/*
MIT License
Copyright (c) 2024 - 2025 René Amthor (tobid7)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
 */

#include <3ds.h>
#include <pd/external/stb_truetype.h>

#include <pd/core/io.hpp>
#include <pd/core/strings.hpp>
#include <pd/core/sys.hpp>
#include <pd/lithium/font.hpp>

namespace PD {
namespace LI {
void Font::LoadTTF(const std::string& path, int height) {
  sysfont = false;
  TT::Scope st("LI_LoadTTF_" + path);
  pixel_height = height;
  int quad = height * 16;
  stbtt_fontinfo inf;
  std::ifstream loader(path, std::ios::binary);
  if (!loader.is_open()) return;
  loader.seekg(0, std::ios::end);
  size_t len = loader.tellg();
  loader.seekg(0, std::ios::beg);
  unsigned char* buffer = new unsigned char[len];
  loader.read(reinterpret_cast<char*>(buffer), len);
  loader.close();
  stbtt_InitFont(&inf, buffer, 0);
  std::vector<unsigned char> font_tex(quad * quad);
  float scale = stbtt_ScaleForPixelHeight(&inf, pixel_height);

  int ascent, descent, lineGap;
  stbtt_GetFontVMetrics(&inf, &ascent, &descent, &lineGap);
  int baseline = static_cast<int>(ascent * scale);

  std::map<u32, int> buf_cache;

  auto tex = Texture::New();
  vec2 off;
  for (u32 ii = 0x0000; ii < 0xFFFF; ii++) {
    int i = stbtt_FindGlyphIndex(&inf, ii);
    if (i == 0) {
      continue;
    }
    if (stbtt_IsGlyphEmpty(&inf, i)) {
      continue;
    }

    Codepoint c;
    int w = 0, h = 0, xo = 0, yo = 0;
    unsigned char* bitmap =
        stbtt_GetCodepointBitmap(&inf, scale, scale, i, &w, &h, &xo, &yo);
    int x0, y0, x1, y1;
    stbtt_GetCodepointBitmapBox(&inf, i, scale, scale, &x0, &y0, &x1, &y1);

    u32 hashed_map = IO::HashMemory(std::vector<u8>(bitmap, bitmap + (w * h)));
    if (buf_cache.find(hashed_map) != buf_cache.end()) {
      c = GetCodepoint(buf_cache[hashed_map]);
      c.cp(i);
      cpmap[i] = c;
      free(bitmap);
      continue;
    } else {
      buf_cache[hashed_map] = i;
    }

    if (off[0] + w > quad) {
      off[1] += pixel_height;
      off[0] = 0;
    }

    vec4 uvs;
    uvs[0] = static_cast<float>(off.x() / (float)quad);
    uvs[1] = static_cast<float>(1.f - (off.y() / (float)quad));
    uvs[2] = static_cast<float>((float)(off.x() + w) / (float)quad);
    uvs[3] = static_cast<float>(1.f - (float)(off.y() + h) / (float)quad);
    c.uv(uvs);

    c.tex(tex);
    c.size(vec2(w, h));
    c.off(baseline + yo);

    for (int y = 0; y < h; ++y) {
      for (int x = 0; x < w; ++x) {
        int map_pos = ((off[1] + y) * quad + (off[0] + x));
        font_tex[map_pos] = bitmap[x + y * w];
      }
    }

    free(bitmap);
    cpmap[i] = c;

    // Small Patch to avoid some possible artifacts
    off[0] += w + 1;
    if (off[0] + w > quad) {
      off[1] += pixel_height;
      if (off[1] + pixel_height > quad) {
        break;
      }
      off[0] = 0;
    }
  }
  tex->LoadPixels(font_tex, quad, quad, Texture::A8, Texture::LINEAR);
  textures.push_back(tex);
}

