// Aseprite Document Library
// Copyright (c) 2019-2023 Igara Studio S.A.
// Copyright (c) 2001-2016 David Capello
//
// This file is released under the terms of the MIT license.
// Read LICENSE.txt for more information.

#ifdef HAVE_CONFIG_H
  #include "config.h"
#endif

#include "doc/algorithm/shrink_bounds.h"

#include "doc/cel.h"
#include "doc/grid.h"
#include "doc/image.h"
#include "doc/image_impl.h"
#include "doc/layer.h"
#include "doc/layer_tilemap.h"
#include "doc/primitives.h"
#include "doc/primitives_fast.h"
#include "doc/tileset.h"

#include <thread>

namespace doc { namespace algorithm {

namespace {

template<typename ImageTraits>
bool is_same_pixel(color_t pixel1, color_t pixel2)
{
  static_assert(false && sizeof(ImageTraits), "No is_same_pixel impl");
  return false;
}

template<>
bool is_same_pixel<RgbTraits>(color_t pixel1, color_t pixel2)
{
  return (rgba_geta(pixel1) == 0 && rgba_geta(pixel2) == 0) || (pixel1 == pixel2);
}

template<>
bool is_same_pixel<GrayscaleTraits>(color_t pixel1, color_t pixel2)
{
  return (graya_geta(pixel1) == 0 && graya_geta(pixel2) == 0) || (pixel1 == pixel2);
}

template<>
bool is_same_pixel<IndexedTraits>(color_t pixel1, color_t pixel2)
{
  return pixel1 == pixel2;
}

template<>
bool is_same_pixel<BitmapTraits>(color_t pixel1, color_t pixel2)
{
  return pixel1 == pixel2;
}

template<typename ImageTraits>
bool shrink_bounds_left_templ(const Image* image, gfx::Rect& bounds, color_t refpixel, int rowPixels)
{
  int u, v;
  // Shrink left side
  for (u = bounds.x; u < bounds.x2(); ++u) {
    auto ptr = get_pixel_address_fast<ImageTraits>(image, u, v = bounds.y);
    for (; v < bounds.y2(); ++v, ptr += rowPixels) {
      ASSERT(ptr == get_pixel_address_fast<ImageTraits>(image, u, v));
      if (!is_same_pixel<ImageTraits>(*ptr, refpixel))
        return (!bounds.isEmpty());
    }
    ++bounds.x;
    --bounds.w;
  }
  return (!bounds.isEmpty());
}

template<typename ImageTraits>
bool shrink_bounds_right_templ(const Image* image,
                               gfx::Rect& bounds,
                               color_t refpixel,
                               int rowPixels)
{
  int u, v;
  // Shrink right side
  for (u = bounds.x2() - 1; u >= bounds.x; --u) {
    auto ptr = get_pixel_address_fast<ImageTraits>(image, u, v = bounds.y);
    for (; v < bounds.y2(); ++v, ptr += rowPixels) {
      ASSERT(ptr == get_pixel_address_fast<ImageTraits>(image, u, v));
      if (!is_same_pixel<ImageTraits>(*ptr, refpixel))
        return (!bounds.isEmpty());
    }
    --bounds.w;
  }
  return (!bounds.isEmpty());
}

template<typename ImageTraits>
bool shrink_bounds_top_templ(const Image* image, gfx::Rect& bounds, color_t refpixel)
{
  int u, v;
  // Shrink top side
  for (v = bounds.y; v < bounds.y2(); ++v) {
    auto ptr = get_pixel_address_fast<ImageTraits>(image, u = bounds.x, v);
    for (; u < bounds.x2(); ++u, ++ptr) {
      ASSERT(ptr == get_pixel_address_fast<ImageTraits>(image, u, v));
      if (!is_same_pixel<ImageTraits>(*ptr, refpixel))
        return (!bounds.isEmpty());
    }
    ++bounds.y;
    --bounds.h;
  }
  return (!bounds.isEmpty());
}

template<typename ImageTraits>
bool shrink_bounds_bottom_templ(const Image* image, gfx::Rect& bounds, color_t refpixel)
{
  int u, v;
  // Shrink bottom side
  for (v = bounds.y2() - 1; v >= bounds.y; --v) {
    auto ptr = get_pixel_address_fast<ImageTraits>(image, u = bounds.x, v);
    for (; u < bounds.x2(); ++u, ++ptr) {
      ASSERT(ptr == get_pixel_address_fast<ImageTraits>(image, u, v));
      if (!is_same_pixel<ImageTraits>(*ptr, refpixel))
        return (!bounds.isEmpty());
    }
    --bounds.h;
  }
  return (!bounds.isEmpty());
}

