class FeeManagementService {
  constructor(apiKey) {
    this.apiKey = apiKey;
    this.baseUrl = 'https://api.wepayments.com/v2';
  }
  
  async changeFeeTarget(merchantId, targetMerchantId, useFeeWallet = true) {
    const url = `${this.baseUrl}/account/${merchantId}/fee-target`;
    
    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${this.apiKey}`,
        'Content-Type': 'application/json',
        'Accept': 'application/json'
      },
      body: JSON.stringify({
        merchant_fee: targetMerchantId,
        fee_wallet: useFeeWallet
      })
    });
    
    if (!response.ok) {
      throw new Error(`Failed to change fee target: ${response.statusText}`);
    }
    
    return await response.json();
  }
  
  async setupFeeHierarchy(accounts, centralFeeAccountId) {
    const results = [];
    
    for (const accountId of accounts) {
      try {
        const result = await this.changeFeeTarget(
          accountId,
          centralFeeAccountId,
          true
        );
        
        results.push({
          accountId,
          success: true,
          configuration: result
        });
      } catch (error) {
        results.push({
          accountId,
          success: false,
          error: error.message
        });
      }
      
      // Add delay to avoid rate limiting
      await this.delay(100);
    }
    
    return results;
  }
  
  async validateFeeTargetSetup(sourceAccountId, targetAccountId) {
    // Validate that both accounts exist and belong to same customer
    // This is a placeholder - implement actual validation logic
    return {
      valid: true,
      sourceAccount: sourceAccountId,
      targetAccount: targetAccountId,
      sameDomain: true
    };
  }
  
  delay(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
  }
}

// Usage
const feeService = new FeeManagementService('YOUR_API_KEY');

// Change fee target for a single account
const result = await feeService.changeFeeTarget(123, 456, true);
console.log('Fee target changed:', result);

// Setup fee hierarchy for multiple accounts
const accounts = [101, 102, 103, 104];
const centralFeeAccount = 999;
const hierarchyResults = await feeService.setupFeeHierarchy(accounts, centralFeeAccount);
console.log('Fee hierarchy setup:', hierarchyResults);

// Validate before changing
const validation = await feeService.validateFeeTargetSetup(123, 456);
if (validation.valid) {
  await feeService.changeFeeTarget(123, 456);
}

async function changeFeeTargetWithErrorHandling(merchantId, targetId) {
  try {
    const response = await fetch(
      `https://api.wepayments.com/v2/account/${merchantId}/fee-target`,
      {
        method: 'POST',
        headers: {
          'Authorization': 'Bearer YOUR_TOKEN',
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          merchant_fee: targetId,
          fee_wallet: true
        })
      }
    );
    
    if (response.status === 401) {
      throw new Error('Authentication failed - check your API key');
    }
    
    if (response.status === 403) {
      throw new Error('Accounts do not belong to the same customer domain');
    }
    
    if (response.status === 404) {
      throw new Error('Source or target account not found');
    }
    
    if (!response.ok) {
      throw new Error(`Request failed with status ${response.status}`);
    }
    
    return await response.json();
  } catch (error) {
    console.error('Error changing fee target:', error);
    throw error;
  }
}