// Copyright Istio Authors.
//
// 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 k8sversion

import (
	"bytes"
	"fmt"
	"strings"
	"testing"

	"k8s.io/apimachinery/pkg/version"
	fakediscovery "k8s.io/client-go/discovery/fake"

	"istio.io/istio/operator/pkg/util/clog"
	"istio.io/istio/pkg/kube"
	pkgVersion "istio.io/pkg/version"
)

var (
	version1_17 = &version.Info{
		Major:      "1",
		Minor:      "17",
		GitVersion: "1.17",
	}
	version1_8 = &version.Info{
		Major:      "1",
		Minor:      "8",
		GitVersion: "v1.8",
	}
	version1_18 = &version.Info{
		Major:      "1",
		Minor:      "18",
		GitVersion: "v1.18.5",
	}
	version1_19 = &version.Info{
		Major:      "1",
		Minor:      "19",
		GitVersion: "v1.19.4",
	}
	version1_20 = &version.Info{
		Major:      "1",
		Minor:      "20",
		GitVersion: "v1.20.2",
	}
	version1_22 = &version.Info{
		Major:      "1",
		Minor:      "22",
		GitVersion: "v1.22",
	}
	version1_23 = &version.Info{
		Major:      "1",
		Minor:      "23",
		GitVersion: "v1.23",
	}
	version1_19RC = &version.Info{
		Major:      "1",
		Minor:      "19",
		GitVersion: "v1.19.5-rc.0",
	}
	version1_17GKE = &version.Info{
		Major:      "1",
		Minor:      "17+",
		GitVersion: "v1.17.7-gke.10",
	}
	version1_8GKE = &version.Info{
		Major:      "1",
		Minor:      "8",
		GitVersion: "v1.8.7-gke.8",
	}
	versionInvalid1 = &version.Info{
		Major:      "1",
		Minor:      "7",
		GitVersion: "v1.invalid.7",
	}
	versionInvalid2 = &version.Info{
		Major:      "one",
		Minor:      "seven",
		GitVersion: "one.seven",
	}
)

func TestExtractKubernetesVersion(t *testing.T) {
	cases := []struct {
		version  *version.Info
		expected int
		errMsg   error
		isValid  bool
	}{
		{
			version:  version1_17,
			expected: 17,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_8,
			expected: 8,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_18,
			expected: 18,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_19,
			expected: 19,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_20,
			expected: 20,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_22,
			expected: 22,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_19RC,
			expected: 19,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_17GKE,
			expected: 17,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version:  version1_8GKE,
			expected: 8,
			errMsg:   nil,
			isValid:  true,
		},
		{
			version: versionInvalid1,
			errMsg:  fmt.Errorf("could not parse Malformed version: %v", versionInvalid1.GitVersion),
			isValid: false,
		},
		{
			version: versionInvalid2,
			errMsg:  fmt.Errorf("could not parse Malformed version: %v", versionInvalid2.GitVersion),
			isValid: false,
		},
	}
	for i, c := range cases {
		t.Run(fmt.Sprintf("case %d %s", i, c.version), func(t *testing.T) {
			got, err := extractKubernetesVersion(c.version)
			if c.errMsg != err && c.isValid {
				t.Fatalf("\nwanted: %v \nbut found: %v", c.errMsg, err)
			}
			if got != c.expected {
				t.Fatalf("wanted %v got %v", c.expected, got)
			}
		})
	}
}

func TestIsK8VersionSupported(t *testing.T) {
	cases := []struct {
		version *version.Info
		logMsg  string
		isValid bool
	}{
		{
			version: version1_18,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, version1_18.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: version1_8,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, version1_8.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: version1_17GKE,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, version1_17GKE.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: versionInvalid1,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, versionInvalid1.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: version1_20,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, version1_20.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: version1_22,
			logMsg:  fmt.Sprintf(UnSupportedK8SVersionLogMsg, version1_22.GitVersion, pkgVersion.Info.Version, MinK8SVersion),
			isValid: false,
		},
		{
			version: version1_23,
			isValid: true,
		},
	}

	var outBuf bytes.Buffer
	var errBuf bytes.Buffer

	for i, c := range cases {
		t.Run(fmt.Sprintf("case %d %s", i, c.version), func(t *testing.T) {
			k8sClient := kube.NewFakeClient()
			k8sClient.Kube().Discovery().(*fakediscovery.FakeDiscovery).FakedServerVersion = c.version

			logger := clog.NewConsoleLogger(&outBuf, &errBuf, nil)
			IsK8VersionSupported(k8sClient, logger)

			errMsgTrim := strings.TrimSpace(c.logMsg)
			outBufTrim := strings.TrimSpace(outBuf.String())

			if !c.isValid && strings.Compare(errMsgTrim, outBufTrim) != 0 {
				t.Fatalf("\nwanted: %v \nbut found: %v", errMsgTrim, outBufTrim)
			}

			if c.isValid && outBuf.Len() > 0 {
				t.Fatalf("\nwanted: %v \nbut found: %v", errMsgTrim, outBufTrim)
			}
			outBuf.Reset()
		})
	}
}
