package geo

import "testing"

func TestMeters(t *testing.T) {
	// NYC → Boston ≈ 305 km
	d := Meters(Point{Lat: 40.7128, Lon: -74.006}, Point{Lat: 42.3601, Lon: -71.0589})
	if d < 300_000 || d > 320_000 {
		t.Errorf("NYC-Boston = %.0f m, want ~305km", d)
	}
}

func TestDistToPolyline(t *testing.T) {
	poly := []Point{{Lat: 0, Lon: 0}, {Lat: 10, Lon: 0}} // north-south at lon 0
	// 1 deg lon at equator ≈ 111.3 km
	d := DistToPolylineMeters(Point{Lat: 5, Lon: 1}, poly)
	if d < 110_000 || d > 115_000 {
		t.Errorf("distance = %.0f m, want ~111km", d)
	}
	// on the line
	if d := DistToPolylineMeters(Point{Lat: 5, Lon: 0}, poly); d > 100 {
		t.Errorf("on-line distance = %.0f m, want ~0", d)
	}
	// past the end: distance to endpoint
	if d := DistToPolylineMeters(Point{Lat: 12, Lon: 0}, poly); d < 200_000 || d > 240_000 {
		t.Errorf("past-end distance = %.0f m, want ~222km", d)
	}
}

func TestMinAt(t *testing.T) {
	if m := MinAt(4600, 4.6); m != 60 {
		t.Errorf("MinAt(4600m, 4.6kmh) = %d, want 60", m)
	}
}