#include <png.h>
#include <squish.h>
#include "TXTR.hpp"
#include "PAK.hpp"
#include "athena/FileWriter.hpp"
#include "hecl/hecl.hpp"

namespace DataSpec {

static logvisor::Module Log("libpng");

static int CountBits(uint32_t n) {
  int ret = 0;
  for (int i = 0; i < 32; ++i)
    if (((n >> i) & 1) != 0)
      ++ret;
  return ret;
}

/* Box filter algorithm (for mipmapping) */
static void BoxFilter(const uint8_t* input, unsigned chanCount, unsigned inWidth, unsigned inHeight, uint8_t* output,
                      bool dxt1) {
  unsigned mipWidth = 1;
  unsigned mipHeight = 1;
  if (inWidth > 1)
    mipWidth = inWidth / 2;
  if (inHeight > 1)
    mipHeight = inHeight / 2;

  unsigned y, x, c;
  for (y = 0; y < mipHeight; ++y) {
    unsigned miplineBase = mipWidth * y;
    unsigned in1LineBase = inWidth * (y * 2);
    unsigned in2LineBase = inWidth * (y * 2 + 1);
    for (x = 0; x < mipWidth; ++x) {
      uint8_t* out = &output[(miplineBase + x) * chanCount];
      for (c = 0; c < chanCount; ++c) {
        uint32_t tmp = 0;
        tmp += input[(in1LineBase + (x * 2)) * chanCount + c];
        tmp += input[(in1LineBase + (x * 2 + 1)) * chanCount + c];
        tmp += input[(in2LineBase + (x * 2)) * chanCount + c];
        tmp += input[(in2LineBase + (x * 2 + 1)) * chanCount + c];
        out[c] = uint8_t(tmp / 4);
        if (c == 3 && dxt1)
          out[c] = uint8_t(out[c] ? 0xff : 0x0);
      }
    }
  }
}

static size_t ComputeMippedTexelCount(unsigned inWidth, unsigned inHeight) {
  size_t ret = 0;
  while (inWidth > 0 && inHeight > 0) {
    ret += inWidth * inHeight;
    inWidth /= 2;
    inHeight /= 2;
  }
  return ret;
}

/* GX uses this upsampling technique to extract full 8-bit range */
constexpr uint8_t Convert3To8(uint8_t v) {
  /* Swizzle bits: 00000123 -> 12312312 */
  return (v << 5) | (v << 2) | (v >> 1);
}

constexpr uint8_t Convert8To3(uint8_t v) { return v >> 5; }

constexpr uint8_t Convert4To8(uint8_t v) {
  /* Swizzle bits: 00001234 -> 12341234 */
  return (v << 4) | v;
}

constexpr uint8_t Convert8To4(uint8_t v) { return v >> 4; }

constexpr uint8_t Convert5To8(uint8_t v) {
  /* Swizzle bits: 00012345 -> 12345123 */
  return (v << 3) | (v >> 2);
}

constexpr uint8_t Convert8To5(uint8_t v) { return v >> 3; }

constexpr uint8_t Convert6To8(uint8_t v) {
  /* Swizzle bits: 00123456 -> 12345612 */
  return (v << 2) | (v >> 4);
}

constexpr uint8_t Convert8To6(uint8_t v) { return v >> 2; }

static uint8_t Lookup4BPP(const uint8_t* texels, int width, int x, int y) {
  int bwidth = (width + 7) / 8;
  int bx = x / 8;
  int by = y / 8;
  int rx = x % 8;
  int ry = y % 8;
  int bidx = by * bwidth + bx;
  const uint8_t* btexels = &texels[32 * bidx];
  return btexels[ry * 4 + rx / 2] >> ((rx & 1) ? 0 : 4) & 0xf;
}

static void Set4BPP(uint8_t* texels, int width, int x, int y, uint8_t val) {
  int bwidth = (width + 7) / 8;
  int bx = x / 8;
  int by = y / 8;
  int rx = x % 8;
  int ry = y % 8;
  int bidx = by * bwidth + bx;
  uint8_t* btexels = &texels[32 * bidx];
  btexels[ry * 4 + rx / 2] |= (val & 0xf) << ((rx & 1) ? 0 : 4);
}

static uint8_t Lookup8BPP(const uint8_t* texels, int width, int x, int y) {
  int bwidth = (width + 7) / 8;
  int bx = x / 8;
  int by = y / 4;
  int rx = x % 8;
  int ry = y % 4;
  int bidx = by * bwidth + bx;
  const uint8_t* btexels = &texels[32 * bidx];
  return btexels[ry * 8 + rx];
}

static void Set8BPP(uint8_t* texels, int width, int x, int y, uint8_t val) {
  int bwidth = (width + 7) / 8;
  int bx = x / 8;
  int by = y / 4;
  int rx = x % 8;
  int ry = y % 4;
  int bidx = by * bwidth + bx;
  uint8_t* btexels = &texels[32 * bidx];
  btexels[ry * 8 + rx] = val;
}

static uint16_t Lookup16BPP(const uint8_t* texels, int width, int x, int y) {
  int bwidth = (width + 3) / 4;
  int bx = x / 4;
  int by = y / 4;
  int rx = x % 4;
  int ry = y % 4;
  int bidx = by * bwidth + bx;
  const uint16_t* btexels = (uint16_t*)&texels[32 * bidx];
  return btexels[ry * 4 + rx];
}

static void Set16BPP(uint8_t* texels, int width, int x, int y, uint16_t val) {
  int bwidth = (width + 3) / 4;
  int bx = x / 4;
  int by = y / 4;
  int rx = x % 4;
  int ry = y % 4;
  int bidx = by * bwidth + bx;
  uint16_t* btexels = (uint16_t*)&texels[32 * bidx];
  btexels[ry * 4 + rx] = val;
}

static void LookupRGBA8(const uint8_t* texels, int width, int x, int y, uint8_t* r, uint8_t* g, uint8_t* b,
                        uint8_t* a) {
  int bwidth = (width + 3) / 4;
  int bx = x / 4;
  int by = y / 4;
  int rx = x % 4;
  int ry = y % 4;
  int bidx = (by * bwidth + bx) * 2;
  const uint16_t* artexels = (uint16_t*)&texels[32 * bidx];
  const uint16_t* gbtexels = (uint16_t*)&texels[32 * (bidx + 1)];
  uint16_t ar = hecl::SBig(artexels[ry * 4 + rx]);
  *a = ar >> 8 & 0xff;
  *r = ar & 0xff;
  uint16_t gb = hecl::SBig(gbtexels[ry * 4 + rx]);
  *g = gb >> 8 & 0xff;
  *b = gb & 0xff;
}

static void SetRGBA8(uint8_t* texels, int width, int x, int y, uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
  int bwidth = (width + 3) / 4;
  int bx = x / 4;
  int by = y / 4;
  int rx = x % 4;
  int ry = y % 4;
  int bidx = (by * bwidth + bx) * 2;
  uint16_t* artexels = (uint16_t*)&texels[32 * bidx];
  uint16_t* gbtexels = (uint16_t*)&texels[32 * (bidx + 1)];
  uint16_t ar = (a << 8) | r;
  artexels[ry * 4 + rx] = hecl::SBig(ar);
  uint16_t gb = (g << 8) | b;
  gbtexels[ry * 4 + rx] = hecl::SBig(gb);
}

static void DecodeI4(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width]);
  // memset(buf.get(), 0, width);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      buf[x] = Convert4To8(Lookup4BPP(texels, width, x, y));
    png_write_row(png, buf.get());
  }
}

