import logging
import secrets
from django.conf import settings
from django.core.exceptions import ValidationError
from rest_framework import status
from rest_framework.decorators import api_view, authentication_classes, permission_classes
from rest_framework.permissions import IsAuthenticated, AllowAny
from rest_framework.response import Response
from rest_framework_simplejwt.authentication import JWTAuthentication

from ai_chatbot.serializers import EnableAutoChatSerializer, PropertyCustomQASerializer

from .models import MasterQuestion, PropertyCustomQA, PropertyQA, AgencyAutoChatSetting, PropertyAutoChatState, GlobalQA
from .services import EmbeddingService

logger = logging.getLogger(__name__)
embedding_service = EmbeddingService()


# FIX #8: Add serializer validation
from rest_framework import serializers

class QAAnswerSerializer(serializers.Serializer):
    master_question_id = serializers.UUIDField(required=True)
    answer = serializers.CharField(max_length=5000, required=True, allow_blank=False)

class BulkQASerializer(serializers.Serializer):
    property_id = serializers.UUIDField(required=True)
    answers = QAAnswerSerializer(many=True, required=True)


# FIX #3: Webhook authentication
class WebhookSecretAuthentication:
    """Custom authentication for webhook endpoint"""
    
    def authenticate(self, request):
        secret = request.headers.get('X-Webhook-Secret')
        expected_secret = getattr(settings, 'AI_WEBHOOK_SECRET', None)
        
        if not expected_secret:
            logger.warning("AI_WEBHOOK_SECRET not set in settings")
            return None
        
        if secret and secrets.compare_digest(secret, expected_secret):
            return (None, None)  # Valid
        return None
    
    def authenticate_header(self, request):
        return 'X-Webhook-Secret'


@api_view(['GET'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def get_master_questions(request):
    """Get all master questions for agency to answer"""
    questions = MasterQuestion.objects.filter(is_active=True).order_by('order')
    data = [{'id': str(q.id), 'question': q.question, 'order': q.order} for q in questions]
    return Response({'questions': data})


@api_view(['GET'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def get_property_qa_status(request, property_id):
    """Get Q&A status for a property"""
    user = request.user
    
    master_questions = MasterQuestion.objects.filter(is_active=True).order_by('order')
    
    # Get existing answers
    existing_qa = {
        str(qa.master_question_id): {
            'answer': qa.answer,
            'qa_id': str(qa.id),
            'updated_at': qa.updated_at
        }
        for qa in PropertyQA.objects.filter(
            property_id=property_id,
            agency=user
        ).select_related('master_question')
    }
    
    questions_data = []
    for mq in master_questions:
        mq_id = str(mq.id)
        questions_data.append({
            'id': mq_id,
            'question': mq.question,
            'order': mq.order,
            'is_answered': mq_id in existing_qa,
            'answer': existing_qa[mq_id]['answer'] if mq_id in existing_qa else None,
            'updated_at': existing_qa[mq_id]['updated_at'] if mq_id in existing_qa else None,
        })
    
    # Get settings
    try:
        auto_chat_setting = AgencyAutoChatSetting.objects.get(agency=user)
        auto_chat_enabled = auto_chat_setting.is_enabled
        delay_seconds = auto_chat_setting.delay_seconds
        confidence_threshold = auto_chat_setting.confidence_threshold
    except AgencyAutoChatSetting.DoesNotExist:
        auto_chat_enabled = False
        delay_seconds = 30
        confidence_threshold = 0.6
    
    try:
        property_auto_state = PropertyAutoChatState.objects.get(property_id=property_id)
        property_auto_enabled = property_auto_state.is_auto_chat_enabled
    except PropertyAutoChatState.DoesNotExist:
        property_auto_enabled = False
    
    answered_count = sum(1 for q in questions_data if q['is_answered'])
    total_questions = len(questions_data)
    
    return Response({
        'property_id': property_id,
        'master_questions': questions_data,
        'stats': {
            'total_questions': total_questions,
            'answered_count': answered_count,
            'completion_percentage': round((answered_count / total_questions) * 100, 1) if total_questions > 0 else 0,
            'remaining_count': total_questions - answered_count
        },
        'auto_chat_settings': {
            'is_enabled': auto_chat_enabled,
            'property_auto_enabled': property_auto_enabled,
            'delay_seconds': delay_seconds,
            'confidence_threshold': confidence_threshold
        }
    })


