package command

import (
	"context"
	"fmt"
	"gitea.illuad.fr/adrien/middleman"
	"gitea.illuad.fr/adrien/middleman/flag"
	"github.com/rs/zerolog/log"
	"github.com/urfave/cli/v3"
	"golang.org/x/sync/errgroup"
	"net/http"
)

// healthcheck is the structure representing the command described below.
type healthcheck struct {
	group *errgroup.Group
}

// HealthcheckCmd is the command name.
const HealthcheckCmd = "healthcheck"

const (
	// healthcheckURLFlagName is the flag name used to set the healthcheck URL.
	healthcheckURLFlagName = "healthcheck-url"
)

const (
	// defaultHealthcheckURL is the default healthcheck URL.
	defaultHealthcheckURL = "http://127.0.0.1:5732/healthz"
)

var h healthcheck

// Healthcheck describes the healthcheck command.
func Healthcheck(group *errgroup.Group) *cli.Command {
	h.group = group
	return &cli.Command{
		Name:        HealthcheckCmd,
		Aliases:     middleman.PluckAlias(HealthcheckCmd, HealthcheckCmd),
		Usage:       "Runs healthcheck mode",
		Description: "Perform HTTP HEAD request to the health endpoint",
		Flags: []cli.Flag{
			healthcheckURL(),
			flag.LogFormat(HealthcheckCmd),
			flag.LogLevel(HealthcheckCmd),
		},
		Before: before,
		Action: h.action,
	}
}

// action is executed when the HealthcheckCmd command is called.
func (h healthcheck) action(ctx context.Context, command *cli.Command) error {
	if err := ctx.Err(); err != nil {
		return err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodHead, command.String(healthcheckURLFlagName), http.NoBody)
	if err != nil {
		return err
	}
	var res *http.Response
	res, err = http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer func() {
		if err = res.Body.Close(); err != nil {
			log.Err(err).Send()
		}
	}()
	if res.StatusCode != http.StatusOK {
		return fmt.Errorf("healthcheck failed with the following HTTP code: %d (%s)", res.StatusCode, http.StatusText(res.StatusCode))
	}
	return nil
}

func healthcheckURL() cli.Flag {
	return &cli.StringFlag{
		Name:     healthcheckURLFlagName,
		Category: "monitoring",
		Usage:    "full healthcheck URL (protocol, address and path)",
		Sources:  middleman.PluckEnvVar(EnvVarPrefix, healthcheckURLFlagName),
		Value:    defaultHealthcheckURL,
		Aliases:  middleman.PluckAlias(HealthcheckCmd, healthcheckURLFlagName),
	}
}