/*
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 * modification, are permitted provided that the following conditions are
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 *
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 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#include "third_party/blink/renderer/platform/mhtml/mhtml_archive.h"

#include "base/test/metrics/histogram_tester.h"
#include "build/build_config.h"
#include "services/network/public/cpp/is_potentially_trustworthy.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/blink/public/mojom/loader/mhtml_load_result.mojom-blink.h"
#include "third_party/blink/renderer/platform/mhtml/mhtml_parser.h"
#include "third_party/blink/renderer/platform/mhtml/serialized_resource.h"
#include "third_party/blink/renderer/platform/testing/testing_platform_support.h"
#include "third_party/blink/renderer/platform/testing/unit_test_helpers.h"
#include "third_party/blink/renderer/platform/testing/url_test_helpers.h"
#include "third_party/blink/renderer/platform/text/date_components.h"
#include "third_party/blink/renderer/platform/weborigin/kurl.h"
#include "third_party/blink/renderer/platform/weborigin/scheme_registry.h"
#include "third_party/blink/renderer/platform/wtf/shared_buffer.h"
#include "third_party/blink/renderer/platform/wtf/text/string_builder.h"

using blink::mojom::MHTMLLoadResult;
using blink::url_test_helpers::ToKURL;

namespace blink {
namespace test {

namespace {

const char kEndOfPartBoundary[] = "--boundary-example";
const char kEndOfDocumentBoundary[] = "--boundary-example--";

}  // namespace

class MHTMLArchiveTest : public testing::Test {
 public:
  MHTMLArchiveTest() {
    file_path_ = test::CoreTestDataPath("frameserializer/css/");
    mhtml_date_ = base::Time::FromJsTime(1520551829000);
    mhtml_date_header_ = String::FromUTF8("Thu, 8 Mar 2018 23:30:29 -0000");
  }

 protected:
  void AddResource(const char* url,
                   const char* mime,
                   scoped_refptr<SharedBuffer> data) {
    SerializedResource resource(ToKURL(url), mime, std::move(data));
    resources_.push_back(resource);
  }

  void AddResource(const char* url, const char* mime, const char* file_name) {
    AddResource(url, mime, ReadFile(file_name));
  }

  void AddTestMainResource() {
    AddResource("http://www.test.com", "text/html", "css_test_page.html");
  }

  void AddTestResources() {
    AddResource("http://www.test.com", "text/html", "css_test_page.html");
    AddResource("http://www.test.com/link_styles.css", "text/css",
                "link_styles.css");
    AddResource("http://www.test.com/import_style_from_link.css", "text/css",
                "import_style_from_link.css");
    AddResource("http://www.test.com/import_styles.css", "text/css",
                "import_styles.css");
    AddResource("http://www.test.com/red_background.png", "image/png",
                "red_background.png");
    AddResource("http://www.test.com/orange_background.png", "image/png",
                "orange_background.png");
    AddResource("http://www.test.com/yellow_background.png", "image/png",
                "yellow_background.png");
    AddResource("http://www.test.com/green_background.png", "image/png",
                "green_background.png");
    AddResource("http://www.test.com/blue_background.png", "image/png",
                "blue_background.png");
    AddResource("http://www.test.com/purple_background.png", "image/png",
                "purple_background.png");
    AddResource("http://www.test.com/ul-dot.png", "image/png", "ul-dot.png");
    AddResource("http://www.test.com/ol-dot.png", "image/png", "ol-dot.png");
  }

  HashMap<String, String> ExtractHeaders(LineReader& line_reader) {
    // Read the data per line until reaching the empty line.
    HashMap<String, String> mhtml_headers;
    String line;
    line_reader.GetNextLine(&line);
    while (line.length()) {
      StringBuilder builder;
      builder.Append(line);

      // Peek next line to see if it starts with soft line break. If yes, append
      // to current line.
      String next_line;
      while (true) {
        line_reader.GetNextLine(&next_line);
        if (next_line.length() > 1 &&
            (next_line[0] == ' ' || next_line[0] == '\t')) {
          builder.Append(next_line, 1, next_line.length() - 1);
          continue;
        }
        break;
      }

      line = builder.ToString();
      wtf_size_t pos = line.Find(":");
      if (pos == kNotFound)
        continue;
      String key = line.Substring(0, pos);
      String value = line.Substring(pos + 2);
      mhtml_headers.insert(key, value);

      line = next_line;
    }
    return mhtml_headers;
  }

  HashMap<String, String> ExtractMHTMLHeaders() {
    LineReader line_reader(String(mhtml_data_.data(), mhtml_data_.size()));
    return ExtractHeaders(line_reader);
  }

  void GenerateMHTMLData(const Vector<SerializedResource>& resources,
                         MHTMLArchive::EncodingPolicy encoding_policy,
                         const KURL& url,
                         const String& title,
                         const String& mime_type,
                         bool validate) {
    // This boundary is as good as any other.  Plus it gets used in almost
    // all the examples in the MHTML spec - RFC 2557.
    String boundary = String::FromUTF8("boundary-example");

