syntax = "proto3";

import "google/api/annotations.proto";
import "rpc.proto";

package invoicesrpc;

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

// Invoices is a service that can be used to create, accept, settle and cancel
// invoices.
service Invoices {
    /**
    SubscribeSingleInvoice returns a uni-directional stream (server -> client)
    to notify the client of state transitions of the specified invoice.
    Initially the current invoice state is always sent out.
    */
    rpc SubscribeSingleInvoice (lnrpc.PaymentHash) returns (stream lnrpc.Invoice);

    /**
    CancelInvoice cancels a currently open invoice. If the invoice is already 
    canceled, this call will succeed. If the invoice is already settled, it will
    fail.
    */
    rpc CancelInvoice(CancelInvoiceMsg) returns (CancelInvoiceResp);

    /**
    AddHoldInvoice creates a hold invoice. It ties the invoice to the hash
    supplied in the request.
    */
    rpc AddHoldInvoice(AddHoldInvoiceRequest) returns (AddHoldInvoiceResp);
 
    /**
    SettleInvoice settles an accepted invoice. If the invoice is already
    settled, this call will succeed.
    */
    rpc SettleInvoice(SettleInvoiceMsg) returns (SettleInvoiceResp);
}

message CancelInvoiceMsg {
    /// Hash corresponding to the (hold) invoice to cancel.
    bytes payment_hash = 1;
} 
message CancelInvoiceResp {}

message AddHoldInvoiceRequest {
    /**
    An optional memo to attach along with the invoice. Used for record keeping
    purposes for the invoice's creator, and will also be set in the description
    field of the encoded payment request if the description_hash field is not
    being used.
    */
    string memo = 1 [json_name = "memo"];

    /// The hash of the preimage
    bytes hash = 2 [json_name = "hash"];

    /// The value of this invoice in satoshis
    int64 value = 3 [json_name = "value"];

    /**
    Hash (SHA-256) of a description of the payment. Used if the description of
    payment (memo) is too long to naturally fit within the description field
    of an encoded payment request.
    */
    bytes description_hash = 4 [json_name = "description_hash"];

    /// Payment request expiry time in seconds. Default is 3600 (1 hour).
    int64 expiry = 5 [json_name = "expiry"];

    /// Fallback on-chain address.
    string fallback_addr = 6 [json_name = "fallback_addr"];

    /// Delta to use for the time-lock of the CLTV extended to the final hop.
    uint64 cltv_expiry = 7 [json_name = "cltv_expiry"];

    /**
    Route hints that can each be individually used to assist in reaching the
    invoice's destination.
    */
    repeated lnrpc.RouteHint route_hints = 8 [json_name = "route_hints"];

    /// Whether this invoice should include routing hints for private channels.
    bool private = 9 [json_name = "private"];
}

message AddHoldInvoiceResp {
    /**
    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.
    */
    string payment_request = 1 [json_name = "payment_request"];
}

message SettleInvoiceMsg {
    /// Externally discovered pre-image that should be used to settle the hold invoice.
    bytes preimage = 1;
} 

message SettleInvoiceResp {}