#ifndef QEVENTBUS_H
#define QEVENTBUS_H

#include <QObject>
#include <QMap>
#include <QList>
#include <QMutex>
#include <QVariant>
#include <QDateTime>
#include <QMetaMethod>

// 事件类型定义
namespace EventType {
    const QString ORDER_PROCESSED = "order.processed";
    const QString BIG_ORDER_DETECTED = "bigorder.detected";
    const QString SUBSCRIPTION_CHANGED = "subscription.changed";
    const QString CONNECTION_STATUS_CHANGED = "connection.status.changed";
    const QString SYSTEM_ERROR = "system.error";
    const QString PROCESSING_STARTED = "processing.started";
    const QString PROCESSING_FINISHED = "processing.finished";
}

struct Event {
    QString type;
    QVariant data;
    QDateTime timestamp;
    QString source;
    
    Event() : timestamp(QDateTime::currentDateTime()) {}
    Event(const QString& type, const QVariant& data = QVariant(), const QString& source = "")
        : type(type), data(data), timestamp(QDateTime::currentDateTime()), source(source) {}
};

class QEventBus : public QObject
{
    Q_OBJECT
public:
    static QEventBus* instance();
    
    // 事件发布/订阅
    void publish(const QString& eventType, const QVariant& data = QVariant(), 
                 const QString& source = "");
    void subscribe(const QString& eventType, QObject* receiver, const char* method);
    void unsubscribe(const QString& eventType, QObject* receiver);
    void unsubscribeAll(QObject* receiver);
    
    // 事件历史
    QList<Event> getEventHistory(const QString& type = "", int limit = 100) const;
    void clearEventHistory();
    
    // 统计信息
    int getEventCount(const QString& type = "") const;
    QMap<QString, int> getEventStatistics() const;
    
signals:
    void eventPublished(const Event& event);

private:
    explicit QEventBus(QObject *parent = nullptr);
    ~QEventBus();
    
    struct Subscription {
        QObject* receiver;
        QByteArray method;
        int connectionType; // 0: auto, 1: queued, 2: blocking
    };
    
    QMap<QString, QList<Subscription>> m_subscriptions;
    QList<Event> m_eventHistory;
    mutable QMutex m_mutex;
    int m_maxHistorySize = 1000;
    
    // 连接类型枚举
    enum ConnectionType {
        AutoConnection = 0,
        QueuedConnection = 1,
        BlockingQueuedConnection = 2
    };
};

#endif // QEVENTBUS_H