from rest_framework import viewsets, status
from rest_framework.decorators import action
from rest_framework.response import Response
from .models import CrawlTask, CrawlRun
from .serializers import CrawlTaskSerializer, CrawlRunSerializer

class CrawlTaskViewSet(viewsets.ModelViewSet):
    """
    ViewSet for CrawlTask models. Supports CRUD and custom trigger/runs actions.
    """
    queryset = CrawlTask.objects.all().order_by('-created_at')
    serializer_class = CrawlTaskSerializer

    @action(detail=True, methods=['post'], url_path='trigger')
    def trigger(self, request, pk=None):
        task = self.get_object()
        
        # Create a new CrawlRun with status RUNNING
        run = CrawlRun.objects.create(
            crawl_task=task,
            status='RUNNING'
        )
        
        # Check if tasks can be imported.
        # This will integrate with crawlers/tasks.py once it is written in a later step.
        try:
            from crawler.tasks import run_crawl_pipeline
            # run asynchronously
            run_crawl_pipeline.delay(str(run.id))
            is_queued = True
        except ImportError:
            # Fallback if tasks.py doesn't exist yet or run_crawl_pipeline is not defined
            is_queued = False
            
        return Response({
            "status": "queued" if is_queued else "queued_stub",
            "run_id": str(run.id)
        }, status=status.HTTP_202_ACCEPTED)

    @action(detail=True, methods=['get'], url_path='runs')
    def runs(self, request, pk=None):
        task = self.get_object()
        runs = task.runs.all().order_by('-started_at')
        page = self.paginate_queryset(runs)
        if page is not None:
            serializer = CrawlRunSerializer(page, many=True)
            return self.get_paginated_response(serializer.data)
            
        serializer = CrawlRunSerializer(runs, many=True)
        return Response(serializer.data)