package briefing

import (
	"encoding/json"
	"strings"
	"testing"
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/facts"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/weatherdata"
)

func TestDerivedDailySummaryModulePackagesOrdinaryForecast(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.DailyToday)

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDailySummary})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	value := moduleValue[DerivedDailySummaryModule](t, output)

	if value.Date != "Friday, May 29, 2026" {
		t.Fatalf("Date = %q, want friendly local date", value.Date)
	}
	if value.HighTempF == nil || *value.HighTempF != 88 || value.LowTempF == nil || *value.LowTempF != 64 {
		t.Fatalf("daily temperatures = %#v/%#v, want narrative 88/64", value.HighTempF, value.LowTempF)
	}
	if value.DailyPrecipitationProbability == nil || *value.DailyPrecipitationProbability != 55 {
		t.Fatalf("DailyPrecipitationProbability = %#v, want narrative 55", value.DailyPrecipitationProbability)
	}
	if value.MostLikelyPrecipitationHour != "80% at 12 PM" || !value.ThunderMentioned {
		t.Fatalf("precip timing = %#v, want most likely hour and thunder", value)
	}
	if !containsString(value.DominantConditions, "Thunderstorms with gusty wind") || containsString(value.DominantConditions, "Morning storms, then partly sunny.") {
		t.Fatalf("DominantConditions = %#v, want daypart conditions rather than narrative conditions", value.DominantConditions)
	}
	if value.MaxWindGustMph == nil || *value.MaxWindGustMph != 42 {
		t.Fatalf("MaxWindGustMph = %#v, want 42", value.MaxWindGustMph)
	}
	if value.HeatIndexMaxF == nil || *value.HeatIndexMaxF != 101 {
		t.Fatalf("HeatIndexMaxF = %#v, want 101", value.HeatIndexMaxF)
	}
	data, err := json.Marshal(output.Value)
	if err != nil {
		t.Fatalf("marshal daily summary: %v", err)
	}
	jsonText := string(data)
	for _, field := range []string{"high_temp_f", "low_temp_f", "daily_precipitation_probability", "most_likely_precipitation_hour", "heat_index_max_f"} {
		if !strings.Contains(jsonText, field) {
			t.Fatalf("daily json = %s, want field %s", jsonText, field)
		}
	}
	for _, removed := range []string{"max_pop_percent", "max_pop_window", "first_precip_hour", "last_precip_hour"} {
		if strings.Contains(jsonText, removed) {
			t.Fatalf("daily json = %s, want removed field %s omitted", jsonText, removed)
		}
	}
	if strings.Contains(jsonText, "qpf") {
		t.Fatalf("daily json = %s, want no QPF fields without upstream QPF facts", jsonText)
	}
}

func TestDerivedDailySummaryModuleFallsBackWithoutNarrativeFacts(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.DailyToday)
	ctx.Derived.DailySummaries[0].NarrativePeriods = nil

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDailySummary})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	value := moduleValue[DerivedDailySummaryModule](t, output)

	if value.HighTempF == nil || *value.HighTempF != 96 || value.LowTempF == nil || *value.LowTempF != 31 {
		t.Fatalf("daily temperatures = %#v/%#v, want fallback 96/31", value.HighTempF, value.LowTempF)
	}
	if value.DailyPrecipitationProbability == nil || *value.DailyPrecipitationProbability != 80 {
		t.Fatalf("DailyPrecipitationProbability = %#v, want hourly fallback 80", value.DailyPrecipitationProbability)
	}
	if len(value.DominantConditions) == 0 || !containsString(value.DominantConditions, "Thunderstorms with gusty wind") {
		t.Fatalf("DominantConditions = %#v, want fallback daypart conditions", value.DominantConditions)
	}
}

func TestPrecipTimingModuleHandlesRainyAndDryForecasts(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.DailyToday)

