/*
Copyright 2017 The Kubernetes 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 exec

import (
	"context"
	"io"
	"io/ioutil"
	osexec "os/exec"
	"testing"
	"time"
)

func TestExecutorNoArgs(t *testing.T) {
	ex := New()

	cmd := ex.Command("true")
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Errorf("expected success, got %v", err)
	}
	if len(out) != 0 {
		t.Errorf("expected no output, got %q", string(out))
	}

	cmd = ex.Command("false")
	out, err = cmd.CombinedOutput()
	if err == nil {
		t.Errorf("expected failure, got nil error")
	}
	if len(out) != 0 {
		t.Errorf("expected no output, got %q", string(out))
	}
	ee, ok := err.(ExitError)
	if !ok {
		t.Errorf("expected an ExitError, got %+v", err)
	}
	if ee.Exited() {
		if code := ee.ExitStatus(); code != 1 {
			t.Errorf("expected exit status 1, got %d", code)
		}
	}

	cmd = ex.Command("/does/not/exist")
	out, err = cmd.CombinedOutput()
	if err == nil {
		t.Errorf("expected failure, got nil error")
	}
	if ee, ok := err.(ExitError); ok {
		t.Errorf("expected non-ExitError, got %+v", ee)
	}
}

func TestExecutorWithArgs(t *testing.T) {
	ex := New()

	cmd := ex.Command("echo", "stdout")
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Errorf("expected success, got %+v", err)
	}
	if string(out) != "stdout\n" {
		t.Errorf("unexpected output: %q", string(out))
	}

	cmd = ex.Command("/bin/sh", "-c", "echo stderr > /dev/stderr")
	out, err = cmd.CombinedOutput()
	if err != nil {
		t.Errorf("expected success, got %+v", err)
	}
	if string(out) != "stderr\n" {
		t.Errorf("unexpected output: %q", string(out))
	}
}

func TestLookPath(t *testing.T) {
	ex := New()

	shExpected, _ := osexec.LookPath("sh")
	sh, _ := ex.LookPath("sh")
	if sh != shExpected {
		t.Errorf("unexpected result for LookPath: got %s, expected %s", sh, shExpected)
	}
}

func TestExecutableNotFound(t *testing.T) {
	exec := New()

	cmd := exec.Command("fake_executable_name")
	_, err := cmd.CombinedOutput()
	if err != ErrExecutableNotFound {
		t.Errorf("cmd.CombinedOutput(): Expected error ErrExecutableNotFound but got %v", err)
	}

	cmd = exec.Command("fake_executable_name")
	_, err = cmd.Output()
	if err != ErrExecutableNotFound {
		t.Errorf("cmd.Output(): Expected error ErrExecutableNotFound but got %v", err)
	}

	cmd = exec.Command("fake_executable_name")
	err = cmd.Run()
	if err != ErrExecutableNotFound {
		t.Errorf("cmd.Run(): Expected error ErrExecutableNotFound but got %v", err)
	}
}

func TestStopBeforeStart(t *testing.T) {
	cmd := New().Command("echo", "hello")

	// no panic calling Stop before calling Run
	cmd.Stop()

	cmd.Run()

	// no panic calling Stop after command is done
	cmd.Stop()
}

func TestTimeout(t *testing.T) {
	exec := New()
	ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
	defer cancel()

	err := exec.CommandContext(ctx, "sleep", "2").Run()
	if err != context.DeadlineExceeded {
		t.Errorf("expected %v but got %v", context.DeadlineExceeded, err)
	}
}

func TestSetEnv(t *testing.T) {
	ex := New()

	out, err := ex.Command("/bin/sh", "-c", "echo $FOOBAR").CombinedOutput()
	if err != nil {
		t.Errorf("expected success, got %+v", err)
	}
	if string(out) != "\n" {
		t.Errorf("unexpected output: %q", string(out))
	}

	cmd := ex.Command("/bin/sh", "-c", "echo $FOOBAR")
	cmd.SetEnv([]string{"FOOBAR=baz"})
	out, err = cmd.CombinedOutput()
	if err != nil {
		t.Errorf("expected success, got %+v", err)
	}
	if string(out) != "baz\n" {
		t.Errorf("unexpected output: %q", string(out))
	}
}

func TestStdIOPipes(t *testing.T) {
	cmd := New().Command("/bin/sh", "-c", "echo 'OUT'>&1; echo 'ERR'>&2")

	stdoutPipe, err := cmd.StdoutPipe()
	if err != nil {
		t.Fatalf("expected StdoutPipe() not to error, got: %v", err)
	}
	stderrPipe, err := cmd.StderrPipe()
	if err != nil {
		t.Fatalf("expected StderrPipe() not to error, got: %v", err)
	}

	stdout := make(chan string)
	stderr := make(chan string)

	go func() {
		stdout <- readAll(t, stdoutPipe, "StdOut")
	}()
	go func() {
		stderr <- readAll(t, stderrPipe, "StdErr")
	}()

	if err := cmd.Start(); err != nil {
		t.Errorf("expected Start() not to error, got: %v", err)
	}

	if e, a := "OUT\n", <-stdout; e != a {
		t.Errorf("expected StdOut to be '%s', got: '%v'", e, a)
	}

	if e, a := "ERR\n", <-stderr; e != a {
		t.Errorf("expected StdErr to be '%s', got: '%v'", e, a)
	}

	if err := cmd.Wait(); err != nil {
		t.Errorf("expected Wait() not to error, got: %v", err)
	}
}

func readAll(t *testing.T, r io.Reader, n string) string {
	t.Helper()

	b, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatalf("unexpected error when reading from %s: %v", n, err)
	}

	return string(b)
}
