feat: rich change detail display with before/after comparison

Differ artik her degisiklik icin detayli bilgi uretiyor:
change_type (okunabilir etiket), old_value/new_value (field ozeti),
old_preview/new_preview (JSON schema onizleme), description (etki
aciklamasi). Change detail sayfasinda expand/collapse kartlar,
before/after karsilastirma, schema detail onizleme eklendi.
Changes listesinde her satira degisiklik rozetleri eklendi.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: halilibrahimd27

schema-monitor/core/differ.py

@@ -1,5 +1,6 @@
 """Schema karşılaştırma modülü — iki schema arasındaki farkları bulur."""
 
+import json
 import logging
 from datetime import datetime, timezone
 from typing import Any
@@ -10,6 +11,121 @@
 
 logger = logging.getLogger(__name__)
 
+# Değişiklik tipi → okunabilir etiket ve açıklama eşlemesi
+_CHANGE_TYPE_LABELS: dict[str, str] = {
+    "field_removed": "Field Removed",
+    "field_added": "Field Added",
+    "type_changed": "Type Changed",
+    "nullable_changed_to_false": "Nullable Changed",
+    "array_item_schema_changed": "Array Schema Changed",
+    "auth_changed": "Auth Changed",
+    "format_changed": "Format Changed",
+    "enum_value_removed": "Enum Value Removed",
+    "enum_value_added": "Enum Value Added",
+    "required_field_added": "Required Field Added",
+    "depth_changed": "Depth Changed",
+    "status_code_changed_2xx": "Status Code Changed",
+}
+
+_CHANGE_TYPE_DESCRIPTIONS: dict[str, str] = {
+    "field_removed": "Bu alan API response'undan tamamen kaldirildi. Bu alana bagli istemciler hata alabilir.",
+    "field_added": "API response'una yeni bir alan eklendi. Mevcut istemciler etkilenmez.",
+    "type_changed": "Bu alanin veri tipi degisti. Tip uyumsuzlugu istemcilerde parse hatasina yol acabilir.",
+    "nullable_changed_to_false": "Bu alan artik null deger kabul etmiyor. null bekleyen istemciler etkilenebilir.",
+    "array_item_schema_changed": "Array icindeki nesnelerin yapisi degisti. Listelemeye bagli istemciler etkilenebilir.",
+    "auth_changed": "Kimlik dogrulama yapisi degisti.",
+    "format_changed": "Alanin formati degisti (ornek: date -> datetime).",
+    "enum_value_removed": "Izin verilen degerlerden biri kaldirildi.",
+    "enum_value_added": "Izin verilen degerlere yeni bir deger eklendi.",
+    "required_field_added": "Yeni bir zorunlu alan eklendi.",
+    "depth_changed": "Nesnelerin icleme derinligi degisti.",
+    "status_code_changed_2xx": "HTTP basari durum kodu degisti.",
+}
+
+
+def _field_summary(field_data: dict[str, Any]) -> str:
+    """Bir field'ın kısa yapısal özetini oluştur.
+
+    Args:
+        field_data: Schema field verisi
+
+    Returns:
+        Okunabilir field özeti
+    """
+    parts: list[str] = []
+
+    field_type = field_data.get("type", "unknown")
+    parts.append(f"type: {field_type}")
+
+    if field_data.get("nullable"):
+        parts.append("nullable: true")
+
+    if field_type == "object" and "fields" in field_data:
+        sub_fields = list(field_data["fields"].keys())
+        if sub_fields:
+            if len(sub_fields) <= 5:
+                parts.append(f"fields: [{', '.join(sub_fields)}]")
+            else:
+                parts.append(f"fields: [{', '.join(sub_fields[:5])}, ... +{len(sub_fields) - 5}]")
+
+    if field_type == "array" and "items" in field_data:
+        items = field_data["items"]
+        items_type = items.get("type", "unknown")
+        if items_type == "object" and "fields" in items:
+            item_fields = list(items["fields"].keys())
+            if len(item_fields) <= 5:
+                parts.append(f"items: {items_type} [{', '.join(item_fields)}]")
+            else:
+                parts.append(f"items: {items_type} [{', '.join(item_fields[:5])}, ... +{len(item_fields) - 5}]")
+        else:
+            parts.append(f"items: {items_type}")
+
+    if "sample" in field_data:
+        sample = str(field_data["sample"])
+        if len(sample) > 50:
+            sample = sample[:50] + "..."
+        parts.append(f'sample: "{sample}"')
+
+    return "{ " + ", ".join(parts) + " }"
+
+
+def _field_to_json_preview(field_data: dict[str, Any], max_depth: int = 2) -> dict[str, Any]:
+    """Bir field'ın JSON benzeri önizlemesini oluştur.
+
+    Args:
+        field_data: Schema field verisi
+        max_depth: Maksimum derinlik
+
+    Returns:
+        JSON preview dict
+    """
+    result: dict[str, Any] = {"type": field_data.get("type", "unknown")}
+
+    if field_data.get("nullable"):
+        result["nullable"] = True
+
+    if "sample" in field_data:
+        result["sample"] = field_data["sample"]
+
+    if max_depth > 0:
+        if field_data.get("type") == "object" and "fields" in field_data:
+            sub_fields = {}
+            for name, sub_data in field_data["fields"].items():
+                sub_fields[name] = sub_data.get("type", "unknown")
+            result["fields"] = sub_fields
+
+        if field_data.get("type") == "array" and "items" in field_data:
+            items = field_data["items"]
+            if items.get("type") == "object" and "fields" in items:
+                sub_fields = {}
+                for name, sub_data in items["fields"].items():
+                    sub_fields[name] = sub_data.get("type", "unknown")
+                result["items"] = {"type": "object", "fields": sub_fields}
+            else:
+                result["items"] = {"type": items.get("type", "unknown")}
+
+    return result
+
 
