config() {
  cat <<EOF
{
  "onKubernetesEvent": [
    {
      "kind": "Ingress",
      "event": ["$1"],
      "selector": {
        "matchLabels": {
          "certmanager.k8s.io/acme-http01-solver": "true"
        }
      }
    }
  ]
}
EOF
}

mkmap() {
  kubectl apply -f - <<EOF
apiVersion: cio.giftfish.de/v1alpha1
kind: RefMap
metadata:
  name: "$1"
spec:
  namespace: "$2"
  gateway:
    ref: "$3"
    action: "$4"
  virtualService:
    ref: "$5"
    action: "$6"
EOF
}
getmap() { kubectl get refmap "$1" -ojson; }
delmap() { kubectl delete refmap "$1"; }

mkgw() {
  kubectl apply -f - <<EOF
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: "$1"
  namespace: "$2"
spec:
  selector:
    istio: ingressgateway
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts: ["$3"]
EOF
}
delgw() { kubectl -n "$2" delete gateway "$1"; }

mkvs() {
  kubectl apply -f - <<EOF
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: "$1"
  namespace: "$2"
spec:
  gateways: ["$1"]
  hosts: ["$3"]
  http:
  - match:
    - port: 80
      uri:
        exact: "$4"
    route:
    - destination:
        port:
          number: $6
        host: "$5.$2.svc.cluster.local"
EOF
}
addvs() {
  insert=$(jq -c -M . <<EOF
{
  "match": [
    {
      "port": 80,
      "uri": {
        "exact": "$3"
      }
    }
  ],
  "route": [
    {
      "destination": {
        "host": "$4.$2.svc.cluster.local",
        "port": {
          "number": $5
        }
      }
    }
  ]
}
EOF
)
  kubectl -n "$2" get virtualservice "$1" -ojson | jq ".spec.http |= [${insert}] + ." | kubectl -n "$2" apply -f -
}
clearvs() { kubectl -n "$2" get virtualservice "$1" -ojson | jq -r '.spec.http |= .[1:]' | kubectl -n "$2" apply -f -; }
delvs() { kubectl -n "$2" delete virtualservice "$1"; }

mkdr() {
  kubectl apply -f - <<EOF
apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
 name: $1
 namespace: $2
spec:
 host: "$3.$2.svc.cluster.local"
 trafficPolicy:
   tls:
     mode: DISABLE
EOF
}
deldr() { kubectl -n "$2" delete destinationrule "$1"; }

add() {
  res=$1
  ns=$2
  tmp=$(mktemp)
  kubectl -n ${ns} get ingress ${res} -ojson >${tmp} || return 0
  host=$(jq -r '.spec.rules[0].host' ${tmp})
  svcName=$(jq -r '.spec.rules[0].http.paths[0].backend.serviceName' ${tmp})
  svcPort=$(jq -r '.spec.rules[0].http.paths[0].backend.servicePort' ${tmp})
  path=$(jq -r '.spec.rules[0].http.paths[0].path' ${tmp})
  rm -f ${tmp}

  gwName=
  for gw in $(kubectl -n ${ns} get gateway -ojson | jq -r '.items[] | .metadata.name'); do
    contains=$(kubectl -n ${ns} get gateway ${gw} -ojson | jq -r ".spec.servers[0].hosts | contains([\"${host}\"])")
    [[ "${contains}" == "true" ]] && { gwName=${gw}; break; }
  done
  if [[ "${gwName}" == "" ]]; then
    gwName=${res}
    gwAction=delete
  else
    gwAction=none
  fi

  vsName=
  vsAction=
  for vs in $(kubectl -n ${ns} get virtualservice -ojson | jq -r '.items[] | .metadata.name'); do
    contains=$(kubectl -n ${ns} get virtualservice ${vs} -ojson | jq -r ".spec.hosts | contains([\"${host}\"])")
    [[ "${contains}" == "true" ]] && { vsName=${vs}; break; }
  done
  if [[ "${vsName}" == "" ]]; then
    vsName=${res}
    vsAction=delete
  else
    vsAction=clear
  fi

  mkmap "${res}" "${ns}" "${gwName}" "${gwAction}" "${vsName}" "${vsAction}"
  [[ "${gwAction}" == "delete" ]] && mkgw "${gwName}" "${ns}" "${host}"
  [[ "${vsAction}" == "delete" ]] && mkvs "${vsName}" "${ns}" "${host}" "${path}" "${svcName}" "${svcPort}" \
  	|| addvs "${vsName}" "${ns}" "${path}" "${svcName}" "${svcPort}"
  mkdr "${res}" "${ns}" "${svcName}"
}

delete() {
  tmp=$(mktemp)
  getmap $1 >${tmp} || return 0
  ns=$(jq -r '.spec.namespace' ${tmp})
  gwName=$(jq -r '.spec.gateway.ref' ${tmp})
  gwAction=$(jq -r '.spec.gateway.action' ${tmp})
  vsName=$(jq -r '.spec.virtualService.ref' ${tmp})
  vsAction=$(jq -r '.spec.virtualService.action' ${tmp})
  rm -f ${tmp}
  if [[ "${gwName}" != "" ]]; then
    case ${gwAction} in
      delete) delgw "${gwName}" "${ns}" ;;
      none|*) ;;
    esac
  fi
  if [[ "${vsName}" != "" ]]; then
    case ${vsAction} in
      delete) delvs "${vsName}" "${ns}" ;;
      clear)  clearvs "${vsName}" "${ns}" ;;
    esac
  fi
  deldr "$1" "${ns}"
  delmap "$1"
}