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

#include "chrome/browser/image_decoder.h"

#include "chrome/grit/generated_resources.h"
#include "chrome/test/base/in_process_browser_test.h"
#include "content/public/browser/browser_child_process_observer.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/child_process_data.h"
#include "content/public/test/test_utils.h"
#include "ui/base/l10n/l10n_util.h"

using content::BrowserThread;

namespace {

std::string GetValidPngString() {
  // 1x1 PNG. Does not get much smaller than this.
  static const char kPngData[] =
      "\x89\x50\x4e\x47\x0d\x0a\x1a\x0a\x00\x00\x00\x0d\x49\x48\x44\x52"
      "\x00\x00\x00\x01\x00\x00\x00\x01\x08\x02\x00\x00\x00\x90\x77\x53"
      "\xde\x00\x00\x00\x0c\x49\x44\x41\x54\x08\xd7\x63\xf8\xff\xff\x3f"
      "\x00\x05\xfe\x02\xfe\xdc\xcc\x59\xe7\x00\x00\x00\x00\x49\x45\x4e"
      "\x44\xae\x42\x60\x82";
  // Need to specify the buffer size because it contains NULs.
  return std::string(kPngData, sizeof(kPngData) - 1);
}

class TestImageRequest : public ImageDecoder::ImageRequest {
 public:
  explicit TestImageRequest(const base::Closure& quit_closure)
      : decode_succeeded_(false),
        quit_closure_(quit_closure),
        quit_called_(false) {
  }

  ~TestImageRequest() override {
    if (!quit_called_) {
      quit_closure_.Run();
    }
  }

  bool decode_succeeded() const { return decode_succeeded_; }

 private:
  void OnImageDecoded(const SkBitmap& decoded_image) override {
    decode_succeeded_ = true;
    Quit();
  }

  void OnDecodeImageFailed() override {
    Quit();
  }

  void Quit() {
    EXPECT_FALSE(quit_called_);
    quit_called_ = true;
    quit_closure_.Run();
  }

  bool decode_succeeded_;

  base::Closure quit_closure_;
  bool quit_called_;

  DISALLOW_COPY_AND_ASSIGN(TestImageRequest);
};

class KillProcessObserver : public content::BrowserChildProcessObserver {
 public:
  KillProcessObserver()
      : did_kill_(false),
        utility_process_name_(
            l10n_util::GetStringUTF16(IDS_UTILITY_PROCESS_IMAGE_DECODER_NAME)) {
    Add(this);
  }

  ~KillProcessObserver() override {
    Remove(this);
  }

  bool did_kill() const { return did_kill_; }

 private:
  void BrowserChildProcessHostConnected(
      const content::ChildProcessData& data) override {
    DCHECK_CURRENTLY_ON(BrowserThread::UI);
    if (data.handle == base::kNullProcessHandle ||
        data.name != utility_process_name_) {
      return;
    }

    ASSERT_FALSE(did_kill_);
    base::ProcessHandle handle = data.handle;

#if defined(OS_WIN)
    // On windows, duplicate the process handle since base::Process closes it on
    // destruction.
    base::ProcessHandle out_handle;
    if (!::DuplicateHandle(GetCurrentProcess(), handle,
                           GetCurrentProcess(), &out_handle,
                           0, FALSE, DUPLICATE_SAME_ACCESS)) {
      return;
    }
    handle = out_handle;
#endif

    // Use a non-zero exit code so it counts as a crash.
    // Don't wait for the process after sending the termination signal
    // (SIGTERM). According to POSIX, doing so causes the resulting zombie to be
    // removed from the process table. However, Chromium treats an error on
    // |waitpid| (in this case, ECHILD) as a "normal" termination and doesn't
    // invoke the process host delegate's OnProcessCrashed().
    EXPECT_TRUE(base::Process(handle).Terminate(1, false));
    did_kill_ = true;
  }

  bool did_kill_;
  const base::string16 utility_process_name_;

  DISALLOW_COPY_AND_ASSIGN(KillProcessObserver);
};

}  // namespace

class ImageDecoderBrowserTest : public InProcessBrowserTest {
};

IN_PROC_BROWSER_TEST_F(ImageDecoderBrowserTest, Basic) {
  scoped_refptr<content::MessageLoopRunner> runner =
      new content::MessageLoopRunner;
  TestImageRequest test_request(runner->QuitClosure());
  ImageDecoder::Start(&test_request, std::string());
  runner->Run();
  EXPECT_FALSE(test_request.decode_succeeded());
}

IN_PROC_BROWSER_TEST_F(ImageDecoderBrowserTest, BasicDecode) {
  scoped_refptr<content::MessageLoopRunner> runner =
      new content::MessageLoopRunner;
  TestImageRequest test_request(runner->QuitClosure());
  ImageDecoder::Start(&test_request, GetValidPngString());
  runner->Run();
  EXPECT_TRUE(test_request.decode_succeeded());
}

IN_PROC_BROWSER_TEST_F(ImageDecoderBrowserTest, StartAndDestroy) {
  scoped_refptr<content::MessageLoopRunner> runner =
      new content::MessageLoopRunner;
  scoped_ptr<TestImageRequest> test_request(
      new TestImageRequest(runner->QuitClosure()));
  ImageDecoder::Start(test_request.get(), std::string());
  test_request.reset();
  runner->Run();
}

// Killing the utility process counts as a crash. Thus the request fails.
// If ImageDecoder did not handle the crash properly, the request never finishes
// and this test would hang.
// Note: This test is inherently racy because KillProcessObserver lives on the
// UI thread but ImageDecoder does its work mainly on the IO thread. So the test
// checks for both possible valid outcomes.
IN_PROC_BROWSER_TEST_F(ImageDecoderBrowserTest, StartAndKillProcess) {
  KillProcessObserver observer;
  scoped_refptr<content::MessageLoopRunner> runner =
      new content::MessageLoopRunner;
  TestImageRequest test_request(runner->QuitClosure());
  ImageDecoder::Start(&test_request, GetValidPngString());
  runner->Run();
  if (!test_request.decode_succeeded()) {
    // The UI thread won the race. Make sure the utility process did get killed.
    EXPECT_TRUE(observer.did_kill());
  }
  // Else the IO thread won the race and the image got decoded. Oh well.
}