#ifndef __BACKEND_H__
#define __BACKEND_H__

#include <QObject>
#include <QStringList>
#include <QMap>
#include <QVector>
#include "soc_desc.hpp"
#ifdef HAVE_HWSTUB
#include "hwstub.h"
#endif

class IoBackend : public QObject
{
    Q_OBJECT
public:
    IoBackend() {}
    virtual ~IoBackend() {}

    enum AccessType
    {
        ByName,
        ByAddress,
    };

    /* report whether backend supports register access type */
    virtual bool SupportAccess(AccessType type) = 0;
    /* get SoC name */
    virtual QString GetSocName() = 0;
    /* read a register by name or address */
    virtual bool ReadRegister(const QString& name, soc_word_t& value) = 0;
    virtual bool ReadRegister(soc_addr_t addr, soc_word_t& value) = 0;
    /* reload content (if it makes sense) */
    virtual bool Reload() = 0;
    /* check whether backend supports writing */
    virtual bool IsReadOnly() = 0;
    /* write a register by name or address
     * NOTE: even on a read-only backend, a write is allowed be successful as long
     * as commit fails */
    virtual bool WriteRegister(const QString& name, soc_word_t value) = 0;
    virtual bool WriteRegister(soc_addr_t addr, soc_word_t value) = 0;
    /* check whether backend contains uncommitted (ie cached) writes */
    virtual bool IsDirty() = 0;
    /* commit all writes */
    virtual bool Commit() = 0;
};

class DummyIoBackend : public IoBackend
{
    Q_OBJECT
public:
    DummyIoBackend() {}

    virtual bool SupportAccess(AccessType type) { (void) type; return false; }
    virtual QString GetSocName() { return ""; }
    virtual bool ReadRegister(const QString& name, soc_word_t& value) 
        { (void) name; (void) value; return false; }
    virtual bool ReadRegister(soc_addr_t addr, soc_word_t& value) 
        { (void) addr; (void) value; return false; }
    virtual bool Reload() { return false; }
    virtual bool IsReadOnly() { return true; }
    virtual bool WriteRegister(const QString& name, soc_word_t value)
        { (void) name; (void) value; return false; }
    virtual bool WriteRegister(soc_addr_t addr, soc_word_t value)
        { (void) addr; (void) value; return false; }
    virtual bool IsDirty() { return false; }
    virtual bool Commit() { return false; }
};

/** NOTE the File backend makes a difference between writes and commits:
 * a write will *never* touch the underlying file unless it was committed. */
class FileIoBackend : public IoBackend
{
    Q_OBJECT
public:
    FileIoBackend(const QString& filename);

    virtual bool SupportAccess(AccessType type) { return type == ByName; }
    virtual QString GetSocName();
    virtual bool ReadRegister(const QString& name, soc_word_t& value);
    virtual bool ReadRegister(soc_addr_t addr, soc_word_t& value)
        { (void) addr; (void) value; return false; }
    virtual bool Reload();
    virtual bool IsReadOnly() { return m_readonly; }
    virtual bool WriteRegister(const QString& name, soc_word_t value);
    virtual bool WriteRegister(soc_addr_t addr, soc_word_t value)
        { (void) addr; (void) value; return false; }
    virtual bool IsDirty() { return m_dirty; }
    virtual bool Commit();

protected:
    QString m_filename;
    QString m_soc;
    bool m_readonly;
    bool m_dirty;
    QMap< QString, soc_word_t > m_map;
};

#ifdef HAVE_HWSTUB
class HWStubDevice
{
public:
    HWStubDevice(struct libusb_device *dev);
    ~HWStubDevice();
    bool IsValid();
    bool Open();
    void Close();
    int GetBusNumber();
    int GetDevAddress();
    /* Calls below are cached and do not require the device to be opened */
    inline struct hwstub_version_desc_t GetVersionInfo() { return m_hwdev_ver; }
    inline struct hwstub_target_desc_t GetTargetInfo() { return m_hwdev_target; }
    inline struct hwstub_stmp_desc_t GetSTMPInfo() { return m_hwdev_stmp; }
    /* Calls below require the device to be opened */
    bool ReadMem(soc_addr_t addr, size_t length, void *