/node_modules/mysql/lib/ConnectionConfig.js

var urlParse        = require('url').parse;
var ClientConstants = require('./protocol/constants/client');
var Charsets        = require('./protocol/constants/charsets');
var SSLProfiles     = null;

module.exports = ConnectionConfig;
function ConnectionConfig(options) {
  if (typeof options === 'string') {
    options = ConnectionConfig.parseUrl(options);
  }

  this.host               = options.host || 'localhost';
  this.port               = options.port || 3306;
  this.localAddress       = options.localAddress;
  this.socketPath         = options.socketPath;
  this.user               = options.user || undefined;
  this.password           = options.password || undefined;
  this.database           = options.database;
  this.connectTimeout     = (options.connectTimeout === undefined)
    ? (10 * 1000)
    : options.connectTimeout;
  this.insecureAuth       = options.insecureAuth || false;
  this.supportBigNumbers  = options.supportBigNumbers || false;
  this.bigNumberStrings   = options.bigNumberStrings || false;
  this.dateStrings        = options.dateStrings || false;
  this.debug              = options.debug;
  this.trace              = options.trace !== false;
  this.stringifyObjects   = options.stringifyObjects || false;
  this.timezone           = options.timezone || 'local';
  this.flags              = options.flags || '';
  this.queryFormat        = options.queryFormat;
  this.pool               = options.pool || undefined;
  this.ssl                = (typeof options.ssl === 'string')
    ? ConnectionConfig.getSSLProfile(options.ssl)
    : (options.ssl || false);
  this.multipleStatements = options.multipleStatements || false; 
  this.typeCast           = (options.typeCast === undefined)
    ? true
    : options.typeCast;

  if (this.timezone[0] == " ") {
    // "+" is a url encoded char for space so it
    // gets translated to space when giving a
    // connection string..
    this.timezone = "+" + this.timezone.substr(1);
  }

  if (this.ssl) {
    // Default rejectUnauthorized to true
    this.ssl.rejectUnauthorized = this.ssl.rejectUnauthorized !== false;
  }

  this.maxPacketSize = 0;
  this.charsetNumber = (options.charset)
    ? ConnectionConfig.getCharsetNumber(options.charset)
    : options.charsetNumber||Charsets.UTF8_GENERAL_CI;

  // Set the client flags
  var defaultFlags = ConnectionConfig.getDefaultFlags(options);
  this.clientFlags = ConnectionConfig.mergeFlags(defaultFlags, options.flags)
}

ConnectionConfig.mergeFlags = function mergeFlags(defaultFlags, userFlags) {
  var allFlags = ConnectionConfig.parseFlagList(defaultFlags);
  var newFlags = ConnectionConfig.parseFlagList(userFlags);

  // Merge the new flags
  for (var flag in newFlags) {
    if (allFlags[flag] !== false) {
      allFlags[flag] = newFlags[flag];
    }
  }

  // Build flags
  var flags = 0x0;
  for (var flag in allFlags) {
    if (allFlags[flag]) {
      // TODO: Throw here on some future release
      flags |= ClientConstants['CLIENT_' + flag] || 0x0;
    }
  }

  return flags;
};

ConnectionConfig.getCharsetNumber = function getCharsetNumber(charset) {
  var num = Charsets[charset.toUpperCase()];

  if (num === undefined) {
    throw new TypeError('Unknown charset \'' + charset + '\'');
  }

  return num;
};

ConnectionConfig.getDefaultFlags = function getDefaultFlags(options) {
  var defaultFlags = [
    '-COMPRESS',          // Compression protocol *NOT* supported
    '-CONNECT_ATTRS',     // Does *NOT* send connection attributes in Protocol::HandshakeResponse41
    '+CONNECT_WITH_DB',   // One can specify db on connect in Handshake Response Packet
    '+FOUND_ROWS',        // Send found rows instead of affected rows
    '+IGNORE_SIGPIPE',    // Don't issue SIGPIPE if network failures
    '+IGNORE_SPACE',      // Let the parser ignore spaces before '('
    '+LOCAL_FILES',       // Can use LOAD DATA LOCAL
    '+LONG_FLAG',         // Longer flags in Protocol::ColumnDefinition320
    '+LONG_PASSWORD',     // Use the improved version of Old Password Authentication
    '+MULTI_RESULTS',     // Can handle multiple resultsets for COM_QUERY
    '+ODBC',              // Special handling of ODBC behaviour
    '-PLUGIN_AUTH',       // Does *NOT* support auth plugins
    '+PROTOCOL_41',       // Uses the 4.1 protocol
    '+PS_MULTI_RESULTS',  // Can handle multiple resultsets for COM_STMT_EXECUTE
    '+RESERVED',          // Unused
    '+SECURE_CONNECTION', // Supports Authentication::Native41
    '+TRANSACTIONS'       // Expects status flags
  ];

  if (options && options.multipleStatements) {
    // May send multiple statements per COM_QUERY and COM_STMT_PREPARE
    defaultFlags.push('+MULTI_STATEMENTS');
  }

  return defaultFlags;
};

ConnectionConfig.getSSLProfile = function getSSLProfile(name) {
  if (!SSLProfiles) {
    SSLProfiles = require('./protocol/constants/ssl_profiles');
  }

  var ssl = SSLProfiles[name];

  if (ssl === undefined) {
    throw new TypeError('Unknown SSL profile \'' + name + '\'');
  }

  return ssl;
};

ConnectionConfig.parseFlagList = function parseFlagList(flagList) {
  var allFlags = Object.create(null);

  if (!flagList) {
    return allFlags;
  }

  var flags = !Array.isArray(flagList)
    ? String(flagList || '').toUpperCase().split(/\s*,+\s*/)
    : flagList;

  for (var i = 0; i < flags.length; i++) {
    var flag   = flags[i];
    var offset = 1;
    var state  = flag[0];

    if (state === undefined) {
      // TODO: throw here on some future release
      continue;
    }

    if (state !== '-' && state !== '+') {
      offset = 0;
      state  = '+';
    }

    allFlags[flag.substr(offset)] = state === '+';
  }

  return allFlags;
};

ConnectionConfig.parseUrl = function(url) {
  url = urlParse(url, true);

  var options = {
    host     : url.hostname,
    port     : url.port,
    database : url.pathname.substr(1),
  };

  if (url.auth) {
    var auth = url.auth.split(':');
    options.user     = auth[0];
    options.password = auth[1];
  }

  if (url.query) {
    for (var key in url.query) {
      var value = url.query[key];

      try {
        // Try to parse this as a JSON expression first
        options[key] = JSON.parse(value);
      } catch (err) {
        // Otherwise assume it is a plain string
        options[key] = value;
      }
    }
  }

  return options;
};