Embed Reanimator Chart web viewer

audit/internal/webui/server.go

@@ -0,0 +1,77 @@
+package webui
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"os"
+	"strings"
+
+	"reanimator/chart/viewer"
+	chartweb "reanimator/chart/web"
+)
+
+const defaultTitle = "Bee Hardware Audit"
+
+type HandlerOptions struct {
+	Title     string
+	AuditPath string
+}
+
+func NewHandler(opts HandlerOptions) http.Handler {
+	title := strings.TrimSpace(opts.Title)
+	if title == "" {
+		title = defaultTitle
+	}
+
+	auditPath := strings.TrimSpace(opts.AuditPath)
+	mux := http.NewServeMux()
+	mux.Handle("GET /static/", http.StripPrefix("/static/", chartweb.Static()))
+	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Cache-Control", "no-store")
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("ok"))
+	})
+	mux.HandleFunc("GET /audit.json", func(w http.ResponseWriter, r *http.Request) {
+		data, err := loadSnapshot(auditPath)
+		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				http.Error(w, "audit snapshot not found", http.StatusNotFound)
+				return
+			}
+			http.Error(w, fmt.Sprintf("read audit snapshot: %v", err), http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Cache-Control", "no-store")
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		_, _ = w.Write(data)
+	})
+	mux.HandleFunc("GET /", func(w http.ResponseWriter, r *http.Request) {
+		snapshot, err := loadSnapshot(auditPath)
+		if err != nil && !errors.Is(err, os.ErrNotExist) {
+			http.Error(w, fmt.Sprintf("read audit snapshot: %v", err), http.StatusInternalServerError)
+			return
+		}
+
+		html, err := viewer.RenderHTML(snapshot, title)
+		if err != nil {
+			http.Error(w, fmt.Sprintf("render snapshot: %v", err), http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Cache-Control", "no-store")
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		_, _ = w.Write(html)
+	})
+	return mux
+}
+
+func ListenAndServe(addr string, opts HandlerOptions) error {
+	return http.ListenAndServe(addr, NewHandler(opts))
+}
+
+func loadSnapshot(path string) ([]byte, error) {
+	if strings.TrimSpace(path) == "" {
+		return nil, os.ErrNotExist
+	}
+	return os.ReadFile(path)
+}