Event Broken Concept

pkg/eventbroker/event.go

@@ -0,0 +1,175 @@
+package eventbroker
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// EventSource represents where an event originated from
+type EventSource string
+
+const (
+	EventSourceDatabase  EventSource = "database"
+	EventSourceWebSocket EventSource = "websocket"
+	EventSourceFrontend  EventSource = "frontend"
+	EventSourceSystem    EventSource = "system"
+	EventSourceInternal  EventSource = "internal"
+)
+
+// EventStatus represents the current state of an event
+type EventStatus string
+
+const (
+	EventStatusPending    EventStatus = "pending"
+	EventStatusProcessing EventStatus = "processing"
+	EventStatusCompleted  EventStatus = "completed"
+	EventStatusFailed     EventStatus = "failed"
+)
+
+// Event represents a single event in the system with complete metadata
+type Event struct {
+	// Identification
+	ID string `json:"id" db:"id"`
+
+	// Source & Classification
+	Source EventSource `json:"source" db:"source"`
+	Type   string      `json:"type" db:"type"` // Pattern: schema.entity.operation
+
+	// Status Tracking
+	Status     EventStatus `json:"status" db:"status"`
+	RetryCount int         `json:"retry_count" db:"retry_count"`
+	Error      string      `json:"error,omitempty" db:"error"`
+
+	// Payload
+	Payload json.RawMessage `json:"payload" db:"payload"`
+
+	// Context Information
+	UserID     int    `json:"user_id" db:"user_id"`
+	SessionID  string `json:"session_id" db:"session_id"`
+	InstanceID string `json:"instance_id" db:"instance_id"`
+
+	// Database Context
+	Schema    string `json:"schema" db:"schema"`
+	Entity    string `json:"entity" db:"entity"`
+	Operation string `json:"operation" db:"operation"` // create, update, delete, read
+
+	// Timestamps
+	CreatedAt   time.Time  `json:"created_at" db:"created_at"`
+	ProcessedAt *time.Time `json:"processed_at,omitempty" db:"processed_at"`
+	CompletedAt *time.Time `json:"completed_at,omitempty" db:"completed_at"`
+
+	// Extensibility
+	Metadata map[string]interface{} `json:"metadata" db:"metadata"`
+}
+
+// NewEvent creates a new event with defaults
+func NewEvent(source EventSource, eventType string) *Event {
+	return &Event{
+		ID:         uuid.New().String(),
+		Source:     source,
+		Type:       eventType,
+		Status:     EventStatusPending,
+		CreatedAt:  time.Now(),
+		Metadata:   make(map[string]interface{}),
+		RetryCount: 0,
+	}
+}
+
+// EventType generates a type string from schema, entity, and operation
+// Pattern: schema.entity.operation (e.g., "public.users.create")
+func EventType(schema, entity, operation string) string {
+	return fmt.Sprintf("%s.%s.%s", schema, entity, operation)
+}
+
+// MarkProcessing marks the event as being processed
+func (e *Event) MarkProcessing() {
+	e.Status = EventStatusProcessing
+	now := time.Now()
+	e.ProcessedAt = &now
+}
+
+// MarkCompleted marks the event as successfully completed
+func (e *Event) MarkCompleted() {
+	e.Status = EventStatusCompleted
+	now := time.Now()
+	e.CompletedAt = &now
+}
+
+// MarkFailed marks the event as failed with an error message
+func (e *Event) MarkFailed(err error) {
+	e.Status = EventStatusFailed
+	e.Error = err.Error()
+	now := time.Now()
+	e.CompletedAt = &now
+}
+
+// IncrementRetry increments the retry counter
+func (e *Event) IncrementRetry() {
+	e.RetryCount++
+}
+
+// SetPayload sets the event payload from any value by marshaling to JSON
+func (e *Event) SetPayload(v interface{}) error {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return fmt.Errorf("failed to marshal payload: %w", err)
+	}
+	e.Payload = data
+	return nil
+}
+
+// GetPayload unmarshals the payload into the provided value
+func (e *Event) GetPayload(v interface{}) error {
+	if len(e.Payload) == 0 {
+		return fmt.Errorf("payload is empty")
+	}
+	if err := json.Unmarshal(e.Payload, v); err != nil {
+		return fmt.Errorf("failed to unmarshal payload: %w", err)
+	}
+	return nil
+}
+
+// Clone creates a deep copy of the event
+func (e *Event) Clone() *Event {
+	clone := *e
+
+	// Deep copy metadata
+	if e.Metadata != nil {
+		clone.Metadata = make(map[string]interface{})
+		for k, v := range e.Metadata {
+			clone.Metadata[k] = v
+		}
+	}
+
+	// Deep copy timestamps
+	if e.ProcessedAt != nil {
+		t := *e.ProcessedAt
+		clone.ProcessedAt = &t
+	}
+	if e.CompletedAt != nil {
+		t := *e.CompletedAt
+		clone.CompletedAt = &t
+	}
+
+	return &clone
+}
+
+// Validate performs basic validation on the event
+func (e *Event) Validate() error {
+	if e.ID == "" {
+		return fmt.Errorf("event ID is required")
+	}
+	if e.Source == "" {
+		return fmt.Errorf("event source is required")
+	}
+	if e.Type == "" {
+		return fmt.Errorf("event type is required")
+	}
+	if e.InstanceID == "" {
+		return fmt.Errorf("instance ID is required")
+	}
+	return nil
+}