python lookup: add function for simple lookups

diff --git a/nominatim/api/lookup.py b/nominatim/api/lookup.py
index 5c54da4a1823209a9dcede95a7f3fd730b957a4d..823527025d59c65baa729d620cd95ca10ab50d72 100644 (file)
--- a/nominatim/api/lookup.py
+++ b/nominatim/api/lookup.py
@@ -12,7 +12,7 @@ import datetime as dt
 
 import sqlalchemy as sa
 
-from nominatim.typing import SaColumn, SaLabel, SaRow
+from nominatim.typing import SaColumn, SaRow, SaSelect
 from nominatim.api.connection import SearchConnection
 import nominatim.api.types as ntyp
 import nominatim.api.results as nres
@@ -20,23 +20,12 @@ from nominatim.api.logging import log
 
 RowFunc = Callable[[Optional[SaRow], Type[nres.BaseResultT]], Optional[nres.BaseResultT]]
 
-def _select_column_geometry(column: SaColumn,
-                            geometry_output: ntyp.GeometryFormat) -> SaLabel:
-    """ Create the appropriate column expression for selecting a
-        geometry for the details response.
-    """
-    if geometry_output & ntyp.GeometryFormat.GEOJSON:
-        return sa.literal_column(f"""
-                  ST_AsGeoJSON(CASE WHEN ST_NPoints({column.name}) > 5000
-                               THEN ST_SimplifyPreserveTopology({column.name}, 0.0001)
-                               ELSE {column.name} END)
-                  """).label('geometry_geojson')
+GeomFunc = Callable[[SaSelect, SaColumn], SaSelect]
 
-    return sa.func.ST_GeometryType(column).label('geometry_type')
 
 
 async def find_in_placex(conn: SearchConnection, place: ntyp.PlaceRef,
-                         details: ntyp.LookupDetails) -> Optional[SaRow]:
+                         add_geometries: GeomFunc) -> Optional[SaRow]:
     """ Search for the given place in the placex table and return the
         base information.
     """
@@ -49,8 +38,7 @@ async def find_in_placex(conn: SearchConnection, place: ntyp.PlaceRef,
                     t.c.importance, t.c.wikipedia, t.c.indexed_date,
                     t.c.parent_place_id, t.c.rank_address, t.c.rank_search,
                     t.c.linked_place_id,
-                    t.c.centroid,
-                    _select_column_geometry(t.c.geometry, details.geometry_output))
+                    t.c.centroid)
 
     if isinstance(place, ntyp.PlaceID):
         sql = sql.where(t.c.place_id == place.place_id)
@@ -65,11 +53,11 @@ async def find_in_placex(conn: SearchConnection, place: ntyp.PlaceRef,
     else:
         return None
 
-    return (await conn.execute(sql)).one_or_none()
+    return (await conn.execute(add_geometries(sql, t.c.geometry))).one_or_none()
 
 
 async def find_in_osmline(conn: SearchConnection, place: ntyp.PlaceRef,
-                          details: ntyp.LookupDetails) -> Optional[SaRow]:
+                          add_geometries: GeomFunc) -> Optional[SaRow]:
     """ Search for the given place in the osmline table and return the
         base information.
     """
@@ -78,8 +66,7 @@ async def find_in_osmline(conn: SearchConnection, place: ntyp.PlaceRef,
     sql = sa.select(t.c.place_id, t.c.osm_id, t.c.parent_place_id,
                     t.c.indexed_date, t.c.startnumber, t.c.endnumber,
                     t.c.step, t.c.address, t.c.postcode, t.c.country_code,
-                    t.c.linegeo.ST_Centroid().label('centroid'),
-                    _select_column_geometry(t.c.linegeo, details.geometry_output))
+                    t.c.linegeo.ST_Centroid().label('centroid'))
 
     if isinstance(place, ntyp.PlaceID):
         sql = sql.where(t.c.place_id == place.place_id)
@@ -94,14 +81,17 @@ async def find_in_osmline(conn: SearchConnection, place: ntyp.PlaceRef,
     else:
         return None
 
