cdk/crates/cdk-axum/src/router_handlers.rs

use anyhow::Result;
use axum::extract::{ws::WebSocketUpgrade, Json, Path, State};
use axum::http::StatusCode;
use axum::response::{IntoResponse, Response};
use cdk::error::ErrorResponse;
use cdk::nuts::{
    CheckStateRequest, CheckStateResponse, Id, KeysResponse, KeysetResponse, MeltBolt11Request,
    MeltQuoteBolt11Request, MeltQuoteBolt11Response, MintBolt11Request, MintBolt11Response,
    MintInfo, MintQuoteBolt11Request, MintQuoteBolt11Response, RestoreRequest, RestoreResponse,
    SwapRequest, SwapResponse,
};
use cdk::util::unix_time;
use cdk::Error;
use paste::paste;

use crate::{ws::main_websocket, MintState};

macro_rules! post_cache_wrapper {
    ($handler:ident, $request_type:ty, $response_type:ty) => {
        paste! {
            /// Cache wrapper function for $handler:
            /// Wrap $handler into a function that caches responses using the request as key
            pub async fn [<cache_ $handler>](
                state: State<MintState>,
                payload: Json<$request_type>
            ) -> Result<Json<$response_type>, Response> {
                let Json(json_extracted_payload) = payload.clone();
                let State(mint_state) = state.clone();
                let cache_key = serde_json::to_string(&json_extracted_payload).map_err(|err| {
                    into_response(Error::from(err))
                })?;

                if let Some(cached_response) = mint_state.cache.get(&cache_key) {
                    return Ok(Json(serde_json::from_str(&cached_response)
                        .expect("Shouldn't panic: response is json-deserializable.")));
                }

                let Json(response) = $handler(state, payload).await?;
                mint_state.cache.insert(cache_key, serde_json::to_string(&response)
                    .expect("Shouldn't panic: response is json-serializable.")
                ).await;
                Ok(Json(response))
            }
        }
    };
}

post_cache_wrapper!(post_swap, SwapRequest, SwapResponse);
post_cache_wrapper!(post_mint_bolt11, MintBolt11Request, MintBolt11Response);
post_cache_wrapper!(post_melt_bolt11, MeltBolt11Request, MeltQuoteBolt11Response);

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/keys",
    responses(
        (status = 200, description = "Successful response", body = KeysResponse, content_type = "application/json")
    )
))]
/// Get the public keys of the newest mint keyset
///
/// This endpoint returns a dictionary of all supported token values of the mint and their associated public key.
pub async fn get_keys(State(state): State<MintState>) -> Result<Json<KeysResponse>, Response> {
    let pubkeys = state.mint.pubkeys().await.map_err(|err| {
        tracing::error!("Could not get keys: {}", err);
        into_response(err)
    })?;

    Ok(Json(pubkeys))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/keys/{keyset_id}",
    params(
        ("keyset_id" = String, description = "The keyset ID"),
    ),
    responses(
        (status = 200, description = "Successful response", body = KeysResponse, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Get the public keys of a specific keyset
///
/// Get the public keys of the mint from a specific keyset ID.
pub async fn get_keyset_pubkeys(
    State(state): State<MintState>,
    Path(keyset_id): Path<Id>,
) -> Result<Json<KeysResponse>, Response> {
    let pubkeys = state.mint.keyset_pubkeys(&keyset_id).await.map_err(|err| {
        tracing::error!("Could not get keyset pubkeys: {}", err);
        into_response(err)
    })?;

    Ok(Json(pubkeys))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/keysets",
    responses(
        (status = 200, description = "Successful response", body = KeysetResponse, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Get all active keyset IDs of the mint
///
/// This endpoint returns a list of keysets that the mint currently supports and will accept tokens from.
pub async fn get_keysets(State(state): State<MintState>) -> Result<Json<KeysetResponse>, Response> {
    let keysets = state.mint.keysets().await.map_err(|err| {
        tracing::error!("Could not get keysets: {}", err);
        into_response(err)
    })?;

    Ok(Json(keysets))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/mint/quote/bolt11",
    request_body(content = MintQuoteBolt11Request, description = "Request params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = MintQuoteBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Request a quote for minting of new tokens
///
/// Request minting of new tokens. The mint responds with a Lightning invoice. This endpoint can be used for a Lightning invoice UX flow.
pub async fn post_mint_bolt11_quote(
    State(state): State<MintState>,
    Json(payload): Json<MintQuoteBolt11Request>,
) -> Result<Json<MintQuoteBolt11Response>, Response> {
    let quote = state
        .mint
        .get_mint_bolt11_quote(payload)
        .await
        .map_err(into_response)?;

    Ok(Json(quote))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/mint/quote/bolt11/{quote_id}",
    params(
        ("quote_id" = String, description = "The quote ID"),
    ),
    responses(
        (status = 200, description = "Successful response", body = MintQuoteBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Get mint quote by ID
///
/// Get mint quote state.
pub async fn get_check_mint_bolt11_quote(
    State(state): State<MintState>,
    Path(quote_id): Path<String>,
) -> Result<Json<MintQuoteBolt11Response>, Response> {
    let quote = state
        .mint
        .check_mint_quote(&quote_id)
        .await
        .map_err(|err| {
            tracing::error!("Could not check mint quote {}: {}", quote_id, err);
            into_response(err)
        })?;