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.PrecipTiming})
	if err != nil {
		t.Fatalf("BuildModule(rainy) error = %v", err)
	}
	rainy := moduleValue[PrecipTimingModule](t, output)
	if rainy.MaxPopPercent == nil || *rainy.MaxPopPercent != 80 || rainy.MaxPopTime != "12 PM" || rainy.ProbabilityThreshold != forecast.DefaultPrecipWindowProbabilityThreshold || !rainy.ThunderMentioned {
		t.Fatalf("rainy precip timing = %#v, want peak, threshold, and thunder", rainy)
	}
	if len(rainy.PrecipitationWindows) != 2 {
		t.Fatalf("rainy precipitation windows = %#v, want two windows", rainy.PrecipitationWindows)
	}
	if rainy.PrecipitationWindows[0].PeriodBegins != "2026-05-29 at 8:00 AM" || rainy.PrecipitationWindows[0].PeriodBeginsHourLabel != "8:00 AM" || rainy.PrecipitationWindows[0].PeriodEnds != "2026-05-29 at 9:00 AM" || rainy.PrecipitationWindows[0].PeriodEndsHourLabel != "9:00 AM" || rainy.PrecipitationWindows[0].MaxPopPercent == nil || *rainy.PrecipitationWindows[0].MaxPopPercent != 60 || rainy.PrecipitationWindows[0].MaxPopHourLabel != "8:00 AM" {
		t.Fatalf("first precipitation window = %#v, want 8-9 AM at 60%%", rainy.PrecipitationWindows[0])
	}
	if rainy.PrecipitationWindows[1].PeriodBegins != "2026-05-29 at 12:00 PM" || rainy.PrecipitationWindows[1].PeriodBeginsHourLabel != "12:00 PM" || rainy.PrecipitationWindows[1].PeriodEnds != "2026-05-29 at 2:00 PM" || rainy.PrecipitationWindows[1].PeriodEndsHourLabel != "2:00 PM" || rainy.PrecipitationWindows[1].MaxPopPercent == nil || *rainy.PrecipitationWindows[1].MaxPopPercent != 80 || rainy.PrecipitationWindows[1].MaxPopHourLabel != "12:00 PM" {
		t.Fatalf("second precipitation window = %#v, want noon-2 PM at 80%%", rainy.PrecipitationWindows[1])
	}
	data, err := json.Marshal(output.Value)
	if err != nil {
		t.Fatalf("marshal precip timing: %v", err)
	}
	if !strings.Contains(string(data), "precipitation_windows") || !strings.Contains(string(data), "probability_threshold") || !strings.Contains(string(data), "period_begins_hour_label") || !strings.Contains(string(data), "max_pop_hour_label") {
		t.Fatalf("precip timing json = %s, want threshold and windows", string(data))
	}
	if strings.Contains(string(data), `"start"`) || strings.Contains(string(data), `"end"`) {
		t.Fatalf("precip timing json = %s, want period_begins/period_ends instead of start/end", string(data))
	}
	if strings.Contains(string(data), "first_precip_hour") || strings.Contains(string(data), "last_precip_hour") {
		t.Fatalf("precip timing json = %s, want no ambiguous first/last fields", string(data))
	}

	ctx.Derived.PrecipTiming = forecast.BuildPrecipTiming([]weatherdata.ForecastPeriod{derivedHour("2026-05-29T10:00:00-05:00", "Sunny", 0, 70, nil, 5)})
	output, err = registry.BuildModule(ctx, module.ConfigItem{ID: module.PrecipTiming})
	if err != nil {
		t.Fatalf("BuildModule(dry) error = %v", err)
	}
	dry := moduleValue[PrecipTimingModule](t, output)
	if len(dry.PrecipitationWindows) != 0 || dry.ThunderMentioned {
		t.Fatalf("dry precip timing = %#v, want no precip windows and no thunder", dry)
	}
	if dry.MaxPopPercent == nil || *dry.MaxPopPercent != 0 {
		t.Fatalf("dry MaxPopPercent = %#v, want checked zero", dry.MaxPopPercent)
	}
}

func TestPrecipTimingModuleUsesDerivedTimingWithoutDaypartSummaries(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.Hourly)
	ctx.Derived.DailySummaries = nil
	ctx.Derived.DaypartSummaries = nil

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.PrecipTiming})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	value := moduleValue[PrecipTimingModule](t, output)
	if value.MaxPopPercent == nil || *value.MaxPopPercent != 80 || len(value.PrecipitationWindows) != 2 {
		t.Fatalf("precip timing = %#v, want derived timing without daypart summaries", value)
	}
}

func TestDerivedDaypartSummariesExposeConfiguredKeysAndHazards(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.DailyToday)

