package briefing

import (
	"fmt"

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

type DerivedDailySummaryModule struct {
	Date               string   `json:"date,omitempty"`
	HighTempF          *int     `json:"high_temp_f,omitempty"`
	LowTempF           *int     `json:"low_temp_f,omitempty"`
	MaxPopPercent      *int     `json:"max_pop_percent,omitempty"`
	MaxPopWindow       string   `json:"max_pop_window,omitempty"`
	FirstPrecipHour    string   `json:"first_precip_hour,omitempty"`
	LastPrecipHour     string   `json:"last_precip_hour,omitempty"`
	ThunderMentioned   bool     `json:"thunder_mentioned"`
	MaxWindGustMph     *int     `json:"max_wind_gust_mph,omitempty"`
	HeatIndexMaxF      *int     `json:"heat_index_max_f,omitempty"`
	DominantConditions []string `json:"dominant_conditions,omitempty"`
	Hazards            []string `json:"hazards,omitempty"`
}

func buildDerivedDailySummaryModule(ctx ModuleContext, _ any) (*module.Output, error) {
	summary := ctx.Derived.FirstDailySummary()
	if summary == nil {
		return nil, fmt.Errorf("daily summary facts are required")
	}
	value, err := derivedDailySummaryValue(*summary, ctx.Derived.PrecipTiming, ctx.Timezone)
	if err != nil {
		return nil, err
	}
	return &module.Output{ID: module.DerivedDailySummary, StanzaName: "derived_daily_summary", Value: value}, nil
}

func derivedDailySummaryValue(summary forecast.DailySummary, timing forecast.PrecipTiming, timezone string) (DerivedDailySummaryModule, error) {
	value := DerivedDailySummaryModule{
		Date:             summary.Date,
		ThunderMentioned: timing.ThunderMentioned,
	}
	conditions := map[string]struct{}{}
	hazards := map[string]struct{}{}
	var temperature forecast.Range
	var apparent forecast.Range
	var maxPop *forecast.TimedValue
	var maxGust *forecast.TimedValue
	var maxPopWindow timeutil.Period
	for _, daypart := range summary.Dayparts {
		addRange(&temperature, daypart.Temperature)
		addRange(&apparent, daypart.ApparentTemperature)
		if daypart.MaxPrecipitationProbability != nil {
			if maxPop == nil || daypart.MaxPrecipitationProbability.Value > maxPop.Value {
				copied := *daypart.MaxPrecipitationProbability
				maxPop = &copied
				maxPopWindow = daypart.Period
			}
		}
		maxTimedValue(&maxGust, daypart.PeakWindGust)
		if daypart.DominantCondition != "" {
			conditions[daypart.DominantCondition] = struct{}{}
		}
		for _, hazard := range hazardsForIndicators(daypart.Indicators) {
			hazards[hazard] = struct{}{}
		}
	}
	for _, alert := range summary.AlertOverlaps {
		if alert.Event != "" {
			hazards[alert.Event] = struct{}{}
		}
	}
	value.HighTempF = roundedInt(temperature.Max)
	value.LowTempF = roundedInt(temperature.Min)
	value.HeatIndexMaxF = roundedInt(apparent.Max)
	if maxPop != nil {
		value.MaxPopPercent = roundedInt(&maxPop.Value)
		value.MaxPopWindow = periodClockLabel(maxPopWindow, timezone)
	}
	if maxGust != nil {
		value.MaxWindGustMph = roundedInt(&maxGust.Value)
	}
	value.FirstPrecipHour = timedClockLabel(timing.FirstPrecipitation, timezone)
	value.LastPrecipHour = timedClockLabel(timing.LastPrecipitation, timezone)
	value.DominantConditions = sortedSet(conditions)
	value.Hazards = sortedSet(hazards)
	return value, nil
}