package insight

import (
	"testing"
	"time"
)

func TestTimeContextUsesRealTehranTodayAndReportsDatasetLag(t *testing.T) {
	t.Parallel()

	now := time.Date(2026, time.August, 21, 8, 30, 0, 0, time.UTC)
	dataThrough := time.Date(2026, time.June, 30, 0, 0, 0, 0, time.UTC)

	got := BuildTimeContext(now, dataThrough)

	if got.AsOfDate != "2026-08-21" {
		t.Fatalf("AsOfDate = %q, want real Tehran date", got.AsOfDate)
	}
	if got.DataThroughDate != "2026-06-30" {
		t.Fatalf("DataThroughDate = %q", got.DataThroughDate)
	}
	if got.ForecastStartDate != got.AsOfDate {
		t.Fatalf("ForecastStartDate = %q, want %q", got.ForecastStartDate, got.AsOfDate)
	}
	if got.Freshness != FreshnessStale || got.DataLagDays != 52 {
		t.Fatalf("freshness = %s, lag = %d", got.Freshness, got.DataLagDays)
	}
}

func TestClassifyFreshnessUsesProductionBoundaries(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name string
		lag  int
		want Freshness
	}{
		{name: "same day", lag: 0, want: FreshnessFresh},
		{name: "yesterday", lag: 1, want: FreshnessFresh},
		{name: "two days", lag: 2, want: FreshnessLagging},
		{name: "seven days", lag: 7, want: FreshnessLagging},
		{name: "eight days", lag: 8, want: FreshnessStale},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := ClassifyFreshness(tt.lag); got != tt.want {
				t.Fatalf("ClassifyFreshness(%d) = %s, want %s", tt.lag, got, tt.want)
			}
		})
	}
}