HelpChannels: prefix channel names after reading from file

Prefixing them early on means subsequent code doesn't have to deal with
stripping the prefix from channel names in order to get their positions.

* Remove `count` parameter from `get_names`; define it in the body

1 files changed, 19 insertions, 15 deletions

diff --git a/bot/cogs/help_channels.py b/bot/cogs/help_channels.py
index 6bed3199c..d0ebce7a4 100644
--- a/bot/cogs/help_channels.py
+++ b/bot/cogs/help_channels.py
@@ -150,10 +150,9 @@ class HelpChannels(Scheduler, commands.Cog):
         Return None if no more channel names are available.
         """
         log.trace("Getting a name for a new dormant channel.")
-        name = constants.HelpChannels.name_prefix
 
         try:
-            name += self.name_queue.popleft()
+            name = self.name_queue.popleft()
         except IndexError:
             log.debug("No more names available for new dormant channels.")
             return None
@@ -214,13 +213,10 @@ class HelpChannels(Scheduler, commands.Cog):
         """
         log.trace(f"Getting alphabetical position for #{channel.name} ({channel.id}).")
 
-        prefix = constants.HelpChannels.name_prefix
-        element = channel.name[len(prefix):]
-
         try:
-            position = self.elements[element]
+            position = self.elements[channel.name]
         except KeyError:
-            log.warning(f"Channel #{channel.name} ({channel.id}) doesn't have the prefix {prefix}.")
+            log.warning(f"Channel #{channel.name} ({channel.id}) doesn't have a valid name.")
             position = None
 
         log.trace(
@@ -241,8 +237,16 @@ class HelpChannels(Scheduler, commands.Cog):
                 yield channel
 
     @staticmethod
-    def get_names(count: int = constants.HelpChannels.max_total_channels) -> t.Dict[str, int]:
-        """Return a dict with the first `count` element names and their alphabetical indices."""
+    def get_names() -> t.Dict[str, int]:
+        """
+        Return a truncated dict of prefixed element names and their alphabetical indices.
+
+        The amount of names if configured with `HelpChannels.max_total_channels`.
+        The prefix is configured with `HelpChannels.name_prefix`.
+        """
+        count = constants.HelpChannels.max_total_channels
+        prefix = constants.HelpChannels.name_prefix
+
         log.trace(f"Getting the first {count} element names from JSON.")
 
         if count > MAX_CHANNELS_PER_CATEGORY:
@@ -254,20 +258,20 @@ class HelpChannels(Scheduler, commands.Cog):
         with Path("bot/resources/elements.json").open(encoding="utf-8") as elements_file:
             all_names = json.load(elements_file)
 
-        truncated_names = itertools.islice(all_names.items(), count)
-        return dict(truncated_names)
+        names = itertools.islice(all_names.items(), count)
+        if prefix:
+            names = ((prefix + name, pos) for name, pos in names)
+
+        return dict(names)
 
     def get_used_names(self) -> t.Set[str]:
         """Return channels names which are already being used."""
         log.trace("Getting channel names which are already being used.")
 
-        start_index = len(constants.HelpChannels.name_prefix)
-
         names = set()
         for cat in (self.available_category, self.in_use_category, self.dormant_category):
             for channel in self.get_category_channels(cat):
-                name = channel.name[start_index:]
-                names.add(name)
+                names.add(channel.name)
 
         if len(names) > MAX_CHANNELS_PER_CATEGORY:
             log.warning(