WIP: local changes

backend/contacts/serializers.py

@@ -0,0 +1,74 @@
+from rest_framework import serializers
+from .models import Contact, Relation
+
+
+class ContactSerializer(serializers.ModelSerializer):
+    relations_count = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Contact
+        fields = [
+            'id', 'name', 'email', 'phone',
+            'organization', 'position', 'notes',
+            'created_at', 'updated_at', 'relations_count',
+        ]
+        read_only_fields = ['id', 'created_at', 'updated_at', 'relations_count']
+
+    def get_relations_count(self, obj):
+        return (
+            obj.relations_as_source.count() +
+            obj.relations_as_target.count()
+        )
+
+
+class RelationSerializer(serializers.ModelSerializer):
+    source_name = serializers.CharField(source='source.name', read_only=True)
+    target_name = serializers.CharField(source='target.name', read_only=True)
+
+    class Meta:
+        model = Relation
+        fields = [
+            'id', 'source', 'source_name',
+            'target', 'target_name',
+            'relation_type', 'description', 'created_at',
+        ]
+        read_only_fields = ['id', 'created_at', 'source_name', 'target_name']
+
+    def validate(self, data):
+        if data.get('source') == data.get('target'):
+            raise serializers.ValidationError(
+                'Нельзя создать связь контакта с самим собой.'
+            )
+        return data
+
+
+class GraphSerializer(serializers.Serializer):
+    """Граф для vis.js: nodes + edges."""
+
+    nodes = serializers.SerializerMethodField()
+    edges = serializers.SerializerMethodField()
+
+    def get_nodes(self, obj):
+        contacts = Contact.objects.all()
+        return [
+            {
+                'id': c.id,
+                'label': c.name,
+                'title': f'{c.organization}\n{c.position}'.strip() or c.name,
+                'group': c.organization or 'default',
+            }
+            for c in contacts
+        ]
+
+    def get_edges(self, obj):
+        relations = Relation.objects.select_related('source', 'target').all()
+        return [
+            {
+                'id': r.id,
+                'from': r.source_id,
+                'to': r.target_id,
+                'label': r.get_relation_type_display(),
+                'title': r.description or r.get_relation_type_display(),
+            }
+            for r in relations
+        ]