Utilities and Helpers

/**
 * Convert string to ObjectID
 * @param {string|ObjectID|number} hex - Input to convert
 * @returns {ObjectID|*} ObjectID if valid hex string, otherwise original input
 */
helper.toObjectID(hex);

/**
 * Check if string is valid ObjectID format
 * @param {string} idstr - String to validate
 * @returns {boolean} true if valid ObjectID format
 */
helper.isObjectID(idstr);

const mongoskin = require('mongoskin');

// Convert string to ObjectID
const stringId = '507f1f77bcf86cd799439011';
const objectId = mongoskin.helper.toObjectID(stringId);
console.log('ObjectID:', objectId);

// Already ObjectID - returns as-is
const existingId = new mongoskin.ObjectID();
const sameId = mongoskin.helper.toObjectID(existingId);
console.log('Same ObjectID:', sameId === existingId); // true

// Invalid string - returns original
const invalidId = 'not-an-id';
const result = mongoskin.helper.toObjectID(invalidId);
console.log('Invalid ID returned as-is:', result === invalidId); // true

// Validate ObjectID format
console.log('Valid ObjectID?', mongoskin.helper.isObjectID('507f1f77bcf86cd799439011')); // true
console.log('Valid ObjectID?', mongoskin.helper.isObjectID('invalid-id')); // false
console.log('Valid ObjectID?', mongoskin.helper.isObjectID('507f1f77bcf86cd799439011123')); // false (too long)

/**
 * Create a Skin wrapper class for MongoDB native class
 * @param {Function} NativeClass - MongoDB native class constructor
 * @param {boolean} [useNativeConstructor] - Whether to use native constructor
 * @returns {Function} Skin class constructor
 */
utils.makeSkinClass(NativeClass, useNativeConstructor);

const mongoskin = require('mongoskin');
const mongodb = require('mongodb');

// Create custom Skin class wrapper
const CustomCollection = mongoskin.utils.makeSkinClass(mongodb.Collection);

// The created class will have:
// - Lazy connection pattern
// - All native methods proxied
// - State management (CLOSE, OPENING, OPEN)
// - Event-driven connection lifecycle

console.log('Custom class name:', CustomCollection._class_name); // 'SkinCollection'

// Example of extending the custom class
CustomCollection.prototype.findActiveUsers = function(callback) {
  return this.findItems({ active: true }, callback);
};

// Use the custom class
const customCollection = new CustomCollection();
// customCollection now has lazy connection and all Collection methods

/** Connection is closed */
const STATE_CLOSE = 0;

/** Connection is opening */
const STATE_OPENING = 1;

/** Connection is open and ready */
const STATE_OPEN = 2;

/** Default MongoDB port */
const DEFAULT_PORT = 27017;

const mongoskin = require('mongoskin');

// Access state constants
console.log('Close state:', mongoskin.STATE_CLOSE);     // 0
console.log('Opening state:', mongoskin.STATE_OPENING); // 1  
console.log('Open state:', mongoskin.STATE_OPEN);       // 2
console.log('Default port:', mongoskin.DEFAULT_PORT);   // 27017

// Check connection state
const db = mongoskin.db('mongodb://localhost:27017/myapp');
console.log('Initial state:', db._state === mongoskin.STATE_CLOSE); // true

db.open((err, database) => {
  if (err) throw err;
  console.log('Open state:', db._state === mongoskin.STATE_OPEN); // true
});

// Core MongoDB types (re-exported from mongodb module)
class ObjectID {
  constructor(id?: string | Buffer | number): ObjectID;
  toString(): string;
  toHexString(): string;
  equals(otherID: ObjectID): boolean;
  getTimestamp(): Date;
  static createFromHexString(hex: string): ObjectID;
  static createFromTime(time: number): ObjectID;
  static isValid(id: string | ObjectID | number): boolean;
}

class Long {
  constructor(low: number, high: number, unsigned?: boolean): Long;
  toString(radix?: number): string;
  toNumber(): number;
  equals(other: Long): boolean;
  static fromNumber(value: number): Long;
  static fromString(str: string, radix?: number): Long;
}

class Binary {
  constructor(buffer: Buffer, subType?: number): Binary;
  toString(format?: string): string;
  length(): number;
}

class Code {
  constructor(code: string, scope?: object): Code;
  toString(): string;
}

class Timestamp {
  constructor(low: number, high: number): Timestamp;
  toString(): string;
  equals(other: Timestamp): boolean;
}

const mongoskin = require('mongoskin');

