// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package runutil_test

import (
	"bytes"
	"errors"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"syscall"
	"testing"
	"time"

	"v.io/jiri/runutil"
	"v.io/x/lib/envvar"
)

func rmLineNumbers(s string) string {
	re := regexp.MustCompile("(.*\\.go):\\d+:(.*)")
	return re.ReplaceAllString(s, "$1:-:$2")
}

func sanitizeTimestamps(s string) string {
	re := regexp.MustCompile(`\[(\d\d:\d\d:\d\d.\d\d)\]`)
	return re.ReplaceAllString(s, "[hh:mm:ss.xx]")
}

func ExampleSequence() {
	seq := runutil.NewSequence(nil, os.Stdin, ioutil.Discard, ioutil.Discard, false, false, true)
	err := seq.
		Capture(os.Stdout, nil).Run("echo", "a").
		Capture(os.Stdout, nil).Last("echo", "b")
	err = seq.
		Run("echo", "c").
		Run("xxxxxxx").
		Capture(os.Stdout, nil).Last("echo", "d")
	// Get rid of the line#s in the error output.
	fmt.Println(rmLineNumbers(err.Error()))
	// Output:
	// a
	// b
	// sequence_test.go:-: Run("xxxxxxx"): exec: "xxxxxxx": executable file not found in $PATH
}

// TestStdoutStderr exercises the various possible configurations for stdout and
// stderr (via NewSequence, Opts, or Capture) as well as the verbose flag.
func TestStdoutStderr(t *testing.T) {
	cwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	dir := "Current Directory: " + cwd

	// Case 1: we only specify stdout/stderr at constructor time.
	//
	// Verbose mode: All the command's output and execution logging goes to
	// stdout, execution error messages to stderr.
	//
	// Non-Verbose mode: No stdout output; execution error messages to
	// stderr.
	for _, verbose := range []bool{false, true} {
		var cnstrStdout, cnstrStderr bytes.Buffer
		seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
		seq.Run("bash", "-c", "echo a; echo b >&2").
			Timeout(time.Microsecond).
			Run("sleep", "10000")
		wantA, wantB := "", ""
		if verbose {
			// stdout, stderr output can be interleaved in arbitrary order.
			pre := `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
[hh:mm:ss.xx] >> OK`
			post := `[hh:mm:ss.xx] >> sleep 10000
[hh:mm:ss.xx] >> TIMED OUT
`
			wantA = pre + `
a
b
` + post
			wantB = pre + `
b
a
` + post
		}
		if got := sanitizeTimestamps(cnstrStdout.String()); got != wantA && got != wantB {
			t.Errorf("verbose: %t, got %v, want either %v or %v", verbose, got, wantA, wantB)
		}
		if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
	}

	// Case 2: we specify stdout/stderr at constructor time, and also via
	// Capture.
	//
	// Verbose mode: The command execution log goes to constructor stdout,
	// command execution errors go to constructor stderr, and the
	// stdout/stderr output from the command goes to capture stdout/stderr
	// respectively.
	//
	// Non-Verbose mode: The stdout/stderr output from the command goes to
	// capture stdout/stderr respectively.  No command execution log, but
	// the command execution errors go to constructor stderr.
	for _, verbose := range []bool{false, true} {
		var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
		seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, verbose)
		seq.Capture(&captureStdout, &captureStderr).
			Run("bash", "-c", "echo a; echo b >&2").
			Timeout(time.Microsecond).
			Run("sleep", "10000")
		want := ""
		if verbose {
			want = `[hh:mm:ss.xx] >> bash -c "echo a; echo b >&2"
[hh:mm:ss.xx] >> OK
[hh:mm:ss.xx] >> sleep 10000
[hh:mm:ss.xx] >> TIMED OUT
`
		}
		if got := sanitizeTimestamps(cnstrStdout.String()); want != got {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
		if got, want := cnstrStderr.String(), "Waiting for command to exit: [\"sleep\" \"10000\"]\n"+dir+"\n"; want != got {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
		if got, want := captureStdout.String(), "a\n"; want != got {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
		if got, want := captureStderr.String(), "b\n"; want != got {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
	}

