waku-org/go-waku

package rest

import (
    "encoding/json"
    "errors"
    "net/http"

    "github.com/go-chi/chi/v5"
    "github.com/waku-org/go-waku/waku/v2/node"
    "github.com/waku-org/go-waku/waku/v2/protocol/lightpush"
    "go.uber.org/zap"
)

const routeLightPushV1Messages = "/lightpush/v1/message"

type LightpushService struct {
    node *node.WakuNode
    log  *zap.Logger
}

func NewLightpushService(node *node.WakuNode, m *chi.Mux, log *zap.Logger) *LightpushService {
    serv := &LightpushService{
        node: node,
        log:  log.Named("lightpush"),
    }

    m.Post(routeLightPushV1Messages, serv.postMessagev1)

    return serv
}

func (msg lightpushRequest) Check() error {
    if msg.Message == nil {
        return errors.New("waku message is required")
    }

    return nil
}

type lightpushRequest struct {
    PubSubTopic string           `json:"pubsubTopic"`
    Message     *RestWakuMessage `json:"message"`
}

// handled error codes are 200, 400, 500, 503
func (serv *LightpushService) postMessagev1(w http.ResponseWriter, req *http.Request) {
    request := &lightpushRequest{}
    decoder := json.NewDecoder(req.Body)
    if err := decoder.Decode(request); err != nil {
        w.WriteHeader(http.StatusBadRequest)
        return
    }
    defer req.Body.Close()

    if err := request.Check(); err != nil {
        w.WriteHeader(http.StatusBadRequest)
        _, err = w.Write([]byte(err.Error()))
        serv.log.Error("writing response", zap.Error(err))
        return
    }

    if serv.node.Lightpush() == nil {
        w.WriteHeader(http.StatusServiceUnavailable)
        return
    }

    message, err := request.Message.ToProto()
    if err != nil {
        w.WriteHeader(http.StatusBadRequest)
        _, err = w.Write([]byte(err.Error()))
        if err != nil {
            serv.log.Error("writing response", zap.Error(err))
        }
        return
    }

    if err = message.Validate(); err != nil {
        w.WriteHeader(http.StatusServiceUnavailable)
        _, err = w.Write([]byte(err.Error()))
        if err != nil {
            serv.log.Error("writing response", zap.Error(err))
        }
        return
    }

    _, err = serv.node.Lightpush().Publish(req.Context(), message, lightpush.WithPubSubTopic(request.PubSubTopic))
    if err != nil {
        w.WriteHeader(http.StatusServiceUnavailable)
        _, err = w.Write([]byte(err.Error()))
        if err != nil {
            serv.log.Error("writing response", zap.Error(err))
        }
    } else {
        writeErrOrResponse(w, err, true)
    }
}