From f4863db8ea3cba1db0f843b0678f7ed0e938819d Mon Sep 17 00:00:00 2001
From: Mauricio Baeza <git@elmau.net>
Date: Sun, 21 Jan 2018 14:08:49 -0600
Subject: [PATCH] Fix - Issue #139

---
 source/app/models/main.py | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/source/app/models/main.py b/source/app/models/main.py
index c439a45..3bc59fd 100644
--- a/source/app/models/main.py
+++ b/source/app/models/main.py
@@ -2200,10 +2200,20 @@ class Productos(BaseModel):
 
     @classmethod
     def next_key(cls):
-        value = (Productos
-            .select(fn.Max(cast(Productos.clave, 'int')).alias('fm'))
-            .order_by(SQL('fm'))
-            .scalar())
+        try:
+            with database_proxy.transaction():
+                value = (Productos
+                    .select(fn.Max(cast(Productos.clave, 'int')).alias('fm'))
+                    .order_by(SQL('fm'))
+                    .scalar())
+        except Exception as e:
+            values = (Productos
+                .select(Productos.clave)
+                .order_by(Productos.clave)
+                .tuples()
+            )
+            value = max([int(v[0]) for v in values if v[0].isdigit()])
+
         value = value or 0
         value += 1
         return {'value': value}
@@ -3806,7 +3816,7 @@ class PreFacturas(BaseModel):
         totals_tax = {}
         total_trasladados = None
         total_retenciones = None
-        total_iva = 0
+        # ~ total_iva = 0
 
         for product in products:
             id_product = product.pop('id')
@@ -3848,8 +3858,8 @@ class PreFacturas(BaseModel):
                 continue
             import_tax = round(float(tax.tasa) * tax.importe, DECIMALES)
             total_trasladados = (total_trasladados or 0) + import_tax
-            if tax.name == 'IVA':
-                total_iva += import_tax
+            # ~ if tax.name == 'IVA':
+                # ~ total_iva += import_tax
 
             invoice_tax = {
                 'factura': invoice.id,
@@ -3862,10 +3872,10 @@ class PreFacturas(BaseModel):
         for tax in totals_tax.values():
             if tax.tipo == 'E' or tax.tipo == 'T':
                 continue
-            if tax.tasa == round(Decimal(2/3), 6):
-                import_tax = round(float(tax.tasa) * total_iva, DECIMALES)
-            else:
-                import_tax = round(float(tax.tasa) * tax.importe, DECIMALES)
+            # ~ if tax.tasa == round(Decimal(2/3), 6):
+                # ~ import_tax = round(float(tax.tasa) * total_iva, DECIMALES)
+            # ~ else:
+            import_tax = round(float(tax.tasa) * tax.importe, DECIMALES)
             total_retenciones = (total_retenciones or 0) + import_tax
 
             invoice_tax = {