#if 0
static void EncodeI4(const uint8_t* rgbaIn, uint8_t* texels, int width, int height)
{
    for (int y=height-1 ; y>=0 ; --y)
    {
        for (int x=0 ; x<width ; ++x)
            Set4BPP(texels, width, x, y, Convert8To4(rgbaIn[x]));
        rgbaIn += width;
    }
}
#endif

static void DecodeI8(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      buf[x] = Lookup8BPP(texels, width, x, y);
    png_write_row(png, buf.get());
  }
}

static void EncodeI8(const uint8_t* rgbaIn, uint8_t* texels, int width, int height) {
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      Set8BPP(texels, width, x, y, rgbaIn[x]);
    rgbaIn += width;
  }
}

static void DecodeIA4(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_GRAY_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width * 2]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x) {
      uint8_t texel = Lookup8BPP(texels, width, x, y);
      buf[x * 2 ] = Convert4To8(texel & 0xf);
      buf[x * 2 + 1] = Convert4To8(texel >> 4 & 0xf);
    }
    png_write_row(png, buf.get());
  }
}

#if 0
static void EncodeIA4(const uint8_t* rgbaIn, uint8_t* texels, int width, int height)
{
    for (int y=height-1 ; y>=0 ; --y)
    {
        for (int x=0 ; x<width ; ++x)
        {
            uint8_t texel = Convert8To4(rgbaIn[x*2+1]) << 4;
            texel |= Convert8To4(rgbaIn[x*2]);
            Set8BPP(texels, width, x, y, texel);
            rgbaIn += width * 2;
        }
    }
}
#endif

static void DecodeIA8(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_GRAY_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint16_t[]> buf(new uint16_t[width]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      buf[x] = hecl::SBig(Lookup16BPP(texels, width, x, y));
    png_write_row(png, (png_bytep)buf.get());
  }
}

static void EncodeIA8(const uint8_t* rgbaIn, uint8_t* texels, int width, int height) {
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      Set16BPP(texels, width, x, y, hecl::SBig(((uint16_t*)rgbaIn)[x]));
    rgbaIn += width * 2;
  }
}

static const uint8_t* DecodePalette(png_structp png, png_infop info, int numEntries, const uint8_t* data) {
  uint32_t format = hecl::SBig(*(uint32_t*)data);
  data += 8;
  png_color cEntries[256];
  png_byte aEntries[256];
  switch (format) {
  case 0: {
    /* IA8 */
    for (int e = 0; e < numEntries; ++e) {
      cEntries[e].red = data[e * 2];
      cEntries[e].green = data[e * 2];
      cEntries[e].blue = data[e * 2];
      aEntries[e] = data[e * 2 + 1];
    }
    break;
  }
  case 1: {
    /* RGB565 */
    const uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint16_t texel = hecl::SBig(data16[e]);
      cEntries[e].red = Convert5To8(texel >> 11 & 0x1f);
      cEntries[e].green = Convert6To8(texel >> 5 & 0x3f);
      cEntries[e].blue = Convert5To8(texel & 0x1f);
    }
    break;
  }
  case 2: {
    /* RGB5A3 */
    const uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint16_t texel = hecl::SBig(data16[e]);
      if (texel & 0x8000) {
        cEntries[e].red = Convert5To8(texel >> 10 & 0x1f);
        cEntries[e].green = Convert5To8(texel >> 5 & 0x1f);
        cEntries[e].blue = Convert5To8(texel & 0x1f);
        aEntries[e] = 0xff;
      } else {
        cEntries[e].red = Convert4To8(texel >> 8 & 0xf);
        cEntries[e].green = Convert4To8(texel >> 4 & 0xf);
        cEntries[e].blue = Convert4To8(texel & 0xf);
        aEntries[e] = Convert3To8(texel >> 12 & 0x7);
      }
    }
    break;
  }
  }
  png_set_PLTE(png, info, cEntries, numEntries);
  if (format == 0 || format == 2)
    png_set_tRNS(png, info, aEntries, numEntries, nullptr);
  data += numEntries * 2;
  return data;
}

static uint8_t* EncodePalette(png_structp png, png_infop info, int numEntries, uint8_t* data) {
  png_colorp cEntries;
  int pngNumEntries;
  if (png_get_PLTE(png, info, &cEntries, &pngNumEntries) != PNG_INFO_PLTE) {
    cEntries = nullptr;
    pngNumEntries = 0;
  }

  png_bytep aEntries;
  int pngNumAEntries;
  png_color_16p trans_color = nullptr;
  if (png_get_tRNS(png, info, &aEntries, &pngNumAEntries, &trans_color) != PNG_INFO_tRNS) {
    aEntries = nullptr;
    pngNumAEntries = 0;
  }

  uint32_t format = 0; /* Default IA8 */
  for (int e = 0; e < pngNumEntries; ++e) {
    png_colorp ent = &cEntries[e];
    if (ent->red != ent->green || ent->red != ent->blue) {
      if (pngNumAEntries)
        format = 2; /* RGB565 if not greyscale and has alpha */
      else
        format = 1; /* RGB565 if not greyscale */
      break;
    }
  }

  ((uint32_t*)data)[0] = hecl::SBig(format);
  data += 4;
  ((uint16_t*)data)[0] = hecl::SBig(uint16_t(numEntries));
  ((uint16_t*)data)[1] = hecl::SBig(uint16_t(1));
  data += 4;

  switch (format) {
  case 0: {
    /* IA8 */
    for (int e = 0; e < numEntries; ++e) {
      if (e < pngNumEntries)
        data[e * 2] = cEntries[e].green;
      else
        data[e * 2] = 0;
      if (e < pngNumAEntries)
        data[e * 2 + 1] = aEntries[e];
      else
        data[e * 2 + 1] = 0;
    }
    break;
  }
  case 1: {
    /* RGB565 */
    uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      if (e < pngNumEntries) {
        uint16_t texel = Convert8To5(cEntries[e].red) << 11;
        texel |= Convert8To6(cEntries[e].green) << 5;
        texel |= Convert8To5(cEntries[e].blue);
        data16[e] = hecl::SBig(texel);
      } else {
        data16[e] = 0;
      }
    }
    break;
  }
  case 2: {
    /* RGB5A3 */
    uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint8_t alpha = 0;
      if (e < pngNumAEntries)
        alpha = aEntries[e];

      uint16_t texel = 0;
      if (alpha == 0xff) {
        texel |= 0x8000;
        if (e < pngNumEntries) {
          texel |= Convert8To5(cEntries[e].red) << 10;
          texel |= Convert8To5(cEntries[e].green) << 5;
          texel |= Convert8To5(cEntries[e].blue);
        }
      } else {
        if (e < pngNumEntries) {
          texel |= Convert8To4(cEntries[e].red) << 8;
          texel |= Convert8To4(cEntries[e].green) << 4;
          texel |= Convert8To4(cEntries[e].blue);
          texel |= Convert8To3(alpha << 12);
        }
      }
      data16[e] = hecl::SBig(texel);
    }
    break;
  }
  }
  data += numEntries * 2;
  return data;
}

