// Before
function processOrder(order: Order) {
  // Validate order
  if (!order.items.length) throw new Error('Empty order');
  if (!order.customer) throw new Error('No customer');
  if (order.total < 0) throw new Error('Invalid total');

  // Calculate totals
  let subtotal = 0;
  for (const item of order.items) {
    subtotal += item.price * item.quantity;
  }
  const tax = subtotal * 0.1;
  const total = subtotal + tax;

  // Save order
  db.save({ ...order, subtotal, tax, total });
}

// After
function processOrder(order: Order) {
  validateOrder(order);
  const totals = calculateTotals(order);
  saveOrder(order, totals);
}

function validateOrder(order: Order) {
  if (!order.items.length) throw new Error('Empty order');
  if (!order.customer) throw new Error('No customer');
  if (order.total < 0) throw new Error('Invalid total');
}

function calculateTotals(order: Order) {
  const subtotal = order.items.reduce(
    (sum, item) => sum + item.price * item.quantity, 0
  );
  const tax = subtotal * 0.1;
  return { subtotal, tax, total: subtotal + tax };
}

// Before
function calculatePay(employee: Employee) {
  switch (employee.type) {
    case 'hourly':
      return employee.hours * employee.rate;
    case 'salary':
      return employee.salary / 12;
    case 'commission':
      return employee.sales * employee.commissionRate;
  }
}

// After
interface Employee {
  calculatePay(): number;
}

class HourlyEmployee implements Employee {
  constructor(private hours: number, private rate: number) {}
  calculatePay() { return this.hours * this.rate; }
}

class SalariedEmployee implements Employee {
  constructor(private salary: number) {}
  calculatePay() { return this.salary / 12; }
}

class CommissionEmployee implements Employee {
  constructor(private sales: number, private rate: number) {}
  calculatePay() { return this.sales * this.rate; }
}

// Before
function createReport(
  startDate: Date,
  endDate: Date,
  format: string,
  includeCharts: boolean,
  department: string
) { ... }

// After
interface ReportOptions {
  startDate: Date;
  endDate: Date;
  format: string;
  includeCharts: boolean;
  department: string;
}

function createReport(options: ReportOptions) { ... }

## Refactoring Proposal

### Current State
[Description of current code issues]

### Code Smells Identified
- [Smell 1]: [Where and why it's a problem]
- [Smell 2]: [Where and why it's a problem]

### Proposed Changes

#### Change 1: [Refactoring name]
**What**: [Description]
**Why**: [Benefit]

**Before:**
[code]

**After:**
[code]

#### Change 2: [Refactoring name]
...

### Benefits
- [Improvement 1]
- [Improvement 2]

### Risks and Mitigations
- [Risk]: [Mitigation]

### Refactoring Steps
1. [ ] [Step 1]
2. [ ] [Step 2]
3. [ ] [Step 3]