Add 3-Day Outlook generation

internal/briefing/three_day.go

@@ -0,0 +1,121 @@
+package briefing
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+type ThreeDay struct {
+	Days           []OutlookDay            `json:"days"`
+	RelevantAlerts []forecast.AlertOverlap `json:"relevantAlerts,omitempty"`
+	Discussion     DiscussionContext       `json:"discussion,omitempty"`
+	WeatherStory   *WeatherStoryContext    `json:"weatherStory,omitempty"`
+}
+
+type OutlookDay struct {
+	Date                        string                    `json:"date"`
+	Period                      timeutil.Period           `json:"period"`
+	OverallCharacter            string                    `json:"overallCharacter"`
+	Temperature                 forecast.Range            `json:"temperature,omitempty"`
+	MaxPrecipitationProbability *forecast.TimedValue      `json:"maxPrecipitationProbability,omitempty"`
+	PeakWindGust                *forecast.TimedValue      `json:"peakWindGust,omitempty"`
+	Risks                       []string                  `json:"risks,omitempty"`
+	OutdoorWindows              OutdoorWindows            `json:"outdoorWindows"`
+	RelevantAlerts              []forecast.AlertOverlap   `json:"relevantAlerts,omitempty"`
+	Dayparts                    []forecast.DaypartSummary `json:"dayparts"`
+}
+
+func BuildThreeDay(ctx BuildContext, summaries []forecast.DailySummary) (Package, error) {
+	if ctx.Resolved.Definition.ID != report.ThreeDay {
+		return Package{}, fmt.Errorf("3-day briefing requires a 3-day report definition")
+	}
+	if len(summaries) == 0 {
+		return Package{}, fmt.Errorf("3-day forecast summaries are required")
+	}
+	pkg := Package{
+		Metadata: BuildMetadata(ctx),
+		ThreeDay: &ThreeDay{
+			Discussion:   buildDiscussion(summaries[0].Discussion),
+			WeatherStory: buildWeatherStory(ctx.Bundle),
+		},
+	}
+	alerts := map[string]forecast.AlertOverlap{}
+	for _, summary := range summaries {
+		day := buildOutlookDay(summary)
+		pkg.ThreeDay.Days = append(pkg.ThreeDay.Days, day)
+		for _, alert := range summary.AlertOverlaps {
+			key := alert.Event
+			if key == "" {
+				key = alert.Headline
+			}
+			if key != "" {
+				alerts[key] = alert
+			}
+		}
+	}
+	keys := make([]string, 0, len(alerts))
+	for key := range alerts {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	for _, key := range keys {
+		pkg.ThreeDay.RelevantAlerts = append(pkg.ThreeDay.RelevantAlerts, alerts[key])
+	}
+	return pkg, nil
+}
+
+func buildOutlookDay(summary forecast.DailySummary) OutlookDay {
+	day := OutlookDay{
+		Date:           summary.Date,
+		Period:         summary.Period,
+		OutdoorWindows: buildOutdoorWindows(summary.Dayparts),
+		RelevantAlerts: summary.AlertOverlaps,
+		Dayparts:       summary.Dayparts,
+	}
+	conditions := map[string]struct{}{}
+	risks := map[string]struct{}{}
+	for _, daypart := range summary.Dayparts {
+		addRange(&day.Temperature, daypart.Temperature)
+		maxTimedValue(&day.MaxPrecipitationProbability, daypart.MaxPrecipitationProbability)
+		maxTimedValue(&day.PeakWindGust, daypart.PeakWindGust)
+		if daypart.DominantCondition != "" {
+			conditions[daypart.DominantCondition] = struct{}{}
+		}
+		for _, risk := range hazardsForIndicators(daypart.Indicators) {
+			risks[risk] = struct{}{}
+		}
+		if daypart.MaxPrecipitationProbability != nil && daypart.MaxPrecipitationProbability.Value >= 50 {
+			risks["precipitation"] = struct{}{}
+		}
+		if daypart.PeakWindGust != nil && daypart.PeakWindGust.Value >= 30 {
+			risks["wind"] = struct{}{}
+		}
+	}
+	for _, alert := range summary.AlertOverlaps {
+		if alert.Event != "" {
+			risks[alert.Event] = struct{}{}
+		}
+	}
+	day.Risks = sortedSet(risks)
+	day.OverallCharacter = outlookCharacter(sortedSet(conditions), day.Risks)
+	return day
+}
+
+func outlookCharacter(conditions []string, risks []string) string {
+	if len(conditions) == 0 && len(risks) == 0 {
+		return "Quiet weather is expected."
+	}
+	parts := []string{}
+	if len(conditions) > 0 {
+		parts = append(parts, strings.Join(conditions, "; "))
+	}
+	if len(risks) > 0 {
+		parts = append(parts, "risks: "+strings.Join(risks, "; "))
+	}
+	return strings.Join(parts, ". ") + "."
+}