1 files changed, 64 insertions, 0 deletions
diff --git a/src/DatabaseEngines.py b/src/DatabaseEngines.py
new file mode 100644
index 00000000..165e64d5
--- /dev/null
+++ b/src/DatabaseEngines.py
@@ -0,0 +1,64 @@
+import dataclasses, typing
+import sqlite3
+
+class DatabaseEngineCursor(object):
+    def execute(self, query: str, args: typing.List[str]):
+        pass
+    def fetchone(self) -> typing.Any:
+        pass
+    def fetchall(self) -> typing.List[typing.Any]:
+        pass
+
+class DatabaseEngine(object):
+    def config(self, hostname: str=None, port: int=None, path: str=None,
+            username: str=None, password: str=None):
+        self.hostname = hostname
+        self.port = port
+        self.path = path
+        self.username = username
+        self.password = password
+
+    def database_name(self):
+        return self.path
+    def connect(self):
+        pass
+    def cursor(self) -> DatabaseEngineCursor:
+        pass
+    def has_table(self, name: str):
+        pass
+
+    def execute(self, query: str, args: typing.List[str]):
+        pass
+    def fetchone(self, query: str, args: typing.List[str]):
+        pass
+    def fetchall(self, query: str, args: typing.List[str]):
+        pass
+
+class SQLite3Cursor(DatabaseEngineCursor):
+    def __init__(self, cursor: sqlite3.Cursor):
+        self._cursor = cursor
+    def execute(self, query: str, args: typing.List[str]):
+        self._cursor.execute(query, args)
+    def fetchone(self):
+        return self._cursor.fetchone()
+    def fetchall(self):
+        return self._cursor.fetchall()
+class SQLite3Engine(DatabaseEngine):
+    _connection: sqlite3.Connection
+
+    def connect(self):
+        sqlite3.register_converter("BOOLEAN", lambda v: bool(int(v)))
+        self._connection = sqlite3.connect(self.path,
+            check_same_thread=False, isolation_level=None,
+            detect_types=sqlite3.PARSE_DECLTYPES)
+        self._connection.execute("PRAGMA foreign_keys = ON")
+
+    def has_table(self, name: str):
+        cursor = self.cursor()
+        cursor.execute(
+            "SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name=?",
+            [name])
+        return cursor.fetchone()[0] == 1
+
+    def cursor(self):
+        return SQLite3Cursor(self._connection.cursor())