Initial MVP commit

internal/adapters/postgres/observations_repo.go

@@ -0,0 +1,106 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"gitea.maximumdirect.net/ejr/weatherapi/internal/core/ports"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type ObservationRepository struct {
+	pool *pgxpool.Pool
+}
+
+func NewObservationRepository(pool *pgxpool.Pool) *ObservationRepository {
+	return &ObservationRepository{pool: pool}
+}
+
+func (r *ObservationRepository) GetCurrentSummary(ctx context.Context, window time.Duration) (ports.ObservationSummaryMetric, error) {
+	var temperature sql.NullFloat64
+	var apparent sql.NullFloat64
+
+	if err := r.pool.QueryRow(ctx, queryObservationSummary, windowMinutes(window)).Scan(&temperature, &apparent); err != nil {
+		return ports.ObservationSummaryMetric{}, fmt.Errorf("query observation summary: %w", err)
+	}
+
+	return ports.ObservationSummaryMetric{
+		TemperatureC:         ptrFloat64(temperature),
+		ApparentTemperatureC: ptrFloat64(apparent),
+	}, nil
+}
+
+func (r *ObservationRepository) ListCurrentConditions(ctx context.Context, window time.Duration) ([]ports.ObservationConditionMetric, error) {
+	rows, err := r.pool.Query(ctx, queryObservationConditions, windowMinutes(window))
+	if err != nil {
+		return nil, fmt.Errorf("query observation conditions: %w", err)
+	}
+	defer rows.Close()
+
+	out := make([]ports.ObservationConditionMetric, 0)
+	for rows.Next() {
+		var stationID sql.NullString
+		var observedAt time.Time
+		var temperature sql.NullFloat64
+		var textDescription sql.NullString
+		var providerRawDescription sql.NullString
+		var conditionText sql.NullString
+
+		if err := rows.Scan(
+			&stationID,
+			&observedAt,
+			&temperature,
+			&textDescription,
+			&providerRawDescription,
+			&conditionText,
+		); err != nil {
+			return nil, fmt.Errorf("scan observation condition row: %w", err)
+		}
+
+		out = append(out, ports.ObservationConditionMetric{
+			StationID:              ptrString(stationID),
+			ObservedAt:             observedAt,
+			TemperatureC:           ptrFloat64(temperature),
+			TextDescription:        ptrString(textDescription),
+			ProviderRawDescription: ptrString(providerRawDescription),
+			ConditionText:          ptrString(conditionText),
+		})
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate observation conditions rows: %w", err)
+	}
+
+	return out, nil
+}
+
+func (r *ObservationRepository) ListCurrentPrecipitationEvents(ctx context.Context, window time.Duration) ([]string, error) {
+	rows, err := r.pool.Query(ctx, queryObservationPrecipitation, windowMinutes(window))
+	if err != nil {
+		return nil, fmt.Errorf("query observation precipitation events: %w", err)
+	}
+	defer rows.Close()
+
+	out := make([]string, 0)
+	for rows.Next() {
+		var rawText sql.NullString
+		if err := rows.Scan(&rawText); err != nil {
+			return nil, fmt.Errorf("scan observation precipitation row: %w", err)
+		}
+		if rawText.Valid {
+			out = append(out, rawText.String)
+		}
+	}
+
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("iterate observation precipitation rows: %w", err)
+	}
+
+	return out, nil
+}
+
+func windowMinutes(window time.Duration) int {
+	return int(window / time.Minute)
+}