class Redis::Client

def _parse_driver(driver)
  driver = driver.to_s if driver.is_a?(Symbol)
  if driver.kind_of?(String)
    case driver
    when "ruby"
      require "redis/connection/ruby"
      driver = Connection::Ruby
    when "hiredis"
      require "redis/connection/hiredis"
      driver = Connection::Hiredis
    when "synchrony"
      require "redis/connection/synchrony"
      driver = Connection::Synchrony
    else
      raise "Unknown driver: #{driver}"
    end
  end
  driver
end

def _parse_options(options)
  defaults = DEFAULTS.dup
  url = options[:url] || ENV["REDIS_URL"]
  # Override defaults from URL if given
  if url
    require "uri"
    uri = URI(url)
    if uri.scheme == "unix"
      defaults[:path]   = uri.path
    else
      # Require the URL to have at least a host
      raise ArgumentError, "invalid url" unless uri.host
      defaults[:scheme]   = uri.scheme
      defaults[:host]     = uri.host
      defaults[:port]     = uri.port if uri.port
      defaults[:password] = uri.password if uri.password
      defaults[:db]       = uri.path[1..-1].to_i if uri.path
    end
  end
  options = defaults.merge(options)
  if options[:path]
    options[:scheme] = "unix"
    options.delete(:host)
    options.delete(:port)
  else
    options[:host] = options[:host].to_s
    options[:port] = options[:port].to_i
  end
  options[:timeout] = options[:timeout].to_f
  options[:db] = options[:db].to_i
  options[:driver] = _parse_driver(options[:driver]) || Connection.drivers.last
  options
end

def call(command, &block)
  reply = process([command]) { read }
  raise reply if reply.is_a?(CommandError)
  if block
    block.call(reply)
  else
    reply
  end
end

def call_loop(command)
  error = nil
  result = without_socket_timeout do
    process([command]) do
      loop do
        reply = read
        if reply.is_a?(CommandError)
          error = reply
          break
        else
          yield reply
        end
      end
    end
  end
  # Raise error when previous block broke out of the loop.
  raise error if error
  # Result is set to the value that the provided block used to break.
  result
end

def call_pipeline(pipeline)
  with_reconnect pipeline.with_reconnect? do
    begin
      pipeline.finish(call_pipelined(pipeline.commands))
    rescue ConnectionError => e
      return nil if pipeline.shutdown?
      # Assume the pipeline was sent in one piece, but execution of
      # SHUTDOWN caused none of the replies for commands that were executed
      # prior to it from coming back around.
      raise e
    end
  end
end

def call_pipelined(commands)
  return [] if commands.empty?
  # The method #ensure_connected (called from #process) reconnects once on
  # I/O errors. To make an effort in making sure that commands are not
  # executed more than once, only allow reconnection before the first reply
  # has been read. When an error occurs after the first reply has been
  # read, retrying would re-execute the entire pipeline, thus re-issuing
  # already successfully executed commands. To circumvent this, don't retry
  # after the first reply has been read successfully.
  result = Array.new(commands.size)
  reconnect = @reconnect
  begin
    process(commands) do
      result[0] = read
      @reconnect = false
      (commands.size - 1).times do |i|
        result[i + 1] = read
      end
    end
  ensure
    @reconnect = reconnect
  end
  result
end

def call_without_timeout(command, &blk)
  without_socket_timeout do
    call(command, &blk)
  end
rescue ConnectionError
  retry
end

def connect
  @pid = Process.pid
  establish_connection
  call [:auth, password] if password
  call [:select, db] if db != 0
  self
end

def connected?
  connection && connection.connected?
end

def db
  @options[:db]
end

def db=(db)
  @options[:db] = db.to_i
end

def disconnect
  connection.disconnect if connected?
end

def ensure_connected
  tries = 0
  begin
    if connected?
      if Process.pid != @pid
        raise InheritedError,
          "Tried to use a connection from a child process without reconnecting. " +
          "You need to reconnect to Redis after forking."
      end
    else
      connect
    end
    tries += 1
    yield
  rescue ConnectionError
    disconnect
    if tries < 2 && @reconnect
      retry
    else
      raise
    end
  rescue Exception
    disconnect
    raise
  end
end

def establish_connection
  @connection = @options[:driver].connect(@options.dup)
rescue TimeoutError
  raise CannotConnectError, "Timed out connecting to Redis on #{location}"
rescue Errno::ECONNREFUSED
  raise CannotConnectError, "Error connecting to Redis on #{location} (ECONNREFUSED)"
end

def host
  @options[:host]
end

def id
  @options[:id] || "redis://#{location}/#{db}"
end

def initialize(options = {})
  @options = _parse_options(options)
  @reconnect = true
  @logger = @options[:logger]
  @connection = nil
  @command_map = {}
end

def io
  yield
rescue TimeoutError
  raise TimeoutError, "Connection timed out"
rescue Errno::ECONNRESET, Errno::EPIPE, Errno::ECONNABORTED, Errno::EBADF, Errno::EINVAL => e
  raise ConnectionError, "Connection lost (%s)" % [e.class.name.split("::").last]
end

def location
  path || "#{host}:#{port}"
end

def logging(commands)
  return yield unless @logger && @logger.debug?
  begin
    commands.each do |name, *args|
      @logger.debug("Redis >> #{name.to_s.upcase} #{args.map(&:to_s).join(" ")}")
    end
    t1 = Time.now
    yield
  ensure
    @logger.debug("Redis >> %0.2fms" % ((Time.now - t1) * 1000)) if t1
  end
end

def password
  @options[:password]
end

def path
  @options[:path]
end

def port
  @options[:port]
end

def process(commands)
  logging(commands) do
    ensure_connected do
      commands.each do |command|
        if command_map[command.first]
          command = command.dup
          command[0] = command_map[command.first]
        end
        connection.write(command)
      end
      yield if block_given?
    end
  end
end

def read
  io do
    connection.read
  end
end

def reconnect
  disconnect
  connect
end

def scheme
  @options[:scheme]
end

def timeout
  @options[:timeout]
end

def with_reconnect(val=true)
  begin
    original, @reconnect = @reconnect, val
    yield
  ensure
    @reconnect = original
  end
end

def without_reconnect(&blk)
  with_reconnect(false, &blk)
end

def without_socket_timeout
  connect unless connected?
  begin
    connection.timeout = 0
    yield
  ensure
    connection.timeout = timeout if connected?
  end
end

def write(command)
  io do
    connection.write(command)
  end
end