prepare code for multidb (#55)

* prepare code for multidb

* small refactor

* fix

lib/actual_db_schema.rb

@@ -29,7 +29,28 @@ class << self
   }
 
   def self.migrated_folder
-    Rails.root.join("tmp", "migrated").tap { |folder| FileUtils.mkdir_p(folder) }
+    migrated_folders.first
+  end
+
+  def self.migrated_folders
+    return [default_migrated_folder] unless migrations_paths
+
+    Array(migrations_paths).map do |path|
+      if path.end_with?("db/migrate")
+        default_migrated_folder
+      else
+        postfix = path.split("/").last
+        Rails.root.join("tmp", "migrated_#{postfix}")
+      end
+    end
+  end
+
+  def self.default_migrated_folder
+    Rails.root.join("tmp", "migrated")
+  end
+
+  def self.migrations_paths
+    ActiveRecord::Base.connection_db_config.migrations_paths
   end
 
   def self.migration_filename(fullpath)

lib/actual_db_schema/store.rb

@@ -9,6 +9,7 @@ class Store
 
     def write(filename)
       basename = File.basename(filename)
+      FileUtils.mkdir_p(folder)
       FileUtils.copy(filename, folder.join(basename))
       record_metadata(filename)
     end