-    return (await conn.execute(sql)).one_or_none()
+    return (await conn.execute(add_geometries(sql, t.c.linegeo))).one_or_none()
 
 
 async def find_in_tiger(conn: SearchConnection, place: ntyp.PlaceRef,
-                        details: ntyp.LookupDetails) -> Optional[SaRow]:
+                        add_geometries: GeomFunc) -> Optional[SaRow]:
     """ Search for the given place in the table of Tiger addresses and return
         the base information. Only lookup by place ID is supported.
     """
+    if not isinstance(place, ntyp.PlaceID):
+        return None
+
     log().section("Find in TIGER table")
     t = conn.t.tiger
     parent = conn.t.placex
@@ -109,61 +99,54 @@ async def find_in_tiger(conn: SearchConnection, place: ntyp.PlaceRef,
                     parent.c.osm_type, parent.c.osm_id,
                     t.c.startnumber, t.c.endnumber, t.c.step,
                     t.c.postcode,
-                    t.c.linegeo.ST_Centroid().label('centroid'),
-                    _select_column_geometry(t.c.linegeo, details.geometry_output))
-
-    if isinstance(place, ntyp.PlaceID):
-        sql = sql.where(t.c.place_id == place.place_id)\
-                 .join(parent, t.c.parent_place_id == parent.c.place_id, isouter=True)
-    else:
-        return None
+                    t.c.linegeo.ST_Centroid().label('centroid'))\
+            .where(t.c.place_id == place.place_id)\
+            .join(parent, t.c.parent_place_id == parent.c.place_id, isouter=True)
 
-    return (await conn.execute(sql)).one_or_none()
+    return (await conn.execute(add_geometries(sql, t.c.linegeo))).one_or_none()
 
 
 async def find_in_postcode(conn: SearchConnection, place: ntyp.PlaceRef,
-                           details: ntyp.LookupDetails) -> Optional[SaRow]:
+                           add_geometries: GeomFunc) -> Optional[SaRow]:
     """ Search for the given place in the postcode table and return the
         base information. Only lookup by place ID is supported.
     """
+    if not isinstance(place, ntyp.PlaceID):
+        return None
+
     log().section("Find in postcode table")
     t = conn.t.postcode
     sql = sa.select(t.c.place_id, t.c.parent_place_id,
                     t.c.rank_search, t.c.rank_address,
                     t.c.indexed_date, t.c.postcode, t.c.country_code,
-                    t.c.geometry.label('centroid'),
-                    _select_column_geometry(t.c.geometry, details.geometry_output))
+                    t.c.geometry.label('centroid')) \
+            .where(t.c.place_id == place.place_id)
 
-    if isinstance(place, ntyp.PlaceID):
-        sql = sql.where(t.c.place_id == place.place_id)
-    else:
-        return None
-
-    return (await conn.execute(sql)).one_or_none()
+    return (await conn.execute(add_geometries(sql, t.c.geometry))).one_or_none()
 
 
 async def find_in_all_tables(conn: SearchConnection, place: ntyp.PlaceRef,
-                             details: ntyp.LookupDetails
+                             add_geometries: GeomFunc
                             ) -> Tuple[Optional[SaRow], RowFunc[nres.BaseResultT]]:
     """ Search for the given place in all data tables
         and return the base information.
     """
-    row = await find_in_placex(conn, place, details)
+    row = await find_in_placex(conn, place, add_geometries)
     log().var_dump('Result (placex)', row)
     if row is not None:
         return row, nres.create_from_placex_row
 
-    row = await find_in_osmline(conn, place, details)
+    row = await find_in_osmline(conn, place, add_geometries)
     log().var_dump('Result (osmline)', row)
     if row is not None:
         return row, nres.create_from_osmline_row
 
-    row = await find_in_postcode(conn, place, details)
+    row = await find_in_postcode(conn, place, add_geometries)
     log().var_dump('Result (postcode)', row)
     if row is not None:
         return row, nres.create_from_postcode_row
 
-    row = await find_in_tiger(conn, place, details)
+    row = await find_in_tiger(conn, place, add_geometries)
     log().var_dump('Result (tiger)', row)
     return row, nres.create_from_tiger_row
 
@@ -172,13 +155,24 @@ async def get_detailed_place(conn: SearchConnection, place: ntyp.PlaceRef,
                              details: ntyp.LookupDetails) -> Optional[nres.DetailedResult]:
     """ Retrieve a place with additional details from the database.
     """
-    log().function('get_place_by_id', place=place, details=details)
+    log().function('get_detailed_place', place=place, details=details)
 
     if details.geometry_output and details.geometry_output != ntyp.GeometryFormat.GEOJSON:
         raise ValueError("lookup only supports geojosn polygon output.")
 
