#include "specter/MultiLineTextView.hpp"
#include "specter/ViewResources.hpp"

namespace specter {
static logvisor::Module Log("specter::MultiLineTextView");

std::string MultiLineTextView::LineWrap(std::string_view str, int wrap) {
  size_t rem = str.size();
  const utf8proc_uint8_t* it = reinterpret_cast<const utf8proc_uint8_t*>(str.data());
  uint32_t lCh = UINT32_MAX;
  int adv = 0;

  std::string ret;
  ret.reserve(str.size());
  size_t lastSpaceRem;
  const utf8proc_uint8_t* lastSpaceIt = nullptr;
  size_t rollbackPos;
  while (rem) {
    utf8proc_int32_t ch;
    utf8proc_ssize_t sz = utf8proc_iterate(it, -1, &ch);
    if (sz < 0)
      Log.report(logvisor::Fatal, FMT_STRING("invalid UTF-8 char"));
    if (ch == '\n') {
      ret += '\n';
      lCh = -1;
      rem -= sz;
      it += sz;
      lastSpaceIt = nullptr;
      adv = 0;
      continue;
    }

    const FontAtlas::Glyph* glyph = m_fontAtlas.lookupGlyph(ch);
    if (!glyph) {
      rem -= sz;
      it += sz;
      continue;
    }

    if (lCh != UINT32_MAX)
      adv += TextView::DoKern(m_fontAtlas.lookupKern(lCh, glyph->m_glyphIdx), m_fontAtlas);
    adv += glyph->m_advance;

    if (adv > wrap && lastSpaceIt) {
      ret.assign(ret.cbegin(), ret.cbegin() + rollbackPos);
      ret += '\n';
      lCh = UINT32_MAX;
      rem = lastSpaceRem;
      it = lastSpaceIt;
      lastSpaceIt = nullptr;
      adv = 0;
      continue;
    }

    if (sz == 1 && (it[0] == ' ' || it[0] == '-' || it[0] == '/' || it[0] == '\\')) {
      lastSpaceIt = it + 1;
      lastSpaceRem = rem - 1;
      rollbackPos = ret.size() + 1;
    }
    for (utf8proc_ssize_t i = 0; i < sz; ++i)
      ret += it[i];
    lCh = glyph->m_glyphIdx;
    rem -= sz;
    it += sz;
  }

  return ret;
}

std::wstring MultiLineTextView::LineWrap(std::wstring_view str, int wrap) {
  uint32_t lCh = UINT32_MAX;
  int adv = 0;

  std::wstring ret;
  ret.reserve(str.size());
  std::wstring_view::const_iterator lastSpaceIt = str.cend();
  size_t rollbackPos;
  for (std::wstring_view::const_iterator it = str.cbegin(); it != str.cend(); ++it) {
    wchar_t ch = *it;
    if (ch == L'\n') {
      ret += L'\n';
      lCh = -1;
      lastSpaceIt = str.cend();
      adv = 0;
      continue;
    }

    const FontAtlas::Glyph* glyph = m_fontAtlas.lookupGlyph(ch);
    if (!glyph)
      continue;

    if (lCh != UINT32_MAX)
      adv += TextView::DoKern(m_fontAtlas.lookupKern(lCh, glyph->m_glyphIdx), m_fontAtlas);
    adv += glyph->m_advance;

    if (adv > wrap && lastSpaceIt != str.cend()) {
      ret.assign(ret.cbegin(), ret.cbegin() + rollbackPos);
      ret += L'\n';
      lCh = UINT32_MAX;
      it = lastSpaceIt;
      lastSpaceIt = str.cend();
      adv = 0;
      continue;
    }

    if (ch == L' ' || ch == L'-') {
      lastSpaceIt = it + 1;
      rollbackPos = ret.size() + 1;
    }
    ret += ch;
    lCh = glyph->m_glyphIdx;
  }

  return ret;
}

MultiLineTextView::MultiLineTextView(ViewResources& res, View& parentView, const FontAtlas& font,
                                     TextView::Alignment align, size_t lineCapacity, float lineHeight)
: View(res, parentView)
, m_viewSystem(res)
, m_fontAtlas(font)
, m_align(align)
, m_lineCapacity(lineCapacity)
, m_lineHeight(lineHeight) {
  commitResources(res, [&](boo::IGraphicsDataFactory::Context& ctx) -> bool {
    buildResources(ctx, res);
    return true;
  });
}

