Dovodi_Backend/apps/course/views/live_session.py

import logging

from django.core.exceptions import ImproperlyConfigured
from django.shortcuts import get_object_or_404
from django.utils import timezone

from rest_framework import status
from rest_framework.generics import GenericAPIView
from rest_framework.permissions import IsAuthenticated
from rest_framework.authentication import TokenAuthentication
from rest_framework.response import Response
from drf_yasg.utils import swagger_auto_schema
from drf_yasg import openapi
import time
import jwt
from apps.course.models import Course, CourseLiveSession, Participant, LiveSessionRecording
from apps.course.serializers import LiveSessionRoomCreateSerializer, LiveSessionTokenSerializer, LiveSessionRecordedFileSerializer, LiveSessionRecordingSerializer
from apps.course.services.plugnmeet import PlugNMeetClient, PlugNMeetError
from utils.exceptions import AppAPIException
from django.conf import settings
logger = logging.getLogger(__name__)


class CourseLiveSessionRoomCreateAPIView(GenericAPIView):
    permission_classes = [IsAuthenticated]
    authentication_classes = [TokenAuthentication]
    serializer_class = LiveSessionRoomCreateSerializer

    @swagger_auto_schema(
        operation_description="Create a live session room for a course",
        tags=["Imam-Javad - Course"],
        manual_parameters=[
            openapi.Parameter(
                'slug', openapi.IN_PATH,
                description="Course slug",
                type=openapi.TYPE_STRING,
                required=True
            )
        ],
        responses={
            201: openapi.Response(
                description="Live session room created successfully"
            )
        }
    )

    def post(self, request, slug, *args, **kwargs):
        # 1. Standard Permissions Logic
        course = get_object_or_404(Course, slug=slug)
        if not request.user.can_manage_course(course):
             raise AppAPIException({'message': 'Permission denied'}, status_code=403)

        # 2. Setup ID and Metadata
        room_id = f"room-{course.id}-imamjavad"
        subject = f"{course.title} Live Session"
        
        # 3. Database Logic - Check FIRST before calling PlugNMeet
        # Strategy: 
        # 1. Try to find active session (ended_at is NULL)
        # 2. If not found, try to find ended session with same room_id and reactivate it
        # 3. If not found, create new session
        session = None
        needs_room_creation = False
        
        try:
            # Try to get active session first
            session = CourseLiveSession.objects.get(
                course=course, room_id=room_id, ended_at__isnull=True
            )
            needs_room_creation = False
            logger.info(f"[LiveSession Create] Found active session - session_id={session.id} room_id={room_id}")
        except CourseLiveSession.DoesNotExist:
            # No active session, check if there's an old one with same room_id
            try:
                session = CourseLiveSession.objects.get(
                    course=course, room_id=room_id
                )
                # Reactivate the old session and mark for room recreation
                session.ended_at = None
                session.started_at = timezone.now()
                session.subject = subject
                session.save(update_fields=['ended_at', 'started_at', 'subject', 'updated_at'])
                needs_room_creation = True
                logger.info(f"[LiveSession Create] Reactivated ended session - session_id={session.id} room_id={room_id}")
            except CourseLiveSession.DoesNotExist:
                # No session exists at all, create new one and mark for room creation
                session = CourseLiveSession.objects.create(
                    course=course,
                    room_id=room_id,
                    subject=subject,
                    started_at=timezone.now()
                )
                needs_room_creation = True
                logger.info(f"[LiveSession Create] Created new session - session_id={session.id} room_id={room_id}")

        # 4. Create room in PlugNMeet ONLY if needed
        if needs_room_creation:
            metadata = self._build_metadata(subject)
            try:
                client = PlugNMeetClient()
                plugnmeet_response = client.create_room({
                    'room_id': room_id,
                    'empty_timeout':90,
                    'metadata': metadata,
                })
                logger.info(f"[LiveSession Create] Room created in PlugNMeet - room_id={room_id}")
            except Exception as exc:
                logger.error(f"[LiveSession Create] PlugNMeet Error: {exc}")
                # If room creation fails, revert the session changes
                if session.ended_at is None:
                    session.ended_at = timezone.now()
                    session.save(update_fields=['ended_at', 'updated_at'])
                raise AppAPIException({'message': f'Failed to create room: {str(exc)}'}, status_code=500)
        else:
            logger.info(f"[LiveSession Create] Skipping room creation - room already exists - room_id={room_id}")