	// Case 3: we specify stdout/stderr at constructor and use nil
	// with Capture to verify that the constructor values are used.
	var cnstrStdout, cnstrStderr, captureStdout, captureStderr bytes.Buffer
	seq := runutil.NewSequence(nil, os.Stdin, &cnstrStdout, &cnstrStderr, false, false, false)
	err = seq.
		Capture(&captureStdout, nil).Run("bash", "-c", "echo a; echo b >&2").
		Capture(nil, &captureStderr).Last("bash", "-c", "echo c; echo d >&2")

	if got, want := cnstrStdout.String(), "c\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	if got, want := cnstrStderr.String(), "b\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	if got, want := captureStdout.String(), "a\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	if got, want := captureStderr.String(), "d\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
}

func TestSequence(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	if got, want := seq.Run("echo", "a").Done(), error(nil); got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	var out bytes.Buffer
	err := seq.
		Capture(&out, nil).Run("echo", "hello").
		Capture(&out, nil).Run("echo", "world").
		Done()
	if err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "hello\nworld\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	env := map[string]string{
		"MYTEST":  "hi",
		"MYTEST2": "there",
	}
	err = seq.
		Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
		Env(env).Capture(&out, nil).Run("sh", "-c", "echo $MYTEST2").
		Done()
	if err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "hi\nthere\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	err = seq.Run("./bound-to-fail", "fail").Done()
	if err == nil {
		t.Fatalf("should have experience an error")
	}
	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"./bound-to-fail\", \"fail\"): fork/exec ./bound-to-fail: no such file or directory"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	err = seq.
		Capture(&out, nil).Run("echo", "works, despite previous error").Done()
	if err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "works, despite previous error\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()
	err = seq.Timeout(time.Second).Run("sleep", "10").Done()
	if got, want := rmLineNumbers(err.Error()), "sequence_test.go:-: Run(\"sleep\", \"10\"): command timed out"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
}

// Test that modifiers don't get applied beyond the first invocation of Run.
func TestSequenceModifiers(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	var out bytes.Buffer
	env := map[string]string{
		"MYTEST": "hi",
	}
	err := seq.
		Capture(&out, nil).Env(env).Run("sh", "-c", "echo $MYTEST").
		Capture(&out, nil).Last("sh", "-c", "echo $MYTEST")
	if err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "hi\n\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	err = seq.
		Capture(&out, nil).Run("echo", "hello").
		Run("echo", "world").
		Done()
	if err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "hello\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	in := bytes.Buffer{}
	in.WriteString("Hello\n")
	in.WriteString("World\n")

	if err := seq.Read(&in).Capture(&out, nil).Last("sh", "-c", "read x; echo $x; read y; echo $y"); err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "Hello\nWorld\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
}

func TestMoreSequenceModifiers(t *testing.T) {
	var stderr, stdout bytes.Buffer
	seq := runutil.NewSequence(nil, os.Stdin, &stdout, &stderr, false, false, true)

	for _, verbose := range []bool{false, true} {
		err := seq.Verbose(verbose).Last("sh", "-c", "echo hello")
		if err != nil {
			t.Fatal(err)
		}
		out := stdout.String()
		want := ""
		if verbose {
			out = sanitizeTimestamps(out)
			want = `[hh:mm:ss.xx] >> sh -c "echo hello"
[hh:mm:ss.xx] >> OK
hello
`
		}
		if got, want := out, want; got != want {
			t.Errorf("verbose: %t, got %v, want %v", verbose, got, want)
		}
		stdout.Reset()
	}
	for _, dryRun := range []bool{false, true} {
		err := seq.DryRun(dryRun).Last("sh", "-c", "echo hello")
		if err != nil {
			t.Fatal(err)
		}
		out := sanitizeTimestamps(stdout.String())
		want := `[hh:mm:ss.xx] >> sh -c "echo hello"
[hh:mm:ss.xx] >> OK
`
		if !dryRun {
			want += `hello
`
		}
		if got, want := out, want; got != want {
			t.Errorf("dryRun: %t, got %v, want %v", dryRun, got, want)
		}
		stdout.Reset()
	}
}

func TestSequenceOutputOnError(t *testing.T) {
	var out bytes.Buffer
	// Only the output from the command that generates an error is written
	// to stderr (i.e. out) when not in verbose mode.
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, &out, false, false, false)
	err := seq.Run("sh", "-c", "echo not me").
		Run("sh", "-c", "echo ooh; echo ah; echo me; exit 1").
		Last("sh", "-c", "echo not me either")
	if err == nil {
		t.Errorf("expected an error")
	}
	if got, want := out.String(), "oh\nah\nme\n"; !strings.Contains(got, want) {
		t.Errorf("got %v doesn't contain %v", got, want)
	}
	if got, notWant := out.String(), "not me"; strings.Contains(got, notWant) {
		t.Errorf("got %v contains %v", got, notWant)
	}
	out.Reset()

