package app

import (
	"fmt"
	"strings"
)

func (transportSystemdBackend) ID() string { return "systemd" }

func (transportSystemdBackend) Action(client TransportClient, action string) transportBackendActionResult {
	action = strings.ToLower(strings.TrimSpace(action))
	if action != "start" && action != "stop" && action != "restart" {
		return transportBackendActionResult{
			OK:       false,
			Code:     "TRANSPORT_BACKEND_ACTION_FAILED",
			Message:  "unsupported action: " + action,
			ExitCode: -1,
		}
	}
	units, errCode, errMsg := transportSystemdActionUnits(client, action)
	if len(units) == 0 {
		return transportBackendActionResult{
			OK:       false,
			Code:     errCode,
			Message:  errMsg,
			ExitCode: -1,
		}
	}

	aggOut := make([]string, 0, len(units))
	aggErr := make([]string, 0, len(units))

	netnsEnabled := transportNetnsEnabled(client)
	if res := transportSystemdRunPreActionHooks(client, action, units, netnsEnabled, &aggOut, &aggErr); res != nil {
		return *res
	}
	if res := transportSystemdRunActionUnits(client, action, units, &aggOut, &aggErr); res != nil {
		return *res
	}
	if netnsEnabled && action == "stop" && transportNetnsAutoCleanup(client) {
		transportSystemdRunPostStopCleanup(client, action, &aggOut, &aggErr)
	}

	msg := fmt.Sprintf("systemctl %s ok (%s)", action, strings.Join(units, ", "))
	if len(aggErr) > 0 {
		msg += "; with warnings"
	}
	return transportBackendActionResult{
		OK:       true,
		ExitCode: 0,
		Stdout:   strings.Join(aggOut, "\n"),
		Stderr:   strings.Join(aggErr, "\n"),
		Message:  msg,
	}
}

func transportSystemdStopMissingUnitNoop(stdout, stderr string, exitCode int, err error) bool {
	return transportSystemdUnitMissingError(stdout, stderr, exitCode, err)
}

func transportSystemdUnitMissingError(stdout, stderr string, exitCode int, err error) bool {
	if err == nil && exitCode == 0 {
		return false
	}
	msg := strings.ToLower(strings.TrimSpace(stderr + "\n" + stdout))
	if msg == "" {
		return false
	}
	return strings.Contains(msg, "not loaded") ||
		strings.Contains(msg, "not found") ||
		strings.Contains(msg, "could not be found") ||
		strings.Contains(msg, "unknown unit")
}