    Ok(Json(quote))
}

pub async fn ws_handler(State(state): State<MintState>, ws: WebSocketUpgrade) -> impl IntoResponse {
    ws.on_upgrade(|ws| main_websocket(ws, state))
}

/// Mint tokens by paying a BOLT11 Lightning invoice.
///
/// Requests the minting of tokens belonging to a paid payment request.
///
/// Call this endpoint after `POST /v1/mint/quote`.
#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/mint/bolt11",
    request_body(content = MintBolt11Request, description = "Request params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = MintBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
pub async fn post_mint_bolt11(
    State(state): State<MintState>,
    Json(payload): Json<MintBolt11Request>,
) -> Result<Json<MintBolt11Response>, Response> {
    let res = state
        .mint
        .process_mint_request(payload)
        .await
        .map_err(|err| {
            tracing::error!("Could not process mint: {}", err);
            into_response(err)
        })?;

    Ok(Json(res))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/melt/quote/bolt11",
    request_body(content = MeltQuoteBolt11Request, description = "Quote params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = MeltQuoteBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Request a quote for melting tokens
pub async fn post_melt_bolt11_quote(
    State(state): State<MintState>,
    Json(payload): Json<MeltQuoteBolt11Request>,
) -> Result<Json<MeltQuoteBolt11Response>, Response> {
    let quote = state
        .mint
        .get_melt_bolt11_quote(&payload)
        .await
        .map_err(into_response)?;

    Ok(Json(quote))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/melt/quote/bolt11/{quote_id}",
    params(
        ("quote_id" = String, description = "The quote ID"),
    ),
    responses(
        (status = 200, description = "Successful response", body = MeltQuoteBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Get melt quote by ID
///
/// Get melt quote state.
pub async fn get_check_melt_bolt11_quote(
    State(state): State<MintState>,
    Path(quote_id): Path<String>,
) -> Result<Json<MeltQuoteBolt11Response>, Response> {
    let quote = state
        .mint
        .check_melt_quote(&quote_id)
        .await
        .map_err(|err| {
            tracing::error!("Could not check melt quote: {}", err);
            into_response(err)
        })?;

    Ok(Json(quote))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/melt/bolt11",
    request_body(content = MeltBolt11Request, description = "Melt params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = MeltQuoteBolt11Response, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Melt tokens for a Bitcoin payment that the mint will make for the user in exchange
///
/// Requests tokens to be destroyed and sent out via Lightning.
pub async fn post_melt_bolt11(
    State(state): State<MintState>,
    Json(payload): Json<MeltBolt11Request>,
) -> Result<Json<MeltQuoteBolt11Response>, Response> {
    let res = state
        .mint
        .melt_bolt11(&payload)
        .await
        .map_err(into_response)?;

    Ok(Json(res))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/checkstate",
    request_body(content = CheckStateRequest, description = "State params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = CheckStateResponse, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Check whether a proof is spent already or is pending in a transaction
///
/// Check whether a secret has been spent already or not.
pub async fn post_check(
    State(state): State<MintState>,
    Json(payload): Json<CheckStateRequest>,
) -> Result<Json<CheckStateResponse>, Response> {
    let state = state.mint.check_state(&payload).await.map_err(|err| {
        tracing::error!("Could not check state of proofs");
        into_response(err)
    })?;

    Ok(Json(state))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    get,
    context_path = "/v1",
    path = "/info",
    responses(
        (status = 200, description = "Successful response", body = MintInfo)
    )
))]
/// Mint information, operator contact information, and other info
pub async fn get_mint_info(State(state): State<MintState>) -> Result<Json<MintInfo>, Response> {
    Ok(Json(state.mint.mint_info().clone().time(unix_time())))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/swap",
    request_body(content = SwapRequest, description = "Swap params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = SwapResponse, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Swap inputs for outputs of the same value
///
/// Requests a set of Proofs to be swapped for another set of BlindSignatures.
///
/// This endpoint can be used by Alice to swap a set of proofs before making a payment to Carol. It can then used by Carol to redeem the tokens for new proofs.
pub async fn post_swap(
    State(state): State<MintState>,
    Json(payload): Json<SwapRequest>,
) -> Result<Json<SwapResponse>, Response> {
    let swap_response = state
        .mint
        .process_swap_request(payload)
        .await
        .map_err(|err| {
            tracing::error!("Could not process swap request: {}", err);
            into_response(err)
        })?;
    Ok(Json(swap_response))
}

#[cfg_attr(feature = "swagger", utoipa::path(
    post,
    context_path = "/v1",
    path = "/restore",
    request_body(content = RestoreRequest, description = "Restore params", content_type = "application/json"),
    responses(
        (status = 200, description = "Successful response", body = RestoreResponse, content_type = "application/json"),
        (status = 500, description = "Server error", body = ErrorResponse, content_type = "application/json")
    )
))]
/// Restores blind signature for a set of outputs.
pub async fn post_restore(
    State(state): State<MintState>,
    Json(payload): Json<RestoreRequest>,
) -> Result<Json<RestoreResponse>, Response> {
    let restore_response = state.mint.restore(payload).await.map_err(|err| {
        tracing::error!("Could not process restore: {}", err);
        into_response(err)
    })?;

    Ok(Json(restore_response))
}

pub fn into_response<T>(error: T) -> Response
where
    T: Into<ErrorResponse>,
{
    (
        StatusCode::INTERNAL_SERVER_ERROR,
        Json::<ErrorResponse>(error.into()),
    )
        .into_response()
}