changes

fusion_payroll/models/payroll_entry.py

@@ -291,7 +291,8 @@ class PayrollEntry(models.TransientModel):
 
     @api.depends('gross_pay', 'employee_id')
     def _compute_taxes(self):
-        """Calculate employee tax deductions."""
+        """Calculate employee tax deductions (preview estimate for bi-weekly)."""
+        PAY_PERIODS = 26
         for entry in self:
             if entry.gross_pay <= 0:
                 entry.income_tax = 0
@@ -300,26 +301,81 @@ class PayrollEntry(models.TransientModel):
                 entry.cpp2 = 0
                 entry.total_employee_tax = 0
                 continue
-            
-            # Get tax rates from parameters or use defaults
-            # These are simplified calculations - actual payroll uses full tax rules
+
             gross = entry.gross_pay
-            
-            # Simplified tax calculations (bi-weekly)
-            # Income tax: ~15-20% average for Canadian employees
-            entry.income_tax = round(gross * 0.128, 2)  # Approximate federal + provincial
-            
-            # EI: 1.64% of gross (2025 rate) up to maximum
-            entry.employment_insurance = round(min(gross * 0.0164, 1049.12 / 26), 2)
-            
-            # CPP: 5.95% of pensionable earnings above basic exemption (2025)
-            cpp_exempt = 3500 / 26  # Annual exemption / 26 pay periods
-            pensionable = max(0, gross - cpp_exempt)
-            entry.cpp = round(min(pensionable * 0.0595, 4034.10 / 26), 2)
-            
-            # CPP2: 4% on earnings above first ceiling (2025)
-            entry.cpp2 = 0  # Only applies if earnings exceed $71,300/year
-            
+            annual = gross * PAY_PERIODS
+            emp = entry.employee_id
+
+            is_cpp_exempt = getattr(emp, 'exempt_cpp', False)
+            is_ei_exempt = getattr(emp, 'exempt_ei', False)
+            is_fed_exempt = getattr(emp, 'exempt_federal_tax', False)
+
+            # Federal tax estimate using 2026 brackets + BPA phase-out
+            fed_brackets = [
+                (58523, 0.14), (117045, 0.205), (181440, 0.26),
+                (258482, 0.29), (float('inf'), 0.33),
+            ]
+            bpa_max, bpa_min = 16452, 14829
+            if annual <= 181440:
+                fed_bpa = bpa_max
+            elif annual >= 258482:
+                fed_bpa = bpa_min
+            else:
+                fed_bpa = bpa_max - (bpa_max - bpa_min) * (annual - 181440) / (258482 - 181440)
+
+            fed_tax = 0
+            prev = 0
+            for threshold, rate in fed_brackets:
+                taxable_in = min(annual, threshold) - prev
+                if taxable_in > 0:
+                    fed_tax += taxable_in * rate
+                prev = threshold
+                if annual <= threshold:
+                    break
+            fed_tax = max(fed_tax - fed_bpa * 0.14 - 1433 * 0.14, 0)
+
+            # Ontario provincial estimate (default province)
+            on_brackets = [
+                (53891, 0.0505), (107785, 0.0915), (150000, 0.1116),
+                (220000, 0.1216), (float('inf'), 0.1316),
+            ]
+            prov_tax = 0
+            prev = 0
+            for threshold, rate in on_brackets:
+                taxable_in = min(annual, threshold) - prev
+                if taxable_in > 0:
+                    prov_tax += taxable_in * rate
+                prev = threshold
+                if annual <= threshold:
+                    break
+            prov_tax = max(prov_tax - 12989 * 0.0505, 0)
+
+            entry.income_tax = 0 if is_fed_exempt else round((fed_tax + prov_tax) / PAY_PERIODS, 2)
+
+            if is_ei_exempt:
+                entry.employment_insurance = 0
+            else:
+                period_max_insurable = 68900 / PAY_PERIODS
+                insurable = min(gross, period_max_insurable)
+                entry.employment_insurance = round(min(insurable * 0.0163, 1123.07 / PAY_PERIODS), 2)
+
+            if is_cpp_exempt:
+                entry.cpp = 0
+                entry.cpp2 = 0
+            else:
+                period_ympe = 74600 / PAY_PERIODS
+                cpp_exempt_amt = 3500 / PAY_PERIODS
+                pensionable = min(gross, period_ympe)
+                pensionable = max(0, pensionable - cpp_exempt_amt)
+                entry.cpp = round(min(pensionable * 0.0595, 4230.45 / PAY_PERIODS), 2)
+
+            if not is_cpp_exempt and gross > 74600 / PAY_PERIODS:
+                period_ceiling = 85000 / PAY_PERIODS
+                cpp2_base = min(gross, period_ceiling) - period_ympe
+                entry.cpp2 = round(min(cpp2_base * 0.04, 416.00 / PAY_PERIODS), 2)
+            else:
+                entry.cpp2 = 0
+
             entry.total_employee_tax = entry.income_tax + entry.employment_insurance + entry.cpp + entry.cpp2
 
     @api.depends('employment_insurance', 'cpp', 'cpp2')