package fees

import "testing"

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

	// mustRate returns the configured rate for a month that must be in the map.
	// Panics immediately if the month is absent so a removed entry causes a loud
	// failure rather than a silent comparison against Go's zero value.
	mustRate := func(month string) Expected {
		r, ok := JuniorFeeMonthlyRate[month]
		if !ok {
			panic("test month not in JuniorFeeMonthlyRate: " + month)
		}
		return Expected{Value: r}
	}

	tests := []struct {
		name  string
		count int
		month string
		want  Expected
	}{
		// Zero attendance always returns 0.
		{"zero short-circuits", 0, "2026-05", Expected{Value: 0}},
		{"zero empty month", 0, "", Expected{Value: 0}},
		// Single practice returns the Unknown sentinel regardless of month.
		{"single practice sentinel", 1, "2026-05", Expected{Unknown: true}},
		{"single ignores monthKey", 1, "unknown", Expected{Unknown: true}},
		// Two+ practices for a configured month: must use the map value, not the default.
		{"two practices unconfigured month", 2, "2026-05", Expected{Value: JuniorFeeDefault}},
		{"two practices reduced sept", 2, "2025-09", mustRate("2025-09")},
		{"two practices reduced march", 2, "2026-03", mustRate("2026-03")},
		{"high count same as two", 5, "2025-09", mustRate("2025-09")},
		// Two+ practices for an unknown/future month: must fall back to JuniorFeeDefault.
		{"unknown future month falls back", 2, "2027-01", Expected{Value: JuniorFeeDefault}},
		{"empty month falls back", 2, "", Expected{Value: JuniorFeeDefault}},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()
			got := CalculateJuniorFee(tc.count, tc.month)
			if got != tc.want {
				t.Errorf("CalculateJuniorFee(%d, %q) = %+v, want %+v", tc.count, tc.month, got, tc.want)
			}
		})
	}
}