feat(#32): Enhanced barcode generation with uniqueness - Task 3 completed

- Added barcode field to stock.lot with automatic generation
- Implemented unique barcode generation in format YYMMDDNNNNNNC
- Added Luhn check digit for barcode validation
- Handles high volume scenarios with sample type prefixes
- Collision detection and retry mechanism for uniqueness
- Successful test with ephemeral instance restart

check_stock_lot_fields.py

@@ -0,0 +1,11 @@
+import odoo
+
+db_name = 'lims_demo'
+registry = odoo.registry(db_name)
+with registry.cursor() as cr:
+    env = odoo.api.Environment(cr, 1, {})
+    fields = env['stock.lot']._fields.keys()
+    print("Stock.lot fields containing 'name' or 'barcode':")
+    for f in fields:
+        if 'name' in f or 'barcode' in f:
+            print(f"  - {f}")

lims_management/models/stock_lot.py

@@ -1,11 +1,21 @@
 # -*- coding: utf-8 -*-
 from odoo import models, fields, api
+from datetime import datetime
+import random
 
 class StockLot(models.Model):
     _inherit = 'stock.lot'
 
     is_lab_sample = fields.Boolean(string='Is a Laboratory Sample')
     
+    barcode = fields.Char(
+        string='Código de Barras',
+        compute='_compute_barcode',
+        store=True,
+        readonly=True,
+        help="Código de barras único para la muestra en formato YYMMDDNNNNNNC"
+    )
+    
     patient_id = fields.Many2one(
         'res.partner', 
         string='Patient',
@@ -112,3 +122,96 @@ class StockLot(models.Model):
         elif self.container_type:
             return dict(self._fields['container_type'].selection).get(self.container_type)
         return 'Unknown'
+    
+    @api.depends('is_lab_sample', 'create_date')
+    def _compute_barcode(self):
+        """Generate unique barcode for laboratory samples"""
+        for record in self:
+            if record.is_lab_sample and not record.barcode:
+                record.barcode = record._generate_unique_barcode()
+            elif not record.is_lab_sample:
+                record.barcode = False
+    
+    def _generate_unique_barcode(self):
+        """Generate a unique barcode in format YYMMDDNNNNNNC
+        YY: Year (2 digits)
+        MM: Month (2 digits)
+        DD: Day (2 digits)
+        NNNNNN: Sequential number (6 digits)
+        C: Check digit
+        """
+        self.ensure_one()
+        now = datetime.now()
+        date_prefix = now.strftime('%y%m%d')
+        
+        # Get the highest sequence number for today
+        domain = [
+            ('is_lab_sample', '=', True),
+            ('barcode', 'like', date_prefix + '%'),
+            ('id', '!=', self.id)
+        ]
+        
+        max_barcode = self.search(domain, order='barcode desc', limit=1)
+        
+        if max_barcode and max_barcode.barcode:
+            # Extract sequence number from existing barcode
+            try:
+                sequence = int(max_barcode.barcode[6:12]) + 1
+            except:
+                sequence = 1
+        else:
+            sequence = 1
+        
+        # Ensure we don't exceed 6 digits
+        if sequence > 999999:
+            # Add prefix based on sample type to allow more barcodes
+            prefix_map = {
+                'suero': '1',
+                'edta': '2',
+                'orina': '3',
+                'hisopo': '4',
+                'other': '9'
+            }
+            
+            type_prefix = '9'  # default
+            if self.sample_type_product_id:
+                name_lower = self.sample_type_product_id.name.lower()
+                for key, val in prefix_map.items():
+                    if key in name_lower:
+                        type_prefix = val
+                        break
+            
+            sequence = int(type_prefix + str(sequence % 100000).zfill(5))
+        
+        # Format sequence with leading zeros
+        sequence_str = str(sequence).zfill(6)
+        
+        # Calculate check digit using Luhn algorithm
+        barcode_without_check = date_prefix + sequence_str
+        check_digit = self._calculate_luhn_check_digit(barcode_without_check)
+        
+        final_barcode = barcode_without_check + str(check_digit)
+        
+        # Verify uniqueness
+        existing = self.search([
+            ('barcode', '=', final_barcode),
+            ('id', '!=', self.id)
+        ], limit=1)
+        
+        if existing:
+            # If collision, add random component and retry
+            sequence = sequence * 10 + random.randint(0, 9)
+            sequence_str = str(sequence % 1000000).zfill(6)
+            barcode_without_check = date_prefix + sequence_str
+            check_digit = self._calculate_luhn_check_digit(barcode_without_check)
+            final_barcode = barcode_without_check + str(check_digit)
+        
+        return final_barcode
+    
+    def _calculate_luhn_check_digit(self, number_str):
+        """Calculate Luhn check digit for barcode validation"""
+        digits = [int(d) for d in number_str]
+        odd_sum = sum(digits[-1::-2])
+        even_sum = sum([sum(divmod(2 * d, 10)) for d in digits[-2::-2]])
+        total = odd_sum + even_sum
+        return (10 - (total % 10)) % 10