1 files changed, 63 insertions, 0 deletions
diff --git a/entity_manager.rb b/entity_manager.rb
new file mode 100644
index 0000000..7d0d1ff
--- /dev/null
+++ b/entity_manager.rb
@@ -0,0 +1,63 @@
+class Entity
+  attr_accessor :id
+
+  def initialize(*signature)
+    final_signature = 0
+    signature.each do |sig|
+      final_signature += sig
+    end
+    @id = Entity.generate_new_id
+    self.class.all.push self
+    self.class.signatures.push final_signature
+    Components.entity_created(@id)
+  end
+
+  class <<self
+    # All entities that exist
+    def all
+      @all ||= []
+    end
+
+    def id_queue
+      @id_queue ||= []
+    end
+
+    def generate_new_id
+      if id_queue.empty?
+        all.size
+      else
+        id_queue.shift
+      end
+    end
+
+    # What components a given entity uses
+    def signatures
+      @signatures ||= []
+    end
+
+    def destroy_entity(entity_id)
+      if all[entity_id].nil?
+        puts 'Entity can not be destroyed, id out of bounds'
+      elsif entity_id < all.size - 1
+        Components.constants.each do |constant|
+          unless (signatures[entity_id] & Components::const_get(constant).id).zero?
+            Components::const_get(constant).delete(entity_id)
+          end
+        end
+        all[entity_id] = nil
+        signatures[entity_id] = nil
+        id_queue.push entity_id
+      elsif entity_id == all.size - 1
+        Components.constants.each do |constant|
+          unless (signatures[entity_id] & Components::const_get(constant).id).zero?
+            Components::const_get(constant).delete(entity_id)
+          end
+        end
+        all.pop
+        signatures.pop
+      else
+        puts 'Unknown error with destroy_entity, entity not destroyed'
+      end
+    end
+  end
+end