/*
 * Copyright (c) 2016, Psiphon Inc.
 * All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package common

const (
	TUNNEL_PROTOCOL_SSH                  = "SSH"
	TUNNEL_PROTOCOL_OBFUSCATED_SSH       = "OSSH"
	TUNNEL_PROTOCOL_UNFRONTED_MEEK       = "UNFRONTED-MEEK-OSSH"
	TUNNEL_PROTOCOL_UNFRONTED_MEEK_HTTPS = "UNFRONTED-MEEK-HTTPS-OSSH"
	TUNNEL_PROTOCOL_FRONTED_MEEK         = "FRONTED-MEEK-OSSH"
	TUNNEL_PROTOCOL_FRONTED_MEEK_HTTP    = "FRONTED-MEEK-HTTP-OSSH"

	SERVER_ENTRY_SOURCE_EMBEDDED  = "EMBEDDED"
	SERVER_ENTRY_SOURCE_REMOTE    = "REMOTE"
	SERVER_ENTRY_SOURCE_DISCOVERY = "DISCOVERY"
	SERVER_ENTRY_SOURCE_TARGET    = "TARGET"

	CAPABILITY_SSH_API_REQUESTS            = "ssh-api-requests"
	CAPABILITY_UNTUNNELED_WEB_API_REQUESTS = "handshake"

	PSIPHON_API_HANDSHAKE_REQUEST_NAME           = "psiphon-handshake"
	PSIPHON_API_CONNECTED_REQUEST_NAME           = "psiphon-connected"
	PSIPHON_API_STATUS_REQUEST_NAME              = "psiphon-status"
	PSIPHON_API_CLIENT_VERIFICATION_REQUEST_NAME = "psiphon-client-verification"

	PSIPHON_API_CLIENT_SESSION_ID_LENGTH = 16
)

var SupportedTunnelProtocols = []string{
	TUNNEL_PROTOCOL_FRONTED_MEEK,
	TUNNEL_PROTOCOL_FRONTED_MEEK_HTTP,
	TUNNEL_PROTOCOL_UNFRONTED_MEEK,
	TUNNEL_PROTOCOL_UNFRONTED_MEEK_HTTPS,
	TUNNEL_PROTOCOL_OBFUSCATED_SSH,
	TUNNEL_PROTOCOL_SSH,
}

var SupportedServerEntrySources = []string{
	SERVER_ENTRY_SOURCE_EMBEDDED,
	SERVER_ENTRY_SOURCE_REMOTE,
	SERVER_ENTRY_SOURCE_DISCOVERY,
	SERVER_ENTRY_SOURCE_TARGET,
}

func TunnelProtocolUsesSSH(protocol string) bool {
	return true
}

func TunnelProtocolUsesObfuscatedSSH(protocol string) bool {
	return protocol != TUNNEL_PROTOCOL_SSH
}

func TunnelProtocolUsesMeekHTTP(protocol string) bool {
	return protocol == TUNNEL_PROTOCOL_UNFRONTED_MEEK ||
		protocol == TUNNEL_PROTOCOL_FRONTED_MEEK_HTTP
}

func TunnelProtocolUsesMeekHTTPS(protocol string) bool {
	return protocol == TUNNEL_PROTOCOL_FRONTED_MEEK ||
		protocol == TUNNEL_PROTOCOL_UNFRONTED_MEEK_HTTPS
}