        # 5. Generate the JOIN TOKEN (The Entry Ticket)
        token_payload = {
            "room_id": room_id,
            "user_info": {
                "name": f"{request.user.first_name} {request.user.last_name}",
                "user_id": str(request.user.id),
                "is_admin": True,
                "is_hidden": False
            }
        }
        
        pnm_token = jwt.encode(
            {
                "iss": settings.PLUGNMEET_API_KEY,
                "exp": int(time.time()) + 3600,
                "sub": str(request.user.id),
                **token_payload
            },
            settings.PLUGNMEET_API_SECRET,
            algorithm="HS256"
        )

        logger.info(f"[LiveSession Create] Success - session_id={session.id} room_id={room_id} user_id={request.user.id}")

        return Response({
            'success': True,
            'session': {'id': session.id, 'room_id': session.room_id},
            'access_token': pnm_token
        }, status=201)


    # def post(self, request, slug, *args, **kwargs):
    #     logger.info(f"[LiveSession Create] Request from user_id={request.user.id} for course={slug}")

    #     data = dict(request.data or {})
    #     if 'metadata' in data:
    #         logger.warning("[LiveSession Create] 'metadata' provided by client will be ignored for security reasons.")
    #         data.pop('metadata', None)

    #     serializer = self.get_serializer(data=data)
    #     serializer.is_valid(raise_exception=True)

    #     course = get_object_or_404(Course, slug=slug)
        
    #     if not request.user.can_manage_course(course):
    #         logger.warning(f"[LiveSession Create] Permission denied - user_id={request.user.id} course={slug}")
    #         raise AppAPIException({'message': 'You do not have permission to create a live session for this course.'}, status_code=status.HTTP_403_FORBIDDEN)
        
    #     logger.info(f"[LiveSession Create] Permission granted for user_id={request.user.id} course={slug}")

    #     subject = serializer.validated_data.get('subject') or f"{course.title} Live Session"
    #     room_id = self._build_room_id(course)
    #     metadata = self._build_metadata(subject)

    #     payload = {
    #         'room_id': room_id,
    #         'metadata': metadata,
    #     }

    #     logger.info(f"[LiveSession Create] Calling PlugNMeet API - room_id={room_id} course={slug}")
        
    #     try:
    #         client = PlugNMeetClient()
    #         plugnmeet_response = client.create_room(payload)
    #         logger.info(f"[LiveSession Create] PlugNMeet room created successfully - room_id={room_id}")
    #     except ImproperlyConfigured as exc:
    #         logger.error(f"[LiveSession Create] Configuration error - {str(exc)}")
    #         raise AppAPIException({'message': str(exc)}, status_code=status.HTTP_500_INTERNAL_SERVER_ERROR)
    #     except PlugNMeetError as exc:
    #         logger.error(f"[LiveSession Create] PlugNMeet API error - room_id={room_id} error={str(exc)}")
    #         detail = exc.response_data or {'message': str(exc)}
    #         status_code = exc.status_code or status.HTTP_502_BAD_GATEWAY
    #         raise AppAPIException(detail, status_code=status_code)

    #     session, created = CourseLiveSession.objects.get_or_create(
    #         course=course,
    #         room_id=room_id,
    #         defaults={
    #             'subject': subject,
    #             'started_at': timezone.now(),
    #         },
    #     )

    #     if created:
    #         logger.info(f"[LiveSession Create] New session created - session_id={session.id} room_id={room_id} course={slug}")
    #     else:
    #         logger.info(f"[LiveSession Create] Existing session reactivated - session_id={session.id} room_id={room_id} course={slug}")
    #         updates = {}
    #         if session.subject != subject:
    #             session.subject = subject
    #             updates['subject'] = subject
    #         if session.room_id != room_id:
    #             session.room_id = room_id
    #             updates['room_id'] = room_id
    #         if session.started_at is None:
    #             session.started_at = timezone.now()
    #             updates['started_at'] = session.started_at
    #         if updates:
    #             session.save(update_fields=list(updates.keys()))
    #             logger.info(f"[LiveSession Create] Session updated - session_id={session.id} fields={list(updates.keys())}")