@api_view(['POST'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def save_property_qa_bulk(request):
    """
    FIX #5 & #9: Optimized bulk save with proper auto-enable logic
    """
    user = request.user
    
    # Check role
    if not hasattr(user, 'role') or getattr(user.role, 'role_type', None) != 'agency':
        return Response({'error': 'Only agencies can add Q&A'}, status=status.HTTP_403_FORBIDDEN)
    
    # FIX #8: Validate input
    serializer = BulkQASerializer(data=request.data)
    if not serializer.is_valid():
        return Response({'error': 'Invalid data', 'details': serializer.errors}, 
                       status=status.HTTP_400_BAD_REQUEST)
    
    validated_data = serializer.validated_data
    property_id = validated_data['property_id']
    answers = validated_data['answers']
    
    if not answers:
        return Response({'error': 'No answers provided'}, status=status.HTTP_400_BAD_REQUEST)
    
    # FIX #5: Get existing answers to minimize database operations
    existing_qa = {
        str(qa.master_question_id): qa
        for qa in PropertyQA.objects.filter(
            property_id=property_id,
            agency=user
        ).select_related('master_question')
    }
    
    # Track which master questions were answered
    answered_master_ids = set()
    created_count = 0
    updated_count = 0
    errors = []
    
    for item in answers:
        master_q_id = str(item['master_question_id'])
        answer = item['answer'].strip()
        
        if not answer:
            continue
        
        try:
            master_q = MasterQuestion.objects.get(id=master_q_id, is_active=True)
            answered_master_ids.add(master_q_id)
            
            # Generate embedding
            embedding = embedding_service.generate_embedding(master_q.question)
            
            # Update or create
            if master_q_id in existing_qa:
                # Update existing
                qa = existing_qa[master_q_id]
                qa.answer = answer
                qa.question_embedding = embedding
                qa.save(update_fields=['answer', 'question_embedding', 'updated_at'])
                updated_count += 1
            else:
                # Create new
                PropertyQA.objects.create(
                    agency=user,
                    property_id=property_id,
                    master_question=master_q,
                    answer=answer,
                    question_embedding=embedding
                )
                created_count += 1
                
        except MasterQuestion.DoesNotExist:
            errors.append(f'Master question not found: {master_q_id}')
        except Exception as e:
            errors.append(f'Error for question {master_q_id}: {str(e)}')
    
    # Delete answers that were removed (not in current submission)
    to_delete_ids = set(existing_qa.keys()) - answered_master_ids
    if to_delete_ids:
        deleted_count = PropertyQA.objects.filter(
            property_id=property_id,
            master_question_id__in=to_delete_ids
        ).delete()[0]
        logger.info(f"Deleted {deleted_count} removed answers for property {property_id}")
    
    # FIX #9: Auto-enable only when ALL ACTIVE master questions are answered
    total_active_questions = MasterQuestion.objects.filter(is_active=True).count()
    total_answered = PropertyQA.objects.filter(
        property_id=property_id,
        master_question__is_active=True
    ).count()
    
    auto_chat_enabled = False
    if total_answered >= total_active_questions and total_active_questions > 0:
        property_state, created = PropertyAutoChatState.objects.update_or_create(
            property_id=property_id,
            defaults={'is_auto_chat_enabled': True}
        )
        auto_chat_enabled = True
        logger.info(f"✅ Auto-chat enabled for property {property_id} ({total_answered}/{total_active_questions} questions answered)")
    
    return Response({
        'message': f'Saved answers for property',
        'created': created_count,
        'updated': updated_count,
        'total': created_count + updated_count,
        'auto_chat_enabled': auto_chat_enabled,
        'completion': {
            'answered': total_answered,
            'total': total_active_questions,
            'percentage': round((total_answered / total_active_questions) * 100, 1) if total_active_questions > 0 else 0
        },
        'errors': errors if errors else None
    }, status=status.HTTP_200_OK if (created_count + updated_count) > 0 else status.HTTP_400_BAD_REQUEST)


