/*

 * Copyright (c) 2021, Ben Wiederhake <BenWiederhake.GitHub@gmx.de>

 *

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

 */

#include <AK/Forward.h>

#include <AK/StringBuilder.h>

#include <LibMarkdown/CommentBlock.h>

#include <LibMarkdown/Visitor.h>

namespace Markdown {

ByteString CommentBlock::render_to_html(bool) const

{

    StringBuilder builder;

    builder.append("<!--"sv);

    builder.append(escape_html_entities(m_comment));

    // TODO: This is probably incorrect, because we technically need to escape "--" in some form. However, Browser does not care about this.

    builder.append("-->\n"sv);

    return builder.to_byte_string();

}

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

{

    return Vector<ByteString> {};

}

RecursionDecision CommentBlock::walk(Visitor& visitor) const

{

    RecursionDecision rd = visitor.visit(*this);

    if (rd != RecursionDecision::Recurse)

        return rd;

    // Normalize return value.

    return RecursionDecision::Continue;

}

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

{

    if (lines.is_end())

        return {};

    constexpr auto comment_start = "<!--"sv;

    constexpr auto comment_end = "-->"sv;

    StringView line = *lines;

    if (!line.starts_with(comment_start))

        return {};

    line = line.substring_view(comment_start.length());

    StringBuilder builder;

    while (true) {

        // Invariant: At the beginning of the loop, `line` is valid and should be added to the builder.

        bool ends_here = line.ends_with(comment_end);

        if (ends_here)

            line = line.substring_view(0, line.length() - comment_end.length());

        builder.append(line);

        if (!ends_here)

            builder.append('\n');

        ++lines;

        if (lines.is_end() || ends_here) {

            break;

        }

        line = *lines;

    }

    return make<CommentBlock>(builder.to_byte_string());

}

}