from django.core.management.base import BaseCommand
from django.contrib.auth import get_user_model
from users.models import UserGroup

User = get_user_model()

class Command(BaseCommand):
    help = 'Create default user groups with appropriate permissions'
    
    def handle(self, *args, **options):
        # Create Administrator group
        admin_group, created = UserGroup.objects.get_or_create(
            name='Administrators',
            defaults={
                'description': 'Administrator group with full access to all modules'
            }
        )
        if created:
            admin_group.permissions = {
                'manufacturing': True,
                'inventory': True,
                'purchase': True,
                'sales': True,
                'user_management': True,
                'reporting': True,
                'dashboard': True
            }
            admin_group.save()
            self.stdout.write(
                self.style.SUCCESS('Successfully created Administrators group')
            )
        
        # Create Manager group
        manager_group, created = UserGroup.objects.get_or_create(
            name='Managers',
            defaults={
                'description': 'Manager group with access to core business modules'
            }
        )
        if created:
            manager_group.permissions = {
                'manufacturing': True,
                'inventory': True,
                'purchase': True,
                'sales': True,
                'user_management': False,
                'reporting': True,
                'dashboard': True
            }
            manager_group.save()
            self.stdout.write(
                self.style.SUCCESS('Successfully created Managers group')
            )
        
        # Create Operator group
        operator_group, created = UserGroup.objects.get_or_create(
            name='Operators',
            defaults={
                'description': 'Operator group with access to operational modules'
            }
        )
        if created:
            operator_group.permissions = {
                'manufacturing': True,
                'inventory': True,
                'purchase': False,
                'sales': True,
                'user_management': False,
                'reporting': False,
                'dashboard': True
            }
            operator_group.save()
            self.stdout.write(
                self.style.SUCCESS('Successfully created Operators group')
            )
        
        # Create Viewer group
        viewer_group, created = UserGroup.objects.get_or_create(
            name='Viewers',
            defaults={
                'description': 'Viewer group with read-only access to reports and dashboard'
            }
        )
        if created:
            viewer_group.permissions = {
                'manufacturing': False,
                'inventory': False,
                'purchase': False,
                'sales': False,
                'user_management': False,
                'reporting': True,
                'dashboard': True
            }
            viewer_group.save()
            self.stdout.write(
                self.style.SUCCESS('Successfully created Viewers group')
            )
        
        # Assign existing users to appropriate groups
        self.assign_users_to_groups()
        
        self.stdout.write(
            self.style.SUCCESS('Successfully created default groups and assigned users')
        )
    
    def assign_users_to_groups(self):
        """Assign existing users to appropriate groups"""
        # Get the groups
        try:
            admin_group = UserGroup.objects.get(name='Administrators')
            manager_group = UserGroup.objects.get(name='Managers')
            operator_group = UserGroup.objects.get(name='Operators')
            viewer_group = UserGroup.objects.get(name='Viewers')
        except UserGroup.DoesNotExist:
            self.stdout.write(
                self.style.ERROR('One or more groups do not exist')
            )
            return
        
        # Assign users to groups (this is a simple assignment, you may want to customize this)
        for user in User.objects.all():
            # If user doesn't have a group, assign them to the operator group by default
            if not user.group:
                user.group = operator_group
                user.save()
        
        self.stdout.write(
            self.style.SUCCESS('Successfully assigned users to groups')
        )