// Copyright 2019 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "core/fxcrt/byteorder.h"

#include "core/fxcrt/fx_system.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

constexpr uint32_t kTestValues32[] = {
    0x0,      0x1,        0x2,        0x3,        0x4,       0xfe,
    0xff,     0x100,      0x101,      0xffff,     0x10000,   0x123456,
    0x345167, 0x2f3e4a5b, 0xff000000, 0xfffffffe, 0xffffffff};

}  // namespace

namespace fxcrt {

TEST(ByteOrder, ByteSwapToLE16) {
  // Since there are so few values, test them all.
  for (uint32_t v = 0; v < 0x10000; ++v) {
    const uint16_t v16 = v;
    uint16_t expected =
        FXSYS_UINT16_GET_LSBFIRST(reinterpret_cast<const uint8_t*>(&v16));
    EXPECT_EQ(expected, ByteSwapToLE16(v16)) << v;

    // Check safety against unexpectedly signed bytes.
    expected = FXSYS_UINT16_GET_LSBFIRST(reinterpret_cast<const int8_t*>(&v16));
    EXPECT_EQ(expected, ByteSwapToLE16(v16)) << v;
  }
}

TEST(ByteOrder, ByteSwapToLE32) {
  for (uint32_t v : kTestValues32) {
    uint32_t expected =
        FXSYS_UINT32_GET_LSBFIRST(reinterpret_cast<const uint8_t*>(&v));
    EXPECT_EQ(expected, ByteSwapToLE32(v)) << v;

    // Check safety against unexpectedly signed bytes.
    expected = FXSYS_UINT32_GET_LSBFIRST(reinterpret_cast<const int8_t*>(&v));
    EXPECT_EQ(expected, ByteSwapToLE32(v)) << v;
  }
}

TEST(ByteOrder, ByteSwapToBE16) {
  // Since there are so few values, test them all.
  for (uint32_t v = 0; v < 0x10000; ++v) {
    const uint16_t v16 = v;
    uint16_t expected =
        FXSYS_UINT16_GET_MSBFIRST(reinterpret_cast<const uint8_t*>(&v16));
    EXPECT_EQ(expected, ByteSwapToBE16(v16)) << v;

    // Check safety against unexpectedly signed bytes.
    expected = FXSYS_UINT16_GET_MSBFIRST(reinterpret_cast<const int8_t*>(&v16));
    EXPECT_EQ(expected, ByteSwapToBE16(v16)) << v;
  }
}

TEST(ByteOrder, ByteSwapToBE32) {
  for (uint32_t v : kTestValues32) {
    uint32_t expected =
        FXSYS_UINT32_GET_MSBFIRST(reinterpret_cast<const uint8_t*>(&v));
    EXPECT_EQ(expected, ByteSwapToBE32(v)) << v;

    // Check safety against unexpectedly signed bytes.
    expected = FXSYS_UINT32_GET_MSBFIRST(reinterpret_cast<const int8_t*>(&v));
    EXPECT_EQ(expected, ByteSwapToBE32(v)) << v;
  }
}

}  // namespace fxcrt