    MHTMLArchive::GenerateMHTMLHeader(boundary, url, title, mime_type,
                                      mhtml_date_, mhtml_data_);
    for (const auto& resource : resources) {
      MHTMLArchive::GenerateMHTMLPart(boundary, String(), encoding_policy,
                                      resource, mhtml_data_);
    }
    MHTMLArchive::GenerateMHTMLFooterForTesting(boundary, mhtml_data_);

    if (validate) {
      // Validate the generated MHTML.
      MHTMLParser parser(
          SharedBuffer::Create(mhtml_data_.data(), mhtml_data_.size()));
      EXPECT_FALSE(parser.ParseArchive().IsEmpty())
          << "Generated MHTML is malformed";
    }
  }

  void Serialize(const KURL& url,
                 const String& title,
                 const String& mime,
                 MHTMLArchive::EncodingPolicy encoding_policy) {
    return GenerateMHTMLData(resources_, encoding_policy, url, title, mime,
                             true);
  }

  Vector<char>& mhtml_data() { return mhtml_data_; }

  base::Time mhtml_date() const { return mhtml_date_; }
  const String& mhtml_date_header() const { return mhtml_date_header_; }

  void CheckLoadResult(const KURL url,
                       scoped_refptr<const SharedBuffer> data,
                       MHTMLLoadResult expected_result) {
    // Set up histogram testing (takes snapshot of histogram data).
    base::HistogramTester histogram_tester;

    // Attempt loading the archive and check the returned pointer.
    MHTMLArchive* archive = MHTMLArchive::Create(url, data);
    ASSERT_TRUE(archive);

    EXPECT_EQ(archive->LoadResult(), expected_result);

    // Check that the correct count, and only the correct count, increased.
    histogram_tester.ExpectUniqueSample(
        "PageSerialization.MhtmlLoading.LoadResult", expected_result, 1);
  }

 private:
  scoped_refptr<SharedBuffer> ReadFile(const char* file_name) {
    String file_path = file_path_ + file_name;
    return test::ReadFromFile(file_path);
  }

  String file_path_;
  Vector<SerializedResource> resources_;
  Vector<char> mhtml_data_;
  base::Time mhtml_date_;
  String mhtml_date_header_;
};

TEST_F(MHTMLArchiveTest,
       TestMHTMLHeadersWithTitleContainingAllPrintableCharacters) {
  const char kURL[] = "http://www.example.com/";
  const char kTitle[] = "abc";
  AddTestMainResource();
  Serialize(ToKURL(kURL), String::FromUTF8(kTitle), "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  HashMap<String, String> mhtml_headers = ExtractMHTMLHeaders();

  EXPECT_EQ("<Saved by Blink>", mhtml_headers.find("From")->value);
  EXPECT_FALSE(mhtml_headers.find("Date")->value.IsEmpty());
  EXPECT_EQ(
      "multipart/related;type=\"text/html\";boundary=\"boundary-example\"",
      mhtml_headers.find("Content-Type")->value);
  EXPECT_EQ("abc", mhtml_headers.find("Subject")->value);
  EXPECT_EQ(kURL, mhtml_headers.find("Snapshot-Content-Location")->value);
}

TEST_F(MHTMLArchiveTest,
       TestMHTMLHeadersWithTitleContainingNonPrintableCharacters) {
  const char kURL[] = "http://www.example.com/";
  const char kTitle[] = "abc \t=\xe2\x98\x9d\xf0\x9f\x8f\xbb";
  AddTestMainResource();
  Serialize(ToKURL(kURL), String::FromUTF8(kTitle), "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  HashMap<String, String> mhtml_headers = ExtractMHTMLHeaders();

