package plugin

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"strings"
	"testing"

	"k8s.io/cli-runtime/pkg/genericclioptions"
)

func TestPluginPathsAreUnaltered(t *testing.T) {
	tempDir, err := ioutil.TempDir(os.TempDir(), "test-cmd-plugins")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	tempDir2, err := ioutil.TempDir(os.TempDir(), "test-cmd-plugins2")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	// cleanup
	defer func() {
		if err := os.RemoveAll(tempDir); err != nil {
			panic(fmt.Errorf("unexpected cleanup error: %v", err))
		}
		if err := os.RemoveAll(tempDir2); err != nil {
			panic(fmt.Errorf("unexpected cleanup error: %v", err))
		}
	}()

	ioStreams, _, _, errOut := genericclioptions.NewTestIOStreams()
	verifier := newFakePluginPathVerifier()
	pluginPaths := []string{tempDir, tempDir2}
	o := &PluginListOptions{
		Verifier:  verifier,
		IOStreams: ioStreams,

		PluginPaths: pluginPaths,
	}

	// write at least one valid plugin file
	if _, err := ioutil.TempFile(tempDir, "kubectl-"); err != nil {
		t.Fatalf("unexpected error %v", err)
	}
	if _, err := ioutil.TempFile(tempDir2, "kubectl-"); err != nil {
		t.Fatalf("unexpected error %v", err)
	}

	if err := o.Run(); err != nil {
		t.Fatalf("unexpected error %v - %v", err, errOut.String())
	}

	// ensure original paths remain unaltered
	if len(verifier.seenUnsorted) != len(pluginPaths) {
		t.Fatalf("saw unexpected plugin paths. Expecting %v, got %v", pluginPaths, verifier.seenUnsorted)
	}
	for actual := range verifier.seenUnsorted {
		if !strings.HasPrefix(verifier.seenUnsorted[actual], pluginPaths[actual]) {
			t.Fatalf("expected PATH slice to be unaltered. Expecting %v, but got %v", pluginPaths[actual], verifier.seenUnsorted[actual])
		}
	}
}

func TestPluginPathsAreValid(t *testing.T) {
	tempDir, err := ioutil.TempDir(os.TempDir(), "test-cmd-plugins")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	// cleanup
	defer func() {
		if err := os.RemoveAll(tempDir); err != nil {
			panic(fmt.Errorf("unexpected cleanup error: %v", err))
		}
	}()

	tc := []struct {
		name               string
		pluginPaths        []string
		pluginFile         func() (*os.File, error)
		verifier           *fakePluginPathVerifier
		expectVerifyErrors []error
		expectErr          string
	}{
		{
			name:        "ensure no plugins found if no files begin with kubectl- prefix",
			pluginPaths: []string{tempDir},
			verifier:    newFakePluginPathVerifier(),
			pluginFile: func() (*os.File, error) {
				return ioutil.TempFile(tempDir, "notkubectl-")
			},
			expectErr: "unable to find any kubectl plugins in your PATH",
		},
		{
			name:        "ensure de-duplicated plugin-paths slice",
			pluginPaths: []string{tempDir, tempDir},
			verifier:    newFakePluginPathVerifier(),
			pluginFile: func() (*os.File, error) {
				return ioutil.TempFile(tempDir, "kubectl-")
			},
		},
	}

	for _, test := range tc {
		t.Run(test.name, func(t *testing.T) {
			ioStreams, _, _, errOut := genericclioptions.NewTestIOStreams()
			o := &PluginListOptions{
				Verifier:  test.verifier,
				IOStreams: ioStreams,

				PluginPaths: test.pluginPaths,
			}

			// create files
			if test.pluginFile != nil {
				if _, err := test.pluginFile(); err != nil {
					t.Fatalf("unexpected error creating plugin file: %v", err)
				}
			}

			for _, expected := range test.expectVerifyErrors {
				for _, actual := range test.verifier.errors {
					if expected != actual {
						t.Fatalf("unexpected error: expected %v, but got %v", expected, actual)
					}
				}
			}

			err := o.Run()
			if err == nil && len(test.expectErr) > 0 {
				t.Fatalf("unexpected non-error: expecting %v", test.expectErr)
			}
			if err != nil && len(test.expectErr) == 0 {
				t.Fatalf("unexpected error: %v - %v", err, errOut.String())
			}
			if err == nil {
				return
			}

			allErrs := bytes.NewBuffer(errOut.Bytes())
			if _, err := allErrs.WriteString(err.Error()); err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if len(test.expectErr) > 0 {
				if !strings.Contains(allErrs.String(), test.expectErr) {
					t.Fatalf("unexpected error: expected %v, but got %v", test.expectErr, allErrs.String())
				}
			}
		})
	}
}

type duplicatePathError struct {
	path string
}

func (d *duplicatePathError) Error() string {
	return fmt.Sprintf("path %q already visited", d.path)
}

type fakePluginPathVerifier struct {
	errors       []error
	seen         map[string]bool
	seenUnsorted []string
}

func (f *fakePluginPathVerifier) Verify(path string) []error {
	if f.seen[path] {
		err := &duplicatePathError{path}
		f.errors = append(f.errors, err)
		return []error{err}
	}
	f.seen[path] = true
	f.seenUnsorted = append(f.seenUnsorted, path)
	return nil
}

func newFakePluginPathVerifier() *fakePluginPathVerifier {
	return &fakePluginPathVerifier{seen: make(map[string]bool)}
}