MultiLineTextView::MultiLineTextView(ViewResources& res, View& parentView, FontTag font, TextView::Alignment align,
                                     size_t lineCapacity, float lineHeight)
: MultiLineTextView(res, parentView, res.m_textRes.m_fcache->lookupAtlas(font), align, lineCapacity, lineHeight) {}

void MultiLineTextView::typesetGlyphs(std::string_view str, const zeus::CColor& defaultColor, unsigned wrap) {
  if (wrap) {
    typesetGlyphs(LineWrap(str, wrap), defaultColor);
    return;
  }

  m_width = 0;
  size_t rem = str.size() + 1;
  const utf8proc_uint8_t* it = reinterpret_cast<const utf8proc_uint8_t*>(str.data());

  size_t lineCount = 0;
  while (rem) {
    utf8proc_int32_t ch;
    utf8proc_ssize_t sz = utf8proc_iterate(it, -1, &ch);
    if (sz < 0)
      Log.report(logvisor::Fatal, FMT_STRING("invalid UTF-8 char"));
    if (ch == '\n' || ch == '\0')
      ++lineCount;
    rem -= sz;
    it += sz;
  }

  m_lines.reserve(lineCount);
  rem = str.size() + 1;
  it = reinterpret_cast<const utf8proc_uint8_t*>(str.data());
  const utf8proc_uint8_t* beginIt = it;
  size_t lineIt = 0;

  while (rem) {
    utf8proc_int32_t ch;
    utf8proc_ssize_t sz = utf8proc_iterate(it, -1, &ch);
    if (ch == '\n' || ch == '\0') {
      TextView& tv = (lineIt < m_lines.size()) ? *m_lines[lineIt]
                                               : *m_lines.emplace_back(std::make_unique<TextView>(
                                                     m_viewSystem, *this, m_fontAtlas, m_align, m_lineCapacity));
      tv.typesetGlyphs(std::string((char*)beginIt, it - beginIt), defaultColor);
      m_width = std::max(m_width, tv.nominalWidth());
      beginIt = it + 1;
      ++lineIt;
    }
    rem -= sz;
    it += sz;
  }

  updateSize();
}

void MultiLineTextView::typesetGlyphs(std::wstring_view str, const zeus::CColor& defaultColor, unsigned wrap) {
  if (wrap) {
    typesetGlyphs(LineWrap(str, wrap), defaultColor);
    return;
  }

  m_width = 0;
  size_t rem = str.size() + 1;
  auto it = str.cbegin();

  size_t lineCount = 0;
  while (rem) {
    if (*it == L'\n' || *it == L'\0')
      ++lineCount;
    --rem;
    ++it;
  }

  m_lines.reserve(lineCount);
  rem = str.size() + 1;
  it = str.cbegin();
  auto beginIt = it;
  size_t lineIt = 0;

  while (rem) {
    if (*it == L'\n' || *it == L'\0') {
      TextView& tv = (lineIt < m_lines.size()) ? *m_lines[lineIt]
                                               : *m_lines.emplace_back(std::make_unique<TextView>(
                                                     m_viewSystem, *this, m_fontAtlas, m_align, m_lineCapacity));
      tv.typesetGlyphs(std::wstring(beginIt, it), defaultColor);
      m_width = std::max(m_width, tv.nominalWidth());
      beginIt = it + 1;
      ++lineIt;
    }
    --rem;
    ++it;
  }

  updateSize();
}

void MultiLineTextView::colorGlyphs(const zeus::CColor& newColor) {
  for (std::unique_ptr<TextView>& tv : m_lines)
    tv->colorGlyphs(newColor);
}

void MultiLineTextView::resized(const boo::SWindowRect& root, const boo::SWindowRect& sub) {
  View::resized(root, sub);
  unsigned lHeight = unsigned(m_lineHeight * m_fontAtlas.FT_LineHeight()) >> 6;
  unsigned decumHeight = lHeight * m_lines.size();
  boo::SWindowRect tsub = sub;
  tsub.location[1] += decumHeight;
  tsub.size[1] = 10;
  for (std::unique_ptr<TextView>& tv : m_lines) {
    tsub.location[1] -= lHeight;
    tv->resized(root, tsub);
  }
}

void MultiLineTextView::draw(boo::IGraphicsCommandQueue* gfxQ) {
  View::draw(gfxQ);
  for (std::unique_ptr<TextView>& tv : m_lines)
    tv->draw(gfxQ);
}

} // namespace specter