static const uint8_t* DecodePaletteSPLT(png_structp png, png_infop info, int numEntries, const uint8_t* data) {
  uint32_t format = hecl::SBig(*(uint32_t*)data);
  data += 8;
  png_sPLT_entry entries[256] = {};
  png_sPLT_t GXEntry = {(char*)"GXPalette", 8, entries, numEntries};
  switch (format) {
  case 0: {
    /* IA8 */
    GXEntry.name = (char*)"GX_IA8";
    for (int e = 0; e < numEntries; ++e) {
      entries[e].red = data[e * 2];
      entries[e].green = data[e * 2];
      entries[e].blue = data[e * 2];
      entries[e].alpha = data[e * 2 + 1];
    }
    break;
  }
  case 1: {
    /* RGB565 */
    GXEntry.name = (char*)"GX_RGB565";
    const uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint16_t texel = hecl::SBig(data16[e]);
      entries[e].red = Convert5To8(texel >> 11 & 0x1f);
      entries[e].green = Convert6To8(texel >> 5 & 0x3f);
      entries[e].blue = Convert5To8(texel & 0x1f);
      entries[e].alpha = 0xff;
    }
    break;
  }
  case 2: {
    /* RGB5A3 */
    GXEntry.name = (char*)"GX_RGB5A3";
    const uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint16_t texel = hecl::SBig(data16[e]);
      if (texel & 0x8000) {
        entries[e].red = Convert5To8(texel >> 10 & 0x1f);
        entries[e].green = Convert5To8(texel >> 5 & 0x1f);
        entries[e].blue = Convert5To8(texel & 0x1f);
        entries[e].alpha = 0xff;
      } else {
        entries[e].red = Convert4To8(texel >> 8 & 0xf);
        entries[e].green = Convert4To8(texel >> 4 & 0xf);
        entries[e].blue = Convert4To8(texel & 0xf);
        entries[e].alpha = Convert3To8(texel >> 12 & 0x7);
      }
    }
    break;
  }
  }
  png_set_sPLT(png, info, &GXEntry, 1);
  data += numEntries * 2;
  return data;
}

static uint8_t* EncodePaletteSPLT(png_structp png, png_infop info, int numEntries, uint8_t* data) {
  png_sPLT_tp palettes;
  int pngNumPalettes = png_get_sPLT(png, info, &palettes);
  int pngNumEntries = 0;
  png_sPLT_entryp cEntries = nullptr;
  for (int i = 0; i < pngNumPalettes; ++i) {
    png_sPLT_tp palette = &palettes[i];
    if (!strncmp(palette->name, "GX_", 3)) {
      pngNumEntries = palette->nentries;
      cEntries = palette->entries;
      break;
    }
  }

  uint32_t format = 2; /* Default RGB5A3 */
  for (int e = 0; e < pngNumEntries; ++e) {
    png_sPLT_entryp ent = &cEntries[e];
    if (ent->red != ent->green || ent->red != ent->blue) {
      if (ent->alpha) {
        format = 2;
        break;
      } else
        format = 1;
    }
  }

  ((uint32_t*)data)[0] = hecl::SBig(format);
  data += 4;
  ((uint16_t*)data)[0] = hecl::SBig(uint16_t(1));
  ((uint16_t*)data)[1] = hecl::SBig(uint16_t(numEntries));
  data += 4;

  switch (format) {
  case 0: {
    /* IA8 */
    for (int e = 0; e < numEntries; ++e) {
      if (e < pngNumEntries) {
        data[e * 2] = cEntries[e].green;
        data[e * 2 + 1] = cEntries[e].alpha;
      } else {
        data[e * 2] = 0;
        data[e * 2 + 1] = 0;
      }
    }
    break;
  }
  case 1: {
    /* RGB565 */
    uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      if (e < pngNumEntries) {
        uint16_t texel = Convert8To5(cEntries[e].red) << 11;
        texel |= Convert8To6(cEntries[e].green) << 5;
        texel |= Convert8To5(cEntries[e].blue);
        data16[e] = hecl::SBig(texel);
      } else {
        data16[e] = 0;
      }
    }
    break;
  }
  case 2: {
    /* RGB5A3 */
    uint16_t* data16 = (uint16_t*)data;
    for (int e = 0; e < numEntries; ++e) {
      uint16_t texel = 0;
      if (cEntries && cEntries[e].alpha == 0xff) {
        texel |= 0x8000;
        if (e < pngNumEntries) {
          texel |= Convert8To5(cEntries[e].red) << 10;
          texel |= Convert8To5(cEntries[e].green) << 5;
          texel |= Convert8To5(cEntries[e].blue);
        }
      } else {
        if (e < pngNumEntries) {
          texel |= Convert8To4(cEntries[e].red) << 8;
          texel |= Convert8To4(cEntries[e].green) << 4;
          texel |= Convert8To4(cEntries[e].blue);
          texel |= Convert8To3(cEntries[e].alpha << 12);
        }
      }
      data16[e] = hecl::SBig(texel);
    }
    break;
  }
  }
  data += numEntries * 2;
  return data;
}

static const png_color C4Colors[] = {
    {0, 0, 0},    {155, 0, 0}, {0, 155, 0}, {0, 0, 155}, {155, 155, 0}, {155, 0, 155}, {0, 155, 155}, {155, 155, 155},
    {55, 55, 55}, {255, 0, 0}, {0, 255, 0}, {0, 0, 255}, {255, 255, 0}, {255, 0, 255}, {0, 255, 255}, {255, 255, 255}};

static void C4Palette(png_structp png, png_infop info) { png_set_PLTE(png, info, C4Colors, 16); }

static void DecodeC4(png_structp png, png_infop info, const uint8_t* data, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  C4Palette(png, info);
  const uint8_t* texels = DecodePaletteSPLT(png, info, 16, data);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width]);
  for (int y = 0; y < height; ++y) {
    for (int x = 0; x < width; ++x)
      buf[x] = Lookup4BPP(texels, width, x, y);
    png_write_row(png, buf.get());
  }
}

static void EncodeC4(png_structp png, png_infop info, const uint8_t* rgbaIn, uint8_t* data, int width, int height) {
  uint8_t* texels = EncodePaletteSPLT(png, info, 16, data);
  for (int y = 0; y < height; ++y) {
    for (int x = 0; x < width; ++x)
      Set4BPP(texels, width, x, y, rgbaIn[x]);
    rgbaIn += width;
  }
}

static void DecodeC8(png_structp png, png_infop info, const uint8_t* data, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  const uint8_t* texels = DecodePalette(png, info, 256, data);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width]);
  for (int y = 0; y < height; ++y) {
    for (int x = 0; x < width; ++x)
      buf[x] = Lookup8BPP(texels, width, x, y);
    png_write_row(png, buf.get());
  }
}

static void EncodeC8(png_structp png, png_infop info, const uint8_t* rgbaIn, uint8_t* data, int width, int height) {
  uint8_t* texels = EncodePalette(png, info, 256, data);
  for (int y = 0; y < height; ++y) {
    for (int x = 0; x < width; ++x)
      Set8BPP(texels, width, x, y, rgbaIn[x]);
    rgbaIn += width;
  }
}

static void DecodeRGB565(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width * 3]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x) {
      uint16_t texel = hecl::SBig(Lookup16BPP(texels, width, x, y));
      buf[x * 3] = Convert5To8(texel >> 11 & 0x1f);
      buf[x * 3 + 1] = Convert6To8(texel >> 5 & 0x3f);
      buf[x * 3 + 2] = Convert5To8(texel & 0x1f);
    }
    png_write_row(png, buf.get());
  }
}