	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)

	morning, ok := value["morning"]
	if !ok {
		t.Fatalf("daypart keys = %#v, want configured morning key", value)
	}
	if morning.TempRangeF != "58" || morning.MaxPopPercent == nil || *morning.MaxPopPercent != 60 {
		t.Fatalf("morning = %#v, want temp range and precip peak", morning)
	}
	if morning.DisplayName != "Morning" || morning.DominantConditionLower != "showers" || morning.DominantConditionDisplay != "Showers" || morning.TemperaturePhraseF != "upper 50s" || morning.TemperatureTrend != "steady" || morning.TemperatureSteadyPhraseF != "upper 50s" || !morning.MentionPrecipitation || morning.MaxPopTimeLabel != "6:00 AM" {
		t.Fatalf("morning presentation fields = %#v, want display facts for template composition", morning)
	}
	if morning.Date != "2026-05-29" || morning.PeriodBegins != "2026-05-29 at 6:00 AM" || morning.PeriodEnds != "2026-05-29 at 12:00 PM" {
		t.Fatalf("morning period = %q/%q/%q, want friendly local date and period labels", morning.Date, morning.PeriodBegins, morning.PeriodEnds)
	}
	overnight := value["overnight"]
	if overnight.MentionPrecipitation {
		t.Fatalf("overnight MentionPrecipitation = true, want false below threshold")
	}
	afternoon := value["afternoon"]
	if !afternoon.Heat || !afternoon.Wind || afternoon.MaxWindGustMph == nil || *afternoon.MaxWindGustMph != 42 {
		t.Fatalf("afternoon = %#v, want heat and wind hazard values", afternoon)
	}
	if !overnight.Cold {
		t.Fatalf("overnight = %#v, want cold hazard", overnight)
	}
	data, err := json.Marshal(output.Value)
	if err != nil {
		t.Fatalf("marshal daypart summaries: %v", err)
	}
	jsonText := string(data)
	for _, field := range []string{"date", "display_name", "period_begins", "period_ends", "temp_range_f", "temperature_phrase_f", "temperature_trend", "temperature_steady_phrase_f", "max_pop_percent", "max_pop_time_label", "mention_precipitation", "max_wind_gust_mph", "dominant_condition", "dominant_condition_lower", "dominant_condition_display"} {
		if !strings.Contains(jsonText, field) {
			t.Fatalf("daypart json = %s, want field %s", jsonText, field)
		}
	}
	if strings.Contains(jsonText, `"period":`) || strings.Contains(jsonText, `T06:00:00`) {
		t.Fatalf("daypart json = %s, want friendly period label instead of raw timestamps", jsonText)
	}
}

func TestDerivedDaypartTemperaturePresentationFields(t *testing.T) {
	tests := []struct {
		name       string
		temps      []float64
		wantTrend  string
		wantStart  string
		wantEnd    string
		wantPeak   string
		wantSteady string
	}{
		{
			name:      "rising",
			temps:     []float64{58, 68},
			wantTrend: "rising",
			wantStart: "upper 50s",
			wantEnd:   "upper 60s",
		},
		{
			name:      "falling",
			temps:     []float64{65, 58},
			wantTrend: "falling",
			wantStart: "mid 60s",
			wantEnd:   "upper 50s",
		},
		{
			name:      "peaking",
			temps:     []float64{62, 78, 65},
			wantTrend: "peaking",
			wantPeak:  "upper 70s",
		},
		{
			name:       "steady same band",
			temps:      []float64{77, 78},
			wantTrend:  "steady",
			wantSteady: "upper 70s",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			summary := derivedDaypartWithTemperatures("afternoon", "2026-05-29T12:00:00-05:00", "sunny", test.temps...)
			value := derivedDaypartSummaryValue(summary, "America/Chicago")
			if value.DominantConditionDisplay != "Sunny" {
				t.Fatalf("DominantConditionDisplay = %q, want Sunny", value.DominantConditionDisplay)
			}
			if value.TemperatureTrend != test.wantTrend ||
				value.TemperatureStartPhraseF != test.wantStart ||
				value.TemperatureEndPhraseF != test.wantEnd ||
				value.TemperaturePeakPhraseF != test.wantPeak ||
				value.TemperatureSteadyPhraseF != test.wantSteady {
				t.Fatalf("temperature presentation = %#v", value)
			}
		})
	}
}

