// Process with max 3 concurrent operations
const processor = new AsyncQueue<string, Balance>(
  async (address) => provider.eth_getBalance(address),
  { concurrency: 3 }
);

// Add items
const results = await Promise.all([
  processor.add('0x123...'),
  processor.add('0x456...'),
  processor.add('0x789...'),
  processor.add('0xabc...'),
  processor.add('0xdef...'),
]);

// Only 3 execute concurrently, others wait

// Batch RPC calls
const queue = new BatchQueue({
  maxBatchSize: 10,
  maxWaitTime: 100,
  processBatch: async (addresses) => {
    // Batch call to get multiple balances
    return Promise.all(
      addresses.map(addr => provider.eth_getBalance(addr))
    );
  }
});

// Add items - automatically batched
const balance1 = queue.add('0x123...');
const balance2 = queue.add('0x456...');
const balance3 = queue.add('0x789...');

// Results returned individually
console.log(await balance1); // Balance for 0x123...
console.log(await balance2); // Balance for 0x456...

// Limit to 10 requests per second
const limiter = new RateLimiter({
  maxRequests: 10,
  interval: 1000,
  strategy: 'queue'
});

// Execute with rate limit
const result = await limiter.execute(() => provider.eth_blockNumber());

// Wrap function with rate limiter
const getBalance = limiter.wrap(
  (address: string) => provider.eth_getBalance(address)
);
const balance = await getBalance('0x123...');

// Batch balance lookups
const getBalance = createBatchedFunction(
  async (addresses: string[]) => {
    return Promise.all(
      addresses.map(addr => provider.eth_getBalance(addr))
    );
  },
  50,   // Batch up to 50 addresses
  100   // Wait max 100ms
);

// Use like normal function - batching happens automatically
const balance1 = getBalance('0x123...');
const balance2 = getBalance('0x456...');
const balance3 = getBalance('0x789...');

// All three requests batched into single call
console.log(await balance1);
console.log(await balance2);
console.log(await balance3);

// Manual promise control
const { promise, resolve, reject } = createDeferred<number>();

// Resolve from event handler
provider.on('block', (blockNumber) => {
  if (blockNumber > 1000000) {
    resolve(blockNumber);
  }
});

const result = await promise;

// With timeout
const { promise, resolve, reject } = createDeferred<string>();
setTimeout(() => reject(new TimeoutError()), 5000);

// Resolve from multiple sources
websocket.on('message', (data) => resolve(data));
controller.on('cancel', () => reject(new Error('Cancelled')));

// Debounce search queries
const searchBlocks = debounce(
  (query: string) => provider.eth_getBlockByNumber(query),
  500 // Wait 500ms after last keystroke
);

// Rapid calls - only last executes after 500ms
searchBlocks('latest');  // Cancelled
searchBlocks('pending'); // Cancelled
searchBlocks('0x123');   // Executes after 500ms

// Cancel pending execution
searchBlocks.cancel();

// Execute with timeout and retries
const block = await executeWithTimeout(
  () => provider.eth_getBlockByNumber('latest'),
  5000,  // 5s timeout per attempt
  3      // Retry up to 3 times
);

// Fetch with timeout and retries
const data = await executeWithTimeout(
  async () => {
    const res = await fetch(url);
    return res.json();
  },
  10000,
  2
);

// Wait for transaction confirmation
const receipt = await poll(
  () => provider.eth_getTransactionReceipt(txHash),
  {
    interval: 1000,
    timeout: 60000,
    validate: (receipt) => receipt !== null
  }
);

// Wait for block with backoff
const block = await poll(
  () => provider.eth_getBlockByNumber('latest'),
  {
    interval: 500,
    backoff: true,
    backoffFactor: 2,
    maxInterval: 5000
  }
);

// Poll with progress callback
const balance = await poll(
  () => provider.eth_getBalance(address),
  {
    interval: 2000,
    onPoll: (result, attempt) => {
      console.log(`Attempt ${attempt}: ${result}`);
    }
  }
);

