first commit

app/services/buildings.py

@@ -0,0 +1,90 @@
+from __future__ import annotations
+
+import asyncio
+from typing import Iterable
+
+from psycopg.rows import dict_row
+from psycopg_pool import ConnectionPool
+
+from app.config import settings
+
+
+class BuildingService:
+  def __init__(self, database_url: str | None = None) -> None:
+    self.database_url = database_url or settings.database_url
+    self._pool: ConnectionPool | None = None
+    self._available = False
+
+  def connect(self) -> None:
+    try:
+      self._pool = ConnectionPool(
+        conninfo=self.database_url,
+        min_size=1,
+        max_size=10,
+        kwargs={"row_factory": dict_row},
+        open=True,
+      )
+      with self._pool.connection() as conn:
+        with conn.cursor() as cur:
+          cur.execute("SELECT to_regclass('public.buildings') IS NOT NULL AS exists")
+          row = cur.fetchone()
+          self._available = bool(row and row["exists"])
+    except Exception:
+      self._available = False
+      if self._pool is not None:
+        self._pool.close()
+        self._pool = None
+
+  def close(self) -> None:
+    if self._pool is not None:
+      self._pool.close()
+      self._pool = None
+
+  def is_available(self) -> bool:
+    return self._available and self._pool is not None
+
+  def _get_max_height_sync(self, lat: float, lng: float) -> float:
+    if not self.is_available() or self._pool is None:
+      return 0.0
+
+    with self._pool.connection() as conn:
+      with conn.cursor() as cur:
+        cur.execute(
+          """
+          SELECT COALESCE(MAX(height_m), 0) AS height_m
+          FROM buildings
+          WHERE ST_Contains(geom, ST_SetSRID(ST_Point(%s, %s), 4326))
+          """,
+          (lng, lat),
+        )
+        row = cur.fetchone()
+        return float(row["height_m"]) if row else 0.0
+
+  def _get_max_heights_sync(self, coordinates: Iterable[tuple[float, float]]) -> list[float]:
+    coords = list(coordinates)
+    if not coords:
+      return []
+    if not self.is_available() or self._pool is None:
+      return [0.0] * len(coords)
+
+    values = [0.0] * len(coords)
+    with self._pool.connection() as conn:
+      with conn.cursor() as cur:
+        for index, (lat, lng) in enumerate(coords):
+          cur.execute(
+            """
+            SELECT COALESCE(MAX(height_m), 0) AS height_m
+            FROM buildings
+            WHERE ST_Contains(geom, ST_SetSRID(ST_Point(%s, %s), 4326))
+            """,
+            (lng, lat),
+          )
+          row = cur.fetchone()
+          values[index] = float(row["height_m"]) if row else 0.0
+    return values
+
+  async def get_max_height(self, lat: float, lng: float) -> float:
+    return await asyncio.to_thread(self._get_max_height_sync, lat, lng)
+
+  async def get_max_heights(self, coordinates: list[tuple[float, float]]) -> list[float]:
+    return await asyncio.to_thread(self._get_max_heights_sync, coordinates)