const (
	// DefaultQuotaBytes is the number of bytes the backend Size may
	// consume before exceeding the space quota.
	DefaultQuotaBytes = int64(2 * 1024 * 1024 * 1024) // 2GB
	// MaxQuotaBytes is the maximum number of bytes suggested for a backend
	// quota. A larger quota may lead to degraded performance.
	MaxQuotaBytes = int64(8 * 1024 * 1024 * 1024) // 8GB
)

const (
	DefaultSnapCount = 100000

	StoreClusterPrefix = "/0"
	StoreKeysPrefix    = "/1"

	// HealthInterval is the minimum time the cluster should be healthy
	// before accepting add member requests.
	HealthInterval = 5 * time.Second
)

var (
	ErrUnknownMethod              = errors.New("etcdserver: unknown method")
	ErrStopped                    = errors.New("etcdserver: server stopped")
	ErrCanceled                   = errors.New("etcdserver: request cancelled")
	ErrTimeout                    = errors.New("etcdserver: request timed out")
	ErrTimeoutDueToLeaderFail     = errors.New("etcdserver: request timed out, possibly due to previous leader failure")
	ErrTimeoutDueToConnectionLost = errors.New("etcdserver: request timed out, possibly due to connection lost")
	ErrTimeoutLeaderTransfer      = errors.New("etcdserver: request timed out, leader transfer took too long")
	ErrNotEnoughStartedMembers    = errors.New("etcdserver: re-configuration failed due to not enough started members")
	ErrNoLeader                   = errors.New("etcdserver: no leader")
	ErrRequestTooLarge            = errors.New("etcdserver: request is too large")
	ErrNoSpace                    = errors.New("etcdserver: no space")
	ErrTooManyRequests            = errors.New("etcdserver: too many requests")
	ErrUnhealthy                  = errors.New("etcdserver: unhealthy cluster")
	ErrKeyNotFound                = errors.New("etcdserver: key not found")
)

type ApplierV2 interface {
	Delete(r *pb.Request) Response
	Post(r *pb.Request) Response
	Put(r *pb.Request) Response
	QGet(r *pb.Request) Response
	Sync(r *pb.Request) Response
}

type Authenticator interface {
	AuthEnable(ctx context.Context, r *pb.AuthEnableRequest) (*pb.AuthEnableResponse, error)
	AuthDisable(ctx context.Context, r *pb.AuthDisableRequest) (*pb.AuthDisableResponse, error)
	Authenticate(ctx context.Context, r *pb.AuthenticateRequest) (*pb.AuthenticateResponse, error)
	UserAdd(ctx context.Context, r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
	UserDelete(ctx context.Context, r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
	UserChangePassword(ctx context.Context, r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error)
	UserGrantRole(ctx context.Context, r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error)
	UserGet(ctx context.Context, r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error)
	UserRevokeRole(ctx context.Context, r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error)
	RoleAdd(ctx context.Context, r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error)
	RoleGrantPermission(ctx context.Context, r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error)
	RoleGet(ctx context.Context, r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error)
	RoleRevokePermission(ctx context.Context, r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error)
	RoleDelete(ctx context.Context, r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
	UserList(ctx context.Context, r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
	RoleList(ctx context.Context, r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
}

type DiscoveryError struct {
	Op  string
	Err error
}

type EtcdServer struct {
	Cfg *ServerConfig

	SyncTicker *time.Ticker
	// contains filtered or unexported fields
}

type Lessor interface {
	// LeaseGrant sends LeaseGrant request to raft and apply it after committed.
	LeaseGrant(ctx context.Context, r *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error)
	// LeaseRevoke sends LeaseRevoke request to raft and apply it after committed.
	LeaseRevoke(ctx context.Context, r *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error)

	// LeaseRenew renews the lease with given ID. The renewed TTL is returned. Or an error
	// is returned.
	LeaseRenew(ctx context.Context, id lease.LeaseID) (int64, error)

