#15: Refactoring Main.

src/simple_db_migrate/main.py

@@ -20,45 +20,53 @@ def execute(self):
     def __create_migration(self):
         new_file = self.__db_migrate.create_migration(self.__options.create_migration)
         print "- Created file '%s'" % (new_file)
-
-    #TODO: too big -- needs refactor
+
     def __migrate(self):
-        destination_version = self.__options.schema_version
-
-        if destination_version == None:
-            destination_version = self.__db_migrate.latest_schema_version_available()
-
-        if not self.__db_migrate.check_if_version_exists(destination_version):
-            Log().error_and_exit("version not found (%s)" % destination_version)
-
+        destination_version = self.__get_destination_version()
         current_version = self.__mysql.get_current_schema_version()
+
         if str(current_version) == str(destination_version):
             Log().error_and_exit("current and destination versions are the same (%s)" % current_version)
 
         print "- Current version is: %s" % current_version
         print "- Destination version is: %s" % destination_version
 
-        migration_up = True
-        migration = "up"
+        # if current and destination versions are the same, 
+        # will consider a migration up to execute remaining files
+        is_migration_up = True
         if int(current_version) > int(destination_version):
-            migration_up = False
-            migration = "down"
+            is_migration_up = False
+
+        print "\nStarting migration %s!\n" % "up" if is_migration_up else "down"
+
+        # do it!
+        self.__execute_migrations(current_version, destination_version, is_migration_up)
+
+    def __get_destination_version(self):
+        destination_version = self.__options.schema_version
 
-        print "\nStarting migration %s!\n" % migration
+        if destination_version == None:
+            destination_version = self.__db_migrate.latest_schema_version_available()
+
+        if not self.__db_migrate.check_if_version_exists(destination_version):
+            Log().error_and_exit("version not found (%s)" % destination_version)
 
+        return destination_version
+
+    def __execute_migrations(self, current_version, destination_version, is_migration_up):
         # getting only the migration sql files to be executed
         migration_files_to_be_executed = self.__db_migrate.get_migration_files_between_versions(current_version, destination_version)
 
         sql_statements_executed = ""
         for sql_file in migration_files_to_be_executed:    
 
             file_version = self.__db_migrate.get_migration_version(sql_file)
-            if not migration_up:
+            if not is_migration_up:
                 file_version = destination_version
 
-            print "===== executing %s (%s) =====" % (sql_file, migration)
-            sql = self.__db_migrate.get_sql_command(sql_file, migration_up)
-            self.__mysql.change(sql, file_version, migration_up)
+            print "===== executing %s (%s) =====" % (sql_file, "up" if is_migration_up else "down")
+            sql = self.__db_migrate.get_sql_command(sql_file, is_migration_up)
+            self.__mysql.change(sql, file_version, is_migration_up)
 
             #recording the last statement executed
             sql_statements_executed += sql