refactor(message-builder): move static helper methods to functions

CHANGELOG.md

@@ -107,6 +107,7 @@
 - Dev: Twitch messages are now sent using Twitch's Helix API instead of IRC by default. (#5607)
 - Dev: `GIFTimer` is no longer initialized in tests. (#5608)
 - Dev: Emojis now use flags instead of a set of strings for capabilities. (#5616)
+- Dev: Removed static `MessageBuilder` helpers to standalone functions. (#5652)
 
 ## 2.5.1
 

src/CMakeLists.txt

@@ -409,6 +409,8 @@ set(SOURCE_FILES
         providers/twitch/TwitchEmotes.hpp
         providers/twitch/TwitchHelpers.cpp
         providers/twitch/TwitchHelpers.hpp
+        providers/twitch/TwitchIrc.cpp
+        providers/twitch/TwitchIrc.hpp
         providers/twitch/TwitchIrcServer.cpp
         providers/twitch/TwitchIrcServer.hpp
         providers/twitch/TwitchUser.cpp

src/controllers/ignores/IgnoreController.cpp

@@ -1,12 +1,134 @@
 #include "controllers/ignores/IgnoreController.hpp"
 
 #include "Application.hpp"
+#include "common/Literals.hpp"
 #include "common/QLogging.hpp"
 #include "controllers/accounts/AccountController.hpp"
 #include "controllers/ignores/IgnorePhrase.hpp"
 #include "providers/twitch/TwitchAccount.hpp"
+#include "providers/twitch/TwitchIrc.hpp"
 #include "singletons/Settings.hpp"
 
+namespace {
+
+using namespace chatterino::literals;
+
+/**
+  * Computes (only) the replacement of @a match in @a source.
+  * The parts before and after the match in @a source are ignored.
+  *
+  * Occurrences of \b{\\1}, \b{\\2}, ..., in @a replacement are replaced
+  * with the string captured by the corresponding capturing group.
+  * This function should only be used if the regex contains capturing groups.
+  * 
+  * Since Qt doesn't provide a way of replacing a single match with some replacement
+  * while supporting both capturing groups and lookahead/-behind in the regex,
+  * this is included here. It's essentially the implementation of 
+  * QString::replace(const QRegularExpression &, const QString &).
+  * @see https://github.com/qt/qtbase/blob/97bb0ecfe628b5bb78e798563212adf02129c6f6/src/corelib/text/qstring.cpp#L4594-L4703
+  */
+QString makeRegexReplacement(QStringView source,
+                             const QRegularExpression &regex,
+                             const QRegularExpressionMatch &match,
+                             const QString &replacement)
+{
+    using SizeType = QString::size_type;
+    struct QStringCapture {
+        SizeType pos;
+        SizeType len;
+        int captureNumber;
+    };
+
+    qsizetype numCaptures = regex.captureCount();
+
+    // 1. build the backreferences list, holding where the backreferences
+    //    are in the replacement string
+    QVarLengthArray<QStringCapture> backReferences;
+
+    SizeType replacementLength = replacement.size();
+    for (SizeType i = 0; i < replacementLength - 1; i++)
+    {
+        if (replacement[i] != u'\\')
+        {
+            continue;
+        }
+
+        int no = replacement[i + 1].digitValue();
+        if (no <= 0 || no > numCaptures)
+        {
+            continue;
+        }
+
+        QStringCapture backReference{.pos = i, .len = 2};
+
+        if (i < replacementLength - 2)
+        {
+            int secondDigit = replacement[i + 2].digitValue();
+            if (secondDigit != -1 && ((no * 10) + secondDigit) <= numCaptures)
+            {
+                no = (no * 10) + secondDigit;
+                ++backReference.len;
+            }
+        }
+
+        backReference.captureNumber = no;
+        backReferences.append(backReference);
+    }
+
+    // 2. iterate on the matches.
+    //    For every match, copy the replacement string in chunks
+    //    with the proper replacements for the backreferences
+
+    // length of the new string, with all the replacements
+    SizeType newLength = 0;
+    QVarLengthArray<QStringView> chunks;
+    QStringView replacementView{replacement};
+
+    // Initially: empty, as we only care about the replacement
+    SizeType len = 0;
+    SizeType lastEnd = 0;
+    for (const QStringCapture &backReference : std::as_const(backReferences))
+    {
+        // part of "replacement" before the backreference
+        len = backReference.pos - lastEnd;
+        if (len > 0)
+        {
+            chunks << replacementView.mid(lastEnd, len);
+            newLength += len;
+        }
+
+        // backreference itself
+        len = match.capturedLength(backReference.captureNumber);
+        if (len > 0)
+        {
+            chunks << source.mid(
+                match.capturedStart(backReference.captureNumber), len);
+            newLength += len;
+        }
+
+        lastEnd = backReference.pos + backReference.len;
+    }
+
+    // add the last part of the replacement string
+    len = replacementView.size() - lastEnd;
+    if (len > 0)
+    {
+        chunks << replacementView.mid(lastEnd, len);
+        newLength += len;
+    }
+
+    // 3. assemble the chunks together
+    QString dst;
+    dst.reserve(newLength);
+    for (const QStringView &chunk : std::as_const(chunks))
+    {
+        dst += chunk;
+    }
+    return dst;
+}
+
+}  // namespace
+
 namespace chatterino {
 
