indrasaputra/url-shortener

package handler

import (
    "context"

    "google.golang.org/grpc/codes"
    grpchealthv1 "google.golang.org/grpc/health/grpc_health_v1"
    "google.golang.org/grpc/status"

    "github.com/indrasaputra/aptx/usecase"
)

// HealthService handles HTTP/2 gRPC request for health checking.
type HealthService struct {
    grpchealthv1.UnimplementedHealthServer
    checker usecase.CheckHealth
}

// NewHealthService creates an instance of HealthService.
func NewHealthService(checker usecase.CheckHealth) *HealthService {
    return &HealthService{checker: checker}
}

// Check checks the entire system health, including its dependecies.
func (hc *HealthService) Check(ctx context.Context, request *grpchealthv1.HealthCheckRequest) (*grpchealthv1.HealthCheckResponse, error) {
    if request == nil {
        st := status.New(codes.InvalidArgument, "health check request is nil")
        return createHealthCheckResponse(grpchealthv1.HealthCheckResponse_UNKNOWN), st.Err()
    }

    if err := hc.checker.Check(ctx); err != nil {
        return createHealthCheckResponse(grpchealthv1.HealthCheckResponse_NOT_SERVING), err
    }
    return createHealthCheckResponse(grpchealthv1.HealthCheckResponse_SERVING), nil
}

func createHealthCheckResponse(status grpchealthv1.HealthCheckResponse_ServingStatus) *grpchealthv1.HealthCheckResponse {
    return &grpchealthv1.HealthCheckResponse{
        Status: status,
    }
}