/*
Copyright 2018 Gravitational, Inc.

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 teleport

import (
	"strings"
	"time"
)

// WebAPIVersion is a current webapi version
const WebAPIVersion = "v1"

// ForeverTTL means that object TTL will not expire unless deleted
const ForeverTTL time.Duration = 0

const (
	// SSHAuthSock is the environment variable pointing to the
	// Unix socket the SSH agent is running on.
	SSHAuthSock = "SSH_AUTH_SOCK"
	// SSHAgentPID is the environment variable pointing to the agent
	// process ID
	SSHAgentPID = "SSH_AGENT_PID"

	// SSHTeleportUser is the current Teleport user that is logged in.
	SSHTeleportUser = "SSH_TELEPORT_USER"

	// SSHSessionWebproxyAddr is the address the web proxy.
	SSHSessionWebproxyAddr = "SSH_SESSION_WEBPROXY_ADDR"

	// SSHTeleportClusterName is the name of the cluster this node belongs to.
	SSHTeleportClusterName = "SSH_TELEPORT_CLUSTER_NAME"

	// SSHTeleportHostUUID is the UUID of the host.
	SSHTeleportHostUUID = "SSH_TELEPORT_HOST_UUID"

	// SSHSessionID is the UUID of the current session.
	SSHSessionID = "SSH_SESSION_ID"
)

const (
	// HTTPSProxy is an environment variable pointing to a HTTPS proxy.
	HTTPSProxy = "HTTPS_PROXY"

	// HTTPProxy is an environment variable pointing to a HTTP proxy.
	HTTPProxy = "HTTP_PROXY"

	// NoProxy is an environment variable matching the cases
	// when HTTPS_PROXY or HTTP_PROXY is ignored
	NoProxy = "NO_PROXY"
)

const (
	// TOTPValidityPeriod is the number of seconds a TOTP token is valid.
	TOTPValidityPeriod uint = 30

	// TOTPSkew adds that many periods before and after to the validity window.
	TOTPSkew uint = 1
)

const (
	// ComponentAuthority is a TLS and an SSH certificate authority
	ComponentAuthority = "ca"

	// ComponentProcess is a main control process
	ComponentProcess = "proc"

	// ComponentReverseTunnelServer is reverse tunnel server
	// that together with agent establish a bi-directional SSH revers tunnel
	// to bypass firewall restrictions
	ComponentReverseTunnelServer = "proxy:server"

	// ComponentReverseTunnel is reverse tunnel agent
	// that together with server establish a bi-directional SSH revers tunnel
	// to bypass firewall restrictions
	ComponentReverseTunnelAgent = "proxy:agent"

	// ComponentKube is a kubernetes proxy
	ComponentKube = "proxy:kube"

	// ComponentAuth is the cluster CA node (auth server API)
	ComponentAuth = "auth"

	// ComponentNode is SSH node (SSH server serving requests)
	ComponentNode = "node"

	// ComponentNode is SSH node (SSH server serving requests)
	ComponentForwardingNode = "node:forward"

	// ComponentProxy is SSH proxy (SSH server forwarding connections)
	ComponentProxy = "proxy"

	// ComponentDiagnostic is a diagnostic service
	ComponentDiagnostic = "diag"

	// ComponentClient is a client
	ComponentClient = "client"

	// ComponentTunClient is a tunnel client
	ComponentTunClient = "client:tunnel"

	// ComponentCachingClient is a caching auth client
	ComponentCachingClient = "client:cache"

	// ComponentSubsystemProxy is the proxy subsystem.
	ComponentSubsystemProxy = "subsystem:proxy"

	// ComponentLocalTerm is a terminal on a regular SSH node.
	ComponentLocalTerm = "term:local"

	// ComponentRemoteTerm is a terminal on a forwarding SSH node.
	ComponentRemoteTerm = "term:remote"

	// ComponentRemoteSubsystem is subsystem on a forwarding SSH node.
	ComponentRemoteSubsystem = "subsystem:remote"

	// ComponentAuditLog is audit log component
	ComponentAuditLog = "audit"

	// ComponentKeyAgent is an agent that has loaded the sessions keys and
	// certificates for a user connected to a proxy.
	ComponentKeyAgent = "keyagent"

