#pragma once

#include <list>
#include <map>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>

#include <QObject>
#include <QMutex>
#include <QString>
#include <QtCore/qglobal.h>

#include <nlohmannjson.hpp>
#include <eui_frameworkSdk/TranslationInterfaces.h>

#define translationLRUCacheCapacity 3000
using json = nlohmann::json;

#ifndef EUI_SERVICE_API
#  if defined(EUI_SERVICE_LIBRARY)
#    define EUI_SERVICE_API Q_DECL_EXPORT
#  else
#    define EUI_SERVICE_API Q_DECL_IMPORT
#  endif
#endif

class EUI_SERVICE_API translationLRUCache {
public:
    explicit translationLRUCache(int capacity);

    bool contains(const std::string& key, std::string& value);
    void put(const std::string& key, const std::string& value);
    bool remove(const std::string& key);
    int size();
    int capacity();
    bool isEmpty();
    void clear();

private:
    using EntryList = std::list<std::pair<std::string, std::string>>;

    QMutex mutex;
    int maxCapacity;
    // 标准 LRU 结构：链表头部为最近使用项，哈希表提供 O(1) 查找
    EntryList entries;
    std::unordered_map<std::string, EntryList::iterator> index;
};

class Translation : public eui_frameworkSdk::ITranslation {
public:
    Translation();
private:
    translationLRUCache translatedCache{ translationLRUCacheCapacity };
    std::vector<std::string> sections;
    std::vector<std::map<std::string, std::map<std::string, std::string>, std::less<>>> basicTranslations;
    std::string currentLanguage = "zh-CN";
    std::string translationFilePath_;
    mutable QMutex mutex;

    Translation(const Translation&) = delete;
    Translation& operator=(const Translation&) = delete;

public:
    EUI_SERVICE_API bool loadFromFile(const std::string& filePath);
    EUI_SERVICE_API bool loadFromString(const std::string& jsonString);
    EUI_SERVICE_API bool loadFromJson(const json& j);
    EUI_SERVICE_API bool setLanguage(const std::string& lang) override;
    EUI_SERVICE_API std::string getCurrentLanguage() const override;
    EUI_SERVICE_API std::string translate(const std::string& key) override;
    EUI_SERVICE_API std::string translate(const std::string& key, const std::string& lang) override;
    EUI_SERVICE_API std::vector<std::pair<std::string, std::string>> getAllTranslateResult(const std::string& key);
    EUI_SERVICE_API void addSection(const std::string& lang);
    // 返回副本：返回引用会在 addSection 触发扩容时悬空
    EUI_SERVICE_API std::vector<std::string> getSections() const override;
    EUI_SERVICE_API bool hasTranslation(const std::string& key) const;
    EUI_SERVICE_API std::vector<std::string> getAllKeys();
    EUI_SERVICE_API bool saveToFile(const std::string& filePath);

private:
    json originalJson;

    bool parseJson_unsafe(const json& j);
    void syncJson_unsafe();
    std::string translate_unsafe(const std::string& key);
    std::string translate_unsafe(const std::string& key, const std::string& lang);
    bool addSection_unsafe(const std::string& lang);
};

EUI_SERVICE_API Translation& appTranslation();
EUI_SERVICE_API eui_frameworkSdk::ITranslation& appTranslationService();

#define TR(key) QString::fromStdString(appTranslation().translate(key))