#if 0
static void EncodeRGB565(const uint8_t* rgbaIn, uint8_t* texels, int width, int height)
{
    for (int y=height-1 ; y>=0 ; --y)
    {
        for (int x=0 ; x<width ; ++x)
        {
            uint16_t texel = Convert8To5(rgbaIn[x*3]) << 11;
            texel |= Convert8To6(rgbaIn[x*3+1]) << 5;
            texel |= Convert8To5(rgbaIn[x*3+2]);
            Set16BPP(texels, width, x, y, hecl::SBig(texel));
        }
        rgbaIn += width * 3;
    }
}
#endif

static void DecodeRGB5A3(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width * 4]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x) {
      uint16_t texel = hecl::SBig(Lookup16BPP(texels, width, x, y));
      if (texel & 0x8000) {
        buf[x * 4] = Convert5To8(texel >> 10 & 0x1f);
        buf[x * 4 + 1] = Convert5To8(texel >> 5 & 0x1f);
        buf[x * 4 + 2] = Convert5To8(texel & 0x1f);
        buf[x * 4 + 3] = 0xff;
      } else {
        buf[x * 4] = Convert4To8(texel >> 8 & 0xf);
        buf[x * 4 + 1] = Convert4To8(texel >> 4 & 0xf);
        buf[x * 4 + 2] = Convert4To8(texel & 0xf);
        buf[x * 4 + 3] = Convert3To8(texel >> 12 & 0x7);
      }
    }
    png_write_row(png, buf.get());
  }
}

#if 0
static void EncodeRGB5A3(const uint8_t* rgbaIn, uint8_t* texels, int width, int height)
{
    for (int y=height-1 ; y>=0 ; --y)
    {
        for (int x=0 ; x<width ; ++x)
        {
            uint16_t texel = 0;
            if (rgbaIn[x*4+3] == 0xff)
            {
                texel |= Convert8To5(rgbaIn[x*4]) << 10;
                texel |= Convert8To5(rgbaIn[x*4+1]) << 5;
                texel |= Convert8To5(rgbaIn[x*4+2]);
                texel |= 0x8000;
            }
            else
            {
                texel |= Convert8To4(rgbaIn[x*4]) << 8;
                texel |= Convert8To4(rgbaIn[x*4+1]) << 4;
                texel |= Convert8To4(rgbaIn[x*4+2]);
                texel |= Convert8To3(rgbaIn[x*4+3]) << 12;
            }
            Set16BPP(texels, width, x, y, hecl::SBig(texel));
        }
        rgbaIn += width * 4;
    }
}
#endif

static void DecodeRGBA8(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);
  std::unique_ptr<uint8_t[]> buf(new uint8_t[width * 4]);
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      LookupRGBA8(texels, width, x, y, &buf[x * 4], &buf[x * 4 + 1], &buf[x * 4 + 2], &buf[x * 4 + 3]);
    png_write_row(png, buf.get());
  }
}

static void EncodeRGBA8(const uint8_t* rgbaIn, uint8_t* texels, int width, int height) {
  for (int y = height - 1; y >= 0; --y) {
    for (int x = 0; x < width; ++x)
      SetRGBA8(texels, width, x, y, rgbaIn[x * 4], rgbaIn[x * 4 + 1], rgbaIn[x * 4 + 2], rgbaIn[x * 4 + 3]);
    rgbaIn += width * 4;
  }
}

struct DXTBlock {
  uint16_t color1;
  uint16_t color2;
  uint8_t lines[4];
};

static void DecodeCMPR(png_structp png, png_infop info, const uint8_t* texels, int width, int height) {
  png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT,
               PNG_FILTER_TYPE_DEFAULT);
  png_write_info(png, info);

  /* Decode 8 rows at a time */
  int bwidth = (width + 7) / 8;
  int bpwidth = bwidth * 8;
  std::unique_ptr<uint32_t[]> buf(new uint32_t[bpwidth * 8]);
  uint32_t* bTargets[4] = {buf.get(), buf.get() + 4, buf.get() + 4 * width, buf.get() + 4 * width + 4};
  for (int y = height / 8 - 1; y >= 0; --y) {
    const DXTBlock* blks = (DXTBlock*)(texels + 32 * bwidth * y);
    for (int x = 0; x < width; x += 8) {
      uint32_t blkOut[4][4][4];
      squish::Decompress((uint8_t*)blkOut[0][0], blks++, squish::kDxt1GCN);
      squish::Decompress((uint8_t*)blkOut[1][0], blks++, squish::kDxt1GCN);
      squish::Decompress((uint8_t*)blkOut[2][0], blks++, squish::kDxt1GCN);
      squish::Decompress((uint8_t*)blkOut[3][0], blks++, squish::kDxt1GCN);

      for (int bt = 0; bt < 4; ++bt)
        for (int by = 0; by < 4; ++by)
          memcpy(bTargets[bt] + x + width * by, blkOut[bt][by], 16);
    }
    for (int r = 7; r >= 0; --r)
      png_write_row(png, (png_bytep)(bTargets[0] + width * r));
  }
}

static void EncodeCMPR(const uint8_t* rgbaIn, uint8_t* texels, int width, int height) {
  /* Encode 8 rows at a time */
  int bwidth = (width + 7) / 8;
  int bpwidth = bwidth * 8;
  std::unique_ptr<uint32_t[]> buf(new uint32_t[bpwidth * 8]);
  uint32_t* bTargets[4] = {buf.get(), buf.get() + 4, buf.get() + 4 * width, buf.get() + 4 * width + 4};
  for (int y = height / 8 - 1; y >= 0; --y) {
    for (int r = 7; r >= 0; --r) {
      memcpy(bTargets[0] + width * r, rgbaIn, width * 4);
      rgbaIn += width * 4;
    }
    DXTBlock* blks = (DXTBlock*)(texels + 32 * bwidth * y);
    for (int x = 0; x < width; x += 8) {
      uint32_t blkIn[4][4][4];
      for (int bt = 0; bt < 4; ++bt)
        for (int by = 0; by < 4; ++by)
          memcpy(blkIn[bt][by], bTargets[bt] + x + width * by, 16);

      squish::Compress((uint8_t*)blkIn[0][0], blks++, squish::kDxt1GCN);
      squish::Compress((uint8_t*)blkIn[1][0], blks++, squish::kDxt1GCN);
      squish::Compress((uint8_t*)blkIn[2][0], blks++, squish::kDxt1GCN);
      squish::Compress((uint8_t*)blkIn[3][0], blks++, squish::kDxt1GCN);
    }
  }
}

static void PNGErr(png_structp png, png_const_charp msg) { Log.report(logvisor::Error, fmt("{}"), msg); }

static void PNGWarn(png_structp png, png_const_charp msg) { Log.report(logvisor::Warning, fmt("{}"), msg); }

bool TXTR::Extract(PAKEntryReadStream& rs, const hecl::ProjectPath& outPath) {
  uint32_t format = rs.readUint32Big();
  uint16_t width = rs.readUint16Big();
  uint16_t height = rs.readUint16Big();
  uint32_t numMips = rs.readUint32Big();

