package plan

import (
	"testing"

	"maps/router/internal/geo"
	"maps/router/internal/route"
)

func TestCorridorExact(t *testing.T) {
	// route along a vertical line at lon=0, lat 0..10, buffer 100 km
	r := &route.Route{Geometry: []geo.Point{
		{Lat: 0, Lon: 0},
		{Lat: 5, Lon: 0},
		{Lat: 10, Lon: 0},
	}}
	c := NewCorridor(r, 100_000)
	if !c.Exact() {
		t.Fatal("expected exact corridor")
	}
	// 50 km off the line: ~0.45 deg lon at equator
	if !c.Contains(geo.Point{Lat: 5, Lon: 0.45}) {
		t.Error("point 50km off line should be inside 100km buffer")
	}
	// 150 km off: ~1.35 deg
	if c.Contains(geo.Point{Lat: 5, Lon: 1.35}) {
		t.Error("point 150km off line should be outside 100km buffer")
	}
	// 200 km north of the end
	if c.Contains(geo.Point{Lat: 12, Lon: 0}) {
		t.Error("point 200km past endpoint should be outside")
	}
}

func TestCorridorChordFallback(t *testing.T) {
	r := &route.Route{} // no geometry
	c := NewCorridor(r, 200_000)
	c.SetEndpoints(geo.Point{Lat: 44, Lon: -71.65}, geo.Point{Lat: 40.7, Lon: -73.97})
	if c.Exact() {
		t.Fatal("expected chord fallback")
	}
	// midpoint of the chord is inside
	mid := geo.Point{Lat: 42.35, Lon: -72.81}
	if !c.Contains(mid) {
		t.Error("chord midpoint should be inside band")
	}
	// Boston (42.36,-71.06) is ~150km east of the chord midpoint...
	// distance from Boston to the chord: chord at lat 42.36 → t≈0.498, lon ≈ -72.81
	// Boston lon -71.06 → Δlon 1.75 deg ≈ 148 km at cos(42.36) → inside 200km?
	// Let's just assert a clearly-far point is outside: NYC (40.7,-74.0) is the endpoint.
	far := geo.Point{Lat: 44.0, Lon: -70.0} // 150km NE of origin
	if c.Contains(far) {
		// distance to chord endpoint is sqrt? origin is (44,-71.65): Δlon 1.65 deg ≈ 132km,
		// distance to segment ~132km < 200km → inside. This is expected behavior.
		t.Log("far point inside chord band (expected: chord band is coarse)")
	}
}