 bool isIgnoredMessage(IgnoredMessageParameters &&params)
@@ -65,4 +187,187 @@ bool isIgnoredMessage(IgnoredMessageParameters &&params)
     return false;
 }
 
+void processIgnorePhrases(const std::vector<IgnorePhrase> &phrases,
+                          QString &content,
+                          std::vector<twitchirc::EmoteOccurrence> &twitchEmotes)
+{
+    using SizeType = QString::size_type;
+
+    auto removeEmotesInRange = [&twitchEmotes](SizeType pos, SizeType len) {
+        // all emotes outside the range come before `it`
+        // all emotes in the range start at `it`
+        auto it = std::partition(
+            twitchEmotes.begin(), twitchEmotes.end(),
+            [pos, len](const auto &item) {
+                // returns true for emotes outside the range
+                return !((item.start >= pos) && item.start < (pos + len));
+            });
+        std::vector<twitchirc::EmoteOccurrence> emotesInRange(
+            it, twitchEmotes.end());
+        twitchEmotes.erase(it, twitchEmotes.end());
+        return emotesInRange;
+    };
+
+    auto shiftIndicesAfter = [&twitchEmotes](int pos, int by) {
+        for (auto &item : twitchEmotes)
+        {
+            auto &index = item.start;
+            if (index >= pos)
+            {
+                index += by;
+                item.end += by;
+            }
+        }
+    };
+
+    auto addReplEmotes = [&twitchEmotes](const IgnorePhrase &phrase,
+                                         const auto &midrepl,
+                                         SizeType startIndex) {
+        if (!phrase.containsEmote())
+        {
+            return;
+        }
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+        auto words = midrepl.tokenize(u' ');
+#else
+        auto words = midrepl.split(' ');
+#endif
+        SizeType pos = 0;
+        for (const auto &word : words)
+        {
+            for (const auto &emote : phrase.getEmotes())
+            {
+                if (word == emote.first.string)
+                {
+                    if (emote.second == nullptr)
+                    {
+                        qCDebug(chatterinoTwitch)
+                            << "emote null" << emote.first.string;
+                    }
+                    twitchEmotes.push_back(twitchirc::EmoteOccurrence{
+                        static_cast<int>(startIndex + pos),
+                        static_cast<int>(startIndex + pos +
+                                         emote.first.string.length()),
+                        emote.second,
+                        emote.first,
+                    });
+                }
+            }
+            pos += word.length() + 1;
+        }
+    };
+
+    auto replaceMessageAt = [&](const IgnorePhrase &phrase, SizeType from,
+                                SizeType length, const QString &replacement) {
+        auto removedEmotes = removeEmotesInRange(from, length);
+        content.replace(from, length, replacement);
+        auto wordStart = from;
+        while (wordStart > 0)
+        {
+            if (content[wordStart - 1] == ' ')
+            {
+                break;
+            }
+            --wordStart;
+        }
+        auto wordEnd = from + replacement.length();
+        while (wordEnd < content.length())
+        {
+            if (content[wordEnd] == ' ')
+            {
+                break;
+            }
+            ++wordEnd;
+        }
+
+        shiftIndicesAfter(static_cast<int>(from + length),
+                          static_cast<int>(replacement.length() - length));
+
+        auto midExtendedRef =
+            QStringView{content}.mid(wordStart, wordEnd - wordStart);
+
+        for (auto &emote : removedEmotes)
+        {
+            if (emote.ptr == nullptr)
+            {
+                qCDebug(chatterinoTwitch)
