syntax = "proto3";

import "rpc.proto";

package routerrpc;

option go_package = "github.com/lightningnetwork/lnd/lnrpc/routerrpc";

message SendPaymentRequest {
    /// The identity pubkey of the payment recipient
    bytes dest = 1;

    /**
    Number of satoshis to send.

    The fields amt and amt_msat are mutually exclusive.
    */
    int64 amt = 2;

    /**
    Number of millisatoshis to send.

    The fields amt and amt_msat are mutually exclusive.
    */
    int64 amt_msat = 12;

    /// The hash to use within the payment's HTLC
    bytes payment_hash = 3;

    /**
    The CLTV delta from the current height that should be used to set the
    timelock for the final hop.
    */
    int32 final_cltv_delta = 4;

    /**
    A bare-bones invoice for a payment within the Lightning Network.  With the
    details of the invoice, the sender has all the data necessary to send a
    payment to the recipient. The amount in the payment request may be zero. In
    that case it is required to set the amt field as well. If no payment request
    is specified, the following fields are required: dest, amt and payment_hash.
    */
    string payment_request = 5;

    /**
    An upper limit on the amount of time we should spend when attempting to
    fulfill the payment. This is expressed in seconds. If we cannot make a
    successful payment within this time frame, an error will be returned.
    This field must be non-zero.
    */
    int32 timeout_seconds = 6;

    /**
    The maximum number of satoshis that will be paid as a fee of the payment.
    If this field is left to the default value of 0, only zero-fee routes will
    be considered. This usually means single hop routes connecting directly to
    the destination. To send the payment without a fee limit, use max int here.

    The fields fee_limit_sat and fee_limit_msat are mutually exclusive.
    */
    int64 fee_limit_sat = 7;

    /**
    The maximum number of millisatoshis that will be paid as a fee of the
    payment. If this field is left to the default value of 0, only zero-fee
    routes will be considered. This usually means single hop routes connecting
    directly to the destination. To send the payment without a fee limit, use
    max int here.

    The fields fee_limit_sat and fee_limit_msat are mutually exclusive.
    */
    int64 fee_limit_msat = 13;

    /**
    The channel id of the channel that must be taken to the first hop. If zero,
    any channel may be used.
    */
    uint64 outgoing_chan_id = 8 [jstype = JS_STRING];

    /**
    The pubkey of the last hop of the route. If empty, any hop may be used.
    */
    bytes last_hop_pubkey = 14;

    /**
    An optional maximum total time lock for the route. This should not exceed
    lnd's `--max-cltv-expiry` setting. If zero, then the value of
    `--max-cltv-expiry` is enforced.
    */
    int32 cltv_limit = 9;

    /**
    Optional route hints to reach the destination through private channels.
    */
    repeated lnrpc.RouteHint route_hints = 10;

    /**
    An optional field that can be used to pass an arbitrary set of TLV records
    to a peer which understands the new records. This can be used to pass
    application specific data during the payment attempt. Record types are
    required to be in the custom range >= 65536. When using REST, the values
    must be encoded as base64.
    */
    map<uint64, bytes> dest_custom_records = 11;

    /// If set, circular payments to self are permitted.
    bool allow_self_payment = 15;

    /**
    Features assumed to be supported by the final node. All transitive feature
    dependencies must also be set properly. For a given feature bit pair, either
    optional or remote may be set, but not both. If this field is nil or empty,
    the router will try to load destination features from the graph as a
    fallback.
    */
    repeated lnrpc.FeatureBit dest_features = 16;

    /**
    The maximum number of partial payments that may be use to complete the full
    amount.
    */
    uint32 max_htlcs = 17;
}

message TrackPaymentRequest {
    /// The hash of the payment to look up.
    bytes payment_hash = 1;
}

message RouteFeeRequest {
    /**
    The destination once wishes to obtain a routing fee quote to.
    */
    bytes dest = 1;

    /**
    The amount one wishes to send to the target destination.
    */
    int64 amt_sat = 2;
}

message RouteFeeResponse {
    /**
    A lower bound of the estimated fee to the target destination within the
    network, expressed in milli-satoshis.
    */
    int64 routing_fee_msat = 1;

    /**
    An estimate of the worst case time delay that can occur. Note that callers
    will still need to factor in the final CLTV delta of the last hop into this
    value.
    */
    int64 time_lock_delay = 2;
}

message SendToRouteRequest {
    /// The payment hash to use for the HTLC.
    bytes payment_hash = 1;