	// ComponentKeyStore is all sessions keys and certificates a user has on disk
	// for all proxies.
	ComponentKeyStore = "keystore"

	// ComponentConnectProxy is the HTTP CONNECT proxy used to tunnel connection.
	ComponentConnectProxy = "http:proxy"

	// ComponentSOCKS is a SOCKS5 proxy.
	ComponentSOCKS = "socks"

	// ComponentKeyGen is the public/private keypair generator.
	ComponentKeyGen = "keygen"

	// ComponentSession is an active session.
	ComponentSession = "session"

	// ComponentDynamoDB represents dynamodb clients
	ComponentDynamoDB = "dynamodb"

	// Component pluggable authentication module (PAM)
	ComponentPAM = "pam"

	// ComponentUpload is a session recording upload server
	ComponentUpload = "upload"

	// ComponentWeb is a web server
	ComponentWeb = "web"

	// ComponentWebsocket is websocket server that the web client connects to.
	ComponentWebsocket = "websocket"

	// ComponentRBAC is role-based access control.
	ComponentRBAC = "rbac"

	// ComponentKeepAlive is keep-alive messages sent from clients to servers
	// and vice versa.
	ComponentKeepAlive = "keepalive"

	// ComponentTSH is the "tsh" binary.
	ComponentTSH = "tsh"

	// ComponentKubeClient is the Kubernetes client.
	ComponentKubeClient = "client:kube"

	// DebugEnvVar tells tests to use verbose debug output
	DebugEnvVar = "DEBUG"

	// VerboseLogEnvVar forces all logs to be verbose (down to DEBUG level)
	VerboseLogsEnvVar = "TELEPORT_DEBUG"

	// DefaultTerminalWidth defines the default width of a server-side allocated
	// pseudo TTY
	DefaultTerminalWidth = 80

	// DefaultTerminalHeight defines the default height of a server-side allocated
	// pseudo TTY
	DefaultTerminalHeight = 25

	// SafeTerminalType is the fall-back TTY type to fall back to (when $TERM
	// is not defined)
	SafeTerminalType = "xterm"

	// ConnectorOIDC means connector type OIDC
	ConnectorOIDC = "oidc"

	// ConnectorSAML means connector type SAML
	ConnectorSAML = "saml"

	// ConnectorGithub means connector type Github
	ConnectorGithub = "github"

	// DataDirParameterName is the name of the data dir configuration parameter passed
	// to all backends during initialization
	DataDirParameterName = "data_dir"

	// SSH request type to keep the connection alive. A client and a server keep
	// pining each other with it:
	KeepAliveReqType = "keepalive@openssh.com"

	// RecordingProxyReqType is the name of a global request which returns if
	// the proxy is recording sessions or not.
	RecordingProxyReqType = "recording-proxy@teleport.com"

	// OTP means One-time Password Algorithm for Two-Factor Authentication.
	OTP = "otp"

	// TOTP means Time-based One-time Password Algorithm. for Two-Factor Authentication.
	TOTP = "totp"

	// HOTP means HMAC-based One-time Password Algorithm.for Two-Factor Authentication.
	HOTP = "hotp"

	// U2F means Universal 2nd Factor.for Two-Factor Authentication.
	U2F = "u2f"

	// OFF means no second factor.for Two-Factor Authentication.
	OFF = "off"

	// Local means authentication will happen locally within the Teleport cluster.
	Local = "local"

	// OIDC means authentication will happen remotely using an OIDC connector.
	OIDC = ConnectorOIDC

	// SAML means authentication will happen remotely using a SAML connector.
	SAML = ConnectorSAML

	// Github means authentication will happen remotely using a Github connector.
	Github = ConnectorGithub

	// JSON means JSON serialization format
	JSON = "json"

	// LinuxAdminGID is the ID of the standard adm group on linux
	LinuxAdminGID = 4

	// LinuxOS is the GOOS constant used for Linux.
	LinuxOS = "linux"

	// WindowsOS is the GOOS constant used for Microsoft Windows.
	WindowsOS = "windows"

	// DarwinOS is the GOOS constant for Apple macOS/darwin.
	DarwinOS = "darwin"

