syntax = "proto3";

import "google/api/annotations.proto";

package looprpc;

service SwapServer {
    rpc LoopOutTerms (ServerLoopOutTermsRequest) returns (ServerLoopOutTerms);

    rpc NewLoopOutSwap (ServerLoopOutRequest) returns (ServerLoopOutResponse);

    rpc LoopOutQuote (ServerLoopOutQuoteRequest) returns (ServerLoopOutQuote);

    rpc LoopInTerms (ServerLoopInTermsRequest) returns (ServerLoopInTerms);

    rpc NewLoopInSwap (ServerLoopInRequest) returns (ServerLoopInResponse);

    rpc LoopInQuote (ServerLoopInQuoteRequest)
        returns (ServerLoopInQuoteResponse);
}

/**
This enum defines the protocol versions that clients may adhere to. Note that
this is not a flagged enum. If a particular protocol version adds a feature,
then in general all the preceding features are also supported. Exception to this
is when features get deprecated.
*/
enum ProtocolVersion {
    /// No protocol version reported at all.
    LEGACY = 0;

    /// Client may attempt to send the loop out payment in multiple parts.
    MULTI_LOOP_OUT = 1;

    /**
    Loop will use native segwit (P2WSH) htlcs by default, while externally
    published htlcs may use native (P2WSH) or nested (NP2WSH) segwit as well.
    */
    NATIVE_SEGWIT_LOOP_IN = 2;
}

message ServerLoopOutRequest {
    bytes receiver_key = 1;

    bytes swap_hash = 2;

    uint64 amt = 3;

    /// The unix time in seconds we want the on-chain swap to be published by.
    int64 swap_publication_deadline = 4;

    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 5;
}

message ServerLoopOutResponse {
    string swap_invoice = 1;

    string prepay_invoice = 2;

    bytes sender_key = 3;

    int32 expiry = 4;
}

message ServerLoopOutQuoteRequest {
    /// The swap amount. If zero, a quote for a maximum amt swap will be given.
    uint64 amt = 1;

    /// The unix time in seconds we want the on-chain swap to be published by.
    int64 swap_publication_deadline = 2;

    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 3;
}

message ServerLoopOutQuote {
    string swap_payment_dest = 1;

    /// The total estimated swap fee given the quote amt.
    int64 swap_fee = 2;

    /// Deprecated, total swap fee given quote amt is calculated in swap_fee.
    int64 swap_fee_rate = 3 [deprecated = true];

    uint64 prepay_amt = 4;

    uint64 min_swap_amount = 5 [deprecated = true];

    uint64 max_swap_amount = 6 [deprecated = true];

    int32 cltv_delta = 7;
}

message ServerLoopOutTermsRequest {
    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 1;
}

message ServerLoopOutTerms {
    uint64 min_swap_amount = 1;
    uint64 max_swap_amount = 2;
}

message ServerLoopInRequest {
    bytes sender_key = 1;
    bytes swap_hash = 2;
    uint64 amt = 3;
    string swap_invoice = 4;
    bytes last_hop = 5;

    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 6;
}

message ServerLoopInResponse {
    bytes receiver_key = 1;
    int32 expiry = 2;
}

message ServerLoopInQuoteRequest {
    /// The swap amount. If zero, a quote for a maximum amt swap will be given.
    uint64 amt = 1;

    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 2;
}

message ServerLoopInQuoteResponse {
    int64 swap_fee = 1;
    int64 swap_fee_rate = 2 [deprecated = true];
    uint64 min_swap_amount = 4 [deprecated = true];
    uint64 max_swap_amount = 5 [deprecated = true];
    int32 cltv_delta = 6;
}

message ServerLoopInTermsRequest {
    /// The protocol version that the client adheres to.
    ProtocolVersion protocol_version = 1;
}

message ServerLoopInTerms {
    uint64 min_swap_amount = 1;
    uint64 max_swap_amount = 2;
}