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

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

std::string MultiLineTextView::LineWrap(const std::string& str, int wrap)
{
    size_t rem = str.size();
    const utf8proc_uint8_t* it = reinterpret_cast<const utf8proc_uint8_t*>(str.data());
    uint32_t lCh = -1;
    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, "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 != -1)
            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 = -1;
            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(const std::wstring& str, int wrap)
{
    uint32_t lCh = -1;
    int adv = 0;

    std::wstring ret;
    ret.reserve(str.size());
    std::wstring::const_iterator lastSpaceIt = str.cend();
    size_t rollbackPos;
    for (std::wstring::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 != -1)
            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 = -1;
            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(const std::string& str,
                                      const zeus::CColor& defaultColor,
                                      unsigned wrap)
{
    if (wrap)
    {
        typesetGlyphs(LineWrap(str, wrap), defaultColor);
        return;
    }

    m_width = 0;
    m_lines.clear();
    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, "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;

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

    updateSize();
}

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

    m_width = 0;
    m_lines.clear();
    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;

    while (rem)
    {
        if (*it == L'\n' || *it == L'\0')
        {
            m_lines.emplace_back(new TextView(m_viewSystem, *this, m_fontAtlas, m_align, m_lineCapacity));
            m_lines.back()->typesetGlyphs(std::wstring(beginIt, it), defaultColor);
            m_width = std::max(m_width, m_lines.back()->nominalWidth());
            beginIt = it + 1;
        }
        --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);
}

}