Font::Codepoint& Font::GetCodepoint(u32 cp) {
  auto res = cpmap.find(cp);
  if (res == cpmap.end()) {
    static Codepoint invalid;
    return invalid.invalid(true);
  }
  return res->second;
}

void Font::LoadSystemFont() {
  TT::Scope st("LI_SystemFont");
  sysfont = true;
  fontEnsureMapped();
  const auto fnt = fontGetSystemFont();
  const auto fnt_info = fontGetInfo(fnt);
  const auto glyph_info = fontGetGlyphInfo(fnt);
  this->textures.resize(glyph_info->nSheets + 1);
  /// Modify the Pixel Height by 1.1f to fit the
  /// Size og ttf font Rendering
  pixel_height = glyph_info->cellHeight * 1.1f;
  for (size_t i = 0; i < glyph_info->nSheets; i++) {
    auto stex = Texture::New();
    auto tx = new C3D_Tex;
    tx->data = fontGetGlyphSheetTex(fnt, i);
    tx->fmt = (GPU_TEXCOLOR)glyph_info->sheetFmt;
    tx->size = glyph_info->sheetSize;
    tx->width = glyph_info->sheetWidth;
    tx->height = glyph_info->sheetHeight;
    tx->param = GPU_TEXTURE_MAG_FILTER(GPU_LINEAR) |
                GPU_TEXTURE_MIN_FILTER(GPU_LINEAR) |
                GPU_TEXTURE_WRAP_S(GPU_REPEAT) | GPU_TEXTURE_WRAP_T(GPU_REPEAT);
    tx->border = 0xffffffff;
    tx->lodParam = 0;
    stex->LoadExternal(tx, vec2(tx->width, tx->height), vec4(0, 1, 1, 0));
    stex->AutoUnLoad(false);
    textures[i] = stex;
  }
  std::vector<unsigned int> charSet;
  for (auto cmap = fnt_info->cmap; cmap; cmap = cmap->next) {
    if (cmap->mappingMethod == CMAP_TYPE_DIRECT) {
      if (cmap->codeEnd >= cmap->codeBegin) {
        charSet.reserve(charSet.size() + cmap->codeEnd - cmap->codeBegin + 1);
        for (auto i = cmap->codeBegin; i <= cmap->codeEnd; ++i) {
          if (cmap->indexOffset + (i - cmap->codeBegin) == 0xFFFF) break;
          charSet.emplace_back(i);
        }
      }
    } else if (cmap->mappingMethod == CMAP_TYPE_TABLE) {
      if (cmap->codeEnd >= cmap->codeBegin) {
        charSet.reserve(charSet.size() + cmap->codeEnd - cmap->codeBegin + 1);
        for (auto i = cmap->codeBegin; i <= cmap->codeEnd; ++i) {
          if (cmap->indexTable[i - cmap->codeBegin] == 0xFFFF) continue;
          charSet.emplace_back(i);
        }
      }
    } else if (cmap->mappingMethod == CMAP_TYPE_SCAN) {
      charSet.reserve(charSet.size() + cmap->nScanEntries);
      for (unsigned i = 0; i < cmap->nScanEntries; ++i) {
        if (cmap->scanEntries[i].code >= cmap->codeBegin &&
            cmap->scanEntries[i].code <= cmap->codeEnd) {
          if (cmap->scanEntries[i].glyphIndex != 0xFFFF) {
            charSet.emplace_back(cmap->scanEntries[i].code);
          }
        }
      }
    } else {
      continue;
    }
  }

  std::sort(charSet.begin(), charSet.end());
  charSet.erase(std::unique(charSet.begin(), charSet.end()));

  for (auto cp : charSet) {
    int gidx = fontGlyphIndexFromCodePoint(fnt, cp);
    if (gidx >= 0xFFFF) continue;
    Codepoint codepoint;
    fontGlyphPos_s dat;
    fontCalcGlyphPos(&dat, fnt, gidx, GLYPH_POS_CALC_VTXCOORD, 1.f, 1.f);

    codepoint.cp(cp);
    codepoint.uv(vec4(dat.texcoord.left, dat.texcoord.top, dat.texcoord.right,
                      dat.texcoord.bottom));

    if (dat.sheetIndex < (int)textures.size()) {
      codepoint.tex(textures[dat.sheetIndex]);
    } else {
      codepoint.invalid(true);
    }
    codepoint.size(vec2(dat.vtxcoord.right, dat.vtxcoord.bottom));
    codepoint.off(0);
    cpmap[cp] = codepoint;
  }
}
}  // namespace LI
}  // namespace PD