    #     logger.info(f"[LiveSession Create] Success - session_id={session.id} room_id={room_id} course={slug} user_id={request.user.id}")
        
    #     return Response({
    #         'session': {
    #             'id': session.id,
    #             'room_id': session.room_id,
    #             'subject': session.subject,
    #             'started_at': session.started_at,
    #         },
    #         'plugnmeet': plugnmeet_response,
    #     }, status=status.HTTP_201_CREATED if created else status.HTTP_200_OK)

    @staticmethod
    def _build_room_id(course: Course) -> str:
        return f"room-{course.id}-imamjavad"

    def _build_metadata(self, subject: str) -> dict:
        # Build secured, centralized metadata. Client overrides are NOT allowed.
        return {
            'room_title': subject,
            'default_lock_settings': {
                'lock_microphone': True,
                'lock_webcam': True,
                'lock_screen_sharing': True,
                'lock_whiteboard': False,
                'lock_shared_notepad': False,
                'lock_chat': False,
                'lock_chat_send_message': False,
                'lock_chat_file_share': False,
                'lock_private_chat': False,
            },
            'room_features': {
                'allow_webcams': True,
                'mute_on_start': True,
                'allow_screen_sharing': True,
                'allow_recording': True,
                'allow_rtmp': False,
                'allow_view_other_webcams': True,
                'allow_view_other_participants_list': True,
                'admin_only_webcams': False,
                'allow_polls': True,
                'room_duration': 0,
                'chat_features': {
                    'allow_chat': True,
                    'allow_file_upload': True,
                },
                'shared_note_pad_features': {
                    'allowed_shared_note_pad': True,
                },
                'whiteboard_features': {
                    'allowed_whiteboard': True,
                },
                'breakout_room_features': {
                    'is_allow': True,
                    'allowed_number_rooms': 6,
                },
                'waiting_room_features': {
                    'is_active': False,
                },
                'recording_features': {
                    'is_allow': True,
                    'is_allow_cloud': True,
                    'is_allow_local': True,
                    'enable_auto_cloud_recording': False,
                    'only_record_admin_webcams': False,
                },
            },
        }

    def _deep_update(self, base: dict, overrides: dict) -> dict:
        for key, value in overrides.items():
            if isinstance(value, dict) and isinstance(base.get(key), dict):
                base[key] = self._deep_update(base.get(key, {}), value)
            else:
                base[key] = value
        return base


class CourseLiveSessionTokenAPIView(GenericAPIView):
    permission_classes = [IsAuthenticated]
    authentication_classes = [TokenAuthentication]
    serializer_class = LiveSessionTokenSerializer

    @swagger_auto_schema(
        operation_description="Generate access token for live session",
        tags=["Imam-Javad - Course"],
        responses={
            200: openapi.Response(
                description="Live session token generated successfully"
            )
        }
    )
    def post(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)

        course_slug = serializer.validated_data['course_slug']
        user = request.user
        
        logger.info(f"[LiveSession Token] Request from user_id={user.id} for course={course_slug}")
        
        try:
            course = Course.objects.get(slug=course_slug)
        except Course.DoesNotExist:
            logger.warning(f"[LiveSession Token] Course not found - course={course_slug} user_id={user.id}")
            raise AppAPIException({'message': 'Course not found.'}, status_code=status.HTTP_404_NOT_FOUND)

        if not course.is_online:
            logger.warning(f"[LiveSession Token] Course not configured for online - course={course_slug} user_id={user.id}")
            raise AppAPIException({'message': 'Course is not configured for online sessions.'}, status_code=status.HTTP_400_BAD_REQUEST)

        try:
            session = CourseLiveSession.objects.select_related('course').get(
                course=course,
                ended_at__isnull=True
            )
            logger.info(f"[LiveSession Token] Active session found in DB - session_id={session.id} room_id={session.room_id} course={course_slug}")
        except CourseLiveSession.DoesNotExist:
            logger.warning(f"[LiveSession Token] No active session found - course={course_slug} user_id={user.id}")
            raise AppAPIException({'message': 'No active live session found for this course.'}, status_code=status.HTTP_404_NOT_FOUND)
        
