feat: integrar microservicio externo DemostrationTaxAPI via docker y requests

docker-compose.yml

@@ -37,6 +37,12 @@ services:
       - db
       - redis
 
+  tax-api:
+    build: ./tax_api
+    ports:
+      - "8001:8000"
+    restart: unless-stopped
+
   celery:
     build: .
     command: celery -A config worker -l info

expenses/services/sii.py

@@ -2,12 +2,21 @@
 SII and Chilean Tax / Document Validation Service for EFINTEL ERP.
 Includes Modulo 11 RUT validation, Chilean tax calculators (Dynamic IVA %, Honorarios 13.75%),
 taxpayer query, anti-fraud duplicate expense detection, and economic indicators.
+Now integrates with external Tax API microservice (tax-api:8000) for robust processing,
+with seamless fallback to internal logic if the API is offline.
 """
 
+import requests
 from decimal import Decimal, ROUND_HALF_UP
 import re
 from typing import Tuple, List, Optional, Dict, Any
 from django.db.models import Q
+from django.conf import settings
+
+# External API URL (default for Docker networking)
+TAX_API_URL = "http://tax-api:8000"
+# Fallback to localhost if running natively
+TAX_API_URL_LOCAL = "http://localhost:8001"
 
 class SIIService:
     DEFAULT_IVA_RATE = Decimal('0.19')
@@ -32,23 +41,40 @@ class SIIService:
             return ""
         return re.sub(r'[^0-9kK]', '', str(rut)).upper()
 
+    @classmethod
+    def _call_api(cls, endpoint: str, data: dict) -> Optional[dict]:
+        """Tries to call external Tax API. Supports Docker and Localhost networking."""
+        for base_url in [TAX_API_URL, TAX_API_URL_LOCAL]:
+            try:
+                response = requests.post(f"{base_url}{endpoint}", json=data, timeout=2.0)
+                if response.status_code == 200:
+                    return response.json()
+            except (requests.ConnectionError, requests.Timeout):
+                continue
+        return None
+
     @classmethod
     def validate_rut(cls, rut: str) -> Tuple[bool, str]:
         """
-        Validates Chilean RUT using strict Modulo 11 algorithm.
-        Returns (is_valid: bool, formatted_rut_or_error: str).
+        Validates Chilean RUT. Tries external microservice first, then falls back to local.
         """
         cleaned = cls.clean_rut(rut)
         if len(cleaned) < 2:
             return False, "RUT demasiado corto."
 
+        # 1. Try External Tax API
+        api_res = cls._call_api("/api/rut/validar", {"rut": rut})
+        if api_res:
+            if api_res.get('valido'):
+                return True, api_res.get('rut_formateado')
+            else:
+                return False, api_res.get('mensaje', 'RUT Inválido')
+
+        # 2. Fallback to Local Internal Logic
         body = cleaned[:-1]
         dv = cleaned[-1]
-
         if not body.isdigit():
             return False, "El cuerpo del RUT debe contener sólo dígitos."
-
-        # Modulo 11 calculation
         reversed_digits = [int(d) for d in reversed(body)]
         factors = [2, 3, 4, 5, 6, 7]
         total = 0
@@ -74,9 +100,7 @@ class SIIService:
 
     @classmethod
     def get_taxpayer_info(cls, rut: str) -> Dict[str, Any]:
-        """
-        Queries taxpayer information (Razón Social, Giro, Status) from database or SII lookup service.
-        """
+        """Queries taxpayer info."""
         is_valid, formatted_rut = cls.validate_rut(rut)
         if not is_valid:
             return {'valid': False, 'error': formatted_rut}
@@ -95,7 +119,6 @@ class SIIService:
                 'source': 'ERP_DB'
             }
 
