/*
 * 86Box    A hypervisor and IBM PC system emulator that specializes in
 *          running old operating systems and software designed for IBM
 *          PC systems and compatibles from 1981 through fairly recent
 *          system designs based on the PCI bus.
 *
 *          This file is part of the 86Box distribution.
 *
 *          Header for the media history management module
 *
 *
 *
 * Authors: cold-brewed
 *
 *          Copyright 2022 The 86Box development team
 */

#ifndef QT_MEDIAHISTORYMANAGER_HPP
#define QT_MEDIAHISTORYMANAGER_HPP

#include <QString>
#include <QWidget>
#include <QVector>

#include <initializer_list>

extern "C" {
#include <86box/86box.h>
}

// This macro helps give us the required `qHash()` function in order to use the
// enum as a hash key
#define QHASH_FOR_CLASS_ENUM(T)                                                       \
    inline uint qHash(const T &t, uint seed)                                          \
    {                                                                                 \
        return ::qHash(static_cast<typename std::underlying_type<T>::type>(t), seed); \
    }

typedef QVector<QString>             device_index_list_t;
typedef QHash<int, QVector<QString>> device_media_history_t;

namespace ui {
Q_NAMESPACE

enum class MediaType {
    Floppy,
    Optical,
    Zip,
    Mo,
    Cassette
};
// This macro allows us to do a reverse lookup of the enum with `QMetaEnum`
Q_ENUM_NS(MediaType)

QHASH_FOR_CLASS_ENUM(MediaType)

typedef QHash<ui::MediaType, device_media_history_t> master_list_t;

// Used to iterate over all supported types when preparing data structures
// Also useful to indicate which types support history
static const MediaType AllSupportedMediaHistoryTypes[] = {
    MediaType::Optical,
    MediaType::Floppy,
};

class MediaHistoryManager {

public:
    MediaHistoryManager();
    virtual ~MediaHistoryManager();

    // Get the image name for a particular slot,
    // index, and type combination
    QString getImageForSlot(int index, int slot, ui::MediaType type);

    // Add an image to history
    void addImageToHistory(int index, ui::MediaType type, const QString &image_name, const QString &new_image_name);

    // Convert the enum value to a string
    static QString mediaTypeToString(ui::MediaType type);

    // Clear out the image history
    void clearImageHistory();

private:
    int max_images = MAX_PREV_IMAGES;

    // Main hash of hash of vector of strings
    master_list_t                      master_list;
    [[nodiscard]] const master_list_t &getMasterList() const;
    void                               setMasterList(const master_list_t &masterList);

    device_index_list_t index_list, empty_device_index_list;

    // Return a blank, initialized image history list
    master_list_t &blankImageHistory(master_list_t &initialized_master_list) const;

    // Initialize the image history
    void initializeImageHistory();

    // Max number of devices supported by media type
    static int maxDevicesSupported(ui::MediaType type);

    // Serialize the data back into the C array
    // on the emu side
    void serializeImageHistoryType(ui::MediaType type);
    void serializeAllImageHistory();

    // Deserialize the data from C array on the emu side
    // for the ui side
    void deserializeImageHistoryType(ui::MediaType type);
    void deserializeAllImageHistory();

    // Get emu history variable for a device type
    static char **getEmuHistoryVarForType(ui::MediaType type, int index);

    // Get or set the history for a specific device/index combo
    const device_index_list_t &getHistoryListForDeviceIndex(int index, ui::MediaType type);
    void                       setHistoryListForDeviceIndex(int index, ui::MediaType type, device_index_list_t history_list);

    // Remove missing image files from history list
    static device_index_list_t &removeMissingImages(device_index_list_t &device_history);

    // If an absolute path is contained within `usr_path`, convert to a relative path
    static device_index_list_t &pathAdjustFull(device_index_list_t &device_history);
    static QString              pathAdjustSingle(QString checked_path);

    // Deduplicate history entries
    static device_index_list_t &deduplicateList(device_index_list_t &device_history, const QVector<QString> &filenames);
    void                        initialDeduplication();

    // Gets the `usr_path` from the emu side and appends a
    // trailing slash if necessary
    static QString getUsrPath();
};

} // ui

#endif // QT_MEDIAHISTORYMANAGER_HPP