feat: polish & windviz & deploy

internal/weather/gfs/wind_test.go

@@ -0,0 +1,69 @@
+package gfs
+
+import (
+	"math"
+	"path/filepath"
+	"testing"
+	"time"
+)
+
+// testVariant is a tiny cube (2 hours × 3 levels × 3 lat × 4 lng) used to
+// exercise the sampler without allocating a multi-gigabyte real dataset.
+func testVariant() *Variant {
+	return &Variant{
+		ID:              "gfs-test",
+		ResToken:        "test",
+		Resolution:      90, // 180/90+1 = 3 lats, 360/90 = 4 lngs
+		HourStep:        3,
+		MaxHour:         3, // 2 hours
+		Pressures:       []int{1000, 500, 100},
+		PressuresPgrb2:  []int{1000, 500, 100},
+		PressuresPgrb2b: []int{},
+	}
+}
+
+func TestWindSampler(t *testing.T) {
+	v := testVariant()
+	path := filepath.Join(t.TempDir(), "cube.bin")
+	f, err := Create(path, v)
+	if err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+
+	// HGT increases with level so the altitude bisection has a gradient;
+	// U and V are constant so interpolation must return them exactly.
+	for h := range v.NumHours() {
+		for lvl := range v.NumLevels() {
+			for la := range v.NumLatitudes() {
+				for ln := range v.NumLongitudes() {
+					f.SetVal(h, lvl, VarHeight, la, ln, float32(lvl*1000))
+					f.SetVal(h, lvl, VarWindU, la, ln, 7)
+					f.SetVal(h, lvl, VarWindV, la, ln, 3)
+				}
+			}
+		}
+	}
+	f.Flush()
+	f.Close()
+
+	epoch := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
+	rf, err := Open(path, v, epoch)
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+	defer rf.Close()
+	w := NewWind(rf)
+
+	// Query at the dataset epoch, equator, lng 45, altitude 500m (between
+	// level 0 @ 0m and level 1 @ 1000m).
+	s, err := w.Wind(float64(epoch.Unix()), 0, 45, 500)
+	if err != nil {
+		t.Fatalf("Wind: %v", err)
+	}
+	if math.Abs(s.U-7) > 1e-5 || math.Abs(s.V-3) > 1e-5 {
+		t.Errorf("constant wind not recovered: got U=%v V=%v, want 7,3", s.U, s.V)
+	}
+	if s.AboveModel {
+		t.Errorf("AboveModel should be false at altitude within model range")
+	}
+}