package sms

import (
	"math"
	"testing"
)

func TestHaversineMeters(t *testing.T) {
	cases := []struct {
		name           string
		lat1, lng1     float64
		lat2, lng2     float64
		wantMeters     float64
		tolerancePct   float64
	}{
		{"same point", -33.86, 151.21, -33.86, 151.21, 0, 0},
		{"Sydney CBD to Parramatta (~20km)", -33.8688, 151.2093, -33.8125, 151.0011, 20200, 0.02},
		{"~250m at Sydney latitude", -33.86, 151.21, -33.86, 151.2128, 250, 0.20},
		{"antipodal-ish long distance", 0, 0, 0, 180, 20037500, 0.01},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := HaversineMeters(tc.lat1, tc.lng1, tc.lat2, tc.lng2)
			if tc.wantMeters == 0 {
				if got > 1 {
					t.Fatalf("same point: got %.1f m, want ~0", got)
				}
				return
			}
			diff := math.Abs(got-tc.wantMeters) / tc.wantMeters
			if diff > tc.tolerancePct {
				t.Fatalf("got %.1f m, want ~%.1f m (error %.1f%%)", got, tc.wantMeters, diff*100)
			}
		})
	}
}

func TestNormalizeAU(t *testing.T) {
	cases := []struct{ in, want string }{
		{"+61423274487", "61423274487"},
		{"0423274487", "61423274487"},
		{"61423274487", "61423274487"},
		{"+61 423 274 487", "61423274487"},
		{"0423 274 487", "61423274487"},
		{"", ""},
	}
	for _, tc := range cases {
		if got := NormalizeAU(tc.in); got != tc.want {
			t.Errorf("NormalizeAU(%q) = %q, want %q", tc.in, got, tc.want)
		}
	}
}