add one minute chart + refactor rpc

- add one minute charts
- update disk io to use bytes
- update hub and agent connection interfaces / handlers to be more
flexible
- change agent cache to use cache time instead of session id
- refactor collection of metrics which require deltas to track
separately per cache time

agent/handlers.go

@@ -0,0 +1,101 @@
+package agent
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/fxamacker/cbor/v2"
+	"github.com/henrygd/beszel/internal/common"
+)
+
+// HandlerContext provides context for request handlers
+type HandlerContext struct {
+	Client      *WebSocketClient
+	Agent       *Agent
+	Request     *common.HubRequest[cbor.RawMessage]
+	RequestID   *uint32
+	HubVerified bool
+	// SendResponse abstracts how a handler sends responses (WS or SSH)
+	SendResponse func(data any, requestID *uint32) error
+}
+
+// RequestHandler defines the interface for handling specific websocket request types
+type RequestHandler interface {
+	// Handle processes the request and returns an error if unsuccessful
+	Handle(hctx *HandlerContext) error
+}
+
+// Responder sends handler responses back to the hub (over WS or SSH)
+type Responder interface {
+	SendResponse(data any, requestID *uint32) error
+}
+
+// HandlerRegistry manages the mapping between actions and their handlers
+type HandlerRegistry struct {
+	handlers map[common.WebSocketAction]RequestHandler
+}
+
+// NewHandlerRegistry creates a new handler registry with default handlers
+func NewHandlerRegistry() *HandlerRegistry {
+	registry := &HandlerRegistry{
+		handlers: make(map[common.WebSocketAction]RequestHandler),
+	}
+
+	registry.Register(common.GetData, &GetDataHandler{})
+	registry.Register(common.CheckFingerprint, &CheckFingerprintHandler{})
+
+	return registry
+}
+
+// Register registers a handler for a specific action type
+func (hr *HandlerRegistry) Register(action common.WebSocketAction, handler RequestHandler) {
+	hr.handlers[action] = handler
+}
+
+// Handle routes the request to the appropriate handler
+func (hr *HandlerRegistry) Handle(hctx *HandlerContext) error {
+	handler, exists := hr.handlers[hctx.Request.Action]
+	if !exists {
+		return fmt.Errorf("unknown action: %d", hctx.Request.Action)
+	}
+
+	// Check verification requirement - default to requiring verification
+	if hctx.Request.Action != common.CheckFingerprint && !hctx.HubVerified {
+		return errors.New("hub not verified")
+	}
+
+	// Log handler execution for debugging
+	// slog.Debug("Executing handler", "action", hctx.Request.Action)
+
+	return handler.Handle(hctx)
+}
+
+// GetHandler returns the handler for a specific action
+func (hr *HandlerRegistry) GetHandler(action common.WebSocketAction) (RequestHandler, bool) {
+	handler, exists := hr.handlers[action]
+	return handler, exists
+}
+
+////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////
+
+// GetDataHandler handles system data requests
+type GetDataHandler struct{}
+
+func (h *GetDataHandler) Handle(hctx *HandlerContext) error {
+	var options common.DataRequestOptions
+	_ = cbor.Unmarshal(hctx.Request.Data, &options)
+
+	sysStats := hctx.Agent.gatherStats(options.CacheTimeMs)
+	return hctx.SendResponse(sysStats, hctx.RequestID)
+}
+
+////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////
+
+// CheckFingerprintHandler handles authentication challenges
+type CheckFingerprintHandler struct{}
+
+func (h *CheckFingerprintHandler) Handle(hctx *HandlerContext) error {
+	return hctx.Client.handleAuthChallenge(hctx.Request, hctx.RequestID)
+}