From 7b5f854d510c65c8b9932f48cf255a5dc257a47c Mon Sep 17 00:00:00 2001
From: Ferdinand Thiessen <rpm@fthiessen.de>
Date: Thu, 27 May 2021 01:27:53 +0200
Subject: [PATCH] [db] Support sqlite and postgresql as engine, fixes #5

mysql / mariadb still is the only tested configuration.
This will break existing databases, as UTF8MB4 is enforced for
mysql (real UTF8).
---
 flaschengeist/config.py          | 29 +++++++++++++++++++++--------
 flaschengeist/flaschengeist.toml |  1 +
 flaschengeist/models/__init__.py |  4 ++--
 3 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/flaschengeist/config.py b/flaschengeist/config.py
index ed74470..9820e9e 100644
--- a/flaschengeist/config.py
+++ b/flaschengeist/config.py
@@ -9,7 +9,7 @@ from flaschengeist import _module_path, logger
 
 
 # Default config:
-config = {"DATABASE": {"port": 3306}}
+config = {"DATABASE": {"engine": "mysql", "port": 3306}}
 
 
 def update_dict(d, u):
@@ -65,17 +65,30 @@ def configure_app(app, test_config=None):
     else:
         app.config["SECRET_KEY"] = config["FLASCHENGEIST"]["secret_key"]
 
-    if test_config is None:
-        app.config["SQLALCHEMY_DATABASE_URI"] = "mysql{driver}://{user}:{passwd}@{host}:{port}/{database}".format(
-            driver="+pymysql" if os.name == "nt" else "",
+    if test_config is not None:
+        config["DATABASE"]["engine"] = "sqlite"
+
+    if config["DATABASE"]["engine"] == "mysql":
+        engine = "mysql" + ("+pymysql" if os.name == "nt" else "")
+        options = "?charset=utf8mb4"
+    elif config["DATABASE"]["engine"] == "postgres":
+        engine = "postgresql+psycopg2"
+        options = "?client_encoding=utf8"
+    elif config["DATABASE"]["engine"] == "sqlite":
+        engine = "sqlite"
+        options = ""
+        host = ""
+    else:
+        logger.error(f"Invalid database engine configured. >{config['DATABASE']['engine']}< is unknown")
+        raise Exception
+    if config["DATABASE"]["engine"] in ["mysql", "postgresql"]:
+        host = "{user}:{password}@{host}:{port}".format(
             user=config["DATABASE"]["user"],
-            passwd=config["DATABASE"]["password"],
+            password=config["DATABASE"]["password"],
             host=config["DATABASE"]["host"],
-            database=config["DATABASE"]["database"],
             port=config["DATABASE"]["port"],
         )
-    else:
-        app.config["SQLALCHEMY_DATABASE_URI"] = f"sqlite+pysqlite://{config['DATABASE']['file_path']}"
+    app.config["SQLALCHEMY_DATABASE_URI"] = f"{engine}://{host}/{config['DATABASE']['database']}{options}"
     app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
 
     if "root" in config["FLASCHENGEIST"]:
diff --git a/flaschengeist/flaschengeist.toml b/flaschengeist/flaschengeist.toml
index 0ec50a0..ffbb51d 100644
--- a/flaschengeist/flaschengeist.toml
+++ b/flaschengeist/flaschengeist.toml
@@ -20,6 +20,7 @@ secret_key = "V3ryS3cr3t"
 level = "WARNING"
 
 [DATABASE]
+# engine = "mysql" (default)
 # user = "user"
 # host = "127.0.0.1"
 # password = "password"
diff --git a/flaschengeist/models/__init__.py b/flaschengeist/models/__init__.py
index f63d173..1b503dd 100644
--- a/flaschengeist/models/__init__.py
+++ b/flaschengeist/models/__init__.py
@@ -2,7 +2,7 @@ import sys
 import datetime
 
 from sqlalchemy import BigInteger
-from sqlalchemy.dialects import mysql
+from sqlalchemy.dialects import mysql, sqlite
 from sqlalchemy.types import DateTime, TypeDecorator
 
 
@@ -44,7 +44,7 @@ class ModelSerializeMixin:
 class Serial(TypeDecorator):
     """Same as MariaDB Serial used for IDs"""
 
-    impl = BigInteger().with_variant(mysql.BIGINT(unsigned=True), "mysql")
+    impl = BigInteger().with_variant(mysql.BIGINT(unsigned=True), "mysql").with_variant(sqlite.INTEGER, "sqlite")
 
 
 class UtcDateTime(TypeDecorator):