T4807: Fixed traceroute help completion

Changes in traceroute command:
Added list of possible VRFs in the help.
Added list of possible interfaces in the help.
Changed, if an option was selected before,
it does not appear in possible completion.
Added error message when an unexpected option was selected

1 files changed, 67 insertions, 18 deletions

diff --git a/src/op_mode/traceroute.py b/src/op_mode/traceroute.py
index 4299d6e5f..6c7030ea0 100755
--- a/src/op_mode/traceroute.py
+++ b/src/op_mode/traceroute.py
@@ -18,6 +18,25 @@ import os
 import sys
 import socket
 import ipaddress
+from vyos.util import get_all_vrfs
+from vyos.ifconfig import Section
+
+
+def interface_list() -> list:
+    """
+    Get list of interfaces in system
+    :rtype: list
+    """
+    return Section.interfaces()
+
+
+def vrf_list() -> list:
+    """
+    Get list of VRFs in system
+    :rtype: list
+    """
+    return list(get_all_vrfs().keys())
+
 
 options = {
     'backward-hops': {
@@ -48,6 +67,7 @@ options = {
     'interface': {
         'traceroute': '{command} -i {value}',
         'type': '<interface>',
+        'helpfunction': interface_list,
         'help': 'Source interface'
     },
     'lookup-as': {
@@ -99,6 +119,7 @@ options = {
         'traceroute': 'sudo ip vrf exec {value} {command}',
         'type': '<vrf>',
         'help': 'Use specified VRF table',
+        'helpfunction': vrf_list,
         'dflt': 'default'}
 }
 
@@ -108,20 +129,33 @@ traceroute = {
 }
 
 
-class List (list):
-    def first (self):
+class List(list):
+    def first(self):
         return self.pop(0) if self else ''
 
     def last(self):
         return self.pop() if self else ''
 
-    def prepend(self,value):
-        self.insert(0,value)
+    def prepend(self, value):
+        self.insert(0, value)
+
+
+def completion_failure(option: str) -> None:
+    """
+    Shows failure message after TAB when option is wrong
+    :param option: failure option
+    :type str:
+    """
+    sys.stderr.write('\n\n Invalid option: {}\n\n'.format(option))
+    sys.stdout.write('<nocomps>')
+    sys.exit(1)
 
 
 def expension_failure(option, completions):
     reason = 'Ambiguous' if completions else 'Invalid'
-    sys.stderr.write('\n\n  {} command: {} [{}]\n\n'.format(reason,' '.join(sys.argv), option))
+    sys.stderr.write(
+        '\n\n  {} command: {} [{}]\n\n'.format(reason, ' '.join(sys.argv),
+                                               option))
     if completions:
         sys.stderr.write('  Possible completions:\n   ')
         sys.stderr.write('\n   '.join(completions))
@@ -160,30 +194,46 @@ if __name__ == '__main__':
         sys.exit("traceroute: Missing host")
 
     if host == '--get-options':
-        args.first()  # pop traceroute
+        args.first()  # pop ping
         args.first()  # pop IP
+        usedoptionslist = []
         while args:
-            option = args.first()
-
-            matched = complete(option)
+            option = args.first()  # pop option
+            matched = complete(option)  # get option parameters
+            usedoptionslist.append(option)  # list of used options
+            # Select options
             if not args:
+                # remove from Possible completions used options
+                for o in usedoptionslist:
+                    if o in matched:
+                        matched.remove(o)
                 sys.stdout.write(' '.join(matched))
                 sys.exit(0)
 
-            if len(matched) > 1 :
+            if len(matched) > 1:
                 sys.stdout.write(' '.join(matched))
                 sys.exit(0)
+            # If option doesn't have value
+            if matched:
+                if options[matched[0]]['type'] == 'noarg':
+                    continue
+            else:
+                # Unexpected option
+                completion_failure(option)
 
-            if options[matched[0]]['type'] == 'noarg':
-                continue
-
-            value = args.first()
+            value = args.first()  # pop option's value
             if not args:
                 matched = complete(option)
-                sys.stdout.write(options[matched[0]]['type'])
+                helplines = options[matched[0]]['type']
+                # Run helpfunction to get list of possible values
+                if 'helpfunction' in options[matched[0]]:
+                    result = options[matched[0]]['helpfunction']()
+                    if result:
+                        helplines = '\n' + ' '.join(result)
+                sys.stdout.write(helplines)
                 sys.exit(0)
 
-    for name,option in options.items():
+    for name, option in options.items():
         if 'dflt' in option and name not in args:
             args.append(name)
             args.append(option['dflt'])
@@ -200,8 +250,7 @@ if __name__ == '__main__':
     except ValueError:
         sys.exit(f'traceroute: Unknown host: {host}')
 
-    command = convert(traceroute[version],args)
+    command = convert(traceroute[version], args)
 
     # print(f'{command} {host}')
     os.system(f'{command} {host}')
-