// Copyright 2016 PDFium 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 "core/fpdfapi/parser/cpdf_seekablemultistream.h"

#include <utility>
#include <vector>

#include "core/fpdfapi/parser/cpdf_dictionary.h"
#include "core/fpdfapi/parser/cpdf_stream.h"
#include "testing/gtest/include/gtest/gtest.h"

TEST(CPDFSeekableMultiStreamTest, NoStreams) {
  std::vector<RetainPtr<const CPDF_Stream>> streams;
  auto fileread =
      pdfium::MakeRetain<CPDF_SeekableMultiStream>(std::move(streams));

  uint8_t output_buffer[16];
  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_FALSE(fileread->ReadBlockAtOffset(output_buffer, 0, 0));
  EXPECT_EQ(0xbd, output_buffer[0]);
}

TEST(CXFAFileReadTest, EmptyStreams) {
  std::vector<RetainPtr<const CPDF_Stream>> streams;
  streams.push_back(pdfium::MakeRetain<CPDF_Stream>());
  auto fileread =
      pdfium::MakeRetain<CPDF_SeekableMultiStream>(std::move(streams));

  uint8_t output_buffer[16];
  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_FALSE(fileread->ReadBlockAtOffset(output_buffer, 0, 0));
  EXPECT_EQ(0xbd, output_buffer[0]);
}

TEST(CXFAFileReadTest, NormalStreams) {
  // 16 chars total.
  auto stream1 =
      pdfium::MakeRetain<CPDF_Stream>(ByteStringView("one t").raw_span(),
                                      pdfium::MakeRetain<CPDF_Dictionary>());
  auto stream2 = pdfium::MakeRetain<CPDF_Stream>(
      ByteStringView("wo ").raw_span(), pdfium::MakeRetain<CPDF_Dictionary>());
  auto stream3 =
      pdfium::MakeRetain<CPDF_Stream>(ByteStringView("three!!!").raw_span(),
                                      pdfium::MakeRetain<CPDF_Dictionary>());

  std::vector<RetainPtr<const CPDF_Stream>> streams;
  streams.push_back(std::move(stream1));
  streams.push_back(std::move(stream2));
  streams.push_back(std::move(stream3));
  auto fileread =
      pdfium::MakeRetain<CPDF_SeekableMultiStream>(std::move(streams));

  uint8_t output_buffer[16];
  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_TRUE(fileread->ReadBlockAtOffset(output_buffer, 0, 0));
  EXPECT_EQ(0xbd, output_buffer[0]);

  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_TRUE(fileread->ReadBlockAtOffset(output_buffer, 1, 0));
  EXPECT_EQ(0xbd, output_buffer[0]);

  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_TRUE(fileread->ReadBlockAtOffset(output_buffer, 0, 1));
  EXPECT_EQ(0, memcmp(output_buffer, "o", 1));
  EXPECT_EQ(0xbd, output_buffer[1]);

  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_TRUE(
      fileread->ReadBlockAtOffset(output_buffer, 0, sizeof(output_buffer)));
  EXPECT_EQ(0, memcmp(output_buffer, "one two three!!!", 16));

  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_TRUE(fileread->ReadBlockAtOffset(output_buffer, 2, 10));
  EXPECT_EQ(0, memcmp(output_buffer, "e two thre", 10));
  EXPECT_EQ(0xbd, output_buffer[11]);

  memset(output_buffer, 0xbd, sizeof(output_buffer));
  EXPECT_FALSE(
      fileread->ReadBlockAtOffset(output_buffer, 1, sizeof(output_buffer)));
  EXPECT_EQ(0, memcmp(output_buffer, "ne two three!!!", 15));
  EXPECT_EQ(0xbd, output_buffer[15]);
}