DEV: move discourse_dev gem to the core. (#13360)

And get avatar images from `discourse_dev_assets` gem.

lib/discourse_dev/category.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+require 'discourse_dev/record'
+require 'rails'
+require 'faker'
+
+module DiscourseDev
+  class Category < Record
+
+    def initialize
+      super(::Category, DiscourseDev.config.category[:count])
+      @parent_category_ids = ::Category.where(parent_category_id: nil).pluck(:id)
+    end
+
+    def data
+      name = Faker::Discourse.unique.category
+      parent_category_id = nil
+
+      if Faker::Boolean.boolean(true_ratio: 0.6)
+        offset = Faker::Number.between(from: 0, to: @parent_category_ids.count - 1)
+        parent_category_id = @parent_category_ids[offset]
+        @permissions = ::Category.find(parent_category_id).permissions_params.presence
+      else
+        @permissions = nil
+      end
+
+      {
+        name: name,
+        description: Faker::Lorem.paragraph,
+        user_id: ::Discourse::SYSTEM_USER_ID,
+        color: Faker::Color.hex_color.last(6),
+        parent_category_id: parent_category_id
+      }
+    end
+
+    def permissions
+      return @permissions if @permissions.present?
+      return { everyone: :full } if Faker::Boolean.boolean(true_ratio: 0.75)
+
+      permission = {}
+      group = Group.random
+      permission[group.id] = Faker::Number.between(from: 1, to: 3)
+
+      permission
+    end
+
+    def create!
+      super do |category|
+        category.set_permissions(permissions)
+        category.save!
+
+        @parent_category_ids << category.id if category.parent_category_id.blank?
+      end
+    end
+
+    def self.random
+      super(::Category)
+    end
+  end
+end