File size: 2,542 Bytes
f17ffc5 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | import type { FleetTelemetryPayload, HazardType } from "./api";
export type FleetHazardType = Exclude<HazardType, "other">;
export interface FleetDetection {
hazard_type: FleetHazardType;
confidence: number;
bbox: [number, number, number, number];
}
export interface FleetLocation {
lat: number;
lon: number;
speed: number | null;
at: number;
}
export interface LastFleetReport {
lat: number;
lon: number;
at: number;
}
export const FLEET_CONFIDENCE = 0.55;
export const TRAFFIC_BLOCK_CONFIDENCE = 0.45;
export const TRAFFIC_BLOCK_SPEED_MPS = 2;
export const TRAFFIC_BLOCK_DWELL_MS = 10_000;
export const FLEET_DEBOUNCE_METERS = 10;
const EARTH_RADIUS_M = 6_371_000;
export function haversineMeters(a: Pick<FleetLocation, "lat" | "lon">, b: Pick<FleetLocation, "lat" | "lon">): number {
const dLat = ((b.lat - a.lat) * Math.PI) / 180;
const dLon = ((b.lon - a.lon) * Math.PI) / 180;
const lat1 = (a.lat * Math.PI) / 180;
const lat2 = (b.lat * Math.PI) / 180;
const h =
Math.sin(dLat / 2) ** 2 +
Math.cos(lat1) * Math.cos(lat2) * Math.sin(dLon / 2) ** 2;
return 2 * EARTH_RADIUS_M * Math.asin(Math.sqrt(h));
}
export function createClientEventId(): string {
if ("randomUUID" in crypto) return crypto.randomUUID();
return `fleet-${Date.now().toString(36)}-${Math.random().toString(36).slice(2)}`;
}
export function shouldSendFleetReport(
detection: FleetDetection,
location: FleetLocation,
lastReports: Map<FleetHazardType, LastFleetReport>,
): boolean {
const previous = lastReports.get(detection.hazard_type);
if (!previous) return true;
return haversineMeters(previous, location) > FLEET_DEBOUNCE_METERS;
}
export function bboxAreaFraction(bbox: [number, number, number, number], frameSize: number): number {
const [x1, y1, x2, y2] = bbox;
const w = Math.max(0, x2 - x1);
const h = Math.max(0, y2 - y1);
return Math.min(1, (w * h) / (frameSize * frameSize));
}
export function toFleetPayload(opts: {
detection: FleetDetection;
location: FleetLocation;
thumbnailB64?: string;
frameSize: number;
}): FleetTelemetryPayload {
return {
lat: opts.location.lat,
lon: opts.location.lon,
hazard_type: opts.detection.hazard_type,
confidence: opts.detection.confidence,
timestamp: new Date().toISOString(),
speed: opts.location.speed ?? undefined,
bbox: opts.detection.bbox,
bbox_area_frac: bboxAreaFraction(opts.detection.bbox, opts.frameSize),
thumbnail_b64: opts.thumbnailB64,
client_event_id: createClientEventId(),
};
}
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