  FILE* fp = hecl::Fopen(outPath.getAbsolutePath().data(), _SYS_STR("wb"));
  if (!fp) {
    Log.report(logvisor::Error, fmt(_SYS_STR("Unable to open '{}' for writing")), outPath.getAbsolutePath());
    return false;
  }
  png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, PNGErr, PNGWarn);
  png_init_io(png, fp);
  png_infop info = png_create_info_struct(png);

  png_text textStruct = {};
  textStruct.key = png_charp("urde_nomip");
  if (numMips == 1)
    png_set_text(png, info, &textStruct, 1);

  switch (format) {
  case 0:
    DecodeI4(png, info, rs.data() + 12, width, height);
    break;
  case 1:
    DecodeI8(png, info, rs.data() + 12, width, height);
    break;
  case 2:
    DecodeIA4(png, info, rs.data() + 12, width, height);
    break;
  case 3:
    DecodeIA8(png, info, rs.data() + 12, width, height);
    break;
  case 4:
    DecodeC4(png, info, rs.data() + 12, width, height);
    break;
  case 5:
    DecodeC8(png, info, rs.data() + 12, width, height);
    break;
  case 7:
    DecodeRGB565(png, info, rs.data() + 12, width, height);
    break;
  case 8:
    DecodeRGB5A3(png, info, rs.data() + 12, width, height);
    break;
  case 9:
    DecodeRGBA8(png, info, rs.data() + 12, width, height);
    break;
  case 10:
    DecodeCMPR(png, info, rs.data() + 12, width, height);
    break;
  }

  png_write_end(png, info);
  png_write_flush(png);
  png_destroy_write_struct(&png, &info);
  fclose(fp);

  return true;
}

static std::unique_ptr<uint8_t[]> ReadPalette(png_structp png, png_infop info, size_t& szOut) {
  std::unique_ptr<uint8_t[]> ret;
  png_sPLT_tp palettes;
  int paletteCount = png_get_sPLT(png, info, &palettes);
  if (paletteCount) {
    for (int i = 0; i < paletteCount; ++i) {
      png_sPLT_tp palette = &palettes[i];
      if (!strncmp(palette->name, "GX_", 3)) {
        if (palette->nentries > 16) {
          /* This is a C8 palette */
          ret.reset(new uint8_t[4 * 257]);
          szOut = 4 * 257;
          *reinterpret_cast<uint32_t*>(ret.get()) = hecl::SBig(256);
          uint8_t* cur = ret.get() + 4;
          for (int j = 0; j < 256; ++j) {
            if (j < palette->nentries) {
              png_sPLT_entryp entry = &palette->entries[j];
              if (palette->depth == 16) {
                *cur++ = entry->red >> 8;
                *cur++ = entry->green >> 8;
                *cur++ = entry->blue >> 8;
                *cur++ = entry->alpha >> 8;
              } else {
                *cur++ = entry->red;
                *cur++ = entry->green;
                *cur++ = entry->blue;
                *cur++ = entry->alpha;
              }
            } else {
              *cur++ = 0;
              *cur++ = 0;
              *cur++ = 0;
              *cur++ = 0;
            }
          }
        } else {
          /* This is a C4 palette */
          ret.reset(new uint8_t[4 * 17]);
          szOut = 4 * 17;
          *reinterpret_cast<uint32_t*>(ret.get()) = hecl::SBig(16);
          uint8_t* cur = ret.get() + 4;
          for (int j = 0; j < 16; ++j) {
            if (j < palette->nentries) {
              png_sPLT_entryp entry = &palette->entries[j];
              if (palette->depth == 16) {
                *cur++ = entry->red >> 8;
                *cur++ = entry->green >> 8;
                *cur++ = entry->blue >> 8;
                *cur++ = entry->alpha >> 8;
              } else {
                *cur++ = entry->red;
                *cur++ = entry->green;
                *cur++ = entry->blue;
                *cur++ = entry->alpha;
              }
            } else {
              *cur++ = 0;
              *cur++ = 0;
              *cur++ = 0;
              *cur++ = 0;
            }
          }
        }
        break;
      }
    }
  } else {
    png_colorp palettes;
    int colorCount;
    if (png_get_PLTE(png, info, &palettes, &colorCount) == PNG_INFO_PLTE) {
      if (colorCount > 16) {
        /* This is a C8 palette */
        ret.reset(new uint8_t[4 * 257]);
        szOut = 4 * 257;
        *reinterpret_cast<uint32_t*>(ret.get()) = hecl::SBig(256);
        uint8_t* cur = ret.get() + 4;
        for (int j = 0; j < 256; ++j) {
          if (j < colorCount) {
            png_colorp entry = &palettes[j];
            *cur++ = entry->red;
            *cur++ = entry->green;
            *cur++ = entry->blue;
            *cur++ = 0xff;
          } else {
            *cur++ = 0;
            *cur++ = 0;
            *cur++ = 0;
            *cur++ = 0;
          }
        }
      } else {
        /* This is a C4 palette */
        ret.reset(new uint8_t[4 * 17]);
        szOut = 4 * 17;
        *reinterpret_cast<uint32_t*>(ret.get()) = hecl::SBig(16);
        uint8_t* cur = ret.get() + 4;
        for (int j = 0; j < 16; ++j) {
          if (j < colorCount) {
            png_colorp entry = &palettes[j];
            *cur++ = entry->red;
            *cur++ = entry->green;
            *cur++ = entry->blue;
            *cur++ = 0xff;
          } else {
            *cur++ = 0;
            *cur++ = 0;
            *cur++ = 0;
            *cur++ = 0;
          }
        }
      }
    }
  }
  return ret;
}

static int GetNumPaletteEntriesForGCN(png_structp png, png_infop info) {
  png_sPLT_tp palettes;
  int paletteCount = png_get_sPLT(png, info, &palettes);
  if (paletteCount) {
    for (int i = 0; i < paletteCount; ++i) {
      png_sPLT_tp palette = &palettes[i];
      if (!strncmp(palette->name, "GX_", 3)) {
        if (palette->nentries > 16) {
          /* This is a C8 palette */
          return 256;
        } else {
          /* This is a C4 palette */
          return 16;
        }
        break;
      }
    }
  } else {
    png_colorp palettes;
    int colorCount;
    if (png_get_PLTE(png, info, &palettes, &colorCount) == PNG_INFO_PLTE) {
      if (colorCount > 16) {
        /* This is a C8 palette */
        return 256;
      } else {
        /* This is a C4 palette */
        return 16;
      }
    }
  }
  return 0;
}

bool TXTR::Cook(const hecl::ProjectPath& inPath, const hecl::ProjectPath& outPath) {
  FILE* inf = hecl::Fopen(inPath.getAbsolutePath().data(), _SYS_STR("rb"));
  if (!inf) {
    Log.report(logvisor::Error, fmt(_SYS_STR("Unable to open '{}' for reading")), inPath.getAbsolutePath());
    return false;
  }

  /* Validate PNG */
  char header[8];
  fread(header, 1, 8, inf);
  if (png_sig_cmp((png_const_bytep)header, 0, 8)) {
    Log.report(logvisor::Error, fmt(_SYS_STR("invalid PNG signature in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    return false;
  }