  EXPECT_EQ("<Saved by Blink>", mhtml_headers.find("From")->value);
  EXPECT_FALSE(mhtml_headers.find("Date")->value.IsEmpty());
  EXPECT_EQ(
      "multipart/related;type=\"text/html\";boundary=\"boundary-example\"",
      mhtml_headers.find("Content-Type")->value);
  EXPECT_EQ("=?utf-8?Q?abc=20=09=3D=E2=98=9D=F0=9F=8F=BB?=",
            mhtml_headers.find("Subject")->value);
  EXPECT_EQ(kURL, mhtml_headers.find("Snapshot-Content-Location")->value);
}

TEST_F(MHTMLArchiveTest,
       TestMHTMLHeadersWithLongTitleContainingNonPrintableCharacters) {
  const char kURL[] = "http://www.example.com/";
  const char kTitle[] =
      "01234567890123456789012345678901234567890123456789"
      "01234567890123456789012345678901234567890123456789"
      " \t=\xe2\x98\x9d\xf0\x9f\x8f\xbb";
  AddTestMainResource();
  Serialize(ToKURL(kURL), String::FromUTF8(kTitle), "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  HashMap<String, String> mhtml_headers = ExtractMHTMLHeaders();

  EXPECT_EQ("<Saved by Blink>", mhtml_headers.find("From")->value);
  EXPECT_FALSE(mhtml_headers.find("Date")->value.IsEmpty());
  EXPECT_EQ(
      "multipart/related;type=\"text/html\";boundary=\"boundary-example\"",
      mhtml_headers.find("Content-Type")->value);
  EXPECT_EQ(
      "=?utf-8?Q?012345678901234567890123456789"
      "012345678901234567890123456789012?="
      "=?utf-8?Q?345678901234567890123456789"
      "0123456789=20=09=3D=E2=98=9D=F0=9F?="
      "=?utf-8?Q?=8F=BB?=",
      mhtml_headers.find("Subject")->value);
  EXPECT_EQ(kURL, mhtml_headers.find("Snapshot-Content-Location")->value);
}

TEST_F(MHTMLArchiveTest, TestMHTMLPartsWithBinaryEncoding) {
  const char kURL[] = "http://www.example.com";
  AddTestResources();
  Serialize(ToKURL(kURL), "Test Serialization", "text/html",
            MHTMLArchive::kUseBinaryEncoding);

  // Read the MHTML data line per line and do some pseudo-parsing to make sure
  // the right encoding is used for the different sections.
  LineReader line_reader(String(mhtml_data().data(), mhtml_data().size()));
  int part_count = 0;
  String line, last_line;
  while (line_reader.GetNextLine(&line)) {
    last_line = line;
    if (line != kEndOfPartBoundary)
      continue;
    part_count++;

    HashMap<String, String> part_headers = ExtractHeaders(line_reader);
    EXPECT_FALSE(part_headers.find("Content-Type")->value.IsEmpty());
    EXPECT_EQ("binary", part_headers.find("Content-Transfer-Encoding")->value);
    EXPECT_FALSE(part_headers.find("Content-Location")->value.IsEmpty());
  }
  EXPECT_EQ(12, part_count);

  // Last line should be the end-of-document boundary.
  EXPECT_EQ(kEndOfDocumentBoundary, last_line);
}

TEST_F(MHTMLArchiveTest, TestMHTMLPartsWithDefaultEncoding) {
  const char kURL[] = "http://www.example.com";
  AddTestResources();
  Serialize(ToKURL(kURL), "Test Serialization", "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  // Read the MHTML data line per line and do some pseudo-parsing to make sure
  // the right encoding is used for the different sections.
  LineReader line_reader(String(mhtml_data().data(), mhtml_data().size()));
  int part_count = 0;
  String line, last_line;
  while (line_reader.GetNextLine(&line)) {
    last_line = line;
    if (line != kEndOfPartBoundary)
      continue;
    part_count++;

    HashMap<String, String> part_headers = ExtractHeaders(line_reader);

    String content_type = part_headers.find("Content-Type")->value;
    EXPECT_FALSE(content_type.IsEmpty());

    String encoding = part_headers.find("Content-Transfer-Encoding")->value;
    EXPECT_FALSE(encoding.IsEmpty());

    if (content_type.StartsWith("text/"))
      EXPECT_EQ("quoted-printable", encoding);
    else if (content_type.StartsWith("image/"))
      EXPECT_EQ("base64", encoding);
    else
      FAIL() << "Unexpected Content-Type: " << content_type;
  }
  EXPECT_EQ(12, part_count);

