Correct daypart identity and display handling

internal/briefing/derived_modules_test.go

@@ -355,6 +355,52 @@ func TestDerivedDaypartSummariesExposeConfiguredKeysAndHazards(t *testing.T) {
 	}
 }
 
+func TestDerivedDaypartSummariesRejectCanonicalKeyCollisions(t *testing.T) {
+	registry := MustDefaultModuleRegistry()
+	ctx := derivedModuleContext(report.Daily)
+	first := ctx.Derived.DaypartSummaries[0]
+	first.Name = "Morning"
+	second := first
+	second.Name = "morning!"
+	ctx.Derived.DaypartSummaries = []forecast.DaypartSummary{first, second}
+	ctx.Derived.DailySummaries = []forecast.DailySummary{{Date: first.Period.Start.Format(timeutil.DateLayout)}}
+
+	_, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDaypartSummaries})
+	if err == nil || !strings.Contains(err.Error(), "collides") {
+		t.Fatalf("BuildModule() error = %v, want canonical daypart-key collision", err)
+	}
+}
+
+func TestDerivedDaypartSummaryDisplayCapitalizesUnicodeNames(t *testing.T) {
+	value := derivedDaypartSummaryValue(forecast.DaypartSummary{
+		Name:              "mañana",
+		DominantCondition: "llovizna",
+	}, "UTC")
+	if value.DisplayName != "Mañana" || value.DominantConditionDisplay != "Llovizna" {
+		t.Fatalf("daypart display = %#v, want rune-safe capitalization", value)
+	}
+}
+
+func TestDerivedDaypartSummariesKeepDistinctUnicodeKeys(t *testing.T) {
+	registry := MustDefaultModuleRegistry()
+	ctx := derivedModuleContext(report.Daily)
+	first := ctx.Derived.DaypartSummaries[0]
+	first.Name = "mañana"
+	second := first
+	second.Name = "manana"
+	ctx.Derived.DaypartSummaries = []forecast.DaypartSummary{first, second}
+	ctx.Derived.DailySummaries = []forecast.DailySummary{{Date: first.Period.Start.Format(timeutil.DateLayout)}}
+
+	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDaypartSummaries})
+	if err != nil {
+		t.Fatalf("BuildModule() error = %v", err)
+	}
+	value := moduleValue[map[string]DerivedDaypartSummaryModule](t, output)
+	if len(value) != 2 || value["mañana"].DisplayName != "Mañana" || value["manana"].DisplayName != "Manana" {
+		t.Fatalf("daypart summaries = %#v, want distinct Unicode canonical keys", value)
+	}
+}
+
 func TestDerivedDaypartSummariesPromptExportOmitsTemplateHelpers(t *testing.T) {
 	registry := MustDefaultModuleRegistry()
 	ctx := derivedModuleContext(report.Daily)
@@ -670,6 +716,65 @@ func TestOutdoorWindowsScoreSnowIceAndFog(t *testing.T) {
 	}
 }
 
+func TestPlanningUsesCanonicalDaypartIdentities(t *testing.T) {
+	timedValue := func(value float64) *forecast.TimedValue {
+		return &forecast.TimedValue{Value: value}
+	}
+	containsText := func(values []string, text string) bool {
+		return strings.Contains(strings.Join(values, "\n"), text)
+	}
+	summary := &forecast.DailySummary{Dayparts: []forecast.DaypartSummary{
+		{Name: "Overnight!", MaxPrecipitationProbability: timedValue(60)},
+		{Name: "MORNING", MaxPrecipitationProbability: timedValue(60)},
+		{Name: "Afternoon!!!", MaxPrecipitationProbability: timedValue(60)},
+		{Name: "EVENING!", MaxPrecipitationProbability: timedValue(60)},
+	}}
+
+	today := buildTodayPlanning(summary)
+	if !containsText(today.MorningReadiness, "Morning precipitation chance peaks near 60%.") {
+		t.Fatalf("today morning readiness = %#v, want canonical morning window", today.MorningReadiness)
+	}
+	if !containsText(today.CommuteSchoolWorkdayConcerns, "Afternoon!!! precipitation chance reaches 60%.") ||
+		containsText(today.CommuteSchoolWorkdayConcerns, "Overnight!") ||
+		containsText(today.CommuteSchoolWorkdayConcerns, "EVENING!") {
+		t.Fatalf("today workday concerns = %#v, want only canonical workday windows", today.CommuteSchoolWorkdayConcerns)
+	}
+	if !containsText(today.LateDayChangeWatch, "Afternoon!!! precipitation timing may shift") ||
+		!containsText(today.LateDayChangeWatch, "EVENING! precipitation timing may shift") {
+		t.Fatalf("today late-day watch = %#v, want canonical afternoon and evening windows", today.LateDayChangeWatch)
+	}
+
+	base := buildMorningCommuteOvernightPlanning(summary)
+	if !containsText(base.MorningReadiness, "Morning precipitation chance peaks near 60%.") ||
+		!containsText(base.OvernightChangeWatch, "Overnight precipitation timing may shift") ||
+		containsText(base.CommuteSchoolWorkdayConcerns, "Overnight!") ||
+		containsText(base.CommuteSchoolWorkdayConcerns, "EVENING!") {
+		t.Fatalf("daily/tomorrow planning = %#v, want canonical daypart treatment", base)
+	}
+}
+
+func TestCapitalizeFirst(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{name: "empty", input: "", want: ""},
+		{name: "ASCII", input: "morning", want: "Morning"},
+		{name: "multibyte", input: "mañana", want: "Mañana"},
+		{name: "already uppercase", input: "Morning", want: "Morning"},
+		{name: "leading space", input: " morning", want: " morning"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := capitalizeFirst(tt.input); got != tt.want {
+				t.Fatalf("capitalizeFirst(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
 func TestOutdoorWindowsAndTomorrowPlanningModulesPreserveDailyContent(t *testing.T) {
 	registry := MustDefaultModuleRegistry()
 	ctx := derivedModuleContext(report.Tomorrow)