+    if details.geometry_output & ntyp.GeometryFormat.GEOJSON:
+        def _add_geometry(sql: SaSelect, column: SaColumn) -> SaSelect:
+            return sql.add_columns(sa.literal_column(f"""
+                      ST_AsGeoJSON(CASE WHEN ST_NPoints({column.name}) > 5000
+                                   THEN ST_SimplifyPreserveTopology({column.name}, 0.0001)
+                                   ELSE {column.name} END)
+                       """).label('geometry_geojson'))
+    else:
+        def _add_geometry(sql: SaSelect, column: SaColumn) -> SaSelect:
+            return sql.add_columns(sa.func.ST_GeometryType(column).label('geometry_type'))
+
     row_func: RowFunc[nres.DetailedResult]
-    row, row_func = await find_in_all_tables(conn, place, details)
+    row, row_func = await find_in_all_tables(conn, place, _add_geometry)
 
     if row is None:
         return None
@@ -198,3 +192,48 @@ async def get_detailed_place(conn: SearchConnection, place: ntyp.PlaceRef,
     await nres.add_result_details(conn, result, details)
 
     return result
+
+
+async def get_simple_place(conn: SearchConnection, place: ntyp.PlaceRef,
+                             details: ntyp.LookupDetails) -> Optional[nres.SearchResult]:
+    """ Retrieve a place as a simple search result from the database.
+    """
+    log().function('get_simple_place', place=place, details=details)
+
+    def _add_geometry(sql: SaSelect, col: SaColumn) -> SaSelect:
+        if not details.geometry_output:
+            return sql
+
+        out = []
+
+        if details.geometry_simplification > 0.0:
+            col = col.ST_SimplifyPreserveTopology(details.geometry_simplification)
+
+        if details.geometry_output & ntyp.GeometryFormat.GEOJSON:
+            out.append(col.ST_AsGeoJSON().label('geometry_geojson'))
+        if details.geometry_output & ntyp.GeometryFormat.TEXT:
+            out.append(col.ST_AsText().label('geometry_text'))
+        if details.geometry_output & ntyp.GeometryFormat.KML:
+            out.append(col.ST_AsKML().label('geometry_kml'))
+        if details.geometry_output & ntyp.GeometryFormat.SVG:
+            out.append(col.ST_AsSVG().label('geometry_svg'))
+
+        return sql.add_columns(*out)
+
+
+    row_func: RowFunc[nres.SearchResult]
+    row, row_func = await find_in_all_tables(conn, place, _add_geometry)
+
+    if row is None:
+        return None
+
+    result = row_func(row, nres.SearchResult)
+    assert result is not None
+
+    # add missing details
+    assert result is not None
+    result.bbox = getattr(row, 'bbox', None)
+
+    await nres.add_result_details(conn, result, details)
+
+    return result

diff --git a/nominatim/api/results.py b/nominatim/api/results.py
index 098851ef1b8a39da145eba2b7ba5968f45e84f34..98b13380726e98361bc2571c85bd78928c1afc12 100644 (file)
--- a/nominatim/api/results.py
+++ b/nominatim/api/results.py
@@ -173,6 +173,19 @@ class ReverseResults(List[ReverseResult]):
     """
 
 
+@dataclasses.dataclass
+class SearchResult(BaseResult):
+    """ A search result for forward geocoding.
+    """
+    bbox: Optional[Bbox] = None
+
+
+class SearchResults(List[SearchResult]):
+    """ Sequence of forward lookup results ordered by relevance.
+        May be empty when no result was found.
+    """
+
+
 def _filter_geometries(row: SaRow) -> Dict[str, str]:
     return {k[9:]: v for k, v in row._mapping.items() # pylint: disable=W0212
             if k.startswith('geometry_')}