    /// Route that should be used to attempt to complete the payment.
    lnrpc.Route route = 2;
}

message SendToRouteResponse {
    /// The preimage obtained by making the payment.
    bytes preimage = 1;

    /// The failure message in case the payment failed.
    lnrpc.Failure failure = 2;
}

message ResetMissionControlRequest {
}

message ResetMissionControlResponse {
}

message QueryMissionControlRequest {
}

/// QueryMissionControlResponse contains mission control state.
message QueryMissionControlResponse {
    reserved 1;

    /// Node pair-level mission control state.
    repeated PairHistory pairs = 2;
}

/// PairHistory contains the mission control state for a particular node pair.
message PairHistory {
    /// The source node pubkey of the pair.
    bytes node_from = 1;

    /// The destination node pubkey of the pair.
    bytes node_to = 2;

    reserved 3, 4, 5, 6;

    PairData history = 7;
}

message PairData {
    /// Time of last failure.
    int64 fail_time = 1;

    /**
    Lowest amount that failed to forward rounded to whole sats. This may be
    set to zero if the failure is independent of amount.
    */
    int64 fail_amt_sat = 2;

    /**
    Lowest amount that failed to forward in millisats. This may be
    set to zero if the failure is independent of amount.
    */
    int64 fail_amt_msat = 4;

    reserved 3;

    /// Time of last success.
    int64 success_time = 5;

    /// Highest amount that we could successfully forward rounded to whole sats.
    int64 success_amt_sat = 6;

    /// Highest amount that we could successfully forward in millisats.
    int64 success_amt_msat = 7;
}

message QueryProbabilityRequest {
    /// The source node pubkey of the pair.
    bytes from_node = 1;

    /// The destination node pubkey of the pair.
    bytes to_node = 2;

    /// The amount for which to calculate a probability.
    int64 amt_msat = 3;
}

message QueryProbabilityResponse {
    /// The success probability for the requested pair.
    double probability = 1;

    /// The historical data for the requested pair.
    PairData history = 2;
}

message BuildRouteRequest {
    /**
    The amount to send expressed in msat. If set to zero, the minimum routable
    amount is used.
    */
    int64 amt_msat = 1;

    /**
    CLTV delta from the current height that should be used for the timelock
    of the final hop
    */
    int32 final_cltv_delta = 2;

    /**
    The channel id of the channel that must be taken to the first hop. If zero,
    any channel may be used.
    */
    uint64 outgoing_chan_id = 3 [jstype = JS_STRING];

    /**
    A list of hops that defines the route. This does not include the source hop
    pubkey.
    */
    repeated bytes hop_pubkeys = 4;
}

message BuildRouteResponse {
    /**
    Fully specified route that can be used to execute the payment.
    */
    lnrpc.Route route = 1;
}

message SubscribeHtlcEventsRequest {
}

/**
HtlcEvent contains the htlc event that was processed. These are served on a
best-effort basis; events are not persisted, delivery is not guaranteed
(in the event of a crash in the switch, forward events may be lost) and
some events may be replayed upon restart. Events consumed from this package
should be de-duplicated by the htlc's unique combination of incoming and
outgoing channel id and htlc id. [EXPERIMENTAL]
*/
message HtlcEvent {
    /**
    The short channel id that the incoming htlc arrived at our node on. This
    value is zero for sends.
    */
    uint64 incoming_channel_id = 1;

    /**
    The short channel id that the outgoing htlc left our node on. This value
    is zero for receives.
    */
    uint64 outgoing_channel_id = 2;

    /**
    Incoming id is the index of the incoming htlc in the incoming channel.
    This value is zero for sends.
    */
    uint64 incoming_htlc_id = 3;

    /**
    Outgoing id is the index of the outgoing htlc in the outgoing channel.
    This value is zero for receives.
    */
    uint64 outgoing_htlc_id = 4;

    /**
    The time in unix nanoseconds that the event occurred.
    */
    uint64 timestamp_ns = 5;

    enum EventType {
        UNKNOWN = 0;
        SEND = 1;
        RECEIVE = 2;
        FORWARD = 3;
    }

    /**
    The event type indicates whether the htlc was part of a send, receive or
    forward.
    */
    EventType event_type = 6;

    oneof event {
        ForwardEvent forward_event = 7;
        ForwardFailEvent forward_fail_event = 8;
        SettleEvent settle_event = 9;
        LinkFailEvent link_fail_event = 10;
    }
}

message HtlcInfo {
    // The timelock on the incoming htlc.
    uint32 incoming_timelock = 1;

