#!/usr/bin/env bash
#######################################################
# 
#######################################################
[[ -n ${DEBUG} ]] && set -x
set -eou pipefail
KUBECTL=kubectl

usage() {
  local SELF
  SELF="kubels"
  if [[ "$(basename "$0")" == kubectl-* ]]; then # invoked as plugin
    SELF="kubectl ls"
  fi

  cat <<EOF
USAGE:
  $SELF <kubectl-cmdargs...>: list & select pods/svc/cm to do something, for example:
    $SELF get pod
    $SELF get pod -n kube-system
    $SELF exec -it -- bash
    $SELF logs --tail 100
  $SELF -h,--help           : show this message
EOF
}

exit_err() {
   echo >&2 "${1}"
   exit 1
}

function main() {
    _kube_parse_args "$@"
    local act=${1-""}
    local res=${2-""}

    if [[ "$act" =~ -h|--help|help ]]; then
        usage
        exit 0
    elif [[ "$act $res" == "logs " ]]; then
        _kube_list_pods "$cur_ns_arg"
        shift 1
        $KUBECTL "$act" "$sel_pod" --tail 100 -f
    elif [[ "$act $res" == "exec " ]]; then
        _kube_list_pods "$cur_ns_arg"
        shift 1
        $KUBECTL "$act" "$sel_pod" -it -- sh 
    elif [[ "$act" =~ logs|exec|describe ]]; then
        _kube_list_pods "$cur_ns_arg"
        shift 1
        $KUBECTL "$act" "$sel_pod" $@
    elif [[ "$act $res" =~ "get pod" ]]; then
        _kube_list_pods "$cur_ns_arg"
        shift 2
        $KUBECTL get pod "$sel_pod" $@;
    else
        usage
        exit 1
    fi
}

function _kube_parse_args() {
  local ns=""
  local ns_arg=""
  local opt="${@}"
  local args=$(getopt -o ':n:A' -l ':namespace:all-namespaces:' -- "${@}") || exit
  eval "set -- ${args}"
  
  while true; do
      case "${1}" in
          -A)
              ns=""
              ns_arg="-A"
              shift 1
          ;;
          -n|--namespace)
              ns=${2}
              ns_arg="-n $ns"
              shift 2
          ;;
          --all-namespace)
              ns=""
              ns_arg="-A"
              shift 2
          ;;
          --)
              shift
              break 
          ;;
      esac
  done
  
  eval "set -- ${opt}"
  export cur_ns=${ns:=$(_kube_current_namespace)}
  export cur_ns_arg=${ns_arg:="-n $cur_ns"}
}


function _kube_list_pods() {
  local NS_ARG=$1
  local GO_TPL=""
  GO_TPL="$GO_TPL"'{{range .items}}'
  GO_TPL="$GO_TPL"""'{{.metadata.name}}:'
  GO_TPL="$GO_TPL"""'{{.metadata.namespace}}:'
  GO_TPL="$GO_TPL"""'{{.status.phase}}'
  GO_TPL="$GO_TPL"""'({{range $index, $element := .status.containerStatuses}}'
  GO_TPL="$GO_TPL"""""'{{if $index}}&{{end}}'
  GO_TPL="$GO_TPL"""""'{{if .state.waiting}}{{.state.waiting.reason}}{{end}}'
  GO_TPL="$GO_TPL"""""'{{if .state.running}}Runing{{end}}'
  GO_TPL="$GO_TPL"""'{{end}})'
  GO_TPL="$GO_TPL"""'{{"\n"}}'
  GO_TPL="$GO_TPL"'{{end}}'

  local pods=(`kubectl get pods $NS_ARG -o go-template="$GO_TPL" | sort -k 2 -k 1 -t:`)
  local lines=$(
    local index=1
    for p in ${pods[@]}; do
      IFS=":" read -ra TOKS <<< "${p}"
      printf "  $index) ${TOKS[0]}\t${TOKS[1]}\t${TOKS[2]}\n"
      ((index=index+1))
    done | column -t
  )
  local count=$(echo "$lines" | wc -l)

  if   [ $count -eq 0 ]; then
      echo "Find $count pods in namespace '$cur_ns', exit." >&2
      sel_pod="_NO_POD_FOUNT_"
      exit 0
  elif [ $count -eq 1 ]; then
      echo "Find $count pods in namespace '$cur_ns', auto select it." >&2
      echo "$lines"                                                   >&2
      sel_pod="${pods[0]%%:*}"
      return 0
  fi

  echo "Find $count pods in namespace '$cur_ns', please select:" >&2
  echo "$lines"                                                  >&2
  local sel=0
  while [[ $sel -lt 1 || $sel -gt $count ]]; do
    read -p "Select a Pod: " sel >&2
  done
  sel_pod="${pods[(sel-1)]%%:*}"
}

function _kube_list_pod_containers() {
  POD=$1
  NAMESPACE=$2
  IFS=';' read -ra items <<< "$(kubectl get pod ${POD} -n ${NAMESPACE} -o go-template='{{range .spec.containers}}{{.name}}{{"\n"}}{{end}}' | tr '\n' ';')"
  local count=1
  lines=$(for i in ${items[@]}; do
    printf "  $count) ${i}\n"
    ((count=count+1))
  done | column -t)
  count=$(echo "$lines" | wc -l)
  if [[ $count -gt 1 ]]; then
    printf "\nPod has multiple containers:\n" >&2
    echo "$lines" >&2
    local sel=0
    while [[ $sel -lt 1 || $sel -gt $count ]]; do
      read -p "Select a Container: " sel >&2
    done
  fi
  echo "${items[(sel-1)]}"
}

function _kube_current_namespace() {
  local cur_ctx
  local command="$KUBECTL config current-context"
  cur_ctx=$($command) || exit_err "error getting current context"
  ns="$($KUBECTL config view -o=jsonpath="{.contexts[?(@.name==\"${cur_ctx}\")].context.namespace}")" \
     || exit_err "error getting current namespace"

  if [[ -z "${ns}" ]]; then
    echo "default"
  else
    echo "${ns}"
  fi
}


main ${@}

################################################################   
###   
###   SEL=$(_kube_list_pods)
###   IFS=":" read -ra POD <<< "${SEL}"
###   
###   if [[ ${POD[2]} != Running* ]]; then
###     echo "Status:${POD[2]}" >&2
###     echo "ERROR: Pod ${POD[0]} is not running" >&2
###     exit 1
###   fi
###   
###   SEL=$(_kube_list_pod_containers ${POD[0]} ${POD[1]})
###   
###   kubectl -n ${POD[1]} logs --tail 100 "${POD[0]}" -c ${SEL} $@