"""Turnstone database abstraction — unified SQLite / Postgres interface.

Public API:
    BACKEND          — Backend.SQLITE or Backend.POSTGRES
    get_conn(path)   — context manager yielding a DbConn
    resolve_tenant_id() — this node's tenant ID (env or hostname)
    q(sql)           — rewrite ? placeholders to %s for Postgres
    frag             — SQL fragment helpers (insert_or_ignore, source_group_expr, …)
    ensure_schema    — idempotent schema init
    close_pool       — call during shutdown when using Postgres
"""
from app.db.backend import BACKEND, Backend
from app.db.conn import DbConn, close_pool, get_conn
from app.db.dialect import frag, q
from app.db.schema import (
    ensure_context_schema,
    ensure_incidents_schema,
    ensure_schema,
    migrate_incidents_to_dedicated_db,
)
from app.db.tenant import resolve_tenant_id

__all__ = [
    "BACKEND",
    "Backend",
    "DbConn",
    "close_pool",
    "get_conn",
    "frag",
    "q",
    "ensure_schema",
    "ensure_context_schema",
    "ensure_incidents_schema",
    "migrate_incidents_to_dedicated_db",
    "resolve_tenant_id",
]