template<typename ImageTraits>
bool shrink_bounds_templ(const Image* image, gfx::Rect& bounds, color_t refpixel)
{
  // Pixels per row
  const int rowPixels = image->rowPixels();
  const int canvasSize = image->width() * image->height();
  if ((std::thread::hardware_concurrency() >= 4) &&
      ((image->pixelFormat() == IMAGE_RGB && canvasSize >= 800 * 800) ||
       (image->pixelFormat() != IMAGE_RGB && canvasSize >= 500 * 500))) {
    gfx::Rect leftBounds(bounds), rightBounds(bounds), topBounds(bounds), bottomBounds(bounds);

    // TODO use a base::thread_pool and a base::task for each border

    std::thread left(
      [&] { shrink_bounds_left_templ<ImageTraits>(image, leftBounds, refpixel, rowPixels); });
    std::thread right(
      [&] { shrink_bounds_right_templ<ImageTraits>(image, rightBounds, refpixel, rowPixels); });
    std::thread top([&] { shrink_bounds_top_templ<ImageTraits>(image, topBounds, refpixel); });
    std::thread bottom(
      [&] { shrink_bounds_bottom_templ<ImageTraits>(image, bottomBounds, refpixel); });
    left.join();
    right.join();
    top.join();
    bottom.join();
    bounds = leftBounds;
    bounds &= rightBounds;
    bounds &= topBounds;
    bounds &= bottomBounds;
    return !bounds.isEmpty();
  }
  else {
    return shrink_bounds_left_templ<ImageTraits>(image, bounds, refpixel, rowPixels) &&
           shrink_bounds_right_templ<ImageTraits>(image, bounds, refpixel, rowPixels) &&
           shrink_bounds_top_templ<ImageTraits>(image, bounds, refpixel) &&
           shrink_bounds_bottom_templ<ImageTraits>(image, bounds, refpixel);
  }
}

template<typename ImageTraits>
bool shrink_bounds_templ2(const Image* a, const Image* b, gfx::Rect& bounds)
{
  bool shrink;
  int u, v;

  // Shrink left side
  for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
    shrink = true;
    for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
      if (get_pixel_fast<ImageTraits>(a, u, v) != get_pixel_fast<ImageTraits>(b, u, v)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    ++bounds.x;
    --bounds.w;
  }

  // Shrink right side
  for (u = bounds.x + bounds.w - 1; u >= bounds.x; --u) {
    shrink = true;
    for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
      if (get_pixel_fast<ImageTraits>(a, u, v) != get_pixel_fast<ImageTraits>(b, u, v)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    --bounds.w;
  }

  // Shrink top side
  for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
    shrink = true;
    for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
      if (get_pixel_fast<ImageTraits>(a, u, v) != get_pixel_fast<ImageTraits>(b, u, v)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    ++bounds.y;
    --bounds.h;
  }

  // Shrink bottom side
  for (v = bounds.y + bounds.h - 1; v >= bounds.y; --v) {
    shrink = true;
    for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
      if (get_pixel_fast<ImageTraits>(a, u, v) != get_pixel_fast<ImageTraits>(b, u, v)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    --bounds.h;
  }

  return (!bounds.isEmpty());
}

bool shrink_bounds_tilemap(const Image* image,
                           const color_t refpixel,
                           const Layer* layer,
                           gfx::Rect& bounds)
{
  ASSERT(layer);
  if (!layer)
    return false;

  ASSERT(layer->isTilemap());
  if (!layer->isTilemap())
    return false;

  const Tileset* tileset = static_cast<const LayerTilemap*>(layer)->tileset();

  bool shrink;
  int u, v;

  // Shrink left side
  for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
    shrink = true;
    for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
      const tile_t tile = get_pixel_fast<TilemapTraits>(image, u, v);
      const tile_t tileIndex = tile_geti(tile);
      const ImageRef tileImg = tileset->get(tileIndex);

      if (tileImg && !is_plain_image(tileImg.get(), refpixel)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    ++bounds.x;
    --bounds.w;
  }

