REFACTOR: Remove hardcoded base `KEY_PREFIX`.

app/models/channel.rb

@@ -1,6 +1,4 @@
 class DiscourseChat::Channel < DiscourseChat::PluginModel
-  KEY_PREFIX = 'channel:'
-
   # Setup ActiveRecord::Store to use the JSON field to read/write these values
   store :value, accessors: [ :provider, :error_key, :data ], coder: JSON
 
@@ -12,6 +10,10 @@ class DiscourseChat::Channel < DiscourseChat::PluginModel
 
   validate :provider_valid?, :data_valid?
 
+  def self.key_prefix
+    'channel:'.freeze
+  end
+
   def rules
     DiscourseChat::Rule.with_channel_id(id).order_by_precedence
   end

app/models/plugin_model.rb

@@ -1,6 +1,5 @@
 class DiscourseChat::PluginModel < PluginStoreRow
   PLUGIN_NAME = 'discourse-chat-integration'
-  KEY_PREFIX = 'unimplemented'
 
   default_scope { self.default_scope }
 
@@ -10,7 +9,11 @@ class DiscourseChat::PluginModel < PluginStoreRow
   def self.default_scope
     where(type_name: 'JSON')
       .where(plugin_name: self::PLUGIN_NAME)
-      .where("key LIKE ?", "#{self::KEY_PREFIX}%")
+      .where("key LIKE ?", "#{self.key_prefix}%")
+  end
+
+  def self.key_prefix
+    raise 'Not implemented'
   end
 
   private
@@ -25,12 +28,11 @@ class DiscourseChat::PluginModel < PluginStoreRow
     end
 
     def self.alloc_key
-      raise "KEY_PREFIX must be defined" if self::KEY_PREFIX == 'unimplemented'
+      DistributedMutex.synchronize("#{self::PLUGIN_NAME}_#{self.key_prefix}_id") do
-      DistributedMutex.synchronize("#{self::PLUGIN_NAME}_#{self::KEY_PREFIX}_id") do
+        max_id = PluginStore.get(self::PLUGIN_NAME, "#{self.key_prefix}_id")
-        max_id = PluginStore.get(self::PLUGIN_NAME, "#{self::KEY_PREFIX}_id")
         max_id = 1 unless max_id
-        PluginStore.set(self::PLUGIN_NAME, "#{self::KEY_PREFIX}_id", max_id + 1)
+        PluginStore.set(self::PLUGIN_NAME, "#{self.key_prefix}_id", max_id + 1)
-        "#{self::KEY_PREFIX}#{max_id}"
+        "#{self.key_prefix}#{max_id}"
       end
     end
 

app/models/rule.rb

@@ -1,6 +1,4 @@
 class DiscourseChat::Rule < DiscourseChat::PluginModel
-  KEY_PREFIX = 'rule:'
-
   # Setup ActiveRecord::Store to use the JSON field to read/write these values
   store :value, accessors: [ :channel_id, :type, :group_id, :category_id, :tags, :filter ], coder: JSON
 
@@ -47,6 +45,10 @@ class DiscourseChat::Rule < DiscourseChat::PluginModel
 
   validate :channel_valid?, :category_valid?, :group_valid?, :tags_valid?
 
+  def self.key_prefix
+    'rule:'.freeze
+  end
+
   # We never want an empty array, set it to nil instead
   def tags=(array)
     if array.nil? || array.empty?