/*
 * Copyright 2023 Rive
 */

#include "rive/decoders/bitmap_decoder.hpp"

#ifdef __APPLE__
#include "rive/rive_types.hpp"
#include "rive/math/math_types.hpp"
#include "rive/core/type_conversions.hpp"
#include "utils/auto_cf.hpp"

#include <TargetConditionals.h>

#if TARGET_OS_IPHONE
#include <CoreGraphics/CoreGraphics.h>
#include <ImageIO/ImageIO.h>
#elif TARGET_OS_MAC
#include <ApplicationServices/ApplicationServices.h>
#endif
#endif

#include <stdio.h>
#include <string.h>
#include <vector>

#ifdef RIVE_PNG
std::unique_ptr<Bitmap> DecodePng(const uint8_t bytes[], size_t byteCount);
#endif
#ifdef RIVE_JPEG
std::unique_ptr<Bitmap> DecodeJpeg(const uint8_t bytes[], size_t byteCount);
#endif
#ifdef RIVE_WEBP
std::unique_ptr<Bitmap> DecodeWebP(const uint8_t bytes[], size_t byteCount);
#endif

static Bitmap::ImageFormat _formats[] = {
    {
        "png",
        Bitmap::ImageType::png,
        {0x89, 0x50, 0x4E, 0x47},
#ifdef RIVE_PNG
        DecodePng,
#else
        nullptr,
#endif
    },
    {
        "jpeg",
        Bitmap::ImageType::jpeg,
        {0xFF, 0xD8, 0xFF},
#ifdef RIVE_JPEG
        DecodeJpeg,
#else
        nullptr,
#endif
    },
    {
        "webp",
        Bitmap::ImageType::webp,
        {0x52, 0x49, 0x46},
#ifdef RIVE_WEBP
        DecodeWebP,
#else
        nullptr,
#endif
    },
};

const Bitmap::ImageFormat* Bitmap::RecognizeImageFormat(
    const uint8_t bytes[],
    size_t byteCount)
{
  for (const ImageFormat& format : _formats)
  {
    auto& fingerprint = format.fingerprint;

    // Immediately discard decoders with fingerprints that are longer than
    // the file buffer.
    if (format.fingerprint.size() > byteCount)
    {
      continue;
    }

    // If the fingerprint doesn't match, discrd this decoder. These are all
    // bytes so .size() is fine here.
    if (memcmp(fingerprint.data(), bytes, fingerprint.size()) != 0)
    {
      continue;
    }

    return &format;
  }
  return nullptr;
}

#ifdef __APPLE__
// Represents raw, premultiplied, RGBA image data with tightly packed rows
// (width * 4 bytes).
struct PlatformCGImage
{
  uint32_t width = 0;
  uint32_t height = 0;
  bool opaque = false;
  std::unique_ptr<uint8_t[]> pixels;
};

bool cg_image_decode(
    const uint8_t* encodedBytes,
    size_t encodedSizeInBytes,
    PlatformCGImage* platformImage)
{
  AutoCF data = CFDataCreate(
      kCFAllocatorDefault,
      encodedBytes,
      encodedSizeInBytes);
  if (!data)
  {
    return false;
  }

  AutoCF source = CGImageSourceCreateWithData(data, nullptr);
  if (!source)
  {
    return false;
  }

  AutoCF image = CGImageSourceCreateImageAtIndex(source, 0, nullptr);
  if (!image)
  {
    return false;
  }

  bool isOpaque = false;
  switch (CGImageGetAlphaInfo(image.get()))
  {
    case kCGImageAlphaNone:
    case kCGImageAlphaNoneSkipFirst:
    case kCGImageAlphaNoneSkipLast:
      isOpaque = true;
      break;
    default:
      break;
  }

  const size_t width = CGImageGetWidth(image);
  const size_t height = CGImageGetHeight(image);
  const size_t rowBytes = width * 4; // 4 bytes per pixel
  const size_t size = rowBytes * height;

  const size_t bitsPerComponent = 8;
  CGBitmapInfo cgInfo = kCGBitmapByteOrder32Big; // rgba
  if (isOpaque)
  {
    cgInfo |= kCGImageAlphaNoneSkipLast;
  }
  else
  {
    cgInfo |= kCGImageAlphaPremultipliedLast;
  }

  std::unique_ptr<uint8_t[]> pixels(new uint8_t[size]);

  AutoCF cs = CGColorSpaceCreateDeviceRGB();
  AutoCF cg = CGBitmapContextCreate(
      pixels.get(),
      width,
      height,
      bitsPerComponent,
      rowBytes,
      cs,
      cgInfo);
  if (!cg)
  {
    return false;
  }

  CGContextSetBlendMode(cg, kCGBlendModeCopy);
  CGContextDrawImage(cg, CGRectMake(0, 0, width, height), image);

  platformImage->width = rive::castTo<uint32_t>(width);
  platformImage->height = rive::castTo<uint32_t>(height);
  platformImage->opaque = isOpaque;
  platformImage->pixels = std::move(pixels);

  return true;
}

std::unique_ptr<Bitmap> Bitmap::decode(const uint8_t bytes[], size_t byteCount)
{
  PlatformCGImage image;
  if (!cg_image_decode(bytes, byteCount, &image))
  {
#if defined RIVE_APPLETVOS || defined RIVE_APPLETVOS_SIMULATOR
    const Bitmap::ImageFormat* format = Bitmap::RecognizeImageFormat(
        bytes,
        byteCount);
    if (format != nullptr)
    {
      auto bitmap = format->decodeImage != nullptr
                        ? format->decodeImage(bytes, byteCount)
                        : nullptr;
      return bitmap;
    }
#endif
    return nullptr;
  }

  return std::make_unique<Bitmap>(
      image.width,
      image.height,
      image.width * image.height * 4,
      // CG always premultiplies alpha.
      PixelFormat::RGBAPremul,
      std::move(image.pixels));
}
#else
std::unique_ptr<Bitmap> Bitmap::decode(const uint8_t bytes[], size_t byteCount)
{
  const ImageFormat* format = RecognizeImageFormat(bytes, byteCount);
  if (format != nullptr)
  {
    auto bitmap = format->decodeImage != nullptr
                      ? format->decodeImage(bytes, byteCount)
                      : nullptr;
    if (!bitmap)
    {
      fprintf(
          stderr,
          "Bitmap::decode - failed to decode a %s.\n",
          format->name);
    }
    return bitmap;
  }
  return nullptr;
}
#endif