	err = seq.Run("sh", "-c", "echo hard to not include me").
		Run("sh", "-c", "echo ooh; echo ah; echo me").
		Last("sh", "-c", "echo not me either")
	if err != nil {
		t.Error(err)
	}
	if got, want := len(out.String()), 0; got != want {
		t.Logf(out.String())
		t.Errorf("got %v, want %v", got, want)
	}
	out.Reset()

	err = seq.Last("sh", "-c", "echo should see an error; exit 1")
	if err == nil {
		t.Errorf("expected an error")
	}
	if got, want := out.String(), "should see an error"; !strings.Contains(got, want) {
		t.Errorf("got %v, want %v", got, want)
	}
}

type timestamped struct {
	times []time.Time
	data  [][]byte
}

func (t *timestamped) Write(p []byte) (n int, err error) {
	t.times = append(t.times, time.Now())
	t.data = append(t.data, p)
	return len(p), nil
}

func TestSequenceStreaming(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	ts := &timestamped{}
	err := seq.
		Capture(ts, nil).Last("sh", "-c", `
	for i in $(seq 1 5); do
		echo $i
		sleep 1
	done`)
	if err != nil {
		t.Fatal(err)
	}
	if got, want := len(ts.data), 5; got != want {
		t.Fatalf("got %v, want %v", got, want)
	}
	prev := ts.times[0]
	for _, nth := range ts.times[1:] {
		if nth.Sub(prev) < 500*time.Millisecond {
			t.Errorf("times %s and %s are too close together", nth, prev)
		}
		prev = nth
	}
}

func TestSequenceTerminatingMethod(t *testing.T) {
	seq := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	filename := "./test-file"
	fi, err := os.Create(filename)
	if err != nil {
		t.Fatal(err)
	}
	defer os.Remove(filename)
	data, err := seq.Capture(fi, nil).Run("echo", "aha").ReadFile(filename)
	if err != nil {
		t.Fatal(err)
	}
	if got, want := string(data), "aha\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
}

func getwd(t *testing.T) string {
	here, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	return here
}

func TestSequencePushPop(t *testing.T) {
	here := getwd(t)
	s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	components := []string{here, "test", "a", "b", "c"}
	tree := filepath.Join(components...)
	s.MkdirAll(tree, os.FileMode(0755))
	if err := s.Error(); err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(filepath.Join(here, "test"))

	td := ""
	for _, d := range components {
		s.Pushd(d)
		td = filepath.Join(td, d)
		if got, want := getwd(t), td; got != want {
			t.Errorf("got %v, want %v", got, want)
		}
	}
	s.Done()
	if got, want := getwd(t), here; got != want {
		t.Errorf("got %v, want %v", got, want)
	}

	s.Pushd("test").Pushd("a").Pushd("b")
	if got, want := getwd(t), filepath.Join(here, "test", "a", "b"); got != want {
		t.Errorf("got %v, want %v", got, want)
	}
	err := s.Pushd("x").Done()
	if err == nil {
		t.Fatal(fmt.Errorf("expected an error"))
	}
	// Make sure the stack is unwound on error.
	if got, want := getwd(t), here; got != want {
		t.Errorf("got %v, want %v", got, want)
		if err := os.Chdir(here); err != nil {
			panic(fmt.Sprintf("failed to chdir back to %s", here))
		}

	}
}

func TestExists(t *testing.T) {
	s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	f, err := s.TempFile("", "file-exists")
	if err != nil {
		t.Fatal(err)
	}
	name := f.Name()
	f.Close()
	defer os.RemoveAll(name)
	newName := name + "x"

	err = s.AssertFileExists(name).Rename(name, newName).Done()
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(newName)
	err = s.AssertFileExists(name).Last("exit 1")
	if !runutil.IsNotExist(err) {
		t.Fatal(err)
	}
	err = s.AssertFileExists(newName).Last("sh", "-c", "exit 33")
	if got, want := err.Error(), "exit status 33"; !strings.Contains(got, want) {
		t.Errorf("got %v, does not contain %v", got, want)
	}
	err = s.AssertDirExists(newName).Last("sh", "-c", "exit 33")
	if !runutil.IsNotExist(err) {
		t.Fatal(err)
	}