func TestTemperaturePhraseF(t *testing.T) {
	tests := []struct {
		name  string
		value forecast.Range
		want  string
	}{
		{
			name:  "single low band",
			value: forecast.Range{Min: floatPtr(71), Max: floatPtr(73)},
			want:  "low 70s",
		},
		{
			name:  "single upper value",
			value: forecast.Range{Min: floatPtr(68), Max: floatPtr(68)},
			want:  "upper 60s",
		},
		{
			name:  "range across bands",
			value: forecast.Range{Min: floatPtr(68), Max: floatPtr(75)},
			want:  "upper 60s to mid 70s",
		},
		{
			name:  "max only",
			value: forecast.Range{Max: floatPtr(84)},
			want:  "mid 80s",
		},
		{
			name:  "empty",
			value: forecast.Range{},
			want:  "",
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			if got := temperaturePhraseF(test.value); got != test.want {
				t.Fatalf("temperaturePhraseF() = %q, want %q", got, test.want)
			}
		})
	}
}

func TestOutdoorWindowsAndTomorrowPlanningModulesPreserveDailyContent(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.Tomorrow)

	outdoorOutput, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.OutdoorWindows})
	if err != nil {
		t.Fatalf("BuildModule(outdoor windows) error = %v", err)
	}
	outdoor := moduleValue[OutdoorWindowsModule](t, outdoorOutput)
	if outdoor.Best == nil || outdoor.Worst == nil {
		t.Fatalf("outdoor windows = %#v, want best and worst", outdoor)
	}
	if outdoor.Best.Daypart != "overnight" || outdoor.Worst.Daypart != "afternoon" {
		t.Fatalf("outdoor windows = %#v, want quiet overnight and stormy afternoon", outdoor)
	}
	if outdoor.Best.PeriodBegins != "2026-05-29 at 12:00 AM" || outdoor.Best.PeriodEnds != "2026-05-29 at 6:00 AM" {
		t.Fatalf("best outdoor period = %#v, want overnight period labels", outdoor.Best)
	}
	if outdoor.Worst.PeriodBegins != "2026-05-29 at 12:00 PM" || outdoor.Worst.PeriodEnds != "2026-05-29 at 6:00 PM" {
		t.Fatalf("worst outdoor period = %#v, want afternoon period labels", outdoor.Worst)
	}

	planningOutput, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.TomorrowPlanning})
	if err != nil {
		t.Fatalf("BuildModule(tomorrow planning) error = %v", err)
	}
	planning := moduleValue[TomorrowPlanningModule](t, planningOutput)
	if len(planning.MorningReadiness) == 0 || len(planning.CommuteSchoolWorkdayConcerns) == 0 || len(planning.OvernightChangeWatch) == 0 {
		t.Fatalf("tomorrow planning = %#v, want daily planning notes", planning)
	}
	data, err := json.Marshal(planningOutput.Value)
	if err != nil {
		t.Fatalf("marshal tomorrow planning: %v", err)
	}
	if !strings.Contains(string(data), "morning_readiness") || strings.Contains(string(data), "morningReadiness") {
		t.Fatalf("tomorrow planning json = %s, want snake_case fields", string(data))
	}
}

func TestDailyPlanningModulePackagesPlanningFields(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := dailyModuleContext()

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DailyPlanning})
	if err != nil {
		t.Fatalf("BuildModule(daily planning) error = %v", err)
	}
	if output.ID != module.DailyPlanning || output.StanzaName != "daily_planning" {
		t.Fatalf("output = %#v, want daily planning stanza", output)
	}
	planning := moduleValue[DailyPlanningModule](t, output)
	if len(planning.MorningReadiness) == 0 ||
		len(planning.CommuteSchoolWorkdayConcerns) == 0 ||
		len(planning.OvernightChangeWatch) == 0 {
		t.Fatalf("daily planning = %#v, want populated planning fields", planning)
	}
	if !containsString(planning.MorningReadiness, "Morning precipitation chance peaks near 60%.") {
		t.Fatalf("MorningReadiness = %#v, want precipitation readiness note", planning.MorningReadiness)
	}
	if !containsString(planning.CommuteSchoolWorkdayConcerns, "Afternoon alert overlap needs attention.") {
		t.Fatalf("CommuteSchoolWorkdayConcerns = %#v, want alert-overlap concern", planning.CommuteSchoolWorkdayConcerns)
	}
	if !containsString(planning.OvernightChangeWatch, "Watch for forecast timing or intensity adjustments overnight.") {
		t.Fatalf("OvernightChangeWatch = %#v, want overnight fallback note", planning.OvernightChangeWatch)
	}
	data, err := json.Marshal(output.Value)
	if err != nil {
		t.Fatalf("marshal daily planning: %v", err)
	}
	jsonText := string(data)
	for _, field := range []string{"morning_readiness", "commute_school_workday_concerns", "overnight_change_watch"} {
		if !strings.Contains(jsonText, field) {
			t.Fatalf("daily planning json = %s, want field %s", jsonText, field)
		}
	}
	if strings.Contains(jsonText, "tomorrow_planning") || strings.Contains(jsonText, "morningReadiness") {
		t.Fatalf("daily planning json = %s, want daily snake_case fields only", jsonText)
	}
}

