Wrote simple event to subgraph function.

Updated related code to align.

event.go

@@ -0,0 +1,61 @@
+package heartwood
+
+import (
+	roots "git.wisehodl.dev/jay/go-roots/events"
+)
+
+func EventToSubgraph(e roots.Event) *Subgraph {
+	subgraph := NewSubgraph()
+
+	// Create Event node
+	eventNode := NewEventNode(e.ID)
+	eventNode.Props["created_at"] = e.CreatedAt
+	eventNode.Props["kind"] = e.Kind
+	eventNode.Props["content"] = e.Content
+
+	// Create User node
+	userNode := NewUserNode(e.PubKey)
+
+	// Create SIGNED rel
+	signedRel := NewSignedRel(userNode, eventNode, nil)
+
+	// Create Tag nodes
+	tagNodes := []*Node{}
+	for _, tag := range e.Tags {
+		if !isValidTag(tag) {
+			continue
+		}
+		tagNodes = append(tagNodes, NewTagNode(tag[0], tag[1]))
+	}
+
+	// Create Tag rels
+	tagRels := []*Relationship{}
+	for _, tagNode := range tagNodes {
+		tagRels = append(tagRels, NewTaggedRel(eventNode, tagNode, nil))
+	}
+
+	// Populate subgraph
+	subgraph.AddNode(eventNode)
+	subgraph.AddNode(userNode)
+	subgraph.AddRel(signedRel)
+	for _, node := range tagNodes {
+		subgraph.AddNode(node)
+	}
+	for _, rel := range tagRels {
+		subgraph.AddRel(rel)
+	}
+
+	return subgraph
+}
+
+func isValidTag(t roots.Tag) bool {
+	if len(t) < 2 {
+		// Skip tags that do not have name and value fields
+		return false
+	}
+	if len(t[0])+len(t[1]) > 8192 {
+		// Skip tags that are too large for the neo4j indexer
+		return false
+	}
+	return true
+}