  // Shrink right side
  for (u = bounds.x + bounds.w - 1; u >= bounds.x; --u) {
    shrink = true;
    for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
      const tile_t tile = get_pixel_fast<TilemapTraits>(image, u, v);
      const tile_t tileIndex = tile_geti(tile);
      const ImageRef tileImg = tileset->get(tileIndex);

      if (tileImg && !is_plain_image(tileImg.get(), refpixel)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    --bounds.w;
  }

  // Shrink top side
  for (v = bounds.y; v < bounds.y + bounds.h; ++v) {
    shrink = true;
    for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
      const tile_t tile = get_pixel_fast<TilemapTraits>(image, u, v);
      const tile_t tileIndex = tile_geti(tile);
      const ImageRef tileImg = tileset->get(tileIndex);

      if (tileImg && !is_plain_image(tileImg.get(), refpixel)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    ++bounds.y;
    --bounds.h;
  }

  // Shrink bottom side
  for (v = bounds.y + bounds.h - 1; v >= bounds.y; --v) {
    shrink = true;
    for (u = bounds.x; u < bounds.x + bounds.w; ++u) {
      const tile_t tile = get_pixel_fast<TilemapTraits>(image, u, v);
      const tile_t tileIndex = tile_geti(tile);
      const ImageRef tileImg = tileset->get(tileIndex);

      if (tileImg && !is_plain_image(tileImg.get(), refpixel)) {
        shrink = false;
        break;
      }
    }
    if (!shrink)
      break;
    --bounds.h;
  }

  return (!bounds.isEmpty());
}

} // namespace

bool shrink_bounds(const Image* image,
                   const color_t refpixel,
                   const Layer* layer,
                   const gfx::Rect& startBounds,
                   gfx::Rect& bounds)
{
  bounds = (startBounds & image->bounds());
  switch (image->pixelFormat()) {
    case IMAGE_RGB:       return shrink_bounds_templ<RgbTraits>(image, bounds, refpixel);
    case IMAGE_GRAYSCALE: return shrink_bounds_templ<GrayscaleTraits>(image, bounds, refpixel);
    case IMAGE_INDEXED:   return shrink_bounds_templ<IndexedTraits>(image, bounds, refpixel);
    case IMAGE_BITMAP:    return shrink_bounds_templ<BitmapTraits>(image, bounds, refpixel);
    case IMAGE_TILEMAP:   return shrink_bounds_tilemap(image, refpixel, layer, bounds);
  }
  ASSERT(false);
  bounds = startBounds;
  return true;
}

bool shrink_bounds(const Image* image, const color_t refpixel, const Layer* layer, gfx::Rect& bounds)
{
  return shrink_bounds(image, refpixel, layer, image->bounds(), bounds);
}

bool shrink_cel_bounds(const Cel* cel, const color_t refpixel, gfx::Rect& bounds)
{
  if (shrink_bounds(cel->image(), refpixel, cel->layer(), bounds)) {
    // For tilemaps, we have to convert imgBounds (in tiles
    // coordinates) to canvas coordinates using the Grid specs.
    if (cel->layer()->isTilemap()) {
      doc::LayerTilemap* tilemapLayer = static_cast<doc::LayerTilemap*>(cel->layer());
      doc::Tileset* tileset = tilemapLayer->tileset();
      doc::Grid grid = tileset->grid();
      grid.origin(grid.origin() + cel->position());
      bounds = grid.tileToCanvas(bounds);
    }
    else {
      bounds.offset(cel->position());
    }
    return true;
  }
  else {
    return false;
  }
}

bool shrink_bounds2(const Image* a, const Image* b, const gfx::Rect& startBounds, gfx::Rect& bounds)
{
  ASSERT(a && b);
  ASSERT(a->bounds() == b->bounds());

  bounds = (startBounds & a->bounds());

  switch (a->pixelFormat()) {
    case IMAGE_RGB:       return shrink_bounds_templ2<RgbTraits>(a, b, bounds);
    case IMAGE_GRAYSCALE: return shrink_bounds_templ2<GrayscaleTraits>(a, b, bounds);
    case IMAGE_INDEXED:   return shrink_bounds_templ2<IndexedTraits>(a, b, bounds);
    case IMAGE_BITMAP:    return shrink_bounds_templ2<BitmapTraits>(a, b, bounds);
    case IMAGE_TILEMAP:   return shrink_bounds_templ2<TilemapTraits>(a, b, bounds);
  }
  ASSERT(false);
  return false;
}

}} // namespace doc::algorithm
