changes

app/views.py

@@ -27,6 +27,8 @@ from concurrent.futures import ThreadPoolExecutor
 import json
 import io
 import pandas as pd
+import numpy as np
+from num2words import num2words
 from django.db import transaction
 from django.apps import apps
 from django.core.exceptions import FieldDoesNotExist
@@ -1347,4 +1349,266 @@ def generate_document(request):
         time.sleep(5)
         count += 1
 
-    return Response({"error": "Timeout chờ generate."}, status=status.HTTP_408_REQUEST_TIMEOUT)
+    return Response({"error": "Timeout chờ generate."}, status=status.HTTP_408_REQUEST_TIMEOUT)
+
+#=============================================================================
+# EMAIL TEMPLATE PREVIEW
+#=============================================================================
+class EmailTemplatePreview:
+    """
+    Class để preview nội dung email template với dữ liệu đã được map
+    Không gửi email, chỉ trả về nội dung đã render
+    """
+    
+    def __init__(self, template, context_pks: dict):
+        self.template = template
+        self.context_pks = context_pks
+        self.config = self.template.content  
+        self.data_context = {}
+        self.replacements = {}
+
+    def _get_model(self, model_string):
+        """Lấy model class từ string 'app.Model'"""
+        app_label, model_name = model_string.split(".")
+        return apps.get_model(app_label, model_name)
+
+    def _get_value_from_object(self, obj, field_path):
+        """Lấy giá trị từ object theo field path (hỗ trợ nested: 'user.profile.name')"""
+        if obj is None:
+            return None
+        value = obj
+        for part in field_path.replace("__", ".").split("."):
+            if value is None:
+                return None
+            value = getattr(value, part, None)
+        return value
+
+    def _resolve_lookup_value(self, lookup_from):
+        """Resolve giá trị lookup từ context_pks hoặc data_context"""
+        if lookup_from in self.context_pks:
+            return self.context_pks[lookup_from]
+
+        try:
+            alias, field_path = lookup_from.split(".", 1)
+            if alias not in self.data_context:
+                raise ValueError(f"Alias '{alias}' not found in data context.")
+            
+            source_object = self.data_context.get(alias)
+            return self._get_value_from_object(source_object, field_path)
+        except ValueError:
+            raise ValueError(f"Could not resolve '{lookup_from}'.")
+
+    def fetch_data(self):
+        """Fetch data từ database theo mappings config"""
+        mappings = self.config.get("mappings", [])
+        if not isinstance(mappings, list):
+            raise TypeError("Email template 'mappings' must be a list.")
+
+        # Process trigger object first
+        trigger_model_mapping = next((m for m in mappings if m.get("is_trigger_object", False)), None)
+        if trigger_model_mapping:
+            model_cls = self._get_model(trigger_model_mapping["model"])
+            lookup_field = trigger_model_mapping["lookup_field"]
+            lookup_value = self._resolve_lookup_value(trigger_model_mapping["lookup_value_from"])
+            alias = trigger_model_mapping["alias"]
+            if lookup_value is not None:
+                self.data_context[alias] = model_cls.objects.filter(**{lookup_field: lookup_value}).first()
+            else:
+                self.data_context[alias] = None
+
+        # Process other mappings
+        for mapping in mappings:
+            if mapping.get("is_trigger_object", False):
+                continue 
+
+            model_cls = self._get_model(mapping["model"])
+            lookup_field = mapping["lookup_field"]
+            lookup_value = self._resolve_lookup_value(mapping["lookup_value_from"])
+            alias = mapping["alias"]
+
+            if lookup_value is None:
+                self.data_context[alias] = None if mapping.get("type") == "object" else []
+                continue
+
+            queryset = model_cls.objects.filter(**{lookup_field: lookup_value})
+
+            if mapping.get("type") == "object":
+                self.data_context[alias] = queryset.first()
+            elif mapping.get("type") == "list":
+                self.data_context[alias] = list(queryset)
+
+    def _format_value(self, value, format_config):
+        """Format value theo config (currency, date, number_to_words, conditional)"""
+        if value is None:
+            return ""
+
+        format_type = format_config.get("type")
+        if not format_type:
+            return str(value)
+
+        try:
+            if format_type == "currency":
+                return "{:,}".format(np.int64(value)).replace(",", ".")
+            if format_type == "date":
+                date_format = format_config.get("format", "dd/mm/YYYY").replace("dd", "%d").replace("mm", "%m").replace("YYYY", "%Y")
+                return value.strftime(date_format)
+            if format_type == "number_to_words":
+                return num2words(value, lang=format_config.get("lang", "vi"))
+            if format_type == "conditional":
+                return format_config["true_value"] if value else format_config["false_value"]
+        except Exception as e:
+            print(f"Error formatting value '{value}' with config '{format_config}': {e}")
+            return "" 
+            
+        return str(value)
+
+    def prepare_replacements(self):
+        """Chuẩn bị dict replacements cho placeholders"""
+        # Add date placeholders
+        today = datetime.now()
