feat: plugin discovery, capability/contribution/permission registries, Plugin Manager UI

internal/core/events/bus.go

@@ -0,0 +1,59 @@
+// Package events provides an in-process event bus for plugin and core communication.
+package events
+
+import (
+	"sync"
+)
+
+// Handler is a function that processes an event.
+type Handler func(event Event)
+
+// Event represents a named event with a payload.
+type Event struct {
+	Name      string      `json:"name"`
+	Timestamp string      `json:"timestamp"`
+	Payload   interface{} `json:"payload"`
+}
+
+// Bus is a simple in-process event bus.
+type Bus struct {
+	mu       sync.RWMutex
+	handlers map[string][]Handler
+}
+
+// NewBus creates a new event bus.
+func NewBus() *Bus {
+	return &Bus{
+		handlers: make(map[string][]Handler),
+	}
+}
+
+// Subscribe registers a handler for an event name.
+func (b *Bus) Subscribe(event string, handler Handler) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.handlers[event] = append(b.handlers[event], handler)
+}
+
+// Unsubscribe removes all handlers for a plugin (matched by prefix or exact).
+// For now, a simple version: clear all handlers for a given event name.
+func (b *Bus) Unsubscribe(event string) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	delete(b.handlers, event)
+}
+
+// Publish dispatches an event to all registered handlers.
+func (b *Bus) Publish(event Event) {
+	b.mu.RLock()
+	handlers, ok := b.handlers[event.Name]
+	b.mu.RUnlock()
+
+	if !ok {
+		return
+	}
+
+	for _, handler := range handlers {
+		handler(event)
+	}
+}