@api_view(['POST'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def toggle_auto_chat(request, property_id):
    """Enable/disable auto-chat for a specific property"""
    user = request.user
    
    if not hasattr(user, 'role') or getattr(user.role, 'role_type', None) != 'agency':
        return Response({'error': 'Only agencies can configure auto-chat'}, status=status.HTTP_403_FORBIDDEN)
    
    is_enabled = request.data.get('is_enabled', False)
    
    # Validate before enabling
    if is_enabled:
        total_required = MasterQuestion.objects.filter(is_active=True).count()
        total_answered = PropertyQA.objects.filter(
            property_id=property_id,
            agency=user,
            master_question__is_active=True
        ).count()
        
        if total_answered < total_required:
            return Response({
                'error': f'Please answer all {total_required} active questions first. Currently answered: {total_answered}/{total_required}'
            }, status=status.HTTP_400_BAD_REQUEST)
    
    # Update property auto-chat state
    property_state, created = PropertyAutoChatState.objects.get_or_create(
        property_id=property_id,
        defaults={'is_auto_chat_enabled': is_enabled}
    )
    
    if not created:
        property_state.is_auto_chat_enabled = is_enabled
        property_state.save()
    
    # Also update agency-wide setting
    agency_setting, _ = AgencyAutoChatSetting.objects.get_or_create(
        agency=user,
        defaults={
            'is_enabled': is_enabled,
            'delay_seconds': 30,
            'confidence_threshold': 0.6
        }
    )
    
    if not agency_setting.is_enabled and is_enabled:
        agency_setting.is_enabled = True
        agency_setting.save()
    
    return Response({
        'property_id': property_id,
        'is_enabled': property_state.is_auto_chat_enabled,
        'message': f'Auto-chat {"enabled" if is_enabled else "disabled"} for this property'
    })


@api_view(['POST'])
@authentication_classes([WebhookSecretAuthentication])  # FIX #3: Secure webhook
@permission_classes([AllowAny])
def webhook_auto_reply(request):
    """
    FIX #3: Secured webhook endpoint for Chat app to trigger auto-reply
    """
    from .services import AutoChatService
    
    # Validate required fields
    required_fields = ['chat_id', 'property_id', 'message']
    for field in required_fields:
        if field not in request.data:
            return Response({'error': f'Missing required field: {field}'}, 
                          status=status.HTTP_400_BAD_REQUEST)
    
    data = request.data
    chat_id = data.get('chat_id')
    property_id = data.get('property_id')
    client_message = data.get('message')
    last_agency_reply_at = data.get('last_agency_reply_at')
    last_client_message_at = data.get('last_client_message_at')
    
    auto_chat_service = AutoChatService()
    
    # Check if auto-reply should trigger
    if auto_chat_service.should_auto_reply(chat_id, property_id, last_agency_reply_at, last_client_message_at):
        reply = auto_chat_service.generate_auto_reply(client_message, property_id, chat_id)
        if reply:
            return Response(reply)
        return Response({'should_auto_reply': False, 'error': 'Failed to generate reply'})
    
    return Response({'should_auto_reply': False})


@api_view(['POST'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def enable_auto_chat_with_questions(request):
    """
    Enable auto-chat for a property and add custom questions (max 5)
    """
    user = request.user
    
    # Check if agency
    if not hasattr(user, 'role') or getattr(user.role, 'role_type', None) != 'agency':
        return Response({'error': 'Only agencies can enable auto-chat'}, 
                       status=status.HTTP_403_FORBIDDEN)
    
    # Validate input
    serializer = EnableAutoChatSerializer(data=request.data)
    if not serializer.is_valid():
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
    
    validated_data = serializer.validated_data
    property_id = validated_data['property_id']
    enable = validated_data['enable']
    custom_questions = validated_data.get('custom_questions', [])
    
    # Verify property belongs to this agency
    from Property.models import Property
    try:
        property_obj = Property.objects.get(id=property_id, user=user)
    except Property.DoesNotExist:
        return Response({'error': 'Property not found or does not belong to you'}, 
                       status=status.HTTP_404_NOT_FOUND)
    
