الخطوة 2: التحقق من صحة المدخلات

function validatePhoneNumber(phone) {
  if (typeof phone !== 'string') {
    return { valid: false, error: 'Phone number must be a string' };
  }
  
  phone = phone.trim();
  
  if (!/^0[567][0-9]{8}$/.test(phone)) {
    return { valid: false, error: 'Invalid phone format. Must be 10 digits starting with 05, 06, or 07' };
  }
  
  return { valid: true, phone };
}

function validatePlan(planCode, plans) {
  const plan = plans.find(p => p.code === planCode);
  
  if (!plan) {
    return { valid: false, error: `Plan ${planCode} not found` };
  }
  
  if (!plan.isEnabled) {
    return { valid: false, error: `Plan ${plan.name} is currently unavailable` };
  }
  
  return { valid: true, plan };
}

function validateAmount(amount, plan) {
  // Fixed plans use their predefined amount
  if (plan.type === 'fixed') {
    return { valid: true, amount: plan.fixedAmount };
  }
  
  // Dynamic plans require amount within range
  if (!amount) {
    return { valid: false, error: 'Amount is required for dynamic plans' };
  }
  
  const numAmount = Number(amount);
  
  if (isNaN(numAmount) || !Number.isInteger(numAmount)) {
    return { valid: false, error: 'Amount must be an integer' };
  }
  
  if (numAmount < plan.minAmount) {
    return { valid: false, error: `Amount must be at least ${plan.minAmount} DZD` };
  }
  
  if (numAmount > plan.maxAmount) {
    return { valid: false, error: `Amount cannot exceed ${plan.maxAmount} DZD` };
  }
  
  return { valid: true, amount: numAmount };
}

function validateTopUpRequest(data, plans) {
  const errors = [];
  
  // Validate phone
  const phoneValidation = validatePhoneNumber(data.phone);
  if (!phoneValidation.valid) {
    errors.push({ field: 'phone', message: phoneValidation.error });
  }
  
  // Validate plan
  const planValidation = validatePlan(data.planCode, plans);
  if (!planValidation.valid) {
    errors.push({ field: 'planCode', message: planValidation.error });
    return { valid: false, errors };
  }
  
  // Validate amount
  const amountValidation = validateAmount(data.amount, planValidation.plan);
  if (!amountValidation.valid) {
    errors.push({ field: 'amount', message: amountValidation.error });
  }
  
  if (errors.length > 0) {
    return { valid: false, errors };
  }
  
  return {
    valid: true,
    data: {
      phone: phoneValidation.phone,
      planCode: planValidation.plan.code,
      amount: amountValidation.amount
    }
  };
}

// Usage
const result = validateTopUpRequest({
  phone: '0778037340',
  planCode: 'PREPAID_DJEZZY',
  amount: 500
}, plans);

if (!result.valid) {
  console.error('Validation errors:', result.errors);
} else {
  console.log('Valid request:', result.data);
}