# Neuron — MCP server + Axon webhook hub
# MCP: https://neuron.nook.family (internal, Traefik)
# Webhooks: https://axon.neuralplatform.ai (external, Cloudflare tunnel)
#
# Image: registry.nook.family/neural-platform/neuron:latest
# Built by GitHub Actions runner on Legion — see neural-platform/neuron ci.yml
#
# TODO: Migrate SQLite → Postgres once neuron db migration is ready
# TODO: Wire Gmail OAuth credentials via k8s Secret (currently unauthenticated)

resource "kubernetes_namespace" "neuron" {
  metadata {
    name = "neuron"
    labels = {
      managed-by = "terraform"
      tier       = "platform"
    }
  }
}

resource "kubernetes_persistent_volume_claim" "neuron_data" {
  metadata {
    name      = "neuron-data"
    namespace = kubernetes_namespace.neuron.metadata[0].name
  }

  spec {
    access_modes = ["ReadWriteOnce"]
    resources {
      requests = {
        storage = "5Gi"
      }
    }
  }
}

resource "kubernetes_config_map" "neuron_config" {
  metadata {
    name      = "neuron-config"
    namespace = kubernetes_namespace.neuron.metadata[0].name
  }

  data = {
    MCP_PORT       = "8001"
    MCP_HOST       = "0.0.0.0"
    WEBHOOK_PORT   = "3847"
    NEURON_DB_PATH = "/data/neuron.db"
    AXON_DB_PATH   = "/data/axon.db"
    TUNNEL_NAME    = "neural-platform"

    "default.yaml" = <<-EOT
      runtime:
        name: neuron
        version: 0.1.0
      storage:
        db_path: /data/neuron.db
      cache:
        max_l1_size: 1000
      gc:
        gen0_threshold: 3
        gen1_threshold: 5
      knowledge:
        base_path: /data/knowledge
      synapse:
        path: /data/synapse
    EOT
  }
}

resource "kubernetes_secret" "neuron_secrets" {
  metadata {
    name      = "neuron-secrets"
    namespace = kubernetes_namespace.neuron.metadata[0].name
  }

  data = {
    GITHUB_WEBHOOK_SECRET = var.github_webhook_secret
    GITEA_WEBHOOK_SECRET  = var.gitea_webhook_secret
    SLACK_BOT_TOKEN       = var.slack_bot_token
    SLACK_SIGNING_SECRET  = var.slack_signing_secret
  }
}

resource "kubernetes_deployment" "neuron" {
  metadata {
    name      = "neuron"
    namespace = kubernetes_namespace.neuron.metadata[0].name
    labels = {
      app = "neuron"
    }
  }

  spec {
    replicas = 1

    strategy {
      type = "Recreate"  # SQLite cannot handle concurrent writers
    }

    selector {
      match_labels = {
        app = "neuron"
      }
    }

    template {
      metadata {
        labels = {
          app = "neuron"
        }
      }

      spec {
        container {
          name              = "neuron"
          image             = "registry.nook.family/neural-platform/neuron:latest"
          image_pull_policy = "Always"

          command = [
            "bash", "-c",
            "mkdir -p /root/.neuron && ln -sf /data/neuron.db /root/.neuron/neuron.db && python -m synapse platform serve --mcp-host 0.0.0.0 --mcp-port 8001 --webhook-port 3847"
          ]

          port {
            name           = "mcp"
            container_port = 8001
          }

          port {
            name           = "webhook"
            container_port = 3847
          }

          env_from {
            config_map_ref {
              name = kubernetes_config_map.neuron_config.metadata[0].name
            }
          }

          env_from {
            secret_ref {
              name = kubernetes_secret.neuron_secrets.metadata[0].name
            }
          }

          volume_mount {
            name       = "data"
            mount_path = "/data"
          }

          volume_mount {
            name       = "app-config"
            mount_path = "/app/config/default.yaml"
            sub_path   = "default.yaml"
          }

          resources {
            requests = {
              memory = "256Mi"
              cpu    = "100m"
            }
            limits = {
              memory = "1Gi"
              cpu    = "500m"
            }
          }

          liveness_probe {
            http_get {
              path = "/health"
              port = "mcp"
            }
            initial_delay_seconds = 10
            period_seconds        = 30
          }

          readiness_probe {
            http_get {
              path = "/health"
              port = "mcp"
            }
            initial_delay_seconds = 5
            period_seconds        = 10
          }
        }

        volume {
          name = "data"
          persistent_volume_claim {
            claim_name = kubernetes_persistent_volume_claim.neuron_data.metadata[0].name
          }
        }

        volume {
          name = "app-config"
          config_map {
            name = kubernetes_config_map.neuron_config.metadata[0].name
            items {
              key  = "default.yaml"
              path = "default.yaml"
            }
          }
        }
      }
    }
  }

  depends_on = [kubernetes_persistent_volume_claim.neuron_data]
}

resource "kubernetes_service" "neuron" {
  metadata {
    name      = "neuron"
    namespace = kubernetes_namespace.neuron.metadata[0].name
  }

  spec {
    selector = {
      app = "neuron"
    }

    port {
      name        = "mcp"
      port        = 8001
      target_port = 8001
    }

    port {
      name        = "webhook"
      port        = 3847
      target_port = 3847
    }

    type = "ClusterIP"
  }
}

# Internal MCP ingress — accessible within nook.family network
resource "kubernetes_ingress_v1" "neuron" {
  metadata {
    name      = "neuron"
    namespace = kubernetes_namespace.neuron.metadata[0].name
    annotations = {
      "traefik.ingress.kubernetes.io/router.entrypoints"  = "websecure"
      "cert-manager.io/cluster-issuer"                    = "letsencrypt-prod"
    }
  }

  spec {
    ingress_class_name = "traefik"

    tls {
      secret_name = "neuron-tls"
      hosts       = ["neuron.${var.infra_domain}"]
    }

    rule {
      host = "neuron.${var.infra_domain}"
      http {
        path {
          path      = "/"
          path_type = "Prefix"
          backend {
            service {
              name = kubernetes_service.neuron.metadata[0].name
              port {
                number = 8001
              }
            }
          }
        }
      }
    }
  }

  depends_on = [helm_release.cert_manager]
}

# cloudflared — Cloudflare tunnel for external access to Axon webhooks
# Routes: axon.neuralplatform.ai → neuron:3847
#         webhooks.neuralplatform.ai → neuron:3847
resource "kubernetes_deployment" "cloudflared" {
  metadata {
    name      = "cloudflared"
    namespace = kubernetes_namespace.neuron.metadata[0].name
    labels = {
      app = "cloudflared"
    }
  }

  spec {
    replicas = 1

    selector {
      match_labels = {
        app = "cloudflared"
      }
    }

    template {
      metadata {
        labels = {
          app = "cloudflared"
        }
      }

      spec {
        container {
          name  = "cloudflared"
          image = "cloudflare/cloudflared:latest"
          args  = ["tunnel", "--no-autoupdate", "run"]

          env {
            name  = "TUNNEL_TOKEN"
            value = var.cloudflared_tunnel_token
          }

          resources {
            requests = {
              memory = "64Mi"
              cpu    = "50m"
            }
            limits = {
              memory = "128Mi"
              cpu    = "200m"
            }
          }

          liveness_probe {
            http_get {
              path = "/ready"
              port = 20241
            }
            initial_delay_seconds = 10
            period_seconds        = 30
          }
        }
      }
    }
  }

  depends_on = [kubernetes_deployment.neuron]
}