add count (NIP-45) envelope support, bump to version v0.10.0

pkg/database/count.go

@@ -0,0 +1,44 @@
+package database
+
+import (
+	"context"
+
+	"next.orly.dev/pkg/encoders/filter"
+)
+
+// CountEvents mirrors the initial selection logic of QueryEvents but stops
+// once we have identified candidate event serials (id/pk/ts). It returns the
+// count of those serials. The `approx` flag is always false as requested.
+func (d *D) CountEvents(c context.Context, f *filter.F) (
+	count int, approx bool, err error,
+) {
+	approx = false
+	if f == nil {
+		return 0, false, nil
+	}
+
+	// If explicit Ids are provided, count how many of them resolve to serials.
+	if f.Ids != nil && f.Ids.Len() > 0 {
+		var serials map[string]interface{}
+		// Use type inference without importing extra packages by discarding the
+		// concrete value type via a two-step assignment.
+		if tmp, idErr := d.GetSerialsByIds(f.Ids); idErr != nil {
+			return 0, false, idErr
+		} else {
+			// Reassign to a map with empty interface values to avoid referencing
+			// the concrete Uint40 type here.
+			serials = make(map[string]interface{}, len(tmp))
+			for k := range tmp {
+				serials[k] = struct{}{}
+			}
+		}
+		return len(serials), false, nil
+	}
+
+	// Otherwise, query for candidate Id/Pubkey/Timestamp triplets and count them.
+	if idPkTs, qErr := d.QueryForIds(c, f); qErr != nil {
+		return 0, false, qErr
+	} else {
+		return len(idPkTs), false, nil
+	}
+}