// Package exchange contains Telegram key exchange algorithm flows.
// See https://core.telegram.org/mtproto/auth_key.
package exchange

import (
	
	

	

	
	
	
	
)

// DefaultTimeout is default WithTimeout parameter value.
const DefaultTimeout = 1 * time.Minute

// Exchanger is builder for key exchangers.
type Exchanger struct {
	conn transport.Conn

	clock   clock.Clock
	rand    io.Reader
	log     *zap.Logger
	timeout time.Duration
	dc      int
}

// WithClock sets exchange flow clock.
func ( Exchanger) ( clock.Clock) Exchanger {
	.clock = 
	return 
}

// WithRand sets exchange flow random source.
func ( Exchanger) ( io.Reader) Exchanger {
	.rand = 
	return 
}

// WithLogger sets exchange flow logger.
func ( Exchanger) ( *zap.Logger) Exchanger {
	.log = 
	return 
}

// WithTimeout sets write/read deadline of every exchange request.
func ( Exchanger) ( time.Duration) Exchanger {
	.timeout = 
	return 
}

// NewExchanger creates new Exchanger.
func ( transport.Conn,  int) Exchanger {
	return Exchanger{
		conn: ,

		clock:   clock.System,
		rand:    crypto.DefaultRand(),
		log:     zap.NewNop(),
		timeout: DefaultTimeout,
		dc:      ,
	}
}

func ( Exchanger) (,  proto.MessageType) unencryptedWriter {
	return unencryptedWriter{
		clock:   .clock,
		conn:    .conn,
		timeout: .timeout,
		input:   ,
		output:  ,
	}
}

// Client creates new ClientExchange using parameters from Exchanger.
func ( Exchanger) ( []PublicKey) ClientExchange {
	return ClientExchange{
		unencryptedWriter: .unencryptedWriter(
			proto.MessageServerResponse,
			proto.MessageFromClient,
		),
		rand: .rand,
		log:  .log,
		keys: ,
		dc:   .dc,
	}
}

// Server creates new ServerExchange using parameters from Exchanger.
func ( Exchanger) ( PrivateKey) ServerExchange {
	return ServerExchange{
		unencryptedWriter: .unencryptedWriter(
			proto.MessageFromClient,
			proto.MessageServerResponse,
		),
		rand: .rand,
		log:  .log,
		rng:  TestServerRNG{rand: .rand},
		key:  ,
		dc:   .dc,
	}
}