Add scheduled automation task and update URL routing

- Introduced a new scheduled task for executing automation rules every 5 minutes in the Celery beat schedule.
- Updated URL routing to include a new endpoint for automation-related functionalities.
- Refactored imports in various modules to align with the new business layer structure, ensuring backward compatibility for billing models, exceptions, and services.

backend/igny8_core/business/billing/services/__init__.py

@@ -0,0 +1,4 @@
+"""
+Billing services
+"""
+

backend/igny8_core/business/billing/services/credit_service.py

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+"""
+Credit Service for managing credit transactions and deductions
+"""
+from django.db import transaction
+from django.utils import timezone
+from igny8_core.business.billing.models import CreditTransaction, CreditUsageLog
+from igny8_core.business.billing.constants import CREDIT_COSTS
+from igny8_core.business.billing.exceptions import InsufficientCreditsError, CreditCalculationError
+from igny8_core.auth.models import Account
+
+
+class CreditService:
+    """Service for managing credits"""
+    
+    @staticmethod
+    def get_credit_cost(operation_type, amount=None):
+        """
+        Get credit cost for operation.
+        
+        Args:
+            operation_type: Type of operation (from CREDIT_COSTS)
+            amount: Optional amount (word count, image count, etc.)
+        
+        Returns:
+            int: Number of credits required
+        
+        Raises:
+            CreditCalculationError: If operation type is unknown
+        """
+        base_cost = CREDIT_COSTS.get(operation_type, 0)
+        if base_cost == 0:
+            raise CreditCalculationError(f"Unknown operation type: {operation_type}")
+        
+        # Variable cost operations
+        if operation_type == 'content_generation' and amount:
+            # Per 100 words
+            return max(1, int(base_cost * (amount / 100)))
+        elif operation_type == 'optimization' and amount:
+            # Per 200 words
+            return max(1, int(base_cost * (amount / 200)))
+        elif operation_type == 'image_generation' and amount:
+            # Per image
+            return base_cost * amount
+        elif operation_type == 'idea_generation' and amount:
+            # Per idea
+            return base_cost * amount
+        
+        # Fixed cost operations
+        return base_cost
+    
+    @staticmethod
+    def check_credits(account, operation_type, amount=None):
+        """
+        Check if account has sufficient credits for an operation.
+        
+        Args:
+            account: Account instance
+            operation_type: Type of operation
+            amount: Optional amount (word count, image count, etc.)
+        
+        Raises:
+            InsufficientCreditsError: If account doesn't have enough credits
+        """
+        required = CreditService.get_credit_cost(operation_type, amount)
+        if account.credits < required:
+            raise InsufficientCreditsError(
+                f"Insufficient credits. Required: {required}, Available: {account.credits}"
+            )
+        return True
+    
+    @staticmethod
+    def check_credits_legacy(account, required_credits):
+        """
+        Legacy method: Check if account has enough credits (for backward compatibility).
+        
+        Args:
+            account: Account instance
+            required_credits: Number of credits required
+        
+        Raises:
+            InsufficientCreditsError: If account doesn't have enough credits
+        """
+        if account.credits < required_credits:
+            raise InsufficientCreditsError(
+                f"Insufficient credits. Required: {required_credits}, Available: {account.credits}"
+            )
+    
+    @staticmethod
+    @transaction.atomic
+    def deduct_credits(account, amount, operation_type, description, metadata=None, cost_usd=None, model_used=None, tokens_input=None, tokens_output=None, related_object_type=None, related_object_id=None):
+        """
+        Deduct credits and log transaction.
+        
+        Args:
+            account: Account instance
+            amount: Number of credits to deduct
+            operation_type: Type of operation (from CreditUsageLog.OPERATION_TYPE_CHOICES)
+            description: Description of the transaction
+            metadata: Optional metadata dict
+            cost_usd: Optional cost in USD
+            model_used: Optional AI model used
+            tokens_input: Optional input tokens
+            tokens_output: Optional output tokens
+            related_object_type: Optional related object type
+            related_object_id: Optional related object ID
+        
+        Returns:
+            int: New credit balance
+        """
+        # Check sufficient credits (legacy: amount is already calculated)
+        CreditService.check_credits_legacy(account, amount)
+        
+        # Deduct from account.credits
+        account.credits -= amount
+        account.save(update_fields=['credits'])
+        
+        # Create CreditTransaction
+        CreditTransaction.objects.create(
+            account=account,
+            transaction_type='deduction',
+            amount=-amount,  # Negative for deduction
+            balance_after=account.credits,
+            description=description,
