Improved Vagrant provider detection and support for parallels provider.

Improved the detection of Vagrant provider. The previouse didn't
correctly detect which provider was used.

Added support for detecting the state of Parallels vagrant provider.

fish_prompt.fish

@@ -238,15 +238,24 @@ end
 
 function __bobthefish_prompt_vagrant -S -d 'Display Vagrant status'
   [ "$theme_display_vagrant" = 'yes' -a -f Vagrantfile ]; or return
-  if type -q VBoxManage
-    __bobthefish_prompt_vagrant_vbox
-  else if grep vmware_fusion Vagrantfile >/dev/null ^&1
-    __bobthefish_prompt_vagrant_vmware
+  set provider (__bobthefish_vagrant_provider)
+  switch "$provider"
+    case 'virtualbox'
+      __bobthefish_prompt_vagrant_vbox
+    case 'vmware_fusion'
+      __bobthefish_prompt_vagrant_vmware
+    case 'parallels'
+      __bobthefish_prompt_vagrant_parallels
   end
 end
 
-function __bobthefish_vagrant_ids -S -d 'List Vagrant machine ids'
-  for file in .vagrant/machines/**/id
+function __bobthefish_vagrant_provider -S -d 'Get (first) Vagrant provider'
+  set -l first_provider (ls -1d .vagrant/machines/*/* | head -1)
+  echo $first_provider | sed -e 's/.*\/\(\w*\)/\1/'
+end
+
+function __bobthefish_vagrant_ids -S -a provider -d 'List Vagrant machine ids'
+  for file in .vagrant/machines/*/$provider/id
     read id <$file
     echo $id
   end
@@ -254,7 +263,7 @@ end
 
 function __bobthefish_prompt_vagrant_vbox -S -d 'Display VirtualBox Vagrant status'
   set -l vagrant_status
-  for id in (__bobthefish_vagrant_ids)
+  for id in (__bobthefish_vagrant_ids "virtualbox")
     set -l vm_status (VBoxManage showvminfo --machinereadable $id ^/dev/null | command grep 'VMState=' | tr -d '"' | cut -d '=' -f 2)
     switch "$vm_status"
       case 'running'
@@ -280,7 +289,7 @@ end
 
 function __bobthefish_prompt_vagrant_vmware -S -d 'Display VMWare Vagrant status'
   set -l vagrant_status
-  for id in (__bobthefish_vagrant_ids)
+  for id in (__bobthefish_vagrant_ids "vmware_fusion")
     if [ (pgrep -f "$id") ]
       set vagrant_status "$vagrant_status$__bobthefish_vagrant_running_glyph"
     else
@@ -294,6 +303,32 @@ function __bobthefish_prompt_vagrant_vmware -S -d 'Display VMWare Vagrant status
   set_color normal
 end
 
+function __bobthefish_prompt_vagrant_parallels -S -d 'Display Parallels Vagrant status'
+  set -l vagrant_status
+  for id in (__bobthefish_vagrant_ids "parallels")
+    set -l vm_status (prlctl list $id -o status ^/dev/null | command tail -1)
+    switch "$vm_status"
+      case 'running'
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_running_glyph"
+      case 'stopped'
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_poweroff_glyph"
+      case 'paused'
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_saved_glyph"
+      case 'suspended'
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_saved_glyph"
+      case 'stopping'
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_stopping_glyph"
+      case ''
+        set vagrant_status "$vagrant_status$__bobthefish_vagrant_unknown_glyph"
+    end
+  end
+  [ -z "$vagrant_status" ]; and return
+
+  __bobthefish_start_segment $__color_vagrant
+  echo -ns $vagrant_status ' '
+  set_color normal
+end
+
 function __bobthefish_prompt_docker -S -d 'Show docker machine name'
     [ "$theme_display_docker_machine" = 'no' -o -z "$DOCKER_MACHINE_NAME" ]; and return
     __bobthefish_start_segment $__color_vagrant