	dir, err := s.TempDir("", "dir-exists")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(dir)
	newDir := dir + "x"

	err = s.AssertDirExists(dir).Rename(dir, newDir).Done()
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(newDir)
	err = s.AssertDirExists(dir).Last("exit 1")
	if !runutil.IsNotExist(err) {
		t.Fatal(err)
	}
	err = s.AssertDirExists(newDir).Last("sh", "-c", "exit 33")
	if got, want := err.Error(), "exit status 33"; !strings.Contains(got, want) {
		t.Errorf("got %v, does not contain %v", got, want)
	}
	err = s.AssertFileExists(newDir).Last("sh", "-c", "exit 33")
	if !runutil.IsNotExist(err) {
		t.Fatal(err)
	}
}

func TestDirModifier(t *testing.T) {
	noError := errors.New("no error")
	runner := func(cwd, dir string, ech chan error) {
		s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
		var out bytes.Buffer
		parent := filepath.Dir(dir)
		if err := os.Chdir(parent); err != nil {
			panic(fmt.Sprintf("chdir(%s): %v", parent, err))
		}
		err := s.Dir(dir).Capture(&out, nil).Last("sh", "-c", "pwd")
		pwd := strings.TrimSpace(out.String())
		switch {
		case err != nil:
			ech <- err
		case dir != pwd:
			ech <- fmt.Errorf("got %v, want %v", pwd, dir)
		default:
			ech <- noError
		}
		if err := os.Chdir(cwd); err != nil {
			panic(fmt.Sprintf("chdir(%s): %v", cwd, err))
		}
	}
	cwd, _ := os.Getwd()
	n := 50
	errCh := make(chan error, 10)
	for i := 0; i < n; i++ {
		dir, err := ioutil.TempDir(cwd, fmt.Sprintf("%d", i))
		if err != nil {
			t.Fatal(err)
		}
		go runner(cwd, dir, errCh)
		defer os.RemoveAll(dir)
	}
	for i := 0; i < n; i++ {
		err := <-errCh
		if err != noError {
			t.Errorf("unexpected error: %v", err)
		}
	}
}

func TestStart(t *testing.T) {
	s := runutil.NewSequence(nil, os.Stdin, os.Stdout, os.Stderr, false, false, true)
	path, err := runutil.LookPath("sleep", envvar.SliceToMap(os.Environ()))
	if err != nil {
		t.Fatal(err)
	}
	h, err := s.Start(path, "100")
	if err != nil {
		t.Fatal(err)
	}
	pid := h.Pid()
	time.Sleep(time.Second)
	if err := syscall.Kill(pid, 0); err != nil {
		t.Fatal(err)
	}
	if err := h.Kill(); err != nil {
		t.Fatal(err)
	}
	time.Sleep(time.Second)
	if err := h.Wait(); err == nil || (err != nil && err.Error() != "signal: killed") {
		t.Fatal(err)
	}
	time.Sleep(time.Second)
	if err := syscall.Kill(pid, 0); err == nil {
		t.Fatal("command has not terminated.")
	}
}

func TestStartWithOutput(t *testing.T) {
	cwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	dir := "Current Directory: " + cwd + "\n"
	var out bytes.Buffer
	s := runutil.NewSequence(nil, os.Stdin, &out, &out, false, false, true)
	h, err := s.Verbose(false).Start("sh", "-c", "echo hello; echo world; sleep 1; echo wakeup; exit 1")
	if err != nil {
		t.Fatal(err)
	}
	if err := h.Wait(); err == nil {
		t.Fatal("expected an error")
	}
	if got, want := out.String(), "hello\nworld\nwakeup\n"+dir; got != want {
		t.Errorf("got %v, want %v", got, want)
	}

	out.Reset()
	h, err = s.Verbose(false).Capture(&out, &out).Start("sh", "-c", "echo hello; echo world; sleep 1; echo wakeup")
	if err != nil {
		t.Fatal(err)
	}
	if err := h.Wait(); err != nil {
		t.Fatal(err)
	}
	if got, want := out.String(), "hello\nworld\nwakeup\n"; got != want {
		t.Errorf("got %v, want %v", got, want)
	}
}