    # Delete existing custom questions for this property
    PropertyCustomQA.objects.filter(property_id=property_id).delete()
    
    # Add new custom questions with embeddings
    created_questions = []
    for idx, q_data in enumerate(custom_questions):
        # Generate embedding for the question
        embedding = embedding_service.generate_embedding(q_data['question'])
        
        custom_qa = PropertyCustomQA.objects.create(
            agency=user,
            property=property_obj,
            question=q_data['question'],
            answer=q_data['answer'],
            question_embedding=embedding,
            order=idx + 1,  # 1, 2, 3, 4, 5
            is_active=True
        )
        created_questions.append({
            'order': custom_qa.order,
            'question': custom_qa.question,
            'answer': custom_qa.answer
        })
    
    # Enable or disable auto-chat
    property_state, created = PropertyAutoChatState.objects.update_or_create(
        property_id=property_id,
        defaults={'is_auto_chat_enabled': enable}
    )
    
    # Also update agency settings
    agency_setting, _ = AgencyAutoChatSetting.objects.get_or_create(
        agency=user,
        defaults={
            'is_enabled': enable,
            'delay_seconds': 30,
            'confidence_threshold': 0.7
        }
    )
    if enable and not agency_setting.is_enabled:
        agency_setting.is_enabled = True
        agency_setting.save()
    
    return Response({
        'success': True,
        'property_id': str(property_id),
        'auto_chat_enabled': property_state.is_auto_chat_enabled,
        'custom_questions_added': len(created_questions),
        'custom_questions': created_questions,
        'message': f'Auto-chat {"enabled" if enable else "disabled"} with {len(created_questions)} custom questions'
    }, status=status.HTTP_200_OK)


@api_view(['GET'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def get_custom_questions(request, property_id):
    """
    Get custom questions for a property (for editing)
    """
    user = request.user
    
    # Verify property belongs to agency
    from Property.models import Property
    try:
        property_obj = Property.objects.get(id=property_id, user=user)
    except Property.DoesNotExist:
        return Response({'error': 'Property not found'}, status=status.HTTP_404_NOT_FOUND)
    
    custom_questions = PropertyCustomQA.objects.filter(
        property_id=property_id,
        is_active=True
    ).order_by('order')
    
    serializer = PropertyCustomQASerializer(custom_questions, many=True)
    
    # Get auto-chat status
    auto_chat_state = PropertyAutoChatState.objects.filter(property_id=property_id).first()
    
    return Response({
        'property_id': str(property_id),
        'auto_chat_enabled': auto_chat_state.is_auto_chat_enabled if auto_chat_state else False,
        'custom_questions': serializer.data,
        'max_allowed': 5,
        'remaining_slots': 5 - len(serializer.data)
    })

import uuid
from rest_framework.decorators import api_view, permission_classes
from rest_framework.permissions import IsAdminUser


@api_view(['GET', 'POST', 'PUT', 'DELETE'])
@permission_classes([IsAdminUser])
def admin_master_questions(request, question_id=None):
    """
    Admin CRUD for master questions
    """
    
    # ==================== GET ====================
    if request.method == 'GET':
        if question_id:
            try:
                question = MasterQuestion.objects.get(id=question_id)
                data = {
                    'id': str(question.id),
                    'question': question.question,
                    'order': question.order,
                    'is_active': question.is_active,
                    'created_at': question.created_at
                }
                return Response(data)
            except MasterQuestion.DoesNotExist:
                return Response({'error': 'Question not found'}, status=404)
        else:
            questions = MasterQuestion.objects.all().order_by('order')
            data = [{
                'id': str(q.id),
                'question': q.question,
                'order': q.order,
                'is_active': q.is_active
            } for q in questions]
            return Response({
                'count': len(data),
                'questions': data
            })
    
    # ==================== CREATE (Single) ====================
    elif request.method == 'POST':
        question_text = request.data.get('question')
        order = request.data.get('order')
        is_active = request.data.get('is_active', True)
        
        if not question_text:
            return Response({'error': 'Question text is required'}, status=400)
        
        # Check duplicate
        if MasterQuestion.objects.filter(question=question_text).exists():
            return Response({'error': 'Question already exists'}, status=400)
        