	// DirMaskSharedGroup is the mask for a directory accessible
	// by the owner and group
	DirMaskSharedGroup = 0770

	// FileMaskOwnerOnly is the file mask that allows read write access
	// to owers only
	FileMaskOwnerOnly = 0600

	// On means mode is on
	On = "on"

	// Off means mode is off
	Off = "off"

	// SchemeS3 is S3 file scheme, means upload or download to S3 like object
	// storage
	SchemeS3 = "s3"

	// Region is AWS region parameter
	Region = "region"

	// SchemeFile is a local disk file storage
	SchemeFile = "file"

	// LogsDir is a log subdirectory for events and logs
	LogsDir = "log"

	// Syslog is a mode for syslog logging
	Syslog = "syslog"

	// HumanDateFormat is a human readable date formatting
	HumanDateFormat = "Jan _2 15:04 UTC"

	// HumanDateFormatSeconds is a human readable date formatting with seconds
	HumanDateFormatSeconds = "Jan _2 15:04:05 UTC"

	// HumanDateFormatMilli is a human readable date formatting with milliseconds
	HumanDateFormatMilli = "Jan _2 15:04:05.000 UTC"

	// DebugLevel is a debug logging level name
	DebugLevel = "debug"
)

// Component generates "component:subcomponent1:subcomponent2" strings used
// in debugging
func Component(components ...string) string {
	return strings.Join(components, ":")
}

const (
	// AuthorizedKeys are public keys that check against User CAs.
	AuthorizedKeys = "authorized_keys"
	// KnownHosts are public keys that check against Host CAs.
	KnownHosts = "known_hosts"
)

const (
	// CertExtensionPermitAgentForwarding allows agent forwarding for certificate
	CertExtensionPermitAgentForwarding = "permit-agent-forwarding"
	// CertExtensionPermitPTY allows user to request PTY
	CertExtensionPermitPTY = "permit-pty"
	// CertExtensionPermitPortForwarding allows user to request port forwarding
	CertExtensionPermitPortForwarding = "permit-port-forwarding"
	// CertExtensionTeleportRoles is used to propagate teleport roles
	CertExtensionTeleportRoles = "teleport-roles"
	// CertExtensionTeleportTraits is used to propagate traits about the user.
	CertExtensionTeleportTraits = "teleport-traits"
)

const (
	// NetIQ is an identity provider.
	NetIQ = "netiq"
	// ADFS is Microsoft Active Directory Federation Services
	ADFS = "adfs"
)

const (
	// RemoteCommandSuccess is returned when a command has successfully executed.
	RemoteCommandSuccess = 0
	// RemoteCommandFailure is returned when a command has failed to execute and
	// we don't have another status code for it.
	RemoteCommandFailure = 255
)

// MaxEnvironmentFileLines is the maximum number of lines in a environment file.
const MaxEnvironmentFileLines = 1000

const (
	// CertificateFormatOldSSH is used to make Teleport interoperate with older
	// versions of OpenSSH.
	CertificateFormatOldSSH = "oldssh"

	// CertificateFormatStandard is used for normal Teleport operation without any
	// compatibility modes.
	CertificateFormatStandard = "standard"

	// CertificateFormatUnspecified is used to check if the format was specified
	// or not.
	CertificateFormatUnspecified = ""

	// DurationNever is human friendly shortcut that is interpreted as a Duration of 0
	DurationNever = "never"
)

const (
	// TraitInternalPrefix is the role variable prefix that indicates it's for
	// local accounts.
	TraitInternalPrefix = "internal"

	// TraitLogins is the name the role variable used to store
	// allowed logins.
	TraitLogins = "logins"

	// TraitKubeGroups is the name the role variable used to store
	// allowed kubernetes groups
	TraitKubeGroups = "kubernetes_groups"

	// TraitInternalLoginsVariable is the variable used to store allowed
	// logins for local accounts.
	TraitInternalLoginsVariable = "{{internal.logins}}"

