chore: initial project scaffold and gitignore

app/db/migrations.py

@@ -0,0 +1,81 @@
+"""Alembic helpers for PortfolioHub database migrations."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from alembic import command
+from alembic.config import Config
+import psycopg
+
+from app.core.config import Settings
+
+
+def get_alembic_config(settings: Settings) -> Config:
+    project_root = Path(__file__).resolve().parents[2]
+    config = Config(str(project_root / "alembic.ini"))
+    config.set_main_option("script_location", str(project_root / "migrations"))
+    config.set_main_option("sqlalchemy.url", settings.active_database_url.replace("%", "%%"))
+    return config
+
+
+def upgrade_to_head(settings: Settings) -> None:
+    command.upgrade(get_alembic_config(settings), "head")
+
+
+def bootstrap_or_upgrade_to_head(settings: Settings) -> str:
+    if _has_alembic_version_table(settings):
+        upgrade_to_head(settings)
+        return "head"
+
+    if _has_legacy_portfolio_schema(settings):
+        command.stamp(get_alembic_config(settings), "head")
+        return "head"
+
+    upgrade_to_head(settings)
+    return "head"
+
+
+def current_revision(settings: Settings) -> str | None:
+    output: list[str] = []
+
+    def capture(message: str, *_args, **_kwargs) -> None:
+        if message.strip():
+            output.append(message.strip())
+
+    config = get_alembic_config(settings)
+    command.current(config, verbose=False)
+    return output[-1] if output else None
+
+
+def _connect(settings: Settings) -> psycopg.Connection:
+    return psycopg.connect(
+        host=settings.active_db_host,
+        port=settings.active_db_port,
+        dbname=settings.active_db_name,
+        user=settings.active_db_user,
+        password=settings.active_db_password,
+        sslmode=settings.active_db_sslmode,
+        connect_timeout=settings.active_db_connect_timeout_sec,
+        application_name=settings.active_db_application_name,
+        autocommit=True,
+    )
+
+
+def _has_alembic_version_table(settings: Settings) -> bool:
+    with _connect(settings) as conn:
+        with conn.cursor() as cur:
+            cur.execute("SELECT to_regclass('public.alembic_version')")
+            return cur.fetchone()[0] is not None
+
+
+def _has_legacy_portfolio_schema(settings: Settings) -> bool:
+    required_tables = {"strategy_sets", "portfolios", "portfolio_ledger"}
+    with _connect(settings) as conn:
+        with conn.cursor() as cur:
+            cur.execute(
+                "SELECT tablename FROM pg_tables WHERE schemaname = 'public' AND tablename = ANY(%s)",
+                (list(required_tables),),
+            )
+            found = {row[0] for row in cur.fetchall()}
+    return found == required_tables