// Create ObjectID
const objectId = new mongoskin.ObjectID();
console.log('New ObjectID:', objectId.toString());

// Create ObjectID from hex string
const fromHex = mongoskin.ObjectID.createFromHexString('507f1f77bcf86cd799439011');
console.log('From hex:', fromHex);

// Check if ObjectID is valid
console.log('Valid?', mongoskin.ObjectID.isValid('507f1f77bcf86cd799439011')); // true

// Create Long number
const longNum = mongoskin.Long.fromNumber(12345678901234);
console.log('Long number:', longNum.toString());

// Create Binary data
const binaryData = new mongoskin.Binary(Buffer.from('Hello World'));
console.log('Binary length:', binaryData.length());

// Create Code object
const jsCode = new mongoskin.Code('function() { return this.name; }');
console.log('Code:', jsCode.toString());

// Create Timestamp
const timestamp = new mongoskin.Timestamp(0, Math.floor(Date.now() / 1000));
console.log('Timestamp:', timestamp.toString());

/**
 * Parse MongoDB connection string
 * @param {string} connectionString - MongoDB URI
 * @returns {object} Parsed connection components
 */
parseConnectionString(connectionString);

/**
 * Build connection string from components
 * @param {object} components - Connection components
 * @returns {string} MongoDB connection URI
 */
buildConnectionString(components);

const mongoskin = require('mongoskin');

// Parse connection string (if available)
const parsed = {
  protocol: 'mongodb',
  hosts: [{ host: 'localhost', port: 27017 }],
  database: 'myapp',
  auth: { username: 'user', password: 'pass' },
  options: { authSource: 'admin' }
};

// Common connection patterns
const connections = {
  local: 'mongodb://localhost:27017/myapp',
  authenticated: 'mongodb://user:pass@localhost:27017/myapp',
  replicaSet: 'mongodb://host1:27017,host2:27017/myapp?replicaSet=rs0',
  withOptions: 'mongodb://localhost:27017/myapp?authSource=admin&ssl=true'
};

console.log('Connection examples:', connections);

/**
 * Check if error is a connection error
 * @param {Error} error - Error object
 * @returns {boolean} true if connection error
 */
isConnectionError(error);

/**
 * Check if error is a duplicate key error
 * @param {Error} error - Error object  
 * @returns {boolean} true if duplicate key error
 */
isDuplicateKeyError(error);

/**
 * Get error code from MongoDB error
 * @param {Error} error - Error object
 * @returns {number} Error code
 */
getErrorCode(error);

const mongoskin = require('mongoskin');
const db = mongoskin.db('mongodb://localhost:27017/myapp');

// Error handling in operations
db.collection('users').insert({ email: 'test@example.com' }, (err, result) => {
  if (err) {
    // Check error type (pseudo-code - actual implementation may vary)
    if (err.code === 11000) {
      console.log('Duplicate key error - email already exists');
    } else if (err.name === 'MongoNetworkError') {
      console.log('Connection error - retrying...');
    } else {
      console.log('Other error:', err.message);
    }
    return;
  }
  
  console.log('User inserted successfully');
});

// Connection error handling
db.open((err, database) => {
  if (err) {
    console.log('Failed to connect:', err.message);
    
    // Check specific error conditions
    if (err.name === 'MongoAuthenticationError') {
      console.log('Authentication failed - check credentials');
    } else if (err.name === 'MongoNetworkError') {
      console.log('Network error - check server connectivity');
    }
    
    return;
  }
  
  console.log('Connected successfully');
});

/**
 * Create connection pool with specific size
 * @param {string} connectionString - MongoDB URI
 * @param {number} poolSize - Pool size
 * @returns {SkinDb} Database with connection pool
 */
createPool(connectionString, poolSize);

/**
 * Get connection pool statistics
 * @param {SkinDb} db - Database instance
 * @returns {object} Pool statistics
 */
getPoolStats(db);

const mongoskin = require('mongoskin');

// Connection with specific pool size
const db = mongoskin.db('mongodb://localhost:27017/myapp', {
  poolSize: 10,
  bufferMaxEntries: 0,
  useNewUrlParser: true,
  useUnifiedTopology: true
});

// Monitor connection usage
db.open((err, database) => {
  if (err) throw err;
  
  console.log('Connection pool ready');
  
  // Perform multiple operations to test pool
  for (let i = 0; i < 20; i++) {
    db.collection('test').findOne({}, (err, doc) => {
      if (err) console.log('Query error:', err);
      else console.log('Query', i, 'completed');
    });
  }
});