feat: initial commit

internal/server/grpc.go

@@ -0,0 +1,73 @@
+// Package server exposes the scoreboard Store over gRPC and HTTP/JSON.
+package server
+
+import (
+	"context"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	pb "git.mkz.me/mycroft/root-me-api/gen/scoreboard/v1"
+	"git.mkz.me/mycroft/root-me-api/internal/scoreboard"
+)
+
+// GRPCServer implements pb.ScoreboardServiceServer over a Store.
+type GRPCServer struct {
+	pb.UnimplementedScoreboardServiceServer
+	Store *scoreboard.Store
+}
+
+// NewGRPC returns a gRPC server backed by the given store.
+func NewGRPC(store *scoreboard.Store) *GRPCServer { return &GRPCServer{Store: store} }
+
+func (s *GRPCServer) ListScoreboard(_ context.Context, req *pb.ListScoreboardRequest) (*pb.ListScoreboardResponse, error) {
+	if !s.Store.Ready() {
+		return nil, status.Error(codes.Unavailable, "scoreboard not loaded yet")
+	}
+	entries, fetchedAt := s.Store.List(int(req.GetOffset()), int(req.GetLimit()))
+	resp := &pb.ListScoreboardResponse{
+		Total:     int32(s.Store.Len()),
+		FetchedAt: fetchedAt.Unix(),
+	}
+	resp.Entries = make([]*pb.Entry, len(entries))
+	for i, e := range entries {
+		resp.Entries[i] = toProto(e)
+	}
+	return resp, nil
+}
+
+func (s *GRPCServer) GetByRank(_ context.Context, req *pb.GetByRankRequest) (*pb.Entry, error) {
+	if !s.Store.Ready() {
+		return nil, status.Error(codes.Unavailable, "scoreboard not loaded yet")
+	}
+	e, ok := s.Store.ByRank(int(req.GetRank()))
+	if !ok {
+		return nil, status.Errorf(codes.NotFound, "no entry at rank %d", req.GetRank())
+	}
+	return toProto(e), nil
+}
+
+func (s *GRPCServer) GetByUsername(_ context.Context, req *pb.GetByUsernameRequest) (*pb.Entry, error) {
+	if !s.Store.Ready() {
+		return nil, status.Error(codes.Unavailable, "scoreboard not loaded yet")
+	}
+	if req.GetUsername() == "" {
+		return nil, status.Error(codes.InvalidArgument, "username is required")
+	}
+	e, ok := s.Store.ByUsername(req.GetUsername())
+	if !ok {
+		return nil, status.Errorf(codes.NotFound, "no entry for user %q", req.GetUsername())
+	}
+	return toProto(e), nil
+}
+
+func toProto(e scoreboard.Entry) *pb.Entry {
+	return &pb.Entry{
+		Rank:        int32(e.Rank),
+		Username:    e.Username,
+		ProfilePath: e.ProfilePath,
+		Country:     e.Country,
+		Grade:       e.Grade,
+		Score:       int32(e.Score),
+	}
+}