Publish ITWorx Pulse source

internal/applicationapi/handler.go

@@ -0,0 +1,68 @@
+package applicationapi
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/itworx/pulse/internal/application"
+	"github.com/itworx/pulse/internal/auth"
+	"github.com/itworx/pulse/internal/problem"
+)
+
+type Handler struct {
+	Provider interface {
+		Snapshot(context.Context) (application.Snapshot, error)
+	}
+}
+
+func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet || (r.URL.Path != "/api/v1/applications" && !strings.HasPrefix(r.URL.Path, "/api/v1/applications/")) {
+		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 applications.", 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, "APPLICATIONS_UNAVAILABLE", "Applications not available", "Applicatiegegevens konden niet worden gelezen.", nil)
+		return
+	}
+	if r.URL.Path != "/api/v1/applications" {
+		id := strings.TrimPrefix(r.URL.Path, "/api/v1/applications/")
+		for _, item := range snapshot.Applications {
+			if item.ID == id {
+				writeJSON(w, struct {
+					Source      application.Source      `json:"source"`
+					Application application.Application `json:"application"`
+				}{Source: snapshot.Source, Application: item})
+				return
+			}
+		}
+		http.NotFound(w, r)
+		return
+	}
+	if len(snapshot.Applications) > 100 {
+		snapshot.Applications = snapshot.Applications[:100]
+	}
+	writeJSON(w, snapshot)
+}
+func (h Handler) snapshot(r *http.Request) (application.Snapshot, error) {
+	if h.Provider == nil {
+		return application.UnknownSnapshot(time.Now().UTC(), "applications", "agent", "source_unavailable"), nil
+	}
+	return h.Provider.Snapshot(r.Context())
+}
+func writeJSON(w http.ResponseWriter, value any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.Header().Set("Cache-Control", "private, max-age=5")
+	_ = json.NewEncoder(w).Encode(value)
+}