From 9c31f044cef0a0b9feeebe9ffd6fd63a814bb3aa Mon Sep 17 00:00:00 2001
From: Tiara Rodney <t.rodney@inno-on.de>
Date: Sun, 3 Apr 2022 02:45:01 +0200
Subject: [PATCH] fix(backend/mysql): isolate third-party module imports

currently there is a problem with loading the backends through
the httpaste.Config class, since they aren't being lazily loaded, will have to
rework this sometime later in the future.
---
 src/httpaste/backend/mysql/__init__.py | 70 +++++++++++++++-----------
 1 file changed, 42 insertions(+), 28 deletions(-)

diff --git a/src/httpaste/backend/mysql/__init__.py b/src/httpaste/backend/mysql/__init__.py
index 2a21162..abda80c 100644
--- a/src/httpaste/backend/mysql/__init__.py
+++ b/src/httpaste/backend/mysql/__init__.py
@@ -1,19 +1,6 @@
 """MySQL backend
 """
-try:
-    from mysql.connector import connect
-    from mysql.connector.connection import MySQLConnection
-except ImportError as e:
-    raise ImportError(' '.join((
-        '\'mysql-connector-python\' is not installed.',
-        'Install it by running',
-        '\'python3 -m pip install mysql-connector-python\'.'
-    ))) from e
-
-from typing import NamedTuple, Optional
-
-from . import user
-from . import paste
+from typing import NamedTuple, Optional, Callable
 
 
 class Parameters(NamedTuple):
@@ -29,65 +16,77 @@ class Parameters(NamedTuple):
     #: database identifier
     database: str
     #: a mysql.connection.MySQLConnection object (does not apply to config)
-    connection: Optional[MySQLConnection] = None
+    connection: Optional[object] = None
 
 
 class User(object):
     """MySQL user model backend
     """
 
-    connection: MySQLConnection
+    connection: object
 
     def __init__(self, parameters: Parameters, model_class: type) -> None:
 
+        from . import user
+
+        connect = get_mysql_connect_callee()
+
+        self.interface = user
+
         self.model_class = model_class
 
         self.connection = get_connection(parameters)
 
     def load(self, proto: object) -> object:
 
-        return user.load(proto, self.connection, self.model_class)
+        return self.interface.load(proto, self.connection, self.model_class)
 
     def dump(self, model: object) -> None:
 
-        return user.dump(model, self.connection)
+        return self.interface.dump(model, self.connection)
 
     def delete(self, proto: object) -> None:
 
-        return user.delete(proto, self.connection)
+        return self.interface.delete(proto, self.connection)
 
     def init(self) -> None:
 
-        return user.init(self.connection)
+        return self.interface.init(self.connection)
 
     def sanitize(self) -> None:
 
-        return user.sanitize(self.connection, self.model_class)
+        return self.interface.sanitize(self.connection, self.model_class)
 
 
 class Paste(object):
     """MySQL paste model backend
     """
 
-    connection: MySQLConnection
+    connection: object
 
     def __init__(self, parameters: Parameters, model_class: type) -> None:
 
+        from . import paste
+
+        connect = get_mysql_connect_callee()
+
+        self.interface = paste
+
         self.model_class = model_class
 
-        self.connection = get_connection(parameters)
+        self.connection = get_connection(parameters, connect)
 
     def load(self, proto: object) -> object:
 
-        return paste.load(proto, self.connection, self.model_class)
+        return self.interface.load(proto, self.connection, self.model_class)
 
     def dump(self, model: object) -> None:
 
-        return paste.dump(model, self.connection)
+        return self.interface.dump(model, self.connection)
 
     def delete(self, proto: object) -> None:
 
-        return paste.delete(proto, self.connection)
+        return self.interface.delete(proto, self.connection)
 
     def init(self) -> None:
 
@@ -95,10 +94,25 @@ class Paste(object):
 
     def sanitize(self) -> None:
 
-        return paste.sanitize(self.connection, self.model_class)
+        return self.interface.sanitize(self.connection, self.model_class)
 
 
-def get_connection(parameters: Parameters) -> MySQLConnection:
+def get_mysql_connect_callee() -> object:
+
+    try:
+        from mysql.connector import connect
+        from mysql.connector.connection import MySQLConnection
+    except ImportError as e:
+        raise ImportError(' '.join((
+            '\'mysql-connector-python\' is not installed.',
+            'Install it by running',
+            '\'python3 -m pip install mysql-connector-python\'.'
+        ))) from e
+
+    return connect
+
+
+def get_connection(parameters: Parameters, connect_callee: Callable) -> object:
     """get a mysql.connection.MySQLConnection object
     """