        # Check user role first to determine permissions
        is_admin = user.can_manage_course(course)
        user_role = "professor" if is_admin else "student"
        logger.info(f"[LiveSession Token] User role determined - user_id={user.id} role={user_role} course={course_slug}")
        
        # CRITICAL: Verify the room is actually active in PlugNMeet before issuing token
        # This prevents issuing tokens for rooms that have crashed or ended without webhook notification
        room_id = session.room_id
        room_is_active = self._verify_room_is_active(session)
        
        if not room_is_active:
            # Room is not active in PlugNMeet but we have a session record
            if is_admin:
                # For professors: Auto-recreate the room in PlugNMeet
                logger.info(f"[LiveSession Token] Room inactive but professor requesting - recreating room - room_id={room_id} session_id={session.id}")
                try:
                    self._recreate_room_in_plugnmeet(course, session)
                    logger.info(f"[LiveSession Token] Room recreated successfully - room_id={room_id}")
                except Exception as e:
                    logger.error(f"[LiveSession Token] Failed to recreate room - room_id={room_id} error={str(e)}")
                    raise AppAPIException({
                        'status': 'False',
                        'message': f'Failed to recreate room: {str(e)}',
                        'msg': f'Failed to recreate room: {str(e)}'
                    }, status_code=status.HTTP_500_INTERNAL_SERVER_ERROR)
            else:
                # For students: Refuse token - they cannot create rooms
                logger.error(f"[LiveSession Token] Room not active and user is student - refusing token - room_id={room_id} user_id={user.id}")
                raise AppAPIException({
                    'status': 'False',
                    'message': 'room is not active. Please wait for the professor to start the class.',
                    'msg': 'room is not active. Please wait for the professor to start the class.'
                }, status_code=status.HTTP_400_BAD_REQUEST)

        if not is_admin and not Participant.objects.filter(course=course, student_id=user.id, is_active=True).exists():
            logger.warning(f"[LiveSession Token] Access denied - user_id={user.id} not enrolled in course={course_slug}")
            raise AppAPIException({'message': 'You do not have access to this live session.'}, status_code=status.HTTP_403_FORBIDDEN)

        user_info = {
            'user_id': str(user.id),
            'name': user.get_full_name() or user.email or user.username or f"user-{user.id}",
            'is_admin': is_admin,
        }

        user_metadata = {}
        profile_pic = self._build_profile_url(request, user)
        logger.info(f"[LiveSession Token] Profile pic URL - user_id={user.id} url={profile_pic}")
        if profile_pic:
            user_metadata['profilePic'] = profile_pic

        if not is_admin:
            user_metadata['lock_settings'] = {
                'lock_microphone': True,
                'lock_screen_sharing': True,
                'lock_webcam': True,
                'lock_whiteboard': False,
                'lock_shared_notepad': False,
                'lock_chat': False,
                'lock_chat_send_message': False,
                'lock_chat_file_share': False,
                'lock_private_chat': False,
            }
        else:
            user_metadata['is_hidden'] = False

        if user_metadata:
            user_info['user_metadata'] = user_metadata

        payload = {
            'room_id': room_id,
            'user_info': user_info,
        }

        logger.info(f"[LiveSession Token] Requesting token from PlugNMeet - room_id={room_id} user_id={user.id} role={user_role}")

        try:
            client = PlugNMeetClient()
            plugnmeet_response = client.get_join_token(payload)
            logger.info(f"[LiveSession Token] Token generated successfully - room_id={room_id} user_id={user.id}")
        except ImproperlyConfigured as exc:
            logger.error(f"[LiveSession Token] Configuration error - {str(exc)}")
            raise AppAPIException({'message': str(exc)}, status_code=status.HTTP_500_INTERNAL_SERVER_ERROR)
        except PlugNMeetError as exc:
            logger.error(f"[LiveSession Token] PlugNMeet API error - room_id={room_id} user_id={user.id} error={str(exc)}")
            detail = exc.response_data or {'message': str(exc)}
            status_code = exc.status_code or status.HTTP_502_BAD_GATEWAY
            raise AppAPIException(detail, status_code=status_code)

