class EventMachine::MySQL

# File lib/em-mysqlplus/mysql.rb, line 12
def initialize(opts)
  unless EM.respond_to?(:watch) and Mysql.method_defined?(:socket)
    raise RuntimeError, 'mysqlplus and EM.watch are required for EventedMysql'
  end

  @settings = { :debug => false }.merge!(opts)
  @connection = connect(@settings)
end

# File lib/em-mysqlplus/mysql.rb, line 21
def close
  @connection.close
end

# File lib/em-mysqlplus/mysql.rb, line 41
def connect(opts)
  if conn = connect_socket(opts)
    debug [:connect, conn.socket, opts]
    EM.watch(conn.socket, EventMachine::MySQLConnection, conn, opts, self)
  else
    # invokes :errback callback in opts before firing again
    debug [:reconnect]
    EM.add_timer(5) { connect opts }
  end
end

# File lib/em-mysqlplus/mysql.rb, line 53
def connect_socket(opts)
  conn = Mysql.init

  # set encoding _before_ connecting
  if charset = opts[:charset] || opts[:encoding]
    conn.options(Mysql::SET_CHARSET_NAME, charset)
  end

  conn.options(Mysql::OPT_LOCAL_INFILE, 'client')
  conn.real_connect(
    opts[:host] || 'localhost',
    opts[:user] || 'root',
    opts[:password],
    opts[:database],
    opts[:port],
    opts[:socket],
    0 +
    # XXX multi results require multiple callbacks to parse
    # Mysql::CLIENT_MULTI_RESULTS +
    # Mysql::CLIENT_MULTI_STATEMENTS +
    (opts[:compress] == false ? 0 : Mysql::CLIENT_COMPRESS)
  )

  # increase timeout so mysql server doesn't disconnect us
  # this is especially bad if we're disconnected while EM.attach is
  # still in progress, because by the time it gets to EM, the FD is
  # no longer valid, and it throws a c++ 'bad file descriptor' error
  # (do not use a timeout of -1 for unlimited, it does not work on mysqld > 5.0.60)
  conn.query("set @@wait_timeout = #{opts[:timeout] || 2592000}")

  # we handle reconnecting (and reattaching the new fd to EM)
  conn.reconnect = false

  # By default, MySQL 'where id is null' selects the last inserted id
  # Turn this off. http://dev.rubyonrails.org/ticket/6778
  conn.query("set SQL_AUTO_IS_NULL=0")

  # get results for queries
  conn.query_with_result = true

  conn
rescue Mysql::Error => e
  if cb = opts[:errback]
    cb.call(e)
    nil
  else
    raise e
  end
end

# File lib/em-mysqlplus/mysql.rb, line 103
def debug(data)
  p data if @settings[:debug]
end

# File lib/em-mysqlplus/mysql.rb, line 37
def method_missing(method, *args, &blk)
  @connection.send(method, *args)
end

# File lib/em-mysqlplus/mysql.rb, line 25
def query(sql, &blk)
  df = EventMachine::DefaultDeferrable.new
  cb = blk || Proc.new { |r| df.succeed(r) }
  eb = Proc.new { |r| df.fail(r) }

  @connection.execute(sql, cb, eb)

  df
end