---
# NATS JetStream Deployment
# Data-plane для 150 нод: fan-out/fan-in, online/offline пріоритети
apiVersion: v1
kind: Namespace
metadata:
  name: nats
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nats
  namespace: nats
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: nats-config
  namespace: nats
data:
  nats.conf: |
    # NATS JetStream Configuration
    port: 4222
    http_port: 8222
    cluster {
      port: 6222
      routes = [
        nats://nats-0.nats:6222
        nats://nats-1.nats:6222
        nats://nats-2.nats:6222
      ]
    }
    
    server_name: POD_NAME_PLACEHOLDER
    cluster {
      name: nats-cluster
      port: 6222
      routes = [
        nats://nats-0.nats:6222
        nats://nats-1.nats:6222
      ]
    }
    server_name: POD_NAME_PLACEHOLDER
    cluster {
      name: nats-cluster
      port: 6222
      routes = [
        nats://nats-0.nats:6222
        nats://nats-1.nats:6222
      ]
    }
    jetstream {
      store_dir: /data/jetstream
      max_mem_store: 2G
      max_file_store: 50G
    }
    
    # TODO: Auth: nkeys (operator + system account)
    # operator: /etc/nats/nats-operator.jwt
    # system_account: SYSTEM
    # resolver: MEMORY
    # Для dev: auth вимкнено. Для prod: обов'язково увімкнути!
---
apiVersion: v1
kind: Secret
metadata:
  name: nats-operator
  namespace: nats
type: Opaque
data:
  # TODO: Generate operator JWT and system account
  # nats-operator.jwt: <base64>
  # system-account.jwt: <base64>
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nats
  namespace: nats
  labels:
    app: nats
spec:
  serviceName: nats
  replicas: 2  # Для поточного кластера (2 ноди). Збільшити до 3+ для prod
  selector:
    matchLabels:
      app: nats
  template:
    metadata:
      labels:
        app: nats
    spec:
      serviceAccountName: nats
      initContainers:
        - name: config-init
          image: busybox:latest
          command: ['sh', '-c']
          args:
            - |
              sed "s/POD_NAME_PLACEHOLDER/${POD_NAME}/g" /etc/nats/nats.conf.template > /etc/nats/nats.conf
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
          volumeMounts:
            - name: config
              mountPath: /etc/nats
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
            - weight: 100
              podAffinityTerm:
                labelSelector:
                  matchExpressions:
                    - key: app
                      operator: In
                      values:
                        - nats
                topologyKey: kubernetes.io/hostname
      containers:
        - name: nats
          image: nats:2.10-alpine
          ports:
            - containerPort: 4222
              name: client
            - containerPort: 6222
              name: cluster
            - containerPort: 8222
              name: monitor
          args:
            - -c
            - /etc/nats/nats.conf
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          volumeMounts:
            - name: config-dest
              mountPath: /etc/nats
            - name: data
              mountPath: /data
          resources:
            requests:
              memory: "2Gi"
              cpu: "1"
            limits:
              memory: "4Gi"
              cpu: "2"
          livenessProbe:
            httpGet:
              path: /healthz
              port: 8222
            initialDelaySeconds: 10
            periodSeconds: 10
          readinessProbe:
            httpGet:
              path: /healthz
              port: 8222
            initialDelaySeconds: 5
            periodSeconds: 5
      volumes:
        - name: config
          configMap:
            name: nats-config
            items:
              - key: nats.conf
                path: nats.conf.template
        # TODO: Додати Secret для operator JWT
        # - name: operator-jwt
        #   secret:
        #     secretName: nats-operator
  volumeClaimTemplates:
    - metadata:
        name: data
      spec:
        accessModes: ["ReadWriteOnce"]
        storageClassName: local-path
        resources:
          requests:
            storage: 100Gi
---
apiVersion: v1
kind: Service
metadata:
  name: nats
  namespace: nats
spec:
  type: ClusterIP
  clusterIP: None
  selector:
    app: nats
  ports:
    - name: client
      port: 4222
      targetPort: 4222
    - name: cluster
      port: 6222
      targetPort: 6222
    - name: monitor
      port: 8222
      targetPort: 8222
---
apiVersion: v1
kind: Service
metadata:
  name: nats-client
  namespace: nats
spec:
  type: ClusterIP
  selector:
    app: nats
  ports:
    - name: client
      port: 4222
      targetPort: 4222