/*
 * Teleport
 * Copyright (C) 2023  Gravitational, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package utils

import (
	"strings"
	"testing"

	"github.com/coreos/go-semver/semver"
	"github.com/stretchr/testify/require"
)

// TestKernelVersion checks that version strings for various distributions
// can be parsed correctly.
func TestKernelVersion(t *testing.T) {
	t.Parallel()

	var tests = []struct {
		inRelease  string
		inMin      string
		inMax      string
		outRelease string
	}{
		// Debian 10
		{
			inRelease:  "4.19.0-6-cloud-amd64",
			inMin:      "4.18.0",
			inMax:      "4.20.0",
			outRelease: "4.19.0",
		},
		// CentOS 6
		{
			inRelease:  "4.19.94",
			inMin:      "4.18.0",
			inMax:      "4.20.0",
			outRelease: "4.19.94",
		},
		// CentOS 7
		{
			inRelease:  "4.19.72-25.58.amzn2.x86_64",
			inMin:      "4.18.0",
			inMax:      "4.20.0",
			outRelease: "4.19.72",
		},
		// CentOS 8
		{
			inRelease:  "4.18.0-80.11.2.el8_0.x86_64",
			inMin:      "4.17.0",
			inMax:      "4.29.0",
			outRelease: "4.18.0",
		},
		// Ubuntu 19.04
		{
			inRelease:  "5.0.0-1028-gcp",
			inMin:      "4.18.0",
			inMax:      "5.1.0",
			outRelease: "5.0.0",
		},
		// Windows WSL2
		{
			inRelease:  "5.15.68.1-microsoft-standard-WSL2",
			inMin:      "5.14.0",
			inMax:      "5.16.0",
			outRelease: "5.15.68",
		},
	}

	for _, tt := range tests {
		t.Run(tt.inRelease, func(t *testing.T) {
			// Check the version is parsed correctly.
			version, err := kernelVersion(strings.NewReader(tt.inRelease))
			require.NoError(t, err)
			require.Equal(t, version.String(), tt.outRelease)

			// Check that version comparisons work.
			min, err := semver.NewVersion(tt.inMin)
			require.NoError(t, err)
			max, err := semver.NewVersion(tt.inMax)
			require.NoError(t, err)
			require.True(t, version.LessThan(*max))
			require.False(t, version.LessThan(*min))
		})
	}

	t.Run("invalid kernel version", func(t *testing.T) {
		v, err := kernelVersion(strings.NewReader("10.23"))
		require.Nil(t, v)
		require.EqualError(
			t,
			err,
			`unable to extract kernel semver from string "10.23"`,
		)
	})
}