/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/ScopeGuard.h>
#include <AK/StringBuilder.h>
#include <LibMarkdown/Text.h>
#include <string.h>
namespace Markdown {
static String unescape(const StringView& text)
{
StringBuilder builder;
for (size_t i = 0; i < text.length(); ++i) {
if (text[i] == '\\' && i != text.length() - 1) {
builder.append(text[i + 1]);
i++;
continue;
}
builder.append(text[i]);
}
return builder.build();
}
String Text::render_to_html() const
{
StringBuilder builder;
Vector<String> open_tags;
Style current_style;
for (auto& span : m_spans) {
struct TagAndFlag {
String tag;
bool Style::*flag;
};
TagAndFlag tags_and_flags[] = {
{ "i", &Style::emph },
{ "b", &Style::strong },
{ "code", &Style::code }
};
auto it = open_tags.find([&](const String& open_tag) {
if (open_tag == "a" && current_style.href != span.style.href)
return true;
if (open_tag == "img" && current_style.img != span.style.img)
return true;
for (auto& tag_and_flag : tags_and_flags) {
if (open_tag == tag_and_flag.tag && !(span.style.*tag_and_flag.flag))
return true;
}
return false;
});
if (!it.is_end()) {
// We found an open tag that should
// not be open for the new span. Close
// it and all the open tags that follow
// it.
for (ssize_t j = open_tags.size() - 1; j >= static_cast<ssize_t>(it.index()); --j) {
auto& tag = open_tags[j];
if (tag == "img") {
builder.append("\" />");
current_style.img = {};
continue;
}
builder.appendf("</%s>", tag.characters());
if (tag == "a") {
current_style.href = {};
continue;
}
for (auto& tag_and_flag : tags_and_flags)
if (tag == tag_and_flag.tag)
current_style.*tag_and_flag.flag = false;
}
open_tags.shrink(it.index());
}
if (current_style.href.is_null() && !span.style.href.is_null()) {
open_tags.append("a");
builder.appendf("<a href=\"%s\">", span.style.href.characters());
}
if (current_style.img.is_null() && !span.style.img.is_null()) {
open_tags.append("img");
builder.appendf("<img src=\"%s\" alt=\"", span.style.img.characters());
}
for (auto& tag_and_flag : tags_and_flags) {
if (current_style.*tag_and_flag.flag != span.style.*tag_and_flag.flag) {
open_tags.append(tag_and_flag.tag);
builder.appendf("<%s>", tag_and_flag.tag.characters());
}
}
current_style = span.style;
builder.append(span.text);
}
for (ssize_t i = open_tags.size() - 1; i >= 0; --i) {
auto& tag = open_tags[i];
if (tag == "img") {
builder.append("\" />");
continue;
}
builder.appendf("</%s>", tag.characters());
}
return builder.build();
}
String Text::render_for_terminal() const
{
StringBuilder builder;
for (auto& span : m_spans) {
bool needs_styling = span.style.strong || span.style.emph || span.style.code;
if (needs_styling) {
builder.append("\033[");
bool first = true;
if (span.style.strong || span.style.code) {
builder.append('1');
first = false;
}
if (span.style.emph) {
if (!first)
builder.append(';');
builder.append('4');
}
builder.append('m');
}
builder.append(span.text.characters());
if (needs_styling)
builder.append("\033[0m");
if (!span.style.href.is_null()) {
// When rendering for the terminal, ignore any
// non-absolute links, because the user has no
// chance to follow them anyway.
if (strstr(span.style.href.characters(), "://") != nullptr) {
builder.appendf(" <%s>", span.style.href.characters());
}
}
if (!span.style.img.is_null()) {
if (strstr(span.style.img.characters(), "://") != nullptr) {
builder.appendf(" <%s>", span.style.img.characters());
}
}
}
return builder.build();
}
bool Text::parse(const StringView& str)
{
Style current_style;
size_t current_span_start = 0;
int first_span_in_the_current_link = -1;
bool current_link_is_actually_img = false;
auto append_span_if_needed = [&](size_t offset) {
ASSERT(current_span_start <= offset);
if (current_span_start != offset) {
Span span {
unescape(str.substring_view(current_span_start, offset - current_span_start)),
current_style
};
m_spans.append(move(span));
current_span_start = offset;
}
};
for (size_t offset = 0; offset < str.length(); offset++) {
char ch = str[offset];
bool is_escape = ch == '\\';
if (is_escape && offset != str.length() - 1) {
offset++;
continue;
}
bool is_special_character = false;
is_special_character |= ch == '`';
if (!current_style.code)
is_special_character |= ch == '*' || ch == '_' || ch == '[' || ch == ']' || ch == '!';
if (!is_special_character)
continue;
append_span_if_needed(offset);
switch (ch) {
case '`':
current_style.code = !current_style.code;
break;
case '*':
case '_':
if (offset + 1 < str.length() && str[offset + 1] == ch) {
offset++;
current_style.strong = !current_style.strong;
} else {
current_style.emph = !current_style.emph;
}
break;
case '!':
if (offset + 1 >= str.length() || str[offset + 1] != '[')
continue;
current_link_is_actually_img = true;
break;
case '[':
if (first_span_in_the_current_link != -1)
dbg() << "Dropping the outer link";
first_span_in_the_current_link = m_spans.size();
break;
case ']': {
if (first_span_in_the_current_link == -1) {
dbg() << "Unmatched ]";
continue;
}
ScopeGuard guard = [&] {
first_span_in_the_current_link = -1;
current_link_is_actually_img = false;
};
if (offset + 2 >= str.length() || str[offset + 1] != '(')
continue;
offset += 2;
size_t start_of_href = offset;
do
offset++;
while (offset < str.length() && str[offset] != ')');
if (offset == str.length())
offset--;
const StringView href = str.substring_view(start_of_href, offset - start_of_href);
for (size_t i = first_span_in_the_current_link; i < m_spans.size(); i++) {
if (current_link_is_actually_img)
m_spans[i].style.img = href;
else
m_spans[i].style.href = href;
}
break;
}
default:
ASSERT_NOT_REACHED();
}
// We've processed the character as a special, so the next offset will
// start after it. Note that explicit continue statements skip over this
// line, effectively treating the character as not special.
current_span_start = offset + 1;
}
append_span_if_needed(str.length());
return true;
}
}