add observer runtime model

Instrument command, payload, update, scene, runner, polling, and policy flows
Add observer regression coverage and mark observability backlog item done

observer.go

@@ -0,0 +1,183 @@
+package laniakea
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.scuroneko.dev/scuroneko/laniakea/tgapi"
+)
+
+// HandlerEventKind identifies the kind of handler observed by runtime events.
+type HandlerEventKind string
+
+const (
+	// HandlerCommandKind identifies a command handler.
+	HandlerCommandKind HandlerEventKind = "command"
+	// HandlerPayloadKind identifies a callback payload handler.
+	HandlerPayloadKind HandlerEventKind = "payload"
+	// HandlerUpdateKind identifies a generic update handler.
+	HandlerUpdateKind HandlerEventKind = "update"
+	// HandlerRunnerKind identifies a background runner execution.
+	HandlerRunnerKind HandlerEventKind = "runner"
+	// HandlerPollingKind identifies polling and getUpdates runtime work.
+	HandlerPollingKind HandlerEventKind = "polling"
+	// HandlerSceneKind identifies a scene runtime handler wrapper.
+	HandlerSceneKind HandlerEventKind = "scene"
+	// HandlerSceneStepKind identifies a scene step handler.
+	HandlerSceneStepKind HandlerEventKind = "scene_step"
+	// HandlerSceneCommandKind identifies a scene-local command handler.
+	HandlerSceneCommandKind HandlerEventKind = "scene_command"
+	// HandlerSceneMessageKind identifies a scene message fallback handler.
+	HandlerSceneMessageKind HandlerEventKind = "scene_message"
+)
+
+type Event interface {
+	isEvent()
+}
+
+// UpdateReceivedEvent describes an update entering the bot runtime.
+type UpdateReceivedEvent struct {
+	UpdateID   int
+	UpdateType tgapi.UpdateType
+	FromID     int64
+	ChatID     int64
+}
+
+// UpdateHandledEvent describes a completed update execution path.
+type UpdateHandledEvent struct {
+	UpdateID   int
+	UpdateType tgapi.UpdateType
+	FromID     int64
+	ChatID     int64
+	Duration   time.Duration
+	Handled    bool
+}
+
+// HandlerStartedEvent describes a handler about to execute.
+type HandlerStartedEvent struct {
+	UpdateID    int
+	UpdateType  tgapi.UpdateType
+	Plugin      string
+	HandlerKind HandlerEventKind
+	HandlerName string
+	FromID      int64
+	ChatID      int64
+}
+
+// HandlerFinishedEvent describes a handler that has completed.
+type HandlerFinishedEvent struct {
+	UpdateID    int
+	UpdateType  tgapi.UpdateType
+	Plugin      string
+	HandlerKind HandlerEventKind
+	HandlerName string
+	FromID      int64
+	ChatID      int64
+	Duration    time.Duration
+	Err         error
+	UserFacing  bool
+}
+
+// SceneTransitionEvent describes a scene state transition.
+type SceneTransitionEvent struct {
+	Plugin string
+	Scene  string
+	From   string
+	To     string
+	Action SceneAction
+	FromID int64
+	ChatID int64
+}
+
+// PolicyCheckedEvent describes the result of a policy evaluation.
+type PolicyCheckedEvent struct {
+	Name     string
+	Plugin   string
+	FromID   int64
+	ChatID   int64
+	Passed   bool
+	Err      error
+	Internal bool
+}
+
+// RunnerFinishedEvent describes a completed background runner execution.
+type RunnerFinishedEvent struct {
+	Name     string
+	Duration time.Duration
+	Err      error
+}
+
+// PollingRetryEvent describes a polling retry after a failed getUpdates call.
+type PollingRetryEvent struct {
+	Attempt int
+	Delay   time.Duration
+	Err     error
+}
+
+// ErrorEvent describes an error routed through framework error handling.
+type ErrorEvent struct {
+	UpdateID    int
+	UpdateType  tgapi.UpdateType
+	Plugin      string
+	HandlerKind HandlerEventKind
+	HandlerName string
+	FromID      int64
+	ChatID      int64
+	Err         error
+	UserFacing  bool
+}
+
+func (UpdateReceivedEvent) isEvent()  {}
+func (UpdateHandledEvent) isEvent()   {}
+func (HandlerStartedEvent) isEvent()  {}
+func (HandlerFinishedEvent) isEvent() {}
+func (SceneTransitionEvent) isEvent() {}
+func (PolicyCheckedEvent) isEvent()   {}
+func (RunnerFinishedEvent) isEvent()  {}
+func (PollingRetryEvent) isEvent()    {}
+func (ErrorEvent) isEvent()           {}
+
+// Observer receives best-effort runtime instrumentation events.
+type Observer interface {
+	OnReceiveUpdate(ctx context.Context, event UpdateReceivedEvent)
+	OnHandledUpdate(ctx context.Context, event UpdateHandledEvent)
+	OnHandlerStarted(ctx context.Context, event HandlerStartedEvent)
+	OnHandlerFinished(ctx context.Context, event HandlerFinishedEvent)
+	OnSceneTransition(ctx context.Context, event SceneTransitionEvent)
+	OnPolicyChecked(ctx context.Context, event PolicyCheckedEvent)
+	OnRunnerFinished(ctx context.Context, event RunnerFinishedEvent)
+	OnPollingRetry(ctx context.Context, event PollingRetryEvent)
+	OnError(ctx context.Context, event ErrorEvent)
+}
+
+func (bot *Bot[T]) safeEmitEvent(ctx context.Context, event Event) {
+	if bot.observer == nil {
+		return
+	}
+	defer func() {
+		if r := recover(); r != nil {
+			bot.logger.Errorln(fmt.Sprintf("panic in observer: %v", r))
+		}
+	}()
+	switch e := event.(type) {
+	case UpdateReceivedEvent:
+		bot.observer.OnReceiveUpdate(ctx, e)
+	case UpdateHandledEvent:
+		bot.observer.OnHandledUpdate(ctx, e)
+	case HandlerStartedEvent:
+		bot.observer.OnHandlerStarted(ctx, e)
+	case HandlerFinishedEvent:
+		bot.observer.OnHandlerFinished(ctx, e)
+	case SceneTransitionEvent:
+		bot.observer.OnSceneTransition(ctx, e)
+	case PolicyCheckedEvent:
+		bot.observer.OnPolicyChecked(ctx, e)
+	case RunnerFinishedEvent:
+		bot.observer.OnRunnerFinished(ctx, e)
+	case PollingRetryEvent:
+		bot.observer.OnPollingRetry(ctx, e)
+	case ErrorEvent:
+		bot.observer.OnError(ctx, e)
+	}
+}