  /* Setup PNG reader */
  png_structp pngRead = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
  if (!pngRead) {
    Log.report(logvisor::Error, fmt("unable to initialize libpng"));
    fclose(inf);
    return false;
  }
  png_infop info = png_create_info_struct(pngRead);
  if (!info) {
    Log.report(logvisor::Error, fmt("unable to initialize libpng info"));
    fclose(inf);
    png_destroy_read_struct(&pngRead, nullptr, nullptr);
    return false;
  }

  if (setjmp(png_jmpbuf(pngRead))) {
    Log.report(logvisor::Error, fmt(_SYS_STR("unable to initialize libpng I/O for '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  png_init_io(pngRead, inf);
  png_set_sig_bytes(pngRead, 8);

  png_read_info(pngRead, info);

  png_uint_32 width = png_get_image_width(pngRead, info);
  png_uint_32 height = png_get_image_height(pngRead, info);
  png_byte colorType = png_get_color_type(pngRead, info);
  png_byte bitDepth = png_get_bit_depth(pngRead, info);

  if (width < 4 || height < 4) {
    Log.report(logvisor::Error, fmt("image must be 4x4 or larger"));
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  /* Disable mipmapping if urde_nomip embedded */
  bool mipmap = true;
  png_text* textStruct;
  int numText;
  png_get_text(pngRead, info, &textStruct, &numText);
  for (int i = 0; i < numText; ++i)
    if (!strcmp(textStruct[i].key, "urde_nomip"))
      mipmap = false;
  if (colorType == PNG_COLOR_TYPE_PALETTE)
    mipmap = false;

  /* Compute mipmap levels */
  size_t numMips = 1;
  if (mipmap && CountBits(width) == 1 && CountBits(height) == 1) {
    size_t index = std::min(width, height);
    while (index >>= 1)
      ++numMips;
  }

  if (bitDepth != 8) {
    Log.report(logvisor::Error, fmt(_SYS_STR("'{}' is not 8 bits-per-channel")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  size_t rowSize = 0;
  size_t nComps = 4;
  int nPaletteEntries = 0;
  switch (colorType) {
  case PNG_COLOR_TYPE_GRAY:
    rowSize = width;
    nComps = 1;
    break;
  case PNG_COLOR_TYPE_GRAY_ALPHA:
    rowSize = width * 2;
    nComps = 2;
    break;
  case PNG_COLOR_TYPE_RGB:
    rowSize = width * 3;
    nComps = 4;
    break;
  case PNG_COLOR_TYPE_RGB_ALPHA:
    rowSize = width * 4;
    nComps = 4;
    break;
  case PNG_COLOR_TYPE_PALETTE:
    nPaletteEntries = GetNumPaletteEntriesForGCN(pngRead, info);
    rowSize = width;
    nComps = 1;
    break;
  default:
    Log.report(logvisor::Error, fmt(_SYS_STR("unsupported color type in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  /* Intermediate row-read buf (file components) */
  std::unique_ptr<uint8_t[]> rowBuf;
  if (colorType == PNG_COLOR_TYPE_RGB)
    rowBuf.reset(new uint8_t[rowSize]);

  /* Final mipmapped buf (RGBA components) */
  std::unique_ptr<uint8_t[]> bufOut;
  size_t bufLen = 0;
  if (numMips > 1)
    bufLen = ComputeMippedTexelCount(width, height) * nComps;
  else
    bufLen = width * height * nComps;
  bufOut.reset(new uint8_t[bufLen]);

  if (setjmp(png_jmpbuf(pngRead))) {
    Log.report(logvisor::Fatal, fmt(_SYS_STR("unable to read image in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  /* Track alpha values for DXT1 eligibility */
  bool doDXT1 = (colorType == PNG_COLOR_TYPE_RGB || colorType == PNG_COLOR_TYPE_RGB_ALPHA) && width >= 4 && height >= 4;

  /* Read into mip0 image buffer */
  for (png_uint_32 r = 0; r < height; ++r) {
    if (colorType == PNG_COLOR_TYPE_RGB) {
      png_read_row(pngRead, rowBuf.get(), nullptr);
      for (unsigned i = 0; i < width; ++i) {
        size_t inbase = i * 3;
        size_t outbase = (r * width + i) * 4;
        bufOut[outbase] = rowBuf[inbase];
        bufOut[outbase + 1] = rowBuf[inbase + 1];
        bufOut[outbase + 2] = rowBuf[inbase + 2];
        bufOut[outbase + 3] = 0xff;
      }
    } else {
      png_read_row(pngRead, &bufOut[(r * width) * nComps], nullptr);
      if (colorType == PNG_COLOR_TYPE_RGB_ALPHA) {
        for (unsigned i = 0; i < width; ++i) {
          size_t outbase = (r * width + i) * nComps;
          if (bufOut[outbase + 3] != 0 && bufOut[outbase + 3] != 255)
            doDXT1 = false;
        }
      }
    }
  }

  png_destroy_read_struct(&pngRead, &info, nullptr);
  fclose(inf);

  /* Reduce mipmaps to minimum allowed dimensions */
  unsigned minDimX, minDimY;
  if (doDXT1) {
    minDimX = minDimY = 4;
  } else {
    switch (colorType) {
    case PNG_COLOR_TYPE_GRAY:
      minDimX = 8;
      minDimY = 4;
      break;
    case PNG_COLOR_TYPE_GRAY_ALPHA:
    case PNG_COLOR_TYPE_RGB:
    case PNG_COLOR_TYPE_RGB_ALPHA:
    default:
      minDimX = 4;
      minDimY = 4;
      break;
    case PNG_COLOR_TYPE_PALETTE: {
      if (nPaletteEntries == 256) {
        minDimX = 8;
        minDimY = 4;
      } else {
        minDimX = minDimY = 8;
      }
      break;
    }
    }
  }
  {
    unsigned totalPixels = 0;
    unsigned filterWidth = width;
    unsigned filterHeight = height;
    for (size_t i = 0; i < numMips; ++i) {
      totalPixels += filterWidth * filterHeight;
      if (filterWidth == minDimX || filterHeight == minDimY) {
        numMips = i + 1;
        break;
      }
      filterWidth /= 2;
      filterHeight /= 2;
    }
    bufLen = totalPixels * nComps;
  }

  /* Perform box-filter mipmap */
  std::unique_ptr<uint8_t[]> compOut;
  size_t compLen = 0;
  if (numMips > 1) {
    const uint8_t* filterIn = bufOut.get();
    uint8_t* filterOut = bufOut.get() + width * height * nComps;
    unsigned filterWidth = width;
    unsigned filterHeight = height;
    for (size_t i = 1; i < numMips; ++i) {
      BoxFilter(filterIn, nComps, filterWidth, filterHeight, filterOut, doDXT1);
      filterIn += filterWidth * filterHeight * nComps;
      filterWidth /= 2;
      filterHeight /= 2;
      filterOut += filterWidth * filterHeight * nComps;
    }
  }

  /* Do DXT1 compression */
  int format;
  if (doDXT1) {
    int filterWidth = width;
    int filterHeight = height;
    for (size_t i = 0; i < numMips; ++i) {
      compLen += squish::GetStorageRequirements(filterWidth, filterHeight, squish::kDxt1);
      if (filterWidth == 8 || filterHeight == 8) {
        numMips = i + 1;
        break;
      }
      filterWidth /= 2;
      filterHeight /= 2;
    }

    compOut.reset(new uint8_t[compLen]);

    filterWidth = width;
    filterHeight = height;
    const uint8_t* rgbaIn = bufOut.get();
    uint8_t* blocksOut = compOut.get();
    memset(blocksOut, 0, compLen);
    for (size_t i = 0; i < numMips; ++i) {
      int thisLen = squish::GetStorageRequirements(filterWidth, filterHeight, squish::kDxt1);
      EncodeCMPR(rgbaIn, blocksOut, filterWidth, filterHeight);
      rgbaIn += filterWidth * filterHeight * nComps;
      blocksOut += thisLen;
      filterWidth /= 2;
      filterHeight /= 2;
    }

