generate excel worksheets when data is available instead of on-demand

server/handler/snapshots.go

@@ -111,7 +111,7 @@ func (h *Handler) renderSnapshotList(w http.ResponseWriter, r *http.Request, sna
 		label := report.FormatSnapshotLabel(snapshotType, record.SnapshotTime, record.TableName)
 		entries = append(entries, views.SnapshotEntry{
 			Label: label,
-			Link:  "/api/report/snapshot?table=" + url.QueryEscape(record.TableName),
+			Link:  "/reports/" + url.PathEscape(record.TableName) + ".xlsx",
 			Count: record.SnapshotCount,
 		})
 	}

server/router/router.go

@@ -5,6 +5,8 @@ import (
 	"log/slog"
 	"net/http"
 	"net/http/pprof"
+	"os"
+	"path/filepath"
 	"vctp/db"
 	"vctp/dist"
 	"vctp/internal/secrets"
@@ -28,10 +30,19 @@ func New(logger *slog.Logger, database db.Database, buildTime string, sha1ver st
 
 	mux := http.NewServeMux()
 
+	reportsDir := settings.Values.Settings.ReportsDir
+	if reportsDir == "" {
+		reportsDir = "/var/lib/vctp/reports"
+	}
+	if err := os.MkdirAll(reportsDir, 0o755); err != nil {
+		logger.Warn("failed to create reports directory", "error", err, "path", reportsDir)
+	}
+
 	mux.Handle("/assets/", middleware.CacheMiddleware(http.FileServer(http.FS(dist.AssetsDir))))
 	mux.Handle("/favicon.ico", middleware.CacheMiddleware(http.FileServer(http.FS(dist.AssetsDir))))
 	mux.Handle("/favicon-16x16.png", middleware.CacheMiddleware(http.FileServer(http.FS(dist.AssetsDir))))
 	mux.Handle("/favicon-32x32.png", middleware.CacheMiddleware(http.FileServer(http.FS(dist.AssetsDir))))
+	mux.Handle("/reports/", http.StripPrefix("/reports/", http.FileServer(http.Dir(filepath.Clean(reportsDir)))))
 	mux.HandleFunc("/", h.Home)
 	mux.HandleFunc("/api/event/vm/create", h.VmCreateEvent)
 	mux.HandleFunc("/api/event/vm/modify", h.VmModifyEvent)