func TestDailyPlanningModuleRejectsUnsupportedReports(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	for _, id := range []report.ID{report.DailyToday, report.Today, report.Tomorrow, report.Hourly, report.ThreeDay, report.Weekend, report.Storm} {
		t.Run(string(id), func(t *testing.T) {
			ctx := derivedModuleContext(id)
			_, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DailyPlanning})
			if err == nil || !strings.Contains(err.Error(), `module "daily_planning" is not compatible with report`) {
				t.Fatalf("BuildModule(%s) error = %v, want incompatible report", id, err)
			}
		})
	}
}

func TestDailyPlanningModuleHandlesMissingDailySummary(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := dailyModuleContext()
	ctx.Derived.DailySummaries = nil

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DailyPlanning})
	if err != nil {
		t.Fatalf("BuildModule(daily planning) error = %v", err)
	}
	planning := moduleValue[DailyPlanningModule](t, output)
	if len(planning.MorningReadiness) != 0 ||
		len(planning.CommuteSchoolWorkdayConcerns) != 0 ||
		len(planning.OvernightChangeWatch) != 0 {
		t.Fatalf("daily planning = %#v, want empty output without daily summary", planning)
	}
}

func TestTodayPlanningModulePackagesPlanningFields(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := todayModuleContext()

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.TodayPlanning})
	if err != nil {
		t.Fatalf("BuildModule(today planning) error = %v", err)
	}
	if output.ID != module.TodayPlanning || output.StanzaName != "today_planning" {
		t.Fatalf("output = %#v, want today planning stanza", output)
	}
	planning := moduleValue[TodayPlanningModule](t, output)
	if len(planning.MorningReadiness) == 0 ||
		len(planning.CommuteSchoolWorkdayConcerns) == 0 ||
		len(planning.OutdoorPlanning) == 0 ||
		len(planning.LateDayChangeWatch) == 0 {
		t.Fatalf("today planning = %#v, want populated planning fields", planning)
	}
	if !containsString(planning.MorningReadiness, "Morning precipitation chance peaks near 60%.") {
		t.Fatalf("MorningReadiness = %#v, want precipitation readiness note", planning.MorningReadiness)
	}
	if !containsString(planning.OutdoorPlanning, "Best outdoor window: Overnight (cold risk).") ||
		!containsString(planning.OutdoorPlanning, "Toughest outdoor window: Afternoon (high precipitation chance, gusty wind, alert overlap, heat risk).") {
		t.Fatalf("OutdoorPlanning = %#v, want deterministic best and toughest windows", planning.OutdoorPlanning)
	}
	if !containsString(planning.LateDayChangeWatch, "Afternoon precipitation timing may shift; current peak is near 80%.") {
		t.Fatalf("LateDayChangeWatch = %#v, want late-day change note", planning.LateDayChangeWatch)
	}
	data, err := json.Marshal(output.Value)
	if err != nil {
		t.Fatalf("marshal today planning: %v", err)
	}
	jsonText := string(data)
	for _, field := range []string{"morning_readiness", "commute_school_workday_concerns", "outdoor_planning", "late_day_change_watch"} {
		if !strings.Contains(jsonText, field) {
			t.Fatalf("today planning json = %s, want field %s", jsonText, field)
		}
	}
	if strings.Contains(jsonText, "morningReadiness") || strings.Contains(jsonText, "lateDayChangeWatch") {
		t.Fatalf("today planning json = %s, want snake_case fields", jsonText)
	}
}

func TestTodayPlanningModuleRejectsUnsupportedReports(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	for _, id := range []report.ID{report.Tomorrow, report.DailyToday} {
		t.Run(string(id), func(t *testing.T) {
			ctx := derivedModuleContext(id)
			_, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.TodayPlanning})
			if err == nil || !strings.Contains(err.Error(), `module "today_planning" is not compatible with report`) {
				t.Fatalf("BuildModule(%s) error = %v, want incompatible report", id, err)
			}
		})
	}
}

func TestTodayPlanningModuleHandlesMissingDailySummary(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := todayModuleContext()
	ctx.Derived.DailySummaries = nil