        logger.info(f"[LiveSession Token] Success - room_id={room_id} user_id={user.id} role={user_role} course={course_slug}")

        return Response({
            'room_id': room_id,
            'token': plugnmeet_response.get('token'),
            'plugnmeet': plugnmeet_response,
        })

    def _build_metadata(self, subject: str) -> dict:
        # Build secured, centralized metadata. Client overrides are NOT allowed.
        return {
            'room_title': subject,
            'default_lock_settings': {
                'lock_microphone': True,
                'lock_webcam': True,
                'lock_screen_sharing': True,
                'lock_whiteboard': False,
                'lock_shared_notepad': False,
                'lock_chat': False,
                'lock_chat_send_message': False,
                'lock_chat_file_share': False,
                'lock_private_chat': False,
            },
            'room_features': {
                'allow_webcams': True,
                'mute_on_start': True,
                'allow_screen_sharing': True,
                'allow_recording': True,
                'allow_rtmp': False,
                'allow_view_other_webcams': True,
                'allow_view_other_participants_list': True,
                'admin_only_webcams': False,
                'allow_polls': True,
                'room_duration': 0,
                'chat_features': {
                    'allow_chat': True,
                    'allow_file_upload': True,
                },
                'shared_note_pad_features': {
                    'allowed_shared_note_pad': True,
                },
                'whiteboard_features': {
                    'allowed_whiteboard': True,
                },
                'breakout_room_features': {
                    'is_allow': True,
                    'allowed_number_rooms': 6,
                },
                'waiting_room_features': {
                    'is_active': False,
                },
                'recording_features': {
                    'is_allow': True,
                    'is_allow_cloud': True,
                    'is_allow_local': True,
                    'enable_auto_cloud_recording': False,
                    'only_record_admin_webcams': False,
                },
            },
        }

    @staticmethod
    def _verify_room_is_active(session: CourseLiveSession) -> bool:
        """
        Verify that the room is actually active in PlugNMeet.
        
        Args:
            session: The CourseLiveSession to verify
            
        Returns:
            bool: True if room is active in PlugNMeet, False otherwise
            
        Side effects:
            - Closes session in database if PlugNMeet reports room is inactive
        """
        if not session.room_id:
            logger.warning(f"[Room Verify] Session has no room_id - session_id={session.id}")
            return False
            
        try:
            client = PlugNMeetClient()
            response = client.is_room_active(session.room_id)
            
            # Debug: Log full response
            logger.debug(f"[Room Verify] PlugNMeet response - room_id={session.room_id} response={response}")
            
            # Handle isActive as boolean or string
            is_active_raw = response.get('isActive', False)
            is_active = is_active_raw if isinstance(is_active_raw, bool) else str(is_active_raw).lower() == 'true'
            response_msg = response.get('msg', 'unknown')
            response_status = response.get('status', False)
            
            # Trust status and msg if they indicate active room
            if response_status and 'active' in response_msg.lower() and 'not' not in response_msg.lower():
                is_active = True
            
            if is_active:
                logger.debug(f"[Room Verify] ✓ Room is active - room_id={session.room_id} session_id={session.id}")
                return True
            else:
                logger.warning(f"[Room Verify] ✗ Room is NOT active - room_id={session.room_id} session_id={session.id} msg={response_msg}")
                # Auto-close the session since room is not active
                now = timezone.now()
                session.ended_at = now
                session.save(update_fields=['ended_at', 'updated_at'])
                logger.info(f"[Room Verify] Session auto-closed - session_id={session.id} room_id={session.room_id}")
                return False
                
        except PlugNMeetError as e:
            error_msg = str(e)
            logger.error(f"[Room Verify] PlugNMeet API error - room_id={session.room_id} error={error_msg}")
            
            # If room not found, close the session
            if 'not found' in error_msg.lower() or 'does not exist' in error_msg.lower():
                now = timezone.now()
                session.ended_at = now
                session.save(update_fields=['ended_at', 'updated_at'])
                logger.warning(f"[Room Verify] Room not found - session closed - session_id={session.id}")
            
            return False
            
        except Exception as e:
            logger.error(f"[Room Verify] Unexpected error - room_id={session.room_id} error={type(e).__name__}: {str(e)}")
            return False

    def _recreate_room_in_plugnmeet(self, course: Course, session: CourseLiveSession) -> None:
        """
        Recreate a room in PlugNMeet when session exists but room is inactive.
        