+        self.replacements['[day]'] = str(today.day)
+        self.replacements['[month]'] = str(today.month)
+        self.replacements['[year]'] = str(today.year)
+        self.replacements['[date]'] = today.strftime("%d/%m/%Y")
+
+        # Process field mappings
+        mappings = self.config.get("mappings", [])
+        for mapping in mappings:
+            alias = mapping["alias"]
+            data = self.data_context.get(alias)
+            fields = mapping.get("fields", {})
+
+            if mapping.get("type") == "object":
+                if data is None:
+                    for placeholder in fields:
+                        self.replacements[placeholder] = ""
+                    continue
+                
+                for placeholder, config in fields.items():
+                    if isinstance(config, dict):
+                        value = self._get_value_from_object(data, config["source"])
+                        self.replacements[placeholder] = self._format_value(value, config.get("format", {}))
+                    else: 
+                        value = self._get_value_from_object(data, config)
+                        self.replacements[placeholder] = str(value) if value is not None else ""
+
+    def get_preview(self):
+        """
+        Main method để lấy preview email content - trả về nội dung y nguyên đã thay thế placeholders
+        
+        Returns:
+            dict: {
+                'subject': subject đã thay thế placeholders,
+                'content': body content đã thay thế placeholders (giữ nguyên format, căn lề),
+                'recipient_email': email người nhận,
+                'replacements': dict của tất cả replacements được áp dụng
+            }
+        """
+        try:
+            print(f"Generating preview for template: {self.template.name}")
+            
+            # Fetch data and prepare replacements
+            self.fetch_data()
+            self.prepare_replacements()
+
+            # Get templates from config
+            subject_template = self.config.get("subject", "")
+            body_template = self.config.get("content", "")
+            recipient_placeholder = self.config.get("recipient_placeholder", "[customer.email]")
+
+            # Apply replacements - giữ nguyên format, căn lề của template gốc
+            final_subject = subject_template
+            final_content = body_template
+            
+            for key, value in self.replacements.items():
+                final_subject = final_subject.replace(key, str(value))
+                final_content = final_content.replace(key, str(value))
+
+            recipient_email = self.replacements.get(recipient_placeholder, "")
+
+            result = {
+                'subject': final_subject,
+                'content': final_content,  # Nội dung y nguyên đã thay thế
+                'recipient_email': recipient_email,
+                'replacements': self.replacements.copy()
+            }
+
+            print(f"Preview generated successfully for '{self.template.name}'")
+            return result
+
+        except Exception as e:
+            print(f"Error generating preview for template '{self.template.name}': {e}")
+            import traceback
+            traceback.print_exc()
+            return None
+
+
+@api_view(['POST'])
+def preview_email_template(request):
+    """
+    API để preview email template - trả về nội dung đã thay thế placeholders
+    
+    POST /api/email/preview/
+    Body: {
+        "template_id": 1,
+        "context_pks": {
+            "contract_id": 456,
+            "customer_id": 789
+        }
+    }
+    
+    Response: {
+        "subject": "Thông báo hợp đồng #HD-001",
+        "content": "<div>Nội dung y nguyên đã thay thế...</div>",
+        "recipient_email": "customer@example.com",
+        "replacements": {
+            "[contract.code]": "HD-001",
+            "[customer.name]": "Nguyễn Văn A",
+            ...
+        }
+    }
+    """
+    try:
+        # Validate input
+        template_id = request.data.get('template_id')
+        if not template_id:
+            return Response(
+                {'error': 'template_id is required'}, 
+                status=status.HTTP_400_BAD_REQUEST
+            )
+        
+        context_pks = request.data.get('context_pks', {})
+        if not isinstance(context_pks, dict):
+            return Response(
+                {'error': 'context_pks must be a dictionary'}, 
+                status=status.HTTP_400_BAD_REQUEST
+            )
+        
+        # Get template
+        try:
+            template = Email_Template.objects.get(pk=template_id)
+        except Email_Template.DoesNotExist:
+            return Response(
+                {'error': f'Email_Template with id={template_id} does not exist'}, 
+                status=status.HTTP_404_NOT_FOUND
+            )
+        
+        # Generate preview
+        previewer = EmailTemplatePreview(template, context_pks)
+        preview = previewer.get_preview()
+        
+        if preview:
+            return Response(preview, status=status.HTTP_200_OK)
+        else:
+            return Response(
+                {'error': 'Failed to generate preview'}, 
+                status=status.HTTP_500_INTERNAL_SERVER_ERROR
+            )
+            
+    except Exception as e:
+        import traceback
+        traceback.print_exc()
+        return Response(
+            {'error': f'Unexpected error: {str(e)}'}, 
+            status=status.HTTP_500_INTERNAL_SERVER_ERROR
+        )