	// TraitInternalKubeGroupsVariable is the variable used to store allowed
	// kubernetes groups for local accounts.
	TraitInternalKubeGroupsVariable = "{{internal.kubernetes_groups}}"
)

const (
	// GSuiteIssuerURL is issuer URL used for GSuite provider
	GSuiteIssuerURL = "https://accounts.google.com"
	// GSuiteGroupsEndpoint is gsuite API endpoint
	GSuiteGroupsEndpoint = "https://www.googleapis.com/admin/directory/v1/groups"
	// GSuiteGroupsScope is a scope to get access to admin groups API
	GSuiteGroupsScope = "https://www.googleapis.com/auth/admin.directory.group.readonly"
)

// SCP is Secure Copy.
const SCP = "scp"

// Root is *nix system administrator account name.
const Root = "root"

// DefaultRole is the name of the default admin role for all local users if
// another role is not explicitly assigned (Enterprise only).
const AdminRoleName = "admin"

// DefaultImplicitRole is implicit role that gets added to all service.RoleSet
// objects.
const DefaultImplicitRole = "default-implicit-role"

// APIDomain is a default domain name for Auth server API
const APIDomain = "teleport.cluster.local"

// MinClientVersion is the minimum client version required by the server.
const MinClientVersion = "3.0.0"

const (
	// RemoteClusterStatusOffline indicates that cluster is considered as
	// offline, since it has missed a series of heartbeats
	RemoteClusterStatusOffline = "offline"
	// RemoteClusterStatusOnline indicates that cluster is sending heartbeats
	// at expected interval
	RemoteClusterStatusOnline = "online"
)

const (
	// SharedDirMode is a mode for a directory shared with group
	SharedDirMode = 0750

	// PrivateDirMode is a mode for private directories
	PrivateDirMode = 0700
)

const (
	// SessionEvent is sent by servers to clients when an audit event occurs on
	// the session.
	SessionEvent = "x-teleport-event"

	// VersionRequest is sent by clients to server requesting the Teleport
	// version they are running.
	VersionRequest = "x-teleport-version"
)

const (
	// EnvKubeConfig is environment variable for kubeconfig
	EnvKubeConfig = "KUBECONFIG"

	// KubeConfigDir is a default directory where k8s stores its user local config
	KubeConfigDir = ".kube"

	// KubeConfigFile is a default filename where k8s stores its user local config
	KubeConfigFile = "config"

	// EnvHome is home environment variable
	EnvHome = "HOME"

	// EnvUserProfile is the home directory environment variable on Windows.
	EnvUserProfile = "USERPROFILE"

	// KubeServiceAddr is an address for kubernetes endpoint service
	KubeServiceAddr = "kubernetes.default.svc.cluster.local:443"

	// KubeCAPath is a hardcode of mounted CA inside every pod of K8s
	KubeCAPath = "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"

	// KubeKindCSR is a certificate signing requests
	KubeKindCSR = "CertificateSigningRequest"

	// KubeKindPod is a kubernetes pod
	KubeKindPod = "Pod"

	// KubeMetadataNameSelector is a selector for name metadata in API requests
	KubeMetadataNameSelector = "metadata.name"

	// KubeMetadataLabelSelector is a selector for label
	KubeMetadataLabelSelector = "metadata.label"

	// KubeRunTests turns on kubernetes tests
	KubeRunTests = "TEST_KUBE"

	// KubeSystemMasters is a name of the builtin kubernets group for master nodes
	KubeSystemMasters = "system:masters"

	// KubeSystemAuthenticated is a builtin group that allows
	// any user to access common API methods, e.g. discovery methods
	// required for initial client usage
	KubeSystemAuthenticated = "system:authenticated"

	// UsageKubeOnly specifies certificate usage metadata
	// that limits certificate to be only used for kubernetes proxying
	UsageKubeOnly = "usage:kube"
)

const (
	// UseOfClosedNetworkConnection is a special string some parts of
	// go standard lib are using that is the only way to identify some errors
	UseOfClosedNetworkConnection = "use of closed network connection"
)

const (
	// OpenBrowserLinux is the command used to open a web browser on Linux.
	OpenBrowserLinux = "xdg-open"

	// OpenBrowserDarwin is the command used to open a web browser on macOS/Darwin.
	OpenBrowserDarwin = "open"

	// OpenBrowserWindows is the command used to open a web browser on Windows.
	OpenBrowserWindows = "rundll32.exe"
)
