE}:${IMAGE_TAG}  || true
                    docker rmi ${BACKEND_IMAGE}:latest        || true
                """
            }
        }
    }

    post {
        success {
            echo "✅  Build #${env.BUILD_NUMBER} deployed → http://scrum.local"
        }
        failure {
            withKubeConfig([credentialsId: "${K8S_CRED_ID}"]) {
                sh """
                    echo '=== Pod Status ==='
                    kubectl get pods -n scrum-manager -o wide || true

                    echo '=== Backend Pod Events ==='
                    kubectl describe pods -l app.kubernetes.io/name=backend -n scrum-manager || true

                    echo '=== Backend Logs (last 50 lines) ==='
                    kubectl logs -l app.kubernetes.io/name=backend -n scrum-manager --tail=50 --all-containers=true || true

                    echo '=== Frontend Pod Events ==='
                    kubectl describe pods -l app.kubernetes.io/name=frontend -n scrum-manager || true

                    echo '=== MySQL Pod Events ==='
                    kubectl describe pods -l app.kubernetes.io/name=mysql -n scrum-manager || true
                """
            }
        }
        always {
            sh "docker logout ${HARBOR_URL} || true"
        }
    }
}