 def _flatten_changes(old_schema: dict, new_schema: dict) -> list[dict[str, Any]]:
     """İki schema arasındaki değişiklikleri düzleştirilmiş liste olarak döndür.
@@ -29,28 +145,44 @@ def _flatten_changes(old_schema: dict, new_schema: dict) -> list[dict[str, Any]]
     # Kaldırılan alanlar
     for field_name in old_fields:
         if field_name not in new_fields:
-            old_type = old_fields[field_name].get("type", "unknown")
+            old_field = old_fields[field_name]
+            old_type = old_field.get("type", "unknown")
+            change_type = "field_removed"
             change = {
-                "type": "field_removed",
+                "type": change_type,
+                "change_type": _CHANGE_TYPE_LABELS.get(change_type, change_type),
                 "path": f"$.{field_name}",
                 "old_type": old_type,
                 "new_type": None,
-                "severity": get_severity("field_removed"),
-                "message": f"Alan kaldırıldı: {field_name} ({old_type})",
+                "old_value": _field_summary(old_field),
+                "new_value": None,
+                "old_preview": json.dumps(_field_to_json_preview(old_field), indent=2, ensure_ascii=False),
+                "new_preview": None,
+                "severity": get_severity(change_type),
+                "message": f"Alan kaldirildi: {field_name} ({old_type})",
+                "description": _CHANGE_TYPE_DESCRIPTIONS.get(change_type, ""),
             }
             changes.append(change)
 
     # Eklenen alanlar
     for field_name in new_fields:
         if field_name not in old_fields:
-            new_type = new_fields[field_name].get("type", "unknown")
+            new_field = new_fields[field_name]
+            new_type = new_field.get("type", "unknown")
+            change_type = "field_added"
             change = {
-                "type": "field_added",
+                "type": change_type,
+                "change_type": _CHANGE_TYPE_LABELS.get(change_type, change_type),
                 "path": f"$.{field_name}",
                 "old_type": None,
                 "new_type": new_type,
-                "severity": get_severity("field_added"),
+                "old_value": None,
+                "new_value": _field_summary(new_field),
+                "old_preview": None,
+                "new_preview": json.dumps(_field_to_json_preview(new_field), indent=2, ensure_ascii=False),
+                "severity": get_severity(change_type),
                 "message": f"Yeni alan: {field_name} ({new_type})",
+                "description": _CHANGE_TYPE_DESCRIPTIONS.get(change_type, ""),
             }
             changes.append(change)
 
