Initial MVP commit

internal/application/observations/service.go

@@ -0,0 +1,84 @@
+package observations
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/units"
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/core/ports"
+)
+
+type Service struct {
+	repo      ports.ObservationRepository
+	converter units.Converter
+	window    time.Duration
+}
+
+func NewService(repo ports.ObservationRepository, converter units.Converter, window time.Duration) *Service {
+	return &Service{repo: repo, converter: converter, window: window}
+}
+
+type CurrentResponse struct {
+	Summary             SummaryResponse     `json:"summary"`
+	Conditions          []ConditionResponse `json:"conditions"`
+	PrecipitationEvents []string            `json:"precipitationEvents"`
+}
+
+type SummaryResponse struct {
+	TemperatureF         *float64 `json:"temperatureF"`
+	ApparentTemperatureF *float64 `json:"apparentTemperatureF"`
+	WindowMinutes        int      `json:"windowMinutes"`
+}
+
+type ConditionResponse struct {
+	StationID              *string   `json:"stationId"`
+	ObservedAt             time.Time `json:"observedAt"`
+	TemperatureF           *float64  `json:"temperatureF"`
+	TextDescription        *string   `json:"textDescription"`
+	ProviderRawDescription *string   `json:"providerRawDescription"`
+	ConditionText          *string   `json:"conditionText"`
+}
+
+func (s *Service) GetCurrent(ctx context.Context) (CurrentResponse, error) {
+	if s == nil {
+		return CurrentResponse{}, fmt.Errorf("observations service is nil")
+	}
+
+	summary, err := s.repo.GetCurrentSummary(ctx, s.window)
+	if err != nil {
+		return CurrentResponse{}, err
+	}
+
+	conditionsMetric, err := s.repo.ListCurrentConditions(ctx, s.window)
+	if err != nil {
+		return CurrentResponse{}, err
+	}
+
+	precip, err := s.repo.ListCurrentPrecipitationEvents(ctx, s.window)
+	if err != nil {
+		return CurrentResponse{}, err
+	}
+
+	conditions := make([]ConditionResponse, 0, len(conditionsMetric))
+	for _, c := range conditionsMetric {
+		conditions = append(conditions, ConditionResponse{
+			StationID:              c.StationID,
+			ObservedAt:             c.ObservedAt,
+			TemperatureF:           s.converter.TemperatureCToOutput(c.TemperatureC),
+			TextDescription:        c.TextDescription,
+			ProviderRawDescription: c.ProviderRawDescription,
+			ConditionText:          c.ConditionText,
+		})
+	}
+
+	return CurrentResponse{
+		Summary: SummaryResponse{
+			TemperatureF:         s.converter.TemperatureCToOutput(summary.TemperatureC),
+			ApparentTemperatureF: s.converter.TemperatureCToOutput(summary.ApparentTemperatureC),
+			WindowMinutes:        int(s.window / time.Minute),
+		},
+		Conditions:          conditions,
+		PrecipitationEvents: precip,
+	}, nil
+}