	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.TodayPlanning})
	if err != nil {
		t.Fatalf("BuildModule(today planning) error = %v", err)
	}
	planning := moduleValue[TodayPlanningModule](t, output)
	if len(planning.MorningReadiness) != 0 ||
		len(planning.CommuteSchoolWorkdayConcerns) != 0 ||
		len(planning.OutdoorPlanning) != 0 ||
		len(planning.LateDayChangeWatch) != 0 {
		t.Fatalf("today planning = %#v, want empty output without daily summary", planning)
	}
}

func TestDerivedModulesHandleMissingData(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	ctx := derivedModuleContext(report.DailyToday)
	ctx.Derived.DailySummaries = nil
	ctx.Derived.DaypartSummaries = nil

	if _, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDailySummary}); err == nil {
		t.Fatal("BuildModule(derived daily summary) error = nil, want required facts error")
	}
	if _, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.DerivedDaypartSummaries}); err == nil {
		t.Fatal("BuildModule(daypart summaries) error = nil, want required facts error")
	}
	output, err := registry.BuildModule(ctx, module.ConfigItem{ID: module.OutdoorWindows})
	if err != nil {
		t.Fatalf("BuildModule(outdoor windows) error = %v", err)
	}
	windows := moduleValue[OutdoorWindowsModule](t, output)
	if windows.Best != nil || windows.Worst != nil {
		t.Fatalf("outdoor windows = %#v, want empty output with missing dayparts", windows)
	}
}

func derivedModuleContext(id report.ID) ModuleContext {
	generatedAt := mustParseModuleTime("2026-05-29T08:00:00-05:00")
	definition := report.DefaultRegistry().MustLookup(id)
	summary := forecast.DailySummary{
		Date: "2026-05-29",
		Period: timeutil.Period{
			Start: mustParseModuleTime("2026-05-29T00:00:00-05:00"),
			End:   mustParseModuleTime("2026-05-30T00:00:00-05:00"),
		},
		Dayparts: []forecast.DaypartSummary{
			derivedDaypart("overnight", "2026-05-29T00:00:00-05:00", "2026-05-29T06:00:00-05:00", "Clear and cold", 31, nil, 0, 5),
			derivedDaypart("morning", "2026-05-29T06:00:00-05:00", "2026-05-29T12:00:00-05:00", "Showers", 58, nil, 60, 15),
			derivedDaypart("afternoon", "2026-05-29T12:00:00-05:00", "2026-05-29T18:00:00-05:00", "Thunderstorms with gusty wind", 96, floatPtr(101), 80, 42),
		},
	}
	hours := []weatherdata.ForecastPeriod{
		derivedHour("2026-05-29T00:00:00-05:00", "Clear and cold", 0, 31, nil, 5),
		derivedHour("2026-05-29T08:00:00-05:00", "Showers", 60, 58, nil, 15),
		derivedHour("2026-05-29T09:00:00-05:00", "Dry break", 20, 62, nil, 10),
		derivedHour("2026-05-29T12:00:00-05:00", "Thunderstorms with gusty wind", 80, 96, floatPtr(101), 42),
		derivedHour("2026-05-29T13:00:00-05:00", "Heavy rain", 70, 82, nil, 30),
		derivedHour("2026-05-29T14:00:00-05:00", "Drying out", 20, 78, nil, 12),
	}
	narrative := []weatherdata.ForecastPeriod{
		{
			Name:                              "Today",
			StartTime:                         mustParseModuleTime("2026-05-29T06:00:00-05:00"),
			EndTime:                           mustParseModuleTime("2026-05-29T18:00:00-05:00"),
			IsDay:                             boolPtr(true),
			TextDescription:                   "Morning storms, then partly sunny.",
			TemperatureFMax:                   floatPtr(88),
			ProbabilityOfPrecipitationPercent: floatPtr(55),
		},
		{
			Name:                              "Tonight",
			StartTime:                         mustParseModuleTime("2026-05-29T18:00:00-05:00"),
			EndTime:                           mustParseModuleTime("2026-05-30T00:00:00-05:00"),
			IsDay:                             boolPtr(false),
			TextDescription:                   "Clouds linger tonight.",
			TemperatureFMin:                   floatPtr(64),
			ProbabilityOfPrecipitationPercent: floatPtr(30),
		},
	}
	summary.Dayparts[2].AlertOverlaps = []forecast.AlertOverlap{{Event: "Severe Thunderstorm Watch"}}
	summary.NarrativePeriods = append([]weatherdata.ForecastPeriod(nil), narrative...)
	return ModuleContext{
		Resolved: report.Resolved{
			Definition:  definition,
			GeneratedAt: generatedAt,
			Timezone:    "America/Chicago",
			ValidPeriod: summary.Period,
		},
		Collected: facts.CollectedFacts{
			Narrative: &weatherdata.ForecastRun{
				IssuedAt: mustParseModuleTime("2026-05-29T10:30:00-05:00"),
				Product:  "narrative",
				Periods:  append([]weatherdata.ForecastPeriod(nil), narrative...),
			},
		},
		Derived: facts.DerivedFacts{
			ValidPeriodHourlyPeriods:    hours,
			ValidPeriodNarrativePeriods: narrative,
			DailySummaries:              []forecast.DailySummary{summary},
			DaypartSummaries:            append([]forecast.DaypartSummary(nil), summary.Dayparts...),
			PrecipTiming:                forecast.BuildPrecipTiming(hours),
		},
		Units:    "us",
		Timezone: "America/Chicago",
	}
}

