switch to qdcss for parsing

make it not horrible to look at

Signed-off-by: kumquat-ir <66188216+kumquat-ir@users.noreply.github.com>

libraries/qdcss/src/qdcss.cpp

@@ -0,0 +1,49 @@
+#include "qdcss.h"
+
+#include <QRegularExpression>
+#include <QRegularExpressionMatch>
+#include <QRegularExpressionMatchIterator>
+
+QRegularExpression ruleset_re = QRegularExpression(R"([#.]?(@?\w+?)\s*\{(.*?)\})", QRegularExpression::DotMatchesEverythingOption);
+QRegularExpression rule_re = QRegularExpression(R"((\S+?)\s*:\s*(?:\"(.*?)(?<!\\)\"|'(.*?)(?<!\\)'|(\S+?))\s*(?:;|$))");
+
+QDCSS::QDCSS(QString s)
+{
+    // not much error handling over here...
+    // the original java code used indeces returned by the matcher for them, but QRE does not expose those
+    QRegularExpressionMatchIterator ruleset_i = ruleset_re.globalMatch(s);
+    while (ruleset_i.hasNext()) {
+        QRegularExpressionMatch ruleset = ruleset_i.next();
+        QString selector = ruleset.captured(1);
+        QString rules = ruleset.captured(2);
+        QRegularExpressionMatchIterator rule_i = rule_re.globalMatch(rules);
+        while (rule_i.hasNext()) {
+            QRegularExpressionMatch rule = rule_i.next();
+            QString property = rule.captured(1);
+            QString value;
+            if (!rule.captured(2).isNull()) {
+                value = rule.captured(2);
+            } else if (!rule.captured(3).isNull()) {
+                value = rule.captured(3);
+            } else {
+                value = rule.captured(4);
+            }
+            QString key = selector + "." + property;
+            if (!m_data.contains(key)) {
+                m_data.insert(key, QStringList());
+            }
+            m_data.find(key)->append(value);
+        }
+    }
+}
+
+std::optional<QString>* QDCSS::get(QString key)
+{
+    auto found = m_data.find(key);
+
+    if (found == m_data.end() || found->empty()) {
+        return new std::optional<QString>;
+    }
+
+    return new std::optional<QString>(found->back());
+}