Publish ITWorx Pulse source

internal/forecastapi/handler.go

@@ -0,0 +1,49 @@
+package forecastapi
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"time"
+
+	"github.com/itworx/pulse/internal/auth"
+	"github.com/itworx/pulse/internal/forecast"
+	"github.com/itworx/pulse/internal/problem"
+)
+
+type Handler struct {
+	Provider forecast.Provider
+}
+
+func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet || r.URL.Path != "/api/v1/forecasts" {
+		http.NotFound(w, r)
+		return
+	}
+	if _, ok := auth.PrincipalFromContext(r.Context()); !ok {
+		problem.Write(w, r, http.StatusUnauthorized, "UNAUTHORIZED", "Authentication required", "Authentication is required to read forecasts.", nil)
+		return
+	}
+	if err := r.Context().Err(); err != nil {
+		return
+	}
+	snapshot, err := h.snapshot(r)
+	if err != nil {
+		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+			return
+		}
+		problem.Write(w, r, http.StatusServiceUnavailable, "FORECASTS_UNAVAILABLE", "Forecastgegevens niet beschikbaar", "De capaciteitsvoorspellingen konden niet worden gelezen.", nil)
+		return
+	}
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Cache-Control", "private, max-age=15")
+	_ = json.NewEncoder(w).Encode(snapshot)
+}
+
+func (h Handler) snapshot(r *http.Request) (forecast.Snapshot, error) {
+	if h.Provider == nil {
+		return forecast.UnknownSnapshot(time.Now().UTC(), "source_unavailable"), nil
+	}
+	return h.Provider.Snapshot(r.Context())
+}