	// LeaseTimeToLive retrieves lease information.
	LeaseTimeToLive(ctx context.Context, r *pb.LeaseTimeToLiveRequest) (*pb.LeaseTimeToLiveResponse, error)
}

type Quota interface {
	// Available judges whether the given request fits within the quota.
	Available(req interface{}) bool
	// Cost computes the charge against the quota for a given request.
	Cost(req interface{}) int
	// Remaining is the amount of charge left for the quota.
	Remaining() int64
}

type RaftKV interface {
	Range(ctx context.Context, r *pb.RangeRequest) (*pb.RangeResponse, error)
	Put(ctx context.Context, r *pb.PutRequest) (*pb.PutResponse, error)
	DeleteRange(ctx context.Context, r *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error)
	Txn(ctx context.Context, r *pb.TxnRequest) (*pb.TxnResponse, error)
	Compact(ctx context.Context, r *pb.CompactionRequest) (*pb.CompactionResponse, error)
}

type RaftTimer interface {
	Index() uint64
	Term() uint64
}

type Response struct {
	Event   *store.Event
	Watcher store.Watcher
	// contains filtered or unexported fields
}

type Server interface {
	// Start performs any initialization of the Server necessary for it to
	// begin serving requests. It must be called before Do or Process.
	// Start must be non-blocking; any long-running server functionality
	// should be implemented in goroutines.
	Start()
	// Stop terminates the Server and performs any necessary finalization.
	// Do and Process cannot be called after Stop has been invoked.
	Stop()
	// ID returns the ID of the Server.
	ID() types.ID
	// Leader returns the ID of the leader Server.
	Leader() types.ID
	// Do takes a request and attempts to fulfill it, returning a Response.
	Do(ctx context.Context, r pb.Request) (Response, error)
	// Process takes a raft message and applies it to the server's raft state
	// machine, respecting any timeout of the given context.
	Process(ctx context.Context, m raftpb.Message) error
	// AddMember attempts to add a member into the cluster. It will return
	// ErrIDRemoved if member ID is removed from the cluster, or return
	// ErrIDExists if member ID exists in the cluster.
	AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error)
	// RemoveMember attempts to remove a member from the cluster. It will
	// return ErrIDRemoved if member ID is removed from the cluster, or return
	// ErrIDNotFound if member ID is not in the cluster.
	RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error)

	// UpdateMember attempts to update an existing member in the cluster. It will
	// return ErrIDNotFound if the member ID does not exist.
	UpdateMember(ctx context.Context, updateMemb membership.Member) ([]*membership.Member, error)

	// ClusterVersion is the cluster-wide minimum major.minor version.
	// Cluster version is set to the min version that an etcd member is
	// compatible with when first bootstrap.
	//
	// ClusterVersion is nil until the cluster is bootstrapped (has a quorum).
	//
	// During a rolling upgrades, the ClusterVersion will be updated
	// automatically after a sync. (5 second by default)
	//
	// The API/raft component can utilize ClusterVersion to determine if
	// it can accept a client request or a raft RPC.
	// NOTE: ClusterVersion might be nil when etcd 2.1 works with etcd 2.0 and
	// the leader is etcd 2.0. etcd 2.0 leader will not update clusterVersion since
	// this feature is introduced post 2.0.
	ClusterVersion() *semver.Version
}

type ServerConfig struct {
	Name           string
	DiscoveryURL   string
	DiscoveryProxy string
	ClientURLs     types.URLs
	PeerURLs       types.URLs
	DataDir        string
	// DedicatedWALDir config will make the etcd to write the WAL to the WALDir
	// rather than the dataDir/member/wal.
	DedicatedWALDir     string
	SnapCount           uint64
	MaxSnapFiles        uint
	MaxWALFiles         uint
	InitialPeerURLsMap  types.URLsMap
	InitialClusterToken string
	NewCluster          bool
	ForceNewCluster     bool
	PeerTLSInfo         transport.TLSInfo

	TickMs           uint
	ElectionTicks    int
	BootstrapTimeout time.Duration

	AutoCompactionRetention int
	QuotaBackendBytes       int64

	StrictReconfigCheck bool

	// ClientCertAuthEnabled is true when cert has been signed by the client CA.
	ClientCertAuthEnabled bool

	AuthToken string
}

type Storage interface {
	// Save function saves ents and state to the underlying stable storage.
	// Save MUST block until st and ents are on stable storage.
	Save(st raftpb.HardState, ents []raftpb.Entry) error
	// SaveSnap function saves snapshot to the underlying stable storage.
	SaveSnap(snap raftpb.Snapshot) error
	// Close closes the Storage and performs finalization.
	Close() error
}