Add translator core, mailitem model, main.cpp, and en translation

src/core/translator.cpp

@@ -0,0 +1,59 @@
+#include "translator.h"
+#include <QFile>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QDebug>
+
+Translator& Translator::instance()
+{
+    static Translator instance;
+    return instance;
+}
+
+bool Translator::loadLanguage(const QString& langCode)
+{
+    QMutexLocker locker(&m_mutex);
+    m_translations.clear();
+
+    QString filePath = QStringLiteral("resources/translations/%1/resources.json").arg(langCode);
+    QFile file(filePath);
+    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
+        qWarning() << "Failed to open translation file:" << filePath;
+        return false;
+    }
+
+    QByteArray jsonData = file.readAll();
+    file.close();
+
+    QJsonParseError parseError;
+    QJsonDocument doc = QJsonDocument::fromJson(jsonData, &parseError);
+    if (parseError.error != QJsonParseError::NoError) {
+        qWarning() << "Failed to parse translation JSON:" << parseError.errorString();
+        return false;
+    }
+
+    if (!doc.isObject()) {
+        qWarning() << "Translation JSON is not an object";
+        return false;
+    }
+
+    QJsonObject obj = doc.object();
+    for (auto it = obj.begin(); it != obj.end(); ++it) {
+        if (it.value().isString()) {
+            m_translations.insert(it.key(), it.value().toString());
+        }
+    }
+
+    m_currentLang = langCode;
+    return true;
+}
+
+QString Translator::tr(const QString& key) const
+{
+    QMutexLocker locker(&m_mutex);
+    auto it = m_translations.find(key);
+    if (it != m_translations.end()) {
+        return it.value();
+    }
+    return key; // fallback to key
+}

src/core/translator.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <QString>
+#include <QMap>
+#include <QMutex>
+
+class Translator
+{
+public:
+    static Translator& instance();
+    ~Translator() = default;
+
+    // Load translation file for given language code (e.g., "en_US")
+    bool loadLanguage(const QString& langCode);
+
+    // Translate a key, returns translated string or key if not found
+    QString tr(const QString& key) const;
+
+    // Get current language code
+    QString currentLanguage() const { return m_currentLang; }
+
+private:
+    Translator() = default;
+    Q_DISABLE_COPY(Translator)
+
+    QMap<QString, QString> m_translations;
+    QString m_currentLang;
+    mutable QMutex m_mutex;
+};

src/main.cpp

@@ -0,0 +1,19 @@
+#include <QCoreApplication>
+#include <QDebug>
+#include "core/translator.h"
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication app(argc, argv);
+
+    // Load English translation
+    Translator& translator = Translator::instance();
+    if (!translator.loadLanguage("en_US")) {
+        qWarning() << "Failed to load translation";
+    }
+
+    qDebug() << translator.tr("appName");
+    qDebug() << translator.tr("welcomeMessage");
+
+    return 0;
+}