// Copyright 2020 Authors of Cilium
//
// 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.

package main

import (
	"bytes"
	"os/exec"
	"regexp"
)

var linuxRegexp = regexp.MustCompile(`(?i)linux`)

// A unameCheck checks the output of uname -a.
type unameCheck struct{}

func (unameCheck) Name() string {
	return "uname"
}

func (unameCheck) Run() (checkResult, string) {
	output, err := exec.Command("uname", "-a").CombinedOutput()
	if err != nil {
		return checkFailed, err.Error()
	}

	message := string(bytes.TrimSpace(output))
	if !linuxRegexp.Match(output) {
		return checkWarning, message
	}

	return checkOK, message
}

func (unameCheck) Hint() string {
	return ""
}