// 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 <iterator>
#include <memory>
#include <utility>

#include "core/fxcrt/compiler_specific.h"
#include "core/fxcrt/fx_coordinates.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxge/dib/cfx_dibitmap.h"
#include "core/fxge/dib/fx_dib.h"
#include "testing/fuzzers/pdfium_fuzzer_util.h"

namespace {

// Some unused formats were removed, and their slots have been filled in
// `FXDIB_Format::kInvalid` to keep the fuzzer input stable.
constexpr FXDIB_Format kFormat[] = {
    FXDIB_Format::kInvalid,
    FXDIB_Format::k1bppRgb,
    FXDIB_Format::k8bppRgb,
    FXDIB_Format::kBgr,
    FXDIB_Format::kBgrx,
    FXDIB_Format::k1bppMask,
    FXDIB_Format::k8bppMask,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::k8bppRgba */,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::kBgra */,
    FXDIB_Format::kBgra,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::k1bppCmyk */,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::k8bppCmyk */,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::kCmyk */,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::k8bppCmyka */,
    FXDIB_Format::kInvalid /* Was FXDIB_Format::kCmyka */};

}  // namespace

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
  static constexpr size_t kParameterSize = 33;
  if (size < kParameterSize) {
    return 0;
  }

  UNSAFE_TODO({
    int width = GetInteger(data);
    int height = GetInteger(data + 4);
    uint32_t argb = GetInteger(data + 8);
    int src_left = GetInteger(data + 12);
    int src_top = GetInteger(data + 16);
    int dest_left = GetInteger(data + 20);
    int dest_top = GetInteger(data + 24);

    BlendMode blend_mode = static_cast<BlendMode>(
        data[28] % (static_cast<int>(BlendMode::kLast) + 1));
    FXDIB_Format dest_format = kFormat[data[29] % std::size(kFormat)];
    FXDIB_Format src_format = kFormat[data[30] % std::size(kFormat)];
    bool is_clip = !(data[31] % 2);
    bool is_rgb_byte_order = !(data[32] % 2);
    size -= kParameterSize;
    data += kParameterSize;

    static constexpr uint32_t kMemLimit = 128'000'000;
    static constexpr uint32_t kComponents = 4;
    FX_SAFE_UINT32 mem = width;
    mem *= height;
    mem *= kComponents;
    if (!mem.IsValid() || mem.ValueOrDie() > kMemLimit) {
      return 0;
    }

    auto src_bitmap = pdfium::MakeRetain<CFX_DIBitmap>();
    auto dest_bitmap = pdfium::MakeRetain<CFX_DIBitmap>();
    if (!src_bitmap->Create(width, height, src_format) ||
        !dest_bitmap->Create(width, height, dest_format)) {
      return 0;
    }
    if (src_bitmap->GetBuffer().empty() || dest_bitmap->GetBuffer().empty()) {
      return 0;
    }

    FX_RECT clip_rect(0, 0, width, height);
    if (src_bitmap->IsMaskFormat()) {
      dest_bitmap->CompositeMask(dest_left, dest_top, width, height,
                                 std::move(src_bitmap), argb, src_left, src_top,
                                 blend_mode, is_clip ? &clip_rect : nullptr,
                                 nullptr, is_rgb_byte_order);
    } else {
      dest_bitmap->CompositeBitmap(dest_left, dest_top, width, height,
                                   std::move(src_bitmap), src_left, src_top,
                                   blend_mode, is_clip ? &clip_rect : nullptr,
                                   nullptr, is_rgb_byte_order);
    }
    return 0;
  });
}