email_server: aliases: Minor refactoring

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/email_server/aliases/__init__.py

@@ -9,38 +9,27 @@ from plinth import actions
 
 from . import models
 
-map_db_schema_script = """
-PRAGMA journal_mode=WAL;
-BEGIN;
-CREATE TABLE IF NOT EXISTS Alias (
-    email_name TEXT NOT NULL,
-    uid_number INTEGER NOT NULL,
-    status INTEGER NOT NULL,
-    PRIMARY KEY (email_name)
-);
-COMMIT;
-"""
-
-sqlite_db_path = '/var/lib/postfix/freedombox-aliases/aliases.sqlite3'
-
 
 @contextlib.contextmanager
-def db_cursor():
+def _get_cursor():
+    """Return a DB cursor as context manager."""
     # Turn ON autocommit mode
-    con = sqlite3.connect(sqlite_db_path, isolation_level=None)
-    con.row_factory = sqlite3.Row
+    db_path = '/var/lib/postfix/freedombox-aliases/aliases.sqlite3'
+    connection = sqlite3.connect(db_path, isolation_level=None)
+    connection.row_factory = sqlite3.Row
     try:
-        cur = con.cursor()
-        yield cur
+        cursor = connection.cursor()
+        yield cursor
     finally:
-        con.close()
+        connection.close()
 
 
 def get(uid_number):
-    s = 'SELECT * FROM Alias WHERE uid_number=?'
-    with db_cursor() as cur:
-        rows = cur.execute(s, (uid_number, ))
-        result = [models.Alias(**r) for r in rows]
+    """Get all aliases of a user."""
+    query = 'SELECT * FROM Alias WHERE uid_number=?'
+    with _get_cursor() as cursor:
+        rows = cursor.execute(query, (uid_number, ))
+        result = [models.Alias(**row) for row in rows]
         return result
 
 
@@ -52,53 +41,69 @@ def exists(email_name):
     except KeyError:
         pass
 
-    with db_cursor() as cur:
+    with _get_cursor() as cursor:
         query = 'SELECT COUNT(*) FROM Alias WHERE email_name=?'
-        cur.execute(query, (email_name, ))
-        return cur.fetchone()[0] != 0
+        cursor.execute(query, (email_name, ))
+        return cursor.fetchone()[0] != 0
 
 
 def put(uid_number, email_name):
-    s = """INSERT INTO Alias(email_name, uid_number, status)
-    SELECT ?,?,? WHERE NOT EXISTS(
+    """Insert if not exists a new alias."""
+    query = '''
+INSERT INTO Alias(email_name, uid_number, status)
+    SELECT ?,?,? WHERE NOT EXISTS (
         SELECT 1 FROM Alias WHERE email_name=?
-    )"""
-    with db_cursor() as cur:
-        cur.execute(s, (email_name, uid_number, 1, email_name))
+    )
+'''
+    with _get_cursor() as cursor:
+        cursor.execute(query, (email_name, uid_number, 1, email_name))
 
 
 def delete(uid_number, alias_list):
-    s = 'DELETE FROM Alias WHERE uid_number=? AND email_name=?'
-    parameter_seq = ((uid_number, a) for a in alias_list)
-    with db_cursor() as cur:
-        cur.execute('BEGIN')
-        cur.executemany(s, parameter_seq)
-        cur.execute('COMMIT')
+    """Delete a set of aliases."""
+    query = 'DELETE FROM Alias WHERE uid_number=? AND email_name=?'
+    parameter_seq = ((uid_number, alias) for alias in alias_list)
+    with _get_cursor() as cursor:
+        cursor.execute('BEGIN')
+        cursor.executemany(query, parameter_seq)
+        cursor.execute('COMMIT')
 
 
-def set_enabled(uid_number, alias_list):
+def enable(uid_number, alias_list):
+    """Enable a list of aliases."""
     return _set_status(uid_number, alias_list, 1)
 
 
-def set_disabled(uid_number, alias_list):
+def disable(uid_number, alias_list):
+    """Disable a list of aliases."""
     return _set_status(uid_number, alias_list, 0)
 
 
 def _set_status(uid_number, alias_list, status):
-    s = 'UPDATE Alias SET status=? WHERE uid_number=? AND email_name=?'
-    parameter_seq = ((status, uid_number, a) for a in alias_list)
-    with db_cursor() as cur:
-        cur.execute('BEGIN')
-        cur.executemany(s, parameter_seq)
-        cur.execute('COMMIT')
+    """Set the status value of a list of aliases."""
+    query = 'UPDATE Alias SET status=? WHERE uid_number=? AND email_name=?'
+    parameter_seq = ((status, uid_number, alias) for alias in alias_list)
+    with _get_cursor() as cursor:
+        cursor.execute('BEGIN')
+        cursor.executemany(query, parameter_seq)
+        cursor.execute('COMMIT')
 
 
 def first_setup():
+    """Create the database file and schema inside it."""
     actions.superuser_run('email_server', ['-i', 'aliases', 'setup'])
-    _create_db_schema_if_not_exists()
 
-
-def _create_db_schema_if_not_exists():
     # Create schema if not exists
-    with db_cursor() as cur:
-        cur.executescript(map_db_schema_script)
+    query = '''
+PRAGMA journal_mode=WAL;
+BEGIN;
+CREATE TABLE IF NOT EXISTS Alias (
+    email_name TEXT NOT NULL,
+    uid_number INTEGER NOT NULL,
+    status INTEGER NOT NULL,
+    PRIMARY KEY (email_name)
+);
+COMMIT;
+'''
+    with _get_cursor() as cursor:
+        cursor.executescript(query)

plinth/modules/email_server/views.py

@@ -203,9 +203,9 @@ class AliasView(FormView):
         if action == 'delete':
             aliases_module.delete(uid, alias_list)
         elif action == 'disable':
-            aliases_module.set_disabled(uid, alias_list)
+            aliases_module.disable(uid, alias_list)
         elif action == 'enable':
-            aliases_module.set_enabled(uid, alias_list)
+            aliases_module.enable(uid, alias_list)
 
     def _create_form_valid(self, form):
         """Handle a valid create alias form operation."""