Stav 23.06.2026

postgres_service.py

@@ -0,0 +1,95 @@
+from __future__ import annotations
+
+from contextlib import contextmanager
+
+import data
+
+
+class PostgresServiceError(Exception):
+    pass
+
+
+def _load_driver():
+    try:
+        import psycopg
+        return "psycopg", psycopg
+    except Exception:
+        pass
+    try:
+        import psycopg2
+        return "psycopg2", psycopg2
+    except Exception as e:
+        raise PostgresServiceError("Nie je nainstalovany PostgreSQL driver psycopg ani psycopg2.") from e
+
+
+def is_configured(conn: data.PostgresConnection) -> bool:
+    return bool(
+        conn.host.strip()
+        and conn.database.strip()
+        and conn.user.strip()
+        and int(conn.port or 0) > 0
+    )
+
+
+def connection_kwargs(conn: data.PostgresConnection) -> dict:
+    kwargs = {
+        "host": conn.host,
+        "port": int(conn.port or 5432),
+        "dbname": conn.database,
+        "user": conn.user,
+        "password": conn.password,
+        "connect_timeout": int(conn.connect_timeout or 5),
+    }
+    if conn.sslmode:
+        kwargs["sslmode"] = conn.sslmode
+    return kwargs
+
+
+def test_connection(conn: data.PostgresConnection) -> None:
+    if not conn.enabled:
+        raise PostgresServiceError("PostgreSQL pripojenie nie je povolene pre instalaciu.")
+    if not is_configured(conn):
+        raise PostgresServiceError("PostgreSQL pripojenie nie je vyplnene.")
+    driver_name, driver = _load_driver()
+    try:
+        pg = driver.connect(**connection_kwargs(conn))
+        try:
+            cur = pg.cursor()
+            try:
+                cur.execute("SELECT 1")
+                cur.fetchone()
+            finally:
+                cur.close()
+        finally:
+            pg.close()
+    except Exception as e:
+        raise PostgresServiceError(f"PostgreSQL spojenie zlyhalo ({driver_name}): {e}") from e
+
+
+def open_connection(conn: data.PostgresConnection):
+    if not conn.enabled:
+        raise PostgresServiceError("PostgreSQL pripojenie nie je povolene pre instalaciu.")
+    if not is_configured(conn):
+        raise PostgresServiceError("PostgreSQL pripojenie nie je vyplnene.")
+    driver_name, driver = _load_driver()
+    try:
+        return driver.connect(**connection_kwargs(conn))
+    except Exception as e:
+        raise PostgresServiceError(f"PostgreSQL spojenie zlyhalo ({driver_name}): {e}") from e
+
+
+@contextmanager
+def connect(conn: data.PostgresConnection):
+    if not conn.enabled:
+        raise PostgresServiceError("PostgreSQL pripojenie nie je povolene pre instalaciu.")
+    if not is_configured(conn):
+        raise PostgresServiceError("PostgreSQL pripojenie nie je vyplnene.")
+    driver_name, driver = _load_driver()
+    try:
+        pg = driver.connect(**connection_kwargs(conn))
+    except Exception as e:
+        raise PostgresServiceError(f"PostgreSQL spojenie zlyhalo ({driver_name}): {e}") from e
+    try:
+        yield pg
+    finally:
+        pg.close()