// Wait for transaction receipt
const receipt = await pollForReceipt(
  txHash,
  (hash) => provider.eth_getTransactionReceipt(hash),
  { timeout: 120000 } // 2 minutes
);

if (receipt.status === '0x1') {
  console.log('Transaction successful!');
}

// Wait for specific block number
const blockNumber = await pollUntil(
  () => provider.eth_blockNumber(),
  (num) => num >= 1000000n,
  { interval: 500, timeout: 30000 }
);

// Wait for contract deployment
const code = await pollUntil(
  () => provider.eth_getCode(contractAddress),
  (code) => code.length > 2, // More than '0x'
  { interval: 1000 }
);

// Poll with automatic backoff
const data = await pollWithBackoff(
  () => provider.eth_call({ to, data }),
  {
    interval: 100,      // Start at 100ms
    backoffFactor: 2,   // Double each time
    maxInterval: 5000,  // Cap at 5s
    timeout: 30000
  }
);

// Basic usage - retry RPC call
const blockNumber = await retryWithBackoff(
  () => provider.eth_blockNumber(),
  { maxRetries: 5 }
);

// Custom retry condition - only retry on network errors
const data = await retryWithBackoff(
  () => fetchData(),
  {
    maxRetries: 3,
    shouldRetry: (error) => error.code === 'NETWORK_ERROR',
    onRetry: (error, attempt, delay) => {
      console.log(`Retry ${attempt} after ${delay}ms: ${error.message}`);
    }
  }
);

// Aggressive retry with custom backoff
const result = await retryWithBackoff(
  () => unstableOperation(),
  {
    maxRetries: 10,
    initialDelay: 100,
    factor: 1.5,
    maxDelay: 5000,
    jitter: true
  }
);

// Simple delay
await sleep(1000); // Wait 1 second

// Cancellable delay
const controller = new AbortController();
const sleepPromise = sleep(5000, controller.signal);

// Cancel after 1 second
setTimeout(() => controller.abort(), 1000);

try {
  await sleepPromise;
} catch (error) {
  console.log('Sleep cancelled');
}

// Throttle RPC calls
const getBalance = throttle(
  (address: string) => provider.eth_getBalance(address),
  1000 // Max once per second
);

// Multiple rapid calls - only first executes
getBalance('0x123...'); // Executes immediately
getBalance('0x456...'); // Ignored (within 1s)
getBalance('0x789...'); // Ignored (within 1s)

// Wrap provider method with automatic retry
const getBlockNumberWithRetry = withRetry(
  (provider: Provider) => provider.eth_blockNumber(),
  { maxRetries: 5, initialDelay: 500 }
);

const blockNumber = await getBlockNumberWithRetry(provider);

// Wrap custom function
const fetchWithRetry = withRetry(
  async (url: string) => {
    const res = await fetch(url);
    if (!res.ok) throw new Error('Request failed');
    return res.json();
  },
  { maxRetries: 3 }
);

const data = await fetchWithRetry('https://api.example.com/data');

// Basic timeout
const result = await withTimeout(
  provider.eth_getBlockByNumber('latest'),
  { ms: 5000 }
);

// Custom timeout message
const balance = await withTimeout(
  provider.eth_getBalance(address),
  {
    ms: 10000,
    message: 'Balance fetch timed out after 10s'
  }
);

// With AbortController
const controller = new AbortController();
const dataPromise = withTimeout(
  fetchData(),
  { ms: 30000, signal: controller.signal }
);

// Cancel operation
controller.abort();

// Wrap provider method with timeout
const getBalanceWithTimeout = wrapWithTimeout(
  (address: string) => provider.eth_getBalance(address),
  5000
);

const balance = await getBalanceWithTimeout('0x123...');

// Wrap custom function
const fetchDataWithTimeout = wrapWithTimeout(
  async (url: string) => {
    const res = await fetch(url);
    return res.json();
  },
  10000,
  'Data fetch timeout'
);