// Aseprite
// Copyright (C) 2022  Igara Studio S.A.
// Copyright (C) 2001-2018  David Capello
//
// This program is distributed under the terms of
// the End-User License Agreement for Aseprite.

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

#include "app/modules/palettes.h"

#include "app/app.h"
#include "app/extensions.h"
#include "app/file/palette_file.h"
#include "app/resource_finder.h"
#include "base/fs.h"
#include "doc/image.h"
#include "doc/palette.h"
#include "doc/sprite.h"

#include <cstring>

namespace app {

// The default color palette.
static Palette* ase_default_palette = NULL;

// Palette in current sprite frame.
static Palette* ase_current_palette = NULL;

int init_module_palette()
{
  ase_default_palette = new Palette(frame_t(0), 256);
  ase_current_palette = new Palette(frame_t(0), 256);
  return 0;
}

void exit_module_palette()
{
  delete ase_default_palette;
  delete ase_current_palette;
}

void load_default_palette()
{
  std::unique_ptr<Palette> pal;
  std::string defaultPalName = get_preset_palette_filename(
    get_default_palette_preset_name(), ".ase");

  // If there is no palette in command line, we use the default one.
  std::string palFile = defaultPalName;
  if (base::is_file(palFile)) {
    pal.reset(load_palette(palFile.c_str()));
  }
  else {
    // Migrate old default.gpl to default.ase format
    palFile = get_preset_palette_filename(
      get_default_palette_preset_name(), ".gpl");

    if (base::is_file(palFile)) {
      pal.reset(load_palette(palFile.c_str()));

      // Remove duplicate black entries at the end (as old palettes
      // contains 256 colors)
      if (pal && pal->size() == 256) {
        doc::color_t black = rgba(0, 0, 0, 255);

        // Get the last non-black entry
        int i = 0;
        for (i=pal->size()-1; i>0; --i) {
          if (pal->getEntry(i) != black)
            break;
        }

        if (i < pal->size()-1) {
          // Check if there is a black entry in the first entries.
          bool hasBlack = false;
          for (int j=0; j<i; ++j) {
            if (pal->getEntry(j) == black) {
              hasBlack = true;
              break;
            }
          }
          if (!hasBlack)
            ++i;                // Leave one black entry

          // Resize the palette
          if (i < pal->size()-1)
            pal->resize(i+1);
        }
      }

      // We could remove the old .gpl file (palFile), but as the
      // user could be using multiple versions of Aseprite, it's a
      // good idea to keep both formats (.gpl for Aseprite <=
      // v1.1-beta5, and .ase for future versions).
    }
    // If the default palette file doesn't exist, we copy db32.gpl
    // as the default one (default.ase).
    else {
      std::string path = App::instance()->extensions().palettePath("DB32");
      if (path.empty())
        path = App::instance()->extensions().palettePath("VGA 13h");
      if (!path.empty())
        pal.reset(load_palette(path.c_str()));
    }

    // Save default.ase file
    if (pal) {
      palFile = defaultPalName;
      save_palette(palFile.c_str(), pal.get(), 0, nullptr);
    }
  }

  if (pal)
    set_default_palette(pal.get());

  set_current_palette(nullptr, true);
}

// TODO This palette isn't synced with the current sprite palette when
//      ENABLE_UI=0 and we are running scripts, we should remove this
//      function and use the active Site palette.
Palette* get_current_palette()
{
  return ase_current_palette;
}

Palette* get_default_palette()
{
  return ase_default_palette;
}

void set_default_palette(const Palette* palette)
{
  palette->copyColorsTo(ase_default_palette);
}

// Changes the current system palette and triggers the
// App::PaletteChange signal.
//
// If "_palette" is nullptr the default palette is set.
bool set_current_palette(const Palette *_palette, bool forced)
{
  const Palette* palette = (_palette ? _palette: ase_default_palette);
  bool ret = false;

  // Have changes
  if (forced ||
      palette->countDiff(ase_current_palette, NULL, NULL) > 0) {
    // Copy current palette
    palette->copyColorsTo(ase_current_palette);

    // Call slots in signals
    App::instance()->PaletteChange();

    ret = true;
  }

  return ret;
}

std::string get_preset_palette_filename(const std::string& preset,
                                        const std::string& dot_extension)
{
  std::string palettesDir = get_preset_palettes_dir();

  return base::join_path(palettesDir, preset + dot_extension);
}

std::string get_default_palette_preset_name()
{
  return "default";
}

std::string get_preset_palettes_dir()
{
  ResourceFinder rf;
  rf.includeUserDir(base::join_path("palettes", ".").c_str());
  std::string palettesDir = rf.getFirstOrCreateDefault();

  if (!base::is_directory(palettesDir))
    base::make_directory(palettesDir);

  return palettesDir;
}

} // namespace app