+            metadata=metadata or {}
+        )
+        
+        # Create CreditUsageLog
+        CreditUsageLog.objects.create(
+            account=account,
+            operation_type=operation_type,
+            credits_used=amount,
+            cost_usd=cost_usd,
+            model_used=model_used or '',
+            tokens_input=tokens_input,
+            tokens_output=tokens_output,
+            related_object_type=related_object_type or '',
+            related_object_id=related_object_id,
+            metadata=metadata or {}
+        )
+        
+        return account.credits
+    
+    @staticmethod
+    @transaction.atomic
+    def deduct_credits_for_operation(account, operation_type, amount=None, description=None, metadata=None, cost_usd=None, model_used=None, tokens_input=None, tokens_output=None, related_object_type=None, related_object_id=None):
+        """
+        Deduct credits for an operation (convenience method that calculates cost automatically).
+        
+        Args:
+            account: Account instance
+            operation_type: Type of operation
+            amount: Optional amount (word count, image count, etc.)
+            description: Optional description (auto-generated if not provided)
+            metadata: Optional metadata dict
+            cost_usd: Optional cost in USD
+            model_used: Optional AI model used
+            tokens_input: Optional input tokens
+            tokens_output: Optional output tokens
+            related_object_type: Optional related object type
+            related_object_id: Optional related object ID
+        
+        Returns:
+            int: New credit balance
+        """
+        # Calculate credit cost
+        credits_required = CreditService.get_credit_cost(operation_type, amount)
+        
+        # Check sufficient credits
+        CreditService.check_credits(account, operation_type, amount)
+        
+        # Auto-generate description if not provided
+        if not description:
+            if operation_type == 'clustering':
+                description = f"Clustering operation"
+            elif operation_type == 'idea_generation':
+                description = f"Generated {amount or 1} idea(s)"
+            elif operation_type == 'content_generation':
+                description = f"Generated content ({amount or 0} words)"
+            elif operation_type == 'image_generation':
+                description = f"Generated {amount or 1} image(s)"
+            else:
+                description = f"{operation_type} operation"
+        
+        return CreditService.deduct_credits(
+            account=account,
+            amount=credits_required,
+            operation_type=operation_type,
+            description=description,
+            metadata=metadata,
+            cost_usd=cost_usd,
+            model_used=model_used,
+            tokens_input=tokens_input,
+            tokens_output=tokens_output,
+            related_object_type=related_object_type,
+            related_object_id=related_object_id
+        )
+    
+    @staticmethod
+    @transaction.atomic
+    def add_credits(account, amount, transaction_type, description, metadata=None):
+        """
+        Add credits (purchase, subscription, etc.).
+        
+        Args:
+            account: Account instance
+            amount: Number of credits to add
+            transaction_type: Type of transaction (from CreditTransaction.TRANSACTION_TYPE_CHOICES)
+            description: Description of the transaction
+            metadata: Optional metadata dict
+        
+        Returns:
+            int: New credit balance
+        """
+        # Add to account.credits
+        account.credits += amount
+        account.save(update_fields=['credits'])
+        
+        # Create CreditTransaction
+        CreditTransaction.objects.create(
+            account=account,
+            transaction_type=transaction_type,
+            amount=amount,  # Positive for addition
+            balance_after=account.credits,
+            description=description,
+            metadata=metadata or {}
+        )
+        
+        return account.credits
+    
+    @staticmethod
+    def calculate_credits_for_operation(operation_type, **kwargs):
+        """
+        Calculate credits needed for an operation.
+        Legacy method - use get_credit_cost() instead.
+        
+        Args:
+            operation_type: Type of operation
+            **kwargs: Operation-specific parameters
+        
+        Returns:
+            int: Number of credits required
+        
+        Raises:
+            CreditCalculationError: If calculation fails
+        """
+        # Map legacy operation types
+        if operation_type == 'ideas':
+            operation_type = 'idea_generation'
+        elif operation_type == 'content':
+            operation_type = 'content_generation'
+        elif operation_type == 'images':
+            operation_type = 'image_generation'
+        
+        # Extract amount from kwargs
+        amount = None
+        if 'word_count' in kwargs:
+            amount = kwargs.get('word_count')
+        elif 'image_count' in kwargs:
+            amount = kwargs.get('image_count')
+        elif 'idea_count' in kwargs:
+            amount = kwargs.get('idea_count')
+        
+        return CreditService.get_credit_cost(operation_type, amount)
+