ops: track tif_polygons.ts orphan import

entity.ts imports findTifDistrict from ./tif_polygons.js but the
source file was never committed — only present in the working tree.
Adding it so a fresh clone compiles.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

mcp-server/tif_polygons.ts

@@ -0,0 +1,178 @@
+// TIF (Tax Increment Financing) district point-in-polygon lookup.
+// Given a property's lat/long, returns which Chicago TIF district (if
+// any) contains it. TIF districts are public-subsidy zones — a property
+// inside one is receiving city tax-increment funding for its build.
+// Strong "this project has financial backing" signal for the Project Index.
+//
+// Data: data/_entity_cache/tif_districts.geojson (Chicago Open Data
+// dataset eejr-xtfb, 100 active districts, 3.2MB). Refresh by re-running
+// `curl ... eejr-xtfb.geojson > tif_districts.geojson` — districts
+// change rarely (only when city council approves new ones or repeals).
+//
+// Algorithm: classic ray-casting. For each MultiPolygon's outer ring,
+// count edge crossings of an east-going horizontal ray from the point.
+// Odd crossings = inside. Holes (inner rings) flip the parity. Library-
+// free; correct for arbitrary polygons including the irregular Chicago
+// shapes which often have many small detours.
+
+import { readFile } from "node:fs/promises";
+import { existsSync } from "node:fs";
+import { join } from "node:path";
+
+const TIF_GEOJSON = join("/home/profit/lakehouse/data/_entity_cache", "tif_districts.geojson");
+
+type LngLat = [number, number]; // GeoJSON convention: [longitude, latitude]
+type Ring = LngLat[];
+type Polygon = Ring[]; // outer ring + optional inner rings (holes)
+type MultiPolygon = Polygon[];
+
+type TifFeature = {
+  name: string;
+  trim_name?: string;
+  ref?: string;
+  approval_date?: string;
+  expiration?: string;
+  type?: string; // T-1xx etc.
+  comm_area?: string;
+  wards?: string;
+  // Bounding box for quick reject
+  bbox: { minLon: number; minLat: number; maxLon: number; maxLat: number };
+  geometry: MultiPolygon;
+};
+
+let tifIdx: TifFeature[] | null = null;
+
+function bboxOfMultiPolygon(mp: MultiPolygon): TifFeature["bbox"] {
+  let minLon = Infinity, minLat = Infinity, maxLon = -Infinity, maxLat = -Infinity;
+  for (const poly of mp) {
+    for (const ring of poly) {
+      for (const [lon, lat] of ring) {
+        if (lon < minLon) minLon = lon;
+        if (lat < minLat) minLat = lat;
+        if (lon > maxLon) maxLon = lon;
+        if (lat > maxLat) maxLat = lat;
+      }
+    }
+  }
+  return { minLon, minLat, maxLon, maxLat };
+}
+
+async function ensureLoaded(): Promise<TifFeature[]> {
+  if (tifIdx) return tifIdx;
+  if (!existsSync(TIF_GEOJSON)) {
+    tifIdx = [];
+    return tifIdx;
+  }
+  try {
+    const raw = JSON.parse(await readFile(TIF_GEOJSON, "utf-8"));
+    const out: TifFeature[] = [];
+    for (const f of raw.features || []) {
+      const geom = f.geometry;
+      if (!geom) continue;
+      // Normalize Polygon → MultiPolygon for uniform iteration
+      let mp: MultiPolygon;
+      if (geom.type === "MultiPolygon") {
+        mp = geom.coordinates;
+      } else if (geom.type === "Polygon") {
+        mp = [geom.coordinates];
+      } else {
+        continue;
+      }
+      const props = f.properties || {};
+      out.push({
+        name: props.name || "Unknown TIF",
+        trim_name: props.name_trim,
+        ref: props.ref,
+        approval_date: props.approval_d,
+        expiration: props.expiration,
+        type: props.type,
+        comm_area: props.comm_area,
+        wards: props.wards,
+        bbox: bboxOfMultiPolygon(mp),
+        geometry: mp,
+      });
+    }
+    tifIdx = out;
+    return tifIdx;
+  } catch (e) {
+    console.warn("[tif] load failed:", (e as Error).message);
+    tifIdx = [];
+    return tifIdx;
+  }
+}
+
+// Ray-casting point-in-polygon (single ring). Returns true if (lon, lat)
+// is strictly inside the ring. Edge cases (point exactly on a vertex)
+// resolve by half-open interval convention; for our use case (Chicago
+// boundary precision is ~1m, sites are point queries) this is fine.
+function pointInRing(lon: number, lat: number, ring: Ring): boolean {
+  let inside = false;
+  const n = ring.length;
+  for (let i = 0, j = n - 1; i < n; j = i++) {
+    const [xi, yi] = ring[i];
+    const [xj, yj] = ring[j];
+    const intersect =
+      yi > lat !== yj > lat &&
+      lon < ((xj - xi) * (lat - yi)) / (yj - yi + 0) + xi;
+    if (intersect) inside = !inside;
+  }
+  return inside;
+}
+
+// Polygon = outer ring + holes. Inside outer AND not inside any hole.
+function pointInPolygon(lon: number, lat: number, polygon: Polygon): boolean {
+  if (polygon.length === 0) return false;
+  if (!pointInRing(lon, lat, polygon[0])) return false;
+  for (let i = 1; i < polygon.length; i++) {
+    if (pointInRing(lon, lat, polygon[i])) return false;
+  }
+  return true;
+}
+
+export type TifMatch = {
+  name: string;
+  ref?: string;
+  approval_date?: string;
+  expiration?: string;
+  comm_area?: string;
+  wards?: string;
+};
+
+export async function findTifDistrict(
+  longitude: number | string | undefined,
+  latitude: number | string | undefined,
+): Promise<TifMatch | null> {
+  const lon = typeof longitude === "string" ? parseFloat(longitude) : longitude;
+  const lat = typeof latitude === "string" ? parseFloat(latitude) : latitude;
+  if (!lon || !lat || isNaN(lon) || isNaN(lat)) return null;
+  const idx = await ensureLoaded();
+  if (idx.length === 0) return null;
+  for (const f of idx) {
+    // Bbox reject — cheap O(1) skip for the 99% of districts that
+    // can't possibly contain the point.
+    const b = f.bbox;
+    if (lon < b.minLon || lon > b.maxLon || lat < b.minLat || lat > b.maxLat) continue;
+    // Full point-in-polygon for any polygon in this MultiPolygon
+    for (const poly of f.geometry) {
+      if (pointInPolygon(lon, lat, poly)) {
+        return {
+          name: f.name,
+          ref: f.ref,
+          approval_date: f.approval_date,
+          expiration: f.expiration,
+          comm_area: f.comm_area,
+          wards: f.wards,
+        };
+      }
+    }
+  }
+  return null;
+}
+
+export async function getTifIndexStats(): Promise<{
+  total: number;
+  loaded: boolean;
+}> {
+  const idx = await ensureLoaded();
+  return { total: idx.length, loaded: idx.length > 0 };
+}