[folks] inspect: Split out validation of subcommands from a few commands

[Philip Withnall <pwithnall src gnome org>]

commit fa4f3ea1d7b1799caf7fd02b198cd9217992cc4d
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Wed Feb 25 14:58:53 2015 +0000

    inspect: Split out validation of subcommands from a few commands
    
    And expand the help output to list the expected subcommands.

 tools/inspect/command-linking.vala |   20 ++++++++++----------
 tools/inspect/command-set.vala     |   16 ++++++++--------
 tools/inspect/command-signals.vala |   13 ++++++++-----
 tools/inspect/utils.vala           |   21 +++++++++++++++++++++
 4 files changed, 47 insertions(+), 23 deletions(-)
---
diff --git a/tools/inspect/command-linking.vala b/tools/inspect/command-linking.vala
index 366f13b..aa04fc9 100644
--- a/tools/inspect/command-linking.vala
+++ b/tools/inspect/command-linking.vala
@@ -24,6 +24,13 @@ using GLib;
 
 private class Folks.Inspect.Commands.Linking : Folks.Inspect.Command
 {
+  private const string[] _valid_subcommands =
+    {
+      "link-personas",
+      "link-individuals",
+      "unlink-individual",
+    };
+
   public override string name
     {
       get { return "linking"; }
@@ -68,14 +75,9 @@ private class Folks.Inspect.Commands.Linking : Folks.Inspect.Command
           parts = command_string.split (" ");
         }
 
-      if (parts.length < 1 ||
-          (parts[0] != "link-personas" && parts[0] != "link-individuals" &&
-           parts[0] != "unlink-individual"))
-        {
-          Utils.print_line ("Unrecognised 'linking' command '%s'.",
-            command_string);
+      if (!Utils.validate_subcommand (this.name, command_string, parts[0],
+              Linking._valid_subcommands))
           return;
-        }
 
       if (parts[0] == "link-personas" || parts[0] == "link-individuals")
         {
@@ -301,9 +303,7 @@ private class Folks.Inspect.Commands.Linking : Folks.Inspect.Command
             }
           else
             {
-              subcommand_completions =
-                  { "link-personas", "link-individuals",
-                    "unlink-individual", null };
+              subcommand_completions = Linking._valid_subcommands;
               prefix = "";
             }
 
diff --git a/tools/inspect/command-set.vala b/tools/inspect/command-set.vala
index 670161c..dd2f83a 100644
--- a/tools/inspect/command-set.vala
+++ b/tools/inspect/command-set.vala
@@ -24,6 +24,11 @@ using GLib;
 
 private class Folks.Inspect.Commands.Set : Folks.Inspect.Command
 {
+  private const string[] _valid_subcommands =
+    {
+      "alias",
+    };
+
   public override string name
     {
       get { return "set"; }
@@ -61,13 +66,9 @@ private class Folks.Inspect.Commands.Set : Folks.Inspect.Command
           parts = command_string.split (" ");
         }
 
-      if (parts.length < 1 ||
-          (parts[0] != "alias"))
-        {
-          Utils.print_line ("Unrecognised 'set' command '%s'.",
-            command_string);
+      if (!Utils.validate_subcommand (this.name, command_string, parts[0],
+              Set._valid_subcommands))
           return;
-        }
 
       if (parts[0] == "alias")
         {
@@ -158,8 +159,7 @@ private class Folks.Inspect.Commands.Set : Folks.Inspect.Command
             }
           else
             {
-              subcommand_completions =
-                  { "alias", null };
+              subcommand_completions = Set._valid_subcommands;
               prefix = "";
             }
 
diff --git a/tools/inspect/command-signals.vala b/tools/inspect/command-signals.vala
index afff682..ead4584 100644
--- a/tools/inspect/command-signals.vala
+++ b/tools/inspect/command-signals.vala
@@ -44,6 +44,12 @@ using GLib;
 
 private class Folks.Inspect.Commands.Signals : Folks.Inspect.Command
 {
+  private const string[] _valid_subcommands =
+    {
+      "connect",
+      "disconnect",
+    };
+
   public override string name
     {
       get { return "signals"; }
@@ -106,12 +112,9 @@ private class Folks.Inspect.Commands.Signals : Folks.Inspect.Command
           /* Parse subcommands */
           string[] parts = command_string.split (" ", 2);
 
-          if (parts.length < 1)
-            {
-              Utils.print_line ("Unrecognised 'signals' command '%s'.",
-                command_string);
+          if (!Utils.validate_subcommand (this.name, command_string, parts[0],
+                 Signals._valid_subcommands))
               return;
-            }
 
           Type class_type;
           Object class_instance;
diff --git a/tools/inspect/utils.vala b/tools/inspect/utils.vala
index 5bbacb6..98879b3 100644
--- a/tools/inspect/utils.vala
+++ b/tools/inspect/utils.vala
@@ -621,4 +621,25 @@ private class Folks.Inspect.Utils
       Utils.backend_name_iter = null;
       return null;
     }
+
+  /* Command validation code for commands which take a well-known set of
+   * subcommands. */
+  public static bool validate_subcommand (string command,
+      string? command_string, string? subcommand, string[] valid_subcommands)
+    {
+      if (subcommand != null && subcommand in valid_subcommands)
+          return true;
+
+      /* Print an error. */
+      Utils.print_line ("Unrecognised '%s' command '%s'.", command,
+          (command_string != null) ? command_string : "");
+
+      Utils.print_line ("Valid commands:");
+      Utils.indent ();
+      foreach (var c in valid_subcommands)
+          Utils.print_line ("%s", c);
+      Utils.unindent ();
+
+      return false;
+    }
 }