  // Last line should be the end-of-document boundary.
  EXPECT_EQ(kEndOfDocumentBoundary, last_line);
}

TEST_F(MHTMLArchiveTest, MHTMLFromScheme) {
  const char kURL[] = "http://www.example.com";
  AddTestMainResource();
  Serialize(ToKURL(kURL), "Test Serialization", "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  scoped_refptr<SharedBuffer> data =
      SharedBuffer::Create(mhtml_data().data(), mhtml_data().size());

  // MHTMLArchives can only be initialized from local schemes, http/https
  // schemes, and content scheme(Android specific).
  CheckLoadResult(ToKURL("http://www.example.com"), data.get(),
                  MHTMLLoadResult::kSuccess);

#if defined(OS_ANDROID)
  CheckLoadResult(ToKURL("content://foo"), data.get(),
                  MHTMLLoadResult::kSuccess);
#else
  CheckLoadResult(ToKURL("content://foo"), data.get(),
                  MHTMLLoadResult::kUrlSchemeNotAllowed);
#endif
  CheckLoadResult(ToKURL("file://foo"), data.get(), MHTMLLoadResult::kSuccess);
  CheckLoadResult(ToKURL("fooscheme://bar"), data.get(),
                  MHTMLLoadResult::kUrlSchemeNotAllowed);

  url::ScopedSchemeRegistryForTests scoped_registry;
  url::AddLocalScheme("fooscheme");
  CheckLoadResult(ToKURL("fooscheme://bar"), data.get(),
                  MHTMLLoadResult::kSuccess);
}

TEST_F(MHTMLArchiveTest, MHTMLDate) {
  const char kURL[] = "http://www.example.com";
  AddTestMainResource();
  Serialize(ToKURL(kURL), "Test Serialization", "text/html",
            MHTMLArchive::kUseDefaultEncoding);
  // The serialization process should have added a date header corresponding to
  // mhtml_date().
  HashMap<String, String> mhtml_headers = ExtractMHTMLHeaders();
  ASSERT_EQ(mhtml_date_header(), mhtml_headers.find("Date")->value);

  scoped_refptr<SharedBuffer> data =
      SharedBuffer::Create(mhtml_data().data(), mhtml_data().size());
  KURL http_url = ToKURL("http://www.example.com");
  MHTMLArchive* archive = MHTMLArchive::Create(http_url, data.get());
  ASSERT_NE(nullptr, archive);

  // The deserialization process should have parsed the header into a Date.
  EXPECT_EQ(mhtml_date(), archive->Date());
}

TEST_F(MHTMLArchiveTest, EmptyArchive) {
  // Test failure to load when |data| is null.
  KURL http_url = ToKURL("http://www.example.com");
  CheckLoadResult(http_url, nullptr, MHTMLLoadResult::kEmptyFile);

  // Test failure to load when |data| is non-null but empty.
  const char* buf = "";
  scoped_refptr<SharedBuffer> data =
      SharedBuffer::Create(buf, static_cast<size_t>(0u));
  CheckLoadResult(http_url, data.get(), MHTMLLoadResult::kEmptyFile);
}

TEST_F(MHTMLArchiveTest, NoMainResource) {
  const char kURL[] = "http://www.example.com";
  // Only add a resource to a CSS file, so no main resource is valid for
  // rendering.
  AddResource("http://www.example.com/link_styles.css", "text/css",
              "link_styles.css");
  Serialize(ToKURL(kURL), "Test Serialization", "text/html",
            MHTMLArchive::kUseDefaultEncoding);

  scoped_refptr<SharedBuffer> data =
      SharedBuffer::Create(mhtml_data().data(), mhtml_data().size());
  KURL http_url = ToKURL("http://www.example.com");

  CheckLoadResult(http_url, data.get(), MHTMLLoadResult::kMissingMainResource);
}

TEST_F(MHTMLArchiveTest, InvalidMHTML) {
  const char kURL[] = "http://www.example.com";
  // Intentionally create MHTML data with no resources.
  Vector<SerializedResource> resources;
  GenerateMHTMLData(resources, MHTMLArchive::kUseDefaultEncoding, ToKURL(kURL),
                    "Test invalid mhtml", "text/html", false);

  scoped_refptr<SharedBuffer> data =
      SharedBuffer::Create(mhtml_data().data(), mhtml_data().size());

  CheckLoadResult(ToKURL(kURL), data.get(), MHTMLLoadResult::kInvalidArchive);
}

}  // namespace test

}  // namespace blink