feat: subscribe to RabbitMQ trade signals and notify by rules

Consume configurable queues, format signals (including period), share NotifyService with HTTP, and drop duplicate bodies within 1h.

internal/subscriber/dedup.go

@@ -0,0 +1,70 @@
+package subscriber
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"sync"
+	"time"
+
+	"aiaa-notification-service/internal/cache"
+)
+
+type Deduper interface {
+	Claim(ctx context.Context, hash string) (bool, error)
+	Release(ctx context.Context, hash string) error
+}
+
+func MessageHash(body []byte) string {
+	sum := sha256.Sum256(body)
+	return hex.EncodeToString(sum[:])
+}
+
+type MemoryDeduper struct {
+	mu   sync.Mutex
+	seen map[string]struct{}
+}
+
+func NewMemoryDeduper() *MemoryDeduper {
+	return &MemoryDeduper{seen: make(map[string]struct{})}
+}
+
+func (d *MemoryDeduper) Claim(_ context.Context, hash string) (bool, error) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if _, ok := d.seen[hash]; ok {
+		return false, nil
+	}
+	d.seen[hash] = struct{}{}
+	return true, nil
+}
+
+func (d *MemoryDeduper) Release(_ context.Context, hash string) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	delete(d.seen, hash)
+	return nil
+}
+
+type cacheDeduper struct {
+	c   *cache.Cache
+	ttl time.Duration
+}
+
+func NewCacheDeduper(c *cache.Cache, ttl time.Duration) Deduper {
+	if c == nil {
+		return NewMemoryDeduper()
+	}
+	if ttl <= 0 {
+		ttl = time.Hour
+	}
+	return &cacheDeduper{c: c, ttl: ttl}
+}
+
+func (d *cacheDeduper) Claim(ctx context.Context, hash string) (bool, error) {
+	return d.c.ClaimDedup(ctx, hash, d.ttl)
+}
+
+func (d *cacheDeduper) Release(ctx context.Context, hash string) error {
+	return d.c.ReleaseDedup(ctx, hash)
+}