        # Auto assign order if not provided
        if order is None:
            order = MasterQuestion.objects.count() + 1
        
        question = MasterQuestion.objects.create(
            id=uuid.uuid4(),
            question=question_text,
            order=order,
            is_active=is_active
        )
        
        return Response({
            'id': str(question.id),
            'question': question.question,
            'order': question.order,
            'is_active': question.is_active,
            'message': 'Master question created successfully'
        }, status=201)
    
    # ==================== UPDATE ====================
    elif request.method == 'PUT':
        if not question_id:
            return Response({'error': 'Question ID required'}, status=400)
        
        try:
            question = MasterQuestion.objects.get(id=question_id)
        except MasterQuestion.DoesNotExist:
            return Response({'error': 'Question not found'}, status=404)
        
        question_text = request.data.get('question', question.question)
        order = request.data.get('order', question.order)
        is_active = request.data.get('is_active', question.is_active)
        
        question.question = question_text
        question.order = order
        question.is_active = is_active
        question.save()
        
        return Response({
            'id': str(question.id),
            'question': question.question,
            'order': question.order,
            'is_active': question.is_active,
            'message': 'Master question updated successfully'
        })
    
    # ==================== DELETE ====================
    elif request.method == 'DELETE':
        if not question_id:
            return Response({'error': 'Question ID required'}, status=400)
        
        try:
            question = MasterQuestion.objects.get(id=question_id)
            question.delete()
            return Response({'message': 'Master question deleted successfully'})
        except MasterQuestion.DoesNotExist:
            return Response({'error': 'Question not found'}, status=404)


# ==================== NEW: BULK CREATE ====================
@api_view(['POST'])
@permission_classes([IsAdminUser])
def admin_master_questions_bulk(request):
    """
    Admin can create multiple master questions at once
    """
    questions_data = request.data.get('questions', [])
    
    if not questions_data:
        return Response({'error': 'Questions list is required'}, status=400)
    
    created = []
    errors = []
    
    for idx, q_data in enumerate(questions_data):
        question_text = q_data.get('question')
        order = q_data.get('order', idx + 1)
        is_active = q_data.get('is_active', True)
        
        if not question_text:
            errors.append({'index': idx, 'error': 'Question text required'})
            continue
        
        # Skip duplicates
        if MasterQuestion.objects.filter(question=question_text).exists():
            errors.append({'index': idx, 'question': question_text, 'error': 'Already exists'})
            continue
        
        try:
            question = MasterQuestion.objects.create(
                id=uuid.uuid4(),
                question=question_text,
                order=order,
                is_active=is_active
            )
            created.append({
                'id': str(question.id),
                'question': question.question,
                'order': question.order
            })
        except Exception as e:
            errors.append({'index': idx, 'question': question_text, 'error': str(e)})
    
    return Response({
        'message': f'Created {len(created)} questions',
        'created': created,
        'errors': errors if errors else None
    }, status=201 if created else 400)


# ==================== GET ACTIVE QUESTIONS FOR AGENCY ====================
@api_view(['GET'])
@authentication_classes([JWTAuthentication])
@permission_classes([IsAuthenticated])
def get_master_questions(request):
    """
    Get all active master questions for agency to answer
    """
    questions = MasterQuestion.objects.filter(is_active=True).order_by('order')
    data = [{
        'id': str(q.id),
        'question': q.question,
        'order': q.order
    } for q in questions]
    return Response({
        'total': len(data),
        'questions': data
    })

# ==================== GLOBAL Q&A CRUD ====================

@api_view(['GET', 'POST', 'PUT', 'DELETE'])
@permission_classes([IsAdminUser])
def admin_global_qa(request, qa_id=None):
    """
    Admin CRUD for Global Q&A (applies to ALL properties)
    """
    