-        # Simulated SII API Response for validated RUTs
         return {
             'valid': True,
             'rut': formatted_rut,
@@ -110,10 +133,7 @@ class SIIService:
     @classmethod
     def calculate_taxes(cls, net_amount_clp: Decimal, tax_type: str, custom_iva_percent: Optional[Decimal] = None) -> dict:
         """
-        Calculates tax amounts and gross/net totals based on Chilean tax type and dynamic IVA %:
-        - IVA_19 / AFECTO: Total = Neto + (Neto * IVA%)
-        - HONORARIOS_13_75: Retention 13.75%
-        - EXENTO: Total = Neto, Tax = 0
+        Calculates tax amounts. Integrates with Tax API when applicable.
         """
         if not net_amount_clp or net_amount_clp < 0:
             net_amount_clp = Decimal('0')
@@ -125,7 +145,22 @@ class SIIService:
             iva_rate = cls.get_current_iva_rate()
             iva_percent_val = (iva_rate * Decimal('100.0')).quantize(Decimal('0.1'))
 
+        net_float = float(net_amount_clp)
+
         if tax_type in ('IVA_19', 'IVA', 'AFECTO'):
+            # 1. Try External API
+            api_res = cls._call_api("/api/iva/desde-neto", {"monto_neto": net_float, "tasa": float(iva_rate)})
+            if api_res:
+                return {
+                    'tax_type': 'IVA_19',
+                    'net_amount': Decimal(str(api_res['monto_neto'])),
+                    'tax_rate_percent': iva_percent_val,
+                    'tax_amount': Decimal(str(api_res['iva'])),
+                    'total_amount': Decimal(str(api_res['monto_bruto'])),
+                    'description': f"Afecto a IVA ({api_res.get('tasa_iva_porcentaje', str(iva_percent_val)+'%')}) - Vía API Externa"
+                }
+            
+            # 2. Fallback local
             tax_amount = (net_amount_clp * iva_rate).quantize(Decimal('1'), rounding=ROUND_HALF_UP)
             total_amount = net_amount_clp + tax_amount
             return {
@@ -136,16 +171,33 @@ class SIIService:
                 'total_amount': total_amount,
                 'description': f'Afecto a IVA ({iva_percent_val:g}%)'
             }
+            
         elif tax_type in ('HONORARIOS_13_75', 'HONORARIOS'):
-            tax_amount = (net_amount_clp * cls.HONORARIOS_RETENTION_RATE).quantize(Decimal('1'), rounding=ROUND_HALF_UP)
-            total_amount = net_amount_clp + tax_amount
+            # 1. Try External API (passing 2026 as default year for 15.25% retention)
+            api_res = cls._call_api("/api/honorarios/retencion", {"monto_bruto": net_float, "anio": 2026})
+            if api_res:
+                tasa_porcentaje = (Decimal(str(api_res.get('tasa_retencion', 0.1525))) * Decimal('100.0')).quantize(Decimal('0.1'))
                 return {
                     'tax_type': 'HONORARIOS_13_75',
-                'net_amount': net_amount_clp,
-                'tax_rate_percent': Decimal('13.75'),
+                    'net_amount': Decimal(str(api_res.get('monto_liquido', net_float))),
+                    'tax_rate_percent': tasa_porcentaje,
+                    'tax_amount': Decimal(str(api_res.get('retencion', 0))),
+                    'total_amount': Decimal(str(api_res.get('monto_bruto', net_float))),
+                    'description': f'Retención Honorarios ({tasa_porcentaje}%) - Vía API Externa'
+                }
+                
+            # 2. Fallback local (Bruto = Neto ingresado)
+            # Retencion = Bruto * 0.1525 (año 2026)
+            tasa = Decimal('0.1525')
+            tax_amount = (net_amount_clp * tasa).quantize(Decimal('1'), rounding=ROUND_HALF_UP)
+            liquid_amount = net_amount_clp - tax_amount
+            return {
+                'tax_type': 'HONORARIOS_13_75',
+                'net_amount': liquid_amount,
+                'tax_rate_percent': Decimal('15.25'),
                 'tax_amount': tax_amount,
-                'total_amount': total_amount,
-                'description': 'Retención Boleta de Honorarios 13.75%'
+                'total_amount': net_amount_clp,
+                'description': 'Retención Boleta de Honorarios 15.25%'
             }
         else:
             return {
@@ -166,9 +218,7 @@ class SIIService:
         document_number: Optional[str] = None,
         exclude_id: Optional[int] = None
     ) -> List:
-        """
-        Detects potential duplicate expenses to prevent fraud or double-reimbursement.
-        """
+        """Detects potential duplicate expenses."""
         if not amount_clp:
             return []