    format = 10;
  } else {
    int filterWidth = width;
    int filterHeight = height;
    compLen = bufLen;
    if (colorType == PNG_COLOR_TYPE_PALETTE) {
      if (nPaletteEntries == 16)
        compLen /= 2;
      compLen += 8 + nPaletteEntries * 2;
    }
    compOut.reset(new uint8_t[compLen]);
    const uint8_t* rgbaIn = bufOut.get();
    uint8_t* dataOut = compOut.get();
    memset(dataOut, 0, compLen);
    for (size_t i = 0; i < numMips; ++i) {
      switch (colorType) {
      case PNG_COLOR_TYPE_GRAY:
        EncodeI8(rgbaIn, dataOut, filterWidth, filterHeight);
        format = 1;
        break;
      case PNG_COLOR_TYPE_GRAY_ALPHA:
        EncodeIA8(rgbaIn, dataOut, filterWidth, filterHeight);
        format = 3;
        break;
      case PNG_COLOR_TYPE_RGB:
      case PNG_COLOR_TYPE_RGB_ALPHA:
        EncodeRGBA8(rgbaIn, dataOut, filterWidth, filterHeight);
        format = 9;
        break;
      case PNG_COLOR_TYPE_PALETTE: {
        if (nPaletteEntries == 256) {
          EncodeC8(pngRead, info, rgbaIn, dataOut, filterWidth, filterHeight);
          format = 5;
        } else {
          EncodeC4(pngRead, info, rgbaIn, dataOut, filterWidth, filterHeight);
          format = 4;
        }
        break;
      }
      default:
        break;
      }
      rgbaIn += filterWidth * filterHeight * nComps;
      dataOut += filterWidth * filterHeight * nComps;
      filterWidth /= 2;
      filterHeight /= 2;
    }
  }

  /* Do write out */
  athena::io::FileWriter outf(outPath.getAbsolutePath(), true, false);
  if (outf.hasError()) {
    Log.report(logvisor::Error, fmt(_SYS_STR("Unable to open '{}' for writing")), outPath.getAbsolutePath());
    return false;
  }

  outf.writeInt32Big(format);
  outf.writeInt16Big(width);
  outf.writeInt16Big(height);
  outf.writeInt32Big(numMips);
  outf.writeUBytes(compOut.get(), compLen);

  return true;
}

bool TXTR::CookPC(const hecl::ProjectPath& inPath, const hecl::ProjectPath& outPath) {
  FILE* inf = hecl::Fopen(inPath.getAbsolutePath().data(), _SYS_STR("rb"));
  if (!inf) {
    Log.report(logvisor::Error, fmt(_SYS_STR("Unable to open '{}' for reading")), inPath.getAbsolutePath());
    return false;
  }

  /* Validate PNG */
  char header[8];
  fread(header, 1, 8, inf);
  if (png_sig_cmp((png_const_bytep)header, 0, 8)) {
    Log.report(logvisor::Error, fmt(_SYS_STR("invalid PNG signature in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    return false;
  }

  /* Setup PNG reader */
  png_structp pngRead = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
  if (!pngRead) {
    Log.report(logvisor::Error, fmt("unable to initialize libpng"));
    fclose(inf);
    return false;
  }
  png_infop info = png_create_info_struct(pngRead);
  if (!info) {
    Log.report(logvisor::Error, fmt("unable to initialize libpng info"));
    fclose(inf);
    png_destroy_read_struct(&pngRead, nullptr, nullptr);
    return false;
  }

  if (setjmp(png_jmpbuf(pngRead))) {
    Log.report(logvisor::Error, fmt(_SYS_STR("unable to initialize libpng I/O for '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  png_init_io(pngRead, inf);
  png_set_sig_bytes(pngRead, 8);

  png_read_info(pngRead, info);

  png_uint_32 width = png_get_image_width(pngRead, info);
  png_uint_32 height = png_get_image_height(pngRead, info);
  png_byte colorType = png_get_color_type(pngRead, info);
  png_byte bitDepth = png_get_bit_depth(pngRead, info);

  /* Disable mipmapping if urde_nomip embedded */
  bool mipmap = true;
  png_text* textStruct;
  int numText;
  png_get_text(pngRead, info, &textStruct, &numText);
  for (int i = 0; i < numText; ++i)
    if (!strcmp(textStruct[i].key, "urde_nomip"))
      mipmap = false;
  if (colorType == PNG_COLOR_TYPE_PALETTE)
    mipmap = false;

  /* Compute mipmap levels */
  size_t numMips = 1;
  if (mipmap && CountBits(width) == 1 && CountBits(height) == 1) {
    size_t index = std::min(width, height);
    while (index >>= 1)
      ++numMips;
  }

  if (bitDepth != 8) {
    Log.report(logvisor::Error, fmt(_SYS_STR("'{}' is not 8 bits-per-channel")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  std::unique_ptr<uint8_t[]> paletteBuf;
  size_t paletteSize = 0;

  size_t rowSize = 0;
  size_t nComps = 4;
  switch (colorType) {
  case PNG_COLOR_TYPE_GRAY:
    rowSize = width;
    break;
  case PNG_COLOR_TYPE_GRAY_ALPHA:
    rowSize = width * 2;
    break;
  case PNG_COLOR_TYPE_RGB:
    rowSize = width * 3;
    break;
  case PNG_COLOR_TYPE_RGB_ALPHA:
    rowSize = width * 4;
    break;
  case PNG_COLOR_TYPE_PALETTE:
    rowSize = width;
    nComps = 1;
    paletteBuf = ReadPalette(pngRead, info, paletteSize);
    break;
  default:
    Log.report(logvisor::Error, fmt(_SYS_STR("unsupported color type in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  /* Intermediate row-read buf (file components) */
  std::unique_ptr<uint8_t[]> rowBuf(new uint8_t[rowSize]);

  /* Final mipmapped buf (RGBA components) */
  std::unique_ptr<uint8_t[]> bufOut;
  size_t bufLen = 0;
  if (numMips > 1)
    bufLen = ComputeMippedTexelCount(width, height) * nComps;
  else
    bufLen = width * height * nComps;
  bufOut.reset(new uint8_t[bufLen]);

  if (setjmp(png_jmpbuf(pngRead))) {
    Log.report(logvisor::Fatal, fmt(_SYS_STR("unable to read image in '{}'")), inPath.getAbsolutePath());
    fclose(inf);
    png_destroy_read_struct(&pngRead, &info, nullptr);
    return false;
  }

  /* Track alpha values for DXT1 eligibility */
  bool doDXT = (colorType == PNG_COLOR_TYPE_RGB || colorType == PNG_COLOR_TYPE_RGB_ALPHA) && width >= 4 && height >= 4;
  bool doDXT3 = false;

