// Copyright 2016 Jimmy Zelinskie
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package bittorrent

// ClientID represents the part of a PeerID that identifies a Peer's client
// software.
type ClientID string

// NewClientID parses a ClientID from a PeerID.
func NewClientID(peerID string) ClientID {
	var clientID string
	length := len(peerID)
	if length >= 6 {
		if peerID[0] == '-' {
			if length >= 7 {
				clientID = peerID[1:7]
			}
		} else {
			clientID = peerID[:6]
		}
	}

	return ClientID(clientID)
}