/*

 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <AK/Slugify.h>

#include <AK/StringBuilder.h>

#include <LibMarkdown/Heading.h>

#include <LibMarkdown/Visitor.h>

#include <LibUnicode/Normalize.h>

namespace Markdown {

ByteString Heading::render_to_html(bool) const

{

    auto input = Unicode::normalize(m_text.render_for_raw_print(), Unicode::NormalizationForm::NFD);

    auto slugified = MUST(AK::slugify(input));

    return ByteString::formatted("<h{} id='{}'><a href='#{}'>#</a> {}</h{}>\n", m_level, slugified, slugified, m_text.render_to_html(), m_level);

}

Vector<ByteString> Heading::render_lines_for_terminal(size_t) const

{

    StringBuilder builder;

    builder.append("\n\033[0;31;1m"sv);

    switch (m_level) {

    case 1:

    case 2:

        builder.append(m_text.render_for_terminal().to_uppercase());

        builder.append("\033[0m"sv);

        break;

    default:

        builder.append(m_text.render_for_terminal());

        builder.append("\033[0m"sv);

        break;

    }

    return Vector<ByteString> { builder.to_byte_string() };

}

RecursionDecision Heading::walk(Visitor& visitor) const

{

    RecursionDecision rd = visitor.visit(*this);

    if (rd != RecursionDecision::Recurse)

        return rd;

    return m_text.walk(visitor);

}

OwnPtr<Heading> Heading::parse(LineIterator& lines)

{

    if (lines.is_end())

        return {};

    StringView line = *lines;

    size_t indent = 0;

    // Allow for up to 3 spaces of indentation.

    // https://spec.commonmark.org/0.30/#example-68

    for (size_t i = 0; i < 3; ++i) {

        if (line[i] != ' ')

            break;

        ++indent;

    }

    size_t level;

    for (level = 0; indent + level < line.length(); level++) {

        if (line[indent + level] != '#')

            break;

    }

    if (!level || indent + level >= line.length() || line[indent + level] != ' ' || level > 6)

        return {};

    StringView title_view = line.substring_view(indent + level + 1);

    auto text = Text::parse(title_view);

    auto heading = make<Heading>(move(text), level);

    ++lines;

    return heading;

}

}