        This happens when:
        - Webhook failed to notify us of room closure
        - PlugNMeet server restarted
        - Room was manually ended
        
        Args:
            course: The course for which to recreate the room
            session: The existing session to reactivate
            
        Raises:
            PlugNMeetError: If room creation fails
        """
        subject = session.subject or f"{course.title} Live Session"
        room_id = session.room_id
        metadata = self._build_metadata(subject)
        
        payload = {
            'room_id': room_id,
            'metadata': metadata,
        }
        
        logger.info(f"[Room Recreate] Recreating room in PlugNMeet - room_id={room_id} session_id={session.id}")
        
        try:
            client = PlugNMeetClient()
            plugnmeet_response = client.create_room(payload)
            logger.info(f"[Room Recreate] Room recreated successfully - room_id={room_id} response={plugnmeet_response}")
            
            # Reset session ended_at to mark it as active again
            session.ended_at = None
            session.save(update_fields=['ended_at', 'updated_at'])
            logger.info(f"[Room Recreate] Session reactivated - session_id={session.id}")
            
        except PlugNMeetError as exc:
            logger.error(f"[Room Recreate] Failed to recreate room - room_id={room_id} error={str(exc)}")
            raise

    @staticmethod
    def _build_profile_url(request, user):
        avatar = getattr(user, 'avatar', None)
        if avatar and getattr(avatar, 'url', None):
            return request.build_absolute_uri(avatar.url)
        return None


class CourseLiveSessionRecordedFileAPIView(GenericAPIView):
    permission_classes = [IsAuthenticated]
    authentication_classes = [TokenAuthentication]
    serializer_class = LiveSessionRecordingSerializer

    @swagger_auto_schema(
        operation_description="Update recorded file for live session",
        tags=["Imam-Javad - Course"],
        manual_parameters=[
            openapi.Parameter(
                'course_id', openapi.IN_PATH,
                description="Course ID",
                type=openapi.TYPE_INTEGER,
                required=True
            )
        ],
        responses={
            200: openapi.Response(
                description="Recorded file updated successfully"
            )
        }
    )
    def patch(self, request, course_id, *args, **kwargs):
        logger.info(f"[LiveSession Recorded File] Request from user_id={request.user.id} for course_id={course_id}")

        course = get_object_or_404(Course, id=course_id)
        
        if not request.user.can_manage_course(course):
            logger.warning(f"[LiveSession Recorded File] Permission denied - user_id={request.user.id} course_id={course_id}")
            raise AppAPIException({'message': 'You do not have permission to update this course.'}, status_code=status.HTTP_403_FORBIDDEN)
        
        try:
            session = course.live_sessions.latest('-started_at')
        except CourseLiveSession.DoesNotExist:
            logger.warning(f"[LiveSession Recorded File] No active session found - course_id={course_id} user_id={request.user.id}")
            raise AppAPIException({'message': 'No live session found for this course.'}, status_code=status.HTTP_404_NOT_FOUND)
        
        logger.info(f"[LiveSession Recorded File] Latest session found - session_id={session.id} course_id={course_id}")
        
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)

        recording = LiveSessionRecording.objects.create(
            session=session,
            file=serializer.validated_data['file'],
            title=serializer.validated_data.get('title') or f"{session.subject} Recording",
            recording_type=serializer.validated_data.get('recording_type', 'video'),
            file_time=serializer.validated_data.get('file_time'),
        )

        logger.info(f"[LiveSession Recorded File] Recording created successfully - recording_id={recording.id} session_id={session.id} user_id={request.user.id}")

        return Response({
            'id': recording.id,
            'session_id': session.id,
            'title': recording.title,
            'file': request.build_absolute_uri(recording.file.url),
            'recording_type': recording.recording_type,
            'file_time': recording.file_time,
            'is_active': recording.is_active,
        }, status=status.HTTP_201_CREATED)