feat: add PDF report generation for backtest executions

- Implemented `generate_backtest_report` to create PDF reports for backtest results.
- Added `report_file` field to `StrategyExecution` for storing report paths.
- Introduced `/executions/<execution_id>/report/` endpoint for downloading reports.
- Enhanced backtesting flow to generate and save reports upon completion.
- Updated dependencies to include `matplotlib` for report generation.

strategies/views.py

@@ -1,17 +1,21 @@
+import json
+import logging
+import os
+import threading
+import time
+
+import requests
+from django.conf import settings
+from django.http import FileResponse, JsonResponse
 from django.shortcuts import render, get_object_or_404
-from django.http import JsonResponse
 from django.views.decorators.csrf import csrf_exempt
 from django.views.decorators.http import require_http_methods
 from django.utils import timezone
-import json
-import threading
-import time
-import requests
-import logging
 
 from .models import QuantStrategy, StrategyVersion, StrategyExecution
 from .base import StrategyRegistry
 from .services.backtest import run_backtest
+from .services.report import generate_backtest_report
 from . import implementations  # 구현체들을 로드하여 레지스트리에 등록
 
 logger = logging.getLogger(__name__)
@@ -218,6 +222,9 @@ def execution_status(request, execution_id):
     if execution.status == 'completed' and execution.result:
         response_data['result'] = execution.result
 
+    if execution.report_file:
+        response_data['report_url'] = f'/api/executions/{execution.id}/report/'
+
     if execution.status == 'failed' and execution.error_message:
         response_data['error_message'] = execution.error_message
 
@@ -312,6 +319,13 @@ def backtest_strategy(request):
                 execution.status = 'completed'
                 execution.result = result
                 execution.completed_at = timezone.now()
+
+                try:
+                    report_path = generate_backtest_report(result, execution.id)
+                    execution.report_file = report_path
+                except Exception as report_err:
+                    logger.exception(f'PDF report generation failed for execution {execution.id}: {report_err}')
+
                 execution.save()
 
             except Exception as e:
@@ -343,3 +357,20 @@ def backtest_strategy(request):
         return JsonResponse({
             'error': str(e)
         }, status=500)
+
+
+@require_http_methods(["GET"])
+def download_report(request, execution_id):
+    """백테스트 PDF 리포트 다운로드"""
+    execution = get_object_or_404(StrategyExecution, id=execution_id)
+
+    if not execution.report_file:
+        return JsonResponse({'error': 'Report not available'}, status=404)
+
+    file_path = os.path.join(settings.MEDIA_ROOT, execution.report_file)
+    if not os.path.exists(file_path):
+        return JsonResponse({'error': 'Report file not found'}, status=404)
+
+    response = FileResponse(open(file_path, 'rb'), content_type='application/pdf')
+    response['Content-Disposition'] = f'attachment; filename="backtest_{execution_id}.pdf"'
+    return response