/*
Copyright © contributors to CloudNativePG, established as
CloudNativePG a Series of LF Projects, LLC.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

SPDX-License-Identifier: Apache-2.0
*/

package healthcheck

import (
	"fmt"
	"os"
	"path"

	"github.com/cloudnative-pg/machinery/pkg/log"
	"github.com/spf13/cobra"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/grpc/health/grpc_health_v1"

	"github.com/cloudnative-pg/plugin-barman-cloud/internal/cnpgi/metadata"
)

// NewCmd returns the healthcheck command
func NewCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "healthcheck",
		Short: "healthcheck commands",
	}

	cmd.AddCommand(unixHealthCheck())

	return cmd
}

func unixHealthCheck() *cobra.Command {
	cmd := &cobra.Command{
		Use:   "unix",
		Short: "executes the health check command on unix:///plugins/barman-cloud.cloudnative-pg.io",
		RunE: func(cmd *cobra.Command, _ []string) error {
			dialPath := fmt.Sprintf("unix://%s", path.Join("/plugins", metadata.PluginName))
			cli, cliErr := grpc.NewClient(dialPath, grpc.WithTransportCredentials(insecure.NewCredentials()))
			if cliErr != nil {
				log.Error(cliErr, "while building the client")
				return cliErr
			}

			healthCli := grpc_health_v1.NewHealthClient(cli)
			res, healthErr := healthCli.Check(
				cmd.Context(),
				&grpc_health_v1.HealthCheckRequest{},
			)
			if healthErr != nil {
				log.Error(healthErr, "while executing the healthcheck call")
				return healthErr
			}

			if res.Status == grpc_health_v1.HealthCheckResponse_SERVING {
				log.Trace("healthcheck response OK")
				os.Exit(0)
				return nil
			}

			log.Error(fmt.Errorf("unexpected healthcheck status: %v", res.Status),
				"while processing healthcheck response")

			// exit code 1 is returned when we exit from the function with an error
			switch res.Status {
			case grpc_health_v1.HealthCheckResponse_UNKNOWN:
				os.Exit(2)
			case grpc_health_v1.HealthCheckResponse_NOT_SERVING:
				os.Exit(3)
			default:
				os.Exit(125)
			}

			return nil
		},
	}

	return cmd
}