    # GET all or single
    if request.method == 'GET':
        if qa_id:
            try:
                qa = GlobalQA.objects.get(id=qa_id)
                data = {
                    'id': str(qa.id),
                    'question': qa.question,
                    'answer': qa.answer,
                    'language': qa.language,
                    'priority': qa.priority,
                    'is_active': qa.is_active
                }
                return Response(data)
            except GlobalQA.DoesNotExist:
                return Response({'error': 'Not found'}, status=404)
        else:
            qa_list = GlobalQA.objects.all().order_by('-priority', 'question')
            data = [{
                'id': str(q.id),
                'question': q.question,
                'answer': q.answer[:100],
                'language': q.language,
                'priority': q.priority,
                'is_active': q.is_active
            } for q in qa_list]
            return Response({'total': len(data), 'global_qa': data})
    
    # CREATE single
    elif request.method == 'POST':
        question = request.data.get('question')
        answer = request.data.get('answer')
        language = request.data.get('language', 'both')
        priority = request.data.get('priority', 0)
        is_active = request.data.get('is_active', True)
        
        if not question or not answer:
            return Response({'error': 'Question and answer required'}, status=400)
        
        if GlobalQA.objects.filter(question=question).exists():
            return Response({'error': 'Question already exists'}, status=400)
        
        # Generate embedding
        embedding = embedding_service.generate_embedding(question)
        
        qa = GlobalQA.objects.create(
            id=uuid.uuid4(),
            question=question,
            answer=answer,
            question_embedding=embedding,
            language=language,
            priority=priority,
            is_active=is_active
        )
        
        return Response({
            'id': str(qa.id),
            'question': qa.question,
            'answer': qa.answer,
            'message': 'Global Q&A created successfully'
        }, status=201)
    
    # UPDATE
    elif request.method == 'PUT':
        if not qa_id:
            return Response({'error': 'ID required'}, status=400)
        
        try:
            qa = GlobalQA.objects.get(id=qa_id)
        except GlobalQA.DoesNotExist:
            return Response({'error': 'Not found'}, status=404)
        
        question = request.data.get('question', qa.question)
        answer = request.data.get('answer', qa.answer)
        language = request.data.get('language', qa.language)
        priority = request.data.get('priority', qa.priority)
        is_active = request.data.get('is_active', qa.is_active)
        
        # Update embedding if question changed
        if question != qa.question:
            embedding = embedding_service.generate_embedding(question)
            qa.question_embedding = embedding
        
        qa.question = question
        qa.answer = answer
        qa.language = language
        qa.priority = priority
        qa.is_active = is_active
        qa.save()
        
        return Response({'message': 'Global Q&A updated successfully'})
    
    # DELETE
    elif request.method == 'DELETE':
        if not qa_id:
            return Response({'error': 'ID required'}, status=400)
        
        try:
            qa = GlobalQA.objects.get(id=qa_id)
            qa.delete()
            return Response({'message': 'Global Q&A deleted successfully'})
        except GlobalQA.DoesNotExist:
            return Response({'error': 'Not found'}, status=404)


# ==================== BULK CREATE GLOBAL Q&A ====================

@api_view(['POST'])
@permission_classes([IsAdminUser])
def admin_global_qa_bulk(request):
    """
    Admin can create multiple Global Q&A at once
    """
    items = request.data.get('items', [])
    
    if not items:
        return Response({'error': 'Items list required'}, status=400)
    
    created = []
    errors = []
    
    for idx, item in enumerate(items):
        question = item.get('question')
        answer = item.get('answer')
        language = item.get('language', 'both')
        priority = item.get('priority', 0)
        
        if not question or not answer:
            errors.append({'index': idx, 'error': 'Question and answer required'})
            continue
        
        if GlobalQA.objects.filter(question=question).exists():
            errors.append({'index': idx, 'question': question, 'error': 'Already exists'})
            continue
        
        try:
            embedding = embedding_service.generate_embedding(question)
            qa = GlobalQA.objects.create(
                id=uuid.uuid4(),
                question=question,
                answer=answer,
                question_embedding=embedding,
                language=language,
                priority=priority,
                is_active=True
            )
            created.append({
                'id': str(qa.id),
                'question': qa.question,
                'answer': qa.answer[:50]
            })
        except Exception as e:
            errors.append({'index': idx, 'question': question, 'error': str(e)})
    
    return Response({
        'message': f'Created {len(created)} Global Q&A',
        'created': created,
        'errors': errors if errors else None
    }, status=201 if created else 400)