data layer

data-layer/api/internal/service/query_service.go

@@ -0,0 +1,87 @@
+// Package service holds business logic. It owns cache orchestration around
+// the read repos and never touches HTTP/chi or the SQL drivers directly.
+package service
+
+import (
+	"context"
+	"encoding/json"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/dbiz/cdp/data-layer/api/internal/apperr"
+	"github.com/dbiz/cdp/data-layer/api/internal/cache"
+	"github.com/dbiz/cdp/data-layer/api/internal/model"
+	"github.com/dbiz/cdp/data-layer/api/internal/repo"
+)
+
+type QueryService struct {
+	events    *repo.EventRepo
+	analytics *repo.AnalyticsRepo
+	cache     *cache.Cache
+	queryTTL  time.Duration
+	log       *zap.Logger
+}
+
+func NewQueryService(events *repo.EventRepo, analytics *repo.AnalyticsRepo, c *cache.Cache, queryTTL time.Duration, log *zap.Logger) *QueryService {
+	return &QueryService{events: events, analytics: analytics, cache: c, queryTTL: queryTTL, log: log}
+}
+
+// cached wraps `fetch` with the per-workspace Redis cache. Result is JSON-
+// encoded on miss; CacheHit is set true on hit.
+func (s *QueryService) cached(
+	ctx context.Context,
+	kind, workspaceID string,
+	params any,
+	fetch func(context.Context) (*model.QueryResult, error),
+) (*model.QueryResult, error) {
+	key, err := cache.Key(kind, workspaceID, params)
+	if err != nil {
+		return nil, apperr.Internal(err)
+	}
+	if cached, ok := s.cache.Get(ctx, key); ok {
+		var out model.QueryResult
+		if jerr := json.Unmarshal(cached, &out); jerr == nil {
+			out.CacheHit = true
+			return &out, nil
+		}
+	}
+	start := time.Now()
+	res, err := fetch(ctx)
+	if err != nil {
+		return nil, apperr.Internal(err)
+	}
+	res.DurationMS = time.Since(start).Milliseconds()
+	res.CacheHit = false
+
+	if b, jerr := json.Marshal(res); jerr == nil {
+		if cerr := s.cache.Set(ctx, key, b, s.queryTTL); cerr != nil {
+			s.log.Warn("cache set", zap.String("key", key), zap.Error(cerr))
+		}
+	}
+	return res, nil
+}
+
+func (s *QueryService) Events(ctx context.Context, q model.EventQuery) (*model.QueryResult, error) {
+	return s.cached(ctx, "query:events", q.WorkspaceID, q, func(c context.Context) (*model.QueryResult, error) {
+		return s.events.QueryEvents(c, q)
+	})
+}
+
+func (s *QueryService) Funnel(ctx context.Context, q repo.FunnelQuery) (*model.QueryResult, error) {
+	return s.cached(ctx, "query:funnel", q.WorkspaceID, q, func(c context.Context) (*model.QueryResult, error) {
+		return s.analytics.Funnel(c, q)
+	})
+}
+
+func (s *QueryService) Retention(ctx context.Context, q repo.RetentionQuery) (*model.QueryResult, error) {
+	return s.cached(ctx, "query:retention", q.WorkspaceID, q, func(c context.Context) (*model.QueryResult, error) {
+		return s.analytics.Retention(c, q)
+	})
+}
+
+func (s *QueryService) Sessions(ctx context.Context, q repo.SessionQuery) (*model.QueryResult, error) {
+	return s.cached(ctx, "query:session", q.WorkspaceID, q, func(c context.Context) (*model.QueryResult, error) {
+		return s.analytics.Sessions(c, q)
+	})
+}