func todayModuleContext() ModuleContext {
	ctx := derivedModuleContext(report.DailyToday)
	ctx.Resolved.Definition = report.Definition{
		ID:       report.Today,
		Name:     "Today Report",
		PromptID: "weather.today_generated_text",
	}
	return ctx
}

func dailyModuleContext() ModuleContext {
	ctx := derivedModuleContext(report.Tomorrow)
	ctx.Resolved.Definition = report.Definition{
		ID:       report.ID("daily"),
		Name:     "Daily Report",
		PromptID: "weather.daily_generated_text",
	}
	return ctx
}

func derivedDaypart(name string, start string, end string, text string, temperature float64, apparent *float64, precip float64, gust float64) forecast.DaypartSummary {
	hour := derivedHour(start, text, precip, temperature, apparent, gust)
	return forecast.SummarizeDaypart(name, timeutil.Period{
		Start: mustParseModuleTime(start),
		End:   mustParseModuleTime(end),
	}, []weatherdata.ForecastPeriod{hour})
}

func derivedDaypartWithTemperatures(name string, start string, text string, temperatures ...float64) forecast.DaypartSummary {
	startTime := mustParseModuleTime(start)
	periods := make([]weatherdata.ForecastPeriod, 0, len(temperatures))
	for index, temperature := range temperatures {
		periodStart := startTime.Add(time.Duration(index) * time.Hour)
		periods = append(periods, weatherdata.ForecastPeriod{
			StartTime:       periodStart,
			EndTime:         periodStart.Add(time.Hour),
			TextDescription: text,
			TemperatureF:    floatPtr(temperature),
		})
	}
	return forecast.SummarizeDaypart(name, timeutil.Period{
		Start: startTime,
		End:   startTime.Add(time.Duration(len(temperatures)) * time.Hour),
	}, periods)
}

func derivedHour(start string, text string, precip float64, temperature float64, apparent *float64, gust float64) weatherdata.ForecastPeriod {
	startTime := mustParseModuleTime(start)
	endTime := startTime.Add(time.Hour)
	return weatherdata.ForecastPeriod{
		StartTime:                         startTime,
		EndTime:                           endTime,
		TextDescription:                   text,
		TemperatureF:                      floatPtr(temperature),
		ApparentTemperatureF:              apparent,
		ProbabilityOfPrecipitationPercent: floatPtr(precip),
		WindGustMph:                       floatPtr(gust),
	}
}

func floatPtr(value float64) *float64 {
	return &value
}

func boolPtr(value bool) *bool {
	return &value
}

func containsString(values []string, want string) bool {
	for _, value := range values {
		if value == want {
			return true
		}
	}
	return false
}