    // The timelock on the outgoing htlc.
    uint32 outgoing_timelock = 2;

    // The amount of the incoming htlc.
    uint64 incoming_amt_msat = 3;

    // The amount of the outgoing htlc.
    uint64 outgoing_amt_msat = 4;
}

message ForwardEvent {
    // Info contains details about the htlc that was forwarded.
    HtlcInfo info = 1;
}

message ForwardFailEvent {
}

message SettleEvent {
}

message LinkFailEvent {
    // Info contains details about the htlc that we failed.
    HtlcInfo info = 1;

    // FailureCode is the BOLT error code for the failure.
    lnrpc.Failure.FailureCode wire_failure = 2;

    /**
    FailureDetail provides additional information about the reason for the
    failure. This detail enriches the information provided by the wire message
    and may be 'no detail' if the wire message requires no additional metadata.
    */
    FailureDetail failure_detail = 3;

    // A string representation of the link failure.
    string failure_string = 4;
}

enum FailureDetail {
    UNKNOWN = 0;
    NO_DETAIL = 1;
    ONION_DECODE = 2;
    LINK_NOT_ELIGIBLE = 3;
    ON_CHAIN_TIMEOUT = 4;
    HTLC_EXCEEDS_MAX = 5;
    INSUFFICIENT_BALANCE = 6;
    INCOMPLETE_FORWARD = 7;
    HTLC_ADD_FAILED = 8;
    FORWARDS_DISABLED = 9;
    INVOICE_CANCELED = 10;
    INVOICE_UNDERPAID = 11;
    INVOICE_EXPIRY_TOO_SOON = 12;
    INVOICE_NOT_OPEN = 13;
    MPP_INVOICE_TIMEOUT = 14;
    ADDRESS_MISMATCH = 15;
    SET_TOTAL_MISMATCH = 16;
    SET_TOTAL_TOO_LOW = 17;
    SET_OVERPAID = 18;
    UNKNOWN_INVOICE = 19;
    INVALID_KEYSEND = 20;
    MPP_IN_PROGRESS = 21;
    CIRCULAR_ROUTE = 22;
}

service Router {
    /**
    SendPayment attempts to route a payment described by the passed
    PaymentRequest to the final destination. The call returns a stream of
    payment updates.
    */
    rpc SendPayment (SendPaymentRequest) returns (stream lnrpc.Payment);

    /**
    TrackPayment returns an update stream for the payment identified by the
    payment hash.
    */
    rpc TrackPayment (TrackPaymentRequest) returns (stream lnrpc.Payment);

    /**
    EstimateRouteFee allows callers to obtain a lower bound w.r.t how much it
    may cost to send an HTLC to the target end destination.
    */
    rpc EstimateRouteFee (RouteFeeRequest) returns (RouteFeeResponse);

    /**
    SendToRoute attempts to make a payment via the specified route. This method
    differs from SendPayment in that it allows users to specify a full route
    manually. This can be used for things like rebalancing, and atomic swaps.
    */
    rpc SendToRoute (SendToRouteRequest) returns (SendToRouteResponse);

    /**
    ResetMissionControl clears all mission control state and starts with a clean
    slate.
    */
    rpc ResetMissionControl (ResetMissionControlRequest)
        returns (ResetMissionControlResponse);

    /**
    QueryMissionControl exposes the internal mission control state to callers.
    It is a development feature.
    */
    rpc QueryMissionControl (QueryMissionControlRequest)
        returns (QueryMissionControlResponse);

    /**
    QueryProbability returns the current success probability estimate for a
    given node pair and amount.
    */
    rpc QueryProbability (QueryProbabilityRequest)
        returns (QueryProbabilityResponse);

    /**
    BuildRoute builds a fully specified route based on a list of hop public
    keys. It retrieves the relevant channel policies from the graph in order to
    calculate the correct fees and time locks.
    */
    rpc BuildRoute (BuildRouteRequest) returns (BuildRouteResponse);

    /**
    SubscribeHtlcEvents creates a uni-directional stream from the server to
    the client which delivers a stream of htlc events.
    */
    rpc SubscribeHtlcEvents (SubscribeHtlcEventsRequest)
        returns (stream HtlcEvent);
}