feat(oc): supporting OPENSHIFT_NAMESPACE variable

plugins/oc/oc.plugin.zsh

@@ -5,4 +5,34 @@
 if [ $commands[oc] ]; then
   source <(oc completion zsh)
   compdef _oc oc
+
+  OC_PLUGIN_INITIALIZED=no
+
+  function oc_prompt_info() {
+    [ -n "$OPENSHIFT_NAMESPACE" ] && echo -ne "\n(openshift: $OPENSHIFT_NAMESPACE)\n\x00"
+  }
+
+  # TODO Completion
+  function oc-namespace() {
+    # TODO -h / --help
+    # TODO "--clear" should unset variable
+    # when nothing passed should show usage
+    # TODO Rename this to "oc" and call binary oc with full path
+    # so this can become a subcommand: "oc localenv namespace xyz"
+
+    [ -n "$1" ] \
+      && export OPENSHIFT_NAMESPACE="$1" \
+      || unset OPENSHIFT_NAMESPACE
+
+    [ "$OC_PLUGIN_INITIALIZED" = "no" ] && {
+      export PROMPT='$(oc_prompt_info)'"$PROMPT"
+      # TODO Check if text "oc_prompt_info" is in "$PROMPT"
+      # instead set this variable
+      export OC_PLUGIN_INITIALIZED=yes
+    }
+  }
+
+  alias oc='oc ${OPENSHIFT_NAMESPACE:+"--namespace=$OPENSHIFT_NAMESPACE"}'
+else
+  echo "oc plugin error: oc command not found..."
 fi