  /* Read and make RGBA */
  for (int r = height - 1; r >= 0; --r) {
    png_read_row(pngRead, rowBuf.get(), nullptr);
    switch (colorType) {
    case PNG_COLOR_TYPE_GRAY:
      for (unsigned i = 0; i < width; ++i) {
        size_t outbase = (r * width + i) * 4;
        bufOut[outbase] = rowBuf[i];
        bufOut[outbase + 1] = rowBuf[i];
        bufOut[outbase + 2] = rowBuf[i];
        bufOut[outbase + 3] = rowBuf[i];
      }
      break;
    case PNG_COLOR_TYPE_GRAY_ALPHA:
      for (unsigned i = 0; i < width; ++i) {
        size_t inbase = i * 2;
        size_t outbase = (r * width + i) * 4;
        bufOut[outbase] = rowBuf[inbase];
        bufOut[outbase + 1] = rowBuf[inbase];
        bufOut[outbase + 2] = rowBuf[inbase];
        bufOut[outbase + 3] = rowBuf[inbase + 1];
      }
      break;
    case PNG_COLOR_TYPE_RGB:
      for (unsigned i = 0; i < width; ++i) {
        size_t inbase = i * 3;
        size_t outbase = (r * width + i) * 4;
        bufOut[outbase] = rowBuf[inbase];
        bufOut[outbase + 1] = rowBuf[inbase + 1];
        bufOut[outbase + 2] = rowBuf[inbase + 2];
        bufOut[outbase + 3] = 0xff;
      }
      break;
    case PNG_COLOR_TYPE_RGB_ALPHA:
      for (unsigned i = 0; i < width; ++i) {
        size_t inbase = i * 4;
        size_t outbase = (r * width + i) * 4;
        bufOut[outbase] = rowBuf[inbase];
        bufOut[outbase + 1] = rowBuf[inbase + 1];
        bufOut[outbase + 2] = rowBuf[inbase + 2];
        bufOut[outbase + 3] = rowBuf[inbase + 3];
        if (rowBuf[inbase + 3] != 0 && rowBuf[inbase + 3] != 255)
          doDXT = false;
        else if (rowBuf[inbase + 3] == 0)
          doDXT3 = true;
      }
      break;
    case PNG_COLOR_TYPE_PALETTE:
      for (unsigned i = 0; i < width; ++i)
        bufOut[r * width + i] = rowBuf[i];
      break;
    default:
      break;
    }
  }

  png_destroy_read_struct(&pngRead, &info, nullptr);
  fclose(inf);

  /* Perform box-filter mipmap */
  if (numMips > 1) {
    const uint8_t* filterIn = bufOut.get();
    uint8_t* filterOut = bufOut.get() + width * height * nComps;
    unsigned filterWidth = width;
    unsigned filterHeight = height;
    for (size_t i = 1; i < numMips; ++i) {
      BoxFilter(filterIn, nComps, filterWidth, filterHeight, filterOut, doDXT);
      filterIn += filterWidth * filterHeight * nComps;
      filterWidth /= 2;
      filterHeight /= 2;
      filterOut += filterWidth * filterHeight * nComps;
    }
  }

  /* Do DXT compression */
  std::unique_ptr<uint8_t[]> compOut;
  size_t compLen = 0;
  if (doDXT) {
    int compFlags = doDXT3 ? squish::kDxt3 : squish::kDxt1;
    int filterWidth = width;
    int filterHeight = height;
    size_t i;
    for (i = 0; i < numMips; ++i) {
      compLen += squish::GetStorageRequirements(filterWidth, filterHeight, compFlags);
      if (filterWidth == 4 || filterHeight == 4) {
        ++i;
        break;
      }
      filterWidth /= 2;
      filterHeight /= 2;
    }
    numMips = i;

    compOut.reset(new uint8_t[compLen]);

    filterWidth = width;
    filterHeight = height;
    const uint8_t* rgbaIn = bufOut.get();
    uint8_t* blocksOut = compOut.get();
    for (i = 0; i < numMips; ++i) {
      int thisLen = squish::GetStorageRequirements(filterWidth, filterHeight, compFlags);
      squish::CompressImage(rgbaIn, filterWidth, filterHeight, blocksOut, compFlags);
      rgbaIn += filterWidth * filterHeight * nComps;
      blocksOut += thisLen;
      filterWidth /= 2;
      filterHeight /= 2;
    }
  }

  /* Do write out */
  athena::io::FileWriter outf(outPath.getAbsolutePath(), true, false);
  if (outf.hasError()) {
    Log.report(logvisor::Error, fmt(_SYS_STR("Unable to open '{}' for writing")), outPath.getAbsolutePath());
    return false;
  }

  int format;
  if (paletteBuf && paletteSize)
    format = 17;
  else if (compOut)
    format = doDXT3 ? 19 : 18;
  else
    format = 16;
  outf.writeInt32Big(format);
  outf.writeInt16Big(width);
  outf.writeInt16Big(height);
  outf.writeInt32Big(numMips);
  if (paletteBuf && paletteSize)
    outf.writeUBytes(paletteBuf.get(), paletteSize);
  if (compOut)
    outf.writeUBytes(compOut.get(), compLen);
  else
    outf.writeUBytes(bufOut.get(), bufLen);

  return true;
}

template <class Op>
void DataSpec::TXTR::PaletteMeta::Enumerate(typename Op::StreamT& s) {
  Do<Op>({"format"}, format, s);
  Do<Op>({"elementCount"}, elementCount, s);
  Do<Op>({"dolphinHash"}, dolphinHash, s);
}

AT_SPECIALIZE_DNA_YAML(DataSpec::TXTR::PaletteMeta)

const char* DataSpec::TXTR::PaletteMeta::DNAType() {
  return "DataSpec::TXTR::PaletteMeta";
}

template <class Op>
void DataSpec::TXTR::Meta::Enumerate(typename Op::StreamT& s) {
  Do<Op>({"format"}, format, s);
  Do<Op>({"mips"}, mips, s);
  Do<Op>({"width"}, width, s);
  Do<Op>({"height"}, height, s);
  Do<Op>({"dolphinHash"}, dolphinHash, s);
  Do<Op>({"hasPalette"}, hasPalette, s);
  if (hasPalette)
    Do<Op>({"palette"}, palette, s);
}

AT_SPECIALIZE_DNA_YAML(DataSpec::TXTR::Meta)

const char* DataSpec::TXTR::Meta::DNAType() {
  return "DataSpec::TXTR::Meta";
}

static const atInt32 RetroToDol[11] {
  0, 1, 2, 3, 8, 9, -1, 4, 5, 6, 14
};

TXTR::Meta TXTR::GetMetaData(DataSpec::PAKEntryReadStream& rs) {
  atUint32 retroFormat = rs.readUint32Big();
  atUint32 format = RetroToDol[retroFormat];
  if (format == UINT32_MAX)
    return {};

  Meta meta;
  meta.format = retroFormat;
  meta.width = rs.readUint16Big();
  meta.height = rs.readUint16Big();
  meta.mips = rs.readUint32Big();
  atUint32 textureSize = meta.width * meta.height;
  if (format == 8 || format == 9) {
    meta.hasPalette = true;
    PaletteMeta& palMeta = meta.palette;
    palMeta.format = rs.readUint32Big();
    atUint16 palWidth = rs.readUint16Big();
    atUint16 palHeight = rs.readUint16Big();
    palMeta.elementCount = palWidth * palHeight;
    atUint32 palSize = atUint32(palWidth * palHeight * 2);
    if (format == 8)
      textureSize /= 2;
    std::unique_ptr<u8[]> palData(new u8[palSize]);
    rs.readUBytesToBuf(palData.get(), palSize);
    palMeta.dolphinHash = XXH64(palData.get(), palSize, 0);
  } else {
    switch(format) {
    case 0: // I4
    case 14: // DXT1
      textureSize /= 2;
      break;
    case 3:
    case 4:
    case 5:
      textureSize *= 2;
      break;
    case 6:
      textureSize *= 4;
      break;
    default:
      break;
    }
  }
  std::unique_ptr<u8[]> textureData(new u8[textureSize]);
  rs.readUBytesToBuf(textureData.get(), textureSize);
  meta.dolphinHash = XXH64(textureData.get(), textureSize, 0);

  return meta;
}

} // namespace DataSpec