from __future__ import annotations

from collections.abc import Iterable

from sqlalchemy import text
from sqlalchemy.orm import Session

from app.config import settings


POSTGIS_GEOMETRY_TABLES = {
    "osm_features",
    "gtfs_routes",
    "gtfs_shapes",
    "gtfs_stops",
    "canonical_stops",
    "route_patterns",
    "osm_addresses",
    "routing_nodes",
    "routing_edges",
}


def using_postgresql() -> bool:
    return settings.is_postgresql_database


def refresh_postgis_geometries(
    session: Session,
    *,
    dataset_id: int | None = None,
    tables: Iterable[str] | None = None,
    only_missing: bool = True,
) -> None:
    if not using_postgresql():
        return
    selected = set(tables or POSTGIS_GEOMETRY_TABLES)
    unknown = selected - POSTGIS_GEOMETRY_TABLES
    if unknown:
        raise ValueError(f"Unsupported PostGIS geometry table(s): {', '.join(sorted(unknown))}")

    if "osm_features" in selected:
        _refresh_geojson_geometry(session, "osm_features", dataset_id=dataset_id, only_missing=only_missing)
    if "gtfs_routes" in selected:
        _refresh_geojson_geometry(session, "gtfs_routes", dataset_id=dataset_id, only_missing=only_missing)
    if "gtfs_shapes" in selected:
        _refresh_geojson_geometry(session, "gtfs_shapes", dataset_id=dataset_id, only_missing=only_missing)
    if "route_patterns" in selected:
        _refresh_geojson_geometry(session, "route_patterns", dataset_id=None, only_missing=only_missing)
    if "osm_addresses" in selected:
        _refresh_address_geometry(session, dataset_id=dataset_id, only_missing=only_missing)
    if "gtfs_stops" in selected:
        _refresh_point_geometry(session, "gtfs_stops", dataset_id=dataset_id, only_missing=only_missing)
    if "canonical_stops" in selected:
        _refresh_point_geometry(session, "canonical_stops", dataset_id=None, only_missing=only_missing)
    if "routing_nodes" in selected:
        _refresh_point_geometry(session, "routing_nodes", dataset_id=dataset_id, only_missing=only_missing)
    if "routing_edges" in selected:
        _refresh_routing_edge_geometry(session, dataset_id=dataset_id, only_missing=only_missing)


def analyze_postgresql_tables(session: Session, tables: Iterable[str]) -> None:
    if not using_postgresql():
        return
    for table in tables:
        session.execute(text(f"ANALYZE {table}"))


def _refresh_geojson_geometry(session: Session, table: str, *, dataset_id: int | None, only_missing: bool) -> None:
    where = ["geometry_geojson IS NOT NULL", "geometry_geojson <> ''"]
    params: dict[str, object] = {}
    if dataset_id is not None:
        where.append("dataset_id = :dataset_id")
        params["dataset_id"] = int(dataset_id)
    if only_missing:
        where.append("geom IS NULL")
    session.execute(
        text(
            f"""
            UPDATE {table}
            SET geom = ST_SetSRID(ST_GeomFromGeoJSON(geometry_geojson), 4326)
            WHERE {" AND ".join(where)}
            """
        ),
        params,
    )


def _refresh_point_geometry(session: Session, table: str, *, dataset_id: int | None, only_missing: bool) -> None:
    where = ["lon IS NOT NULL", "lat IS NOT NULL"]
    params: dict[str, object] = {}
    if dataset_id is not None:
        where.append("dataset_id = :dataset_id")
        params["dataset_id"] = int(dataset_id)
    if only_missing:
        where.append("geom IS NULL")
    session.execute(
        text(
            f"""
            UPDATE {table}
            SET geom = ST_SetSRID(ST_MakePoint(lon, lat), 4326)
            WHERE {" AND ".join(where)}
            """
        ),
        params,
    )


def _refresh_address_geometry(session: Session, *, dataset_id: int | None, only_missing: bool) -> None:
    _refresh_point_geometry(session, "osm_addresses", dataset_id=dataset_id, only_missing=only_missing)
    where = ["geometry_geojson IS NOT NULL", "geometry_geojson <> ''"]
    params: dict[str, object] = {}
    if dataset_id is not None:
        where.append("dataset_id = :dataset_id")
        params["dataset_id"] = int(dataset_id)
    if only_missing:
        where.append("area_geom IS NULL")
    session.execute(
        text(
            f"""
            UPDATE osm_addresses
            SET area_geom = ST_SetSRID(ST_GeomFromGeoJSON(geometry_geojson), 4326)
            WHERE {" AND ".join(where)}
            """
        ),
        params,
    )


def _refresh_routing_edge_geometry(session: Session, *, dataset_id: int | None, only_missing: bool) -> None:
    where = [
        "source_lon IS NOT NULL",
        "source_lat IS NOT NULL",
        "target_lon IS NOT NULL",
        "target_lat IS NOT NULL",
    ]
    params: dict[str, object] = {}
    if dataset_id is not None:
        where.append("dataset_id = :dataset_id")
        params["dataset_id"] = int(dataset_id)
    if only_missing:
        where.append("geom IS NULL")
    session.execute(
        text(
            f"""
            UPDATE routing_edges
            SET geom = ST_SetSRID(
                ST_MakeLine(
                    ST_MakePoint(source_lon, source_lat),
                    ST_MakePoint(target_lon, target_lat)
                ),
                4326
            )
            WHERE {" AND ".join(where)}
            """
        ),
        params,
    )