@@ -64,13 +196,20 @@ def _flatten_changes(old_schema: dict, new_schema: dict) -> list[dict[str, Any]]
             old_type = old_field.get("type", "unknown")
             new_type = new_field.get("type", "unknown")
             if old_type != new_type:
+                change_type = "type_changed"
                 change = {
-                    "type": "type_changed",
+                    "type": change_type,
+                    "change_type": _CHANGE_TYPE_LABELS.get(change_type, change_type),
                     "path": f"$.{field_name}",
                     "old_type": old_type,
                     "new_type": new_type,
-                    "severity": get_severity("type_changed"),
-                    "message": f"Tip değişti: {field_name} ({old_type} → {new_type})",
+                    "old_value": _field_summary(old_field),
+                    "new_value": _field_summary(new_field),
+                    "old_preview": json.dumps(_field_to_json_preview(old_field), indent=2, ensure_ascii=False),
+                    "new_preview": json.dumps(_field_to_json_preview(new_field), indent=2, ensure_ascii=False),
+                    "severity": get_severity(change_type),
+                    "message": f"Tip degisti: {field_name} ({old_type} -> {new_type})",
+                    "description": _CHANGE_TYPE_DESCRIPTIONS.get(change_type, ""),
                 }
                 changes.append(change)
 
@@ -84,11 +223,17 @@ def _flatten_changes(old_schema: dict, new_schema: dict) -> list[dict[str, Any]]
                     change_type = "field_added"  # nullable olması INFO seviyesinde
                 change = {
                     "type": change_type,
+                    "change_type": _CHANGE_TYPE_LABELS.get(change_type, change_type),
                     "path": f"$.{field_name}",
                     "old_type": f"nullable={old_nullable}",
                     "new_type": f"nullable={new_nullable}",
+                    "old_value": f"nullable: {str(old_nullable).lower()}",
+                    "new_value": f"nullable: {str(new_nullable).lower()}",
+                    "old_preview": None,
+                    "new_preview": None,
                     "severity": get_severity(change_type),
-                    "message": f"Nullable değişti: {field_name} ({old_nullable} → {new_nullable})",
+                    "message": f"Nullable degisti: {field_name} ({old_nullable} -> {new_nullable})",
+                    "description": _CHANGE_TYPE_DESCRIPTIONS.get(change_type, ""),
                 }
                 changes.append(change)
 
@@ -117,13 +262,20 @@ def _flatten_changes(old_schema: dict, new_schema: dict) -> list[dict[str, Any]]
                                 nested_change["severity"] = get_severity("array_item_schema_changed")
                             changes.append(nested_change)
                     elif old_items.get("type") != new_items.get("type"):
+                        change_type = "array_item_schema_changed"
                         change = {
-                            "type": "array_item_schema_changed",
+                            "type": change_type,
+                            "change_type": _CHANGE_TYPE_LABELS.get(change_type, change_type),
                             "path": f"$.{field_name}[]",
                             "old_type": old_items.get("type", "unknown"),
                             "new_type": new_items.get("type", "unknown"),
-                            "severity": get_severity("array_item_schema_changed"),
-                            "message": f"Array item tipi değişti: {field_name} ({old_items.get('type')} → {new_items.get('type')})",
+                            "old_value": _field_summary(old_items),
+                            "new_value": _field_summary(new_items),
+                            "old_preview": json.dumps(_field_to_json_preview(old_items), indent=2, ensure_ascii=False),
+                            "new_preview": json.dumps(_field_to_json_preview(new_items), indent=2, ensure_ascii=False),
+                            "severity": get_severity(change_type),
+                            "message": f"Array item tipi degisti: {field_name} ({old_items.get('type')} -> {new_items.get('type')})",
+                            "description": _CHANGE_TYPE_DESCRIPTIONS.get(change_type, ""),
                         }
                         changes.append(change)