+                    << "Invalid emote occurrence" << emote.name.string;
+                continue;
+            }
+            QRegularExpression emoteregex(
+                "\\b" + emote.name.string + "\\b",
+                QRegularExpression::UseUnicodePropertiesOption);
+#if QT_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+            auto match = emoteregex.matchView(midExtendedRef);
+#else
+            auto match = emoteregex.match(midExtendedRef);
+#endif
+            if (match.hasMatch())
+            {
+                emote.start = static_cast<int>(from + match.capturedStart());
+                emote.end = static_cast<int>(from + match.capturedEnd());
+                twitchEmotes.push_back(std::move(emote));
+            }
+        }
+
+        addReplEmotes(phrase, midExtendedRef, wordStart);
+    };
+
+    for (const auto &phrase : phrases)
+    {
+        if (phrase.isBlock())
+        {
+            continue;
+        }
+        const auto &pattern = phrase.getPattern();
+        if (pattern.isEmpty())
+        {
+            continue;
+        }
+        if (phrase.isRegex())
+        {
+            const auto &regex = phrase.getRegex();
+            if (!regex.isValid())
+            {
+                continue;
+            }
+
+            QRegularExpressionMatch match;
+            size_t iterations = 0;
+            SizeType from = 0;
+            while ((from = content.indexOf(regex, from, &match)) != -1)
+            {
+                auto replacement = phrase.getReplace();
+                if (regex.captureCount() > 0)
+                {
+                    replacement = makeRegexReplacement(content, regex, match,
+                                                       replacement);
+                }
+
+                replaceMessageAt(phrase, from, match.capturedLength(),
+                                 replacement);
+                from += phrase.getReplace().length();
+                iterations++;
+                if (iterations >= 128)
+                {
+                    content = u"Too many replacements - check your ignores!"_s;
+                    return;
+                }
+            }
+
+            continue;
+        }
+
+        SizeType from = 0;
+        while ((from = content.indexOf(pattern, from,
+                                       phrase.caseSensitivity())) != -1)
+        {
+            replaceMessageAt(phrase, from, pattern.length(),
+                             phrase.getReplace());
+            from += phrase.getReplace().length();
+        }
+    }
+}
+
 }  // namespace chatterino

src/controllers/ignores/IgnoreController.hpp

@@ -2,8 +2,16 @@
 
 #include <QString>
 
+#include <vector>
+
 namespace chatterino {
 
+class IgnorePhrase;
+
+namespace twitchirc {
+    struct EmoteOccurrence;
+}  // namespace twitchirc
+
 enum class ShowIgnoredUsersMessages { Never, IfModerator, IfBroadcaster };
 
 struct IgnoredMessageParameters {
@@ -16,4 +24,17 @@ struct IgnoredMessageParameters {
 
 bool isIgnoredMessage(IgnoredMessageParameters &&params);
 
+/// @brief Processes replacement ignore-phrases for a message
+///
+/// @param phrases A list of IgnorePhrases to process. Block phrases as well as
+/// 	           invalid phrases are ignored.
+/// @param content The message text. This gets altered by replacements.
+/// @param twitchEmotes A list of emotes present in the message. Occurrences
+///                     that have been removed from the message will also be
+///                     removed in this list. Similarly, if new emotes are added
+///                     from a replacement, this list gets updated as well.
+void processIgnorePhrases(
+    const std::vector<IgnorePhrase> &phrases, QString &content,
+    std::vector<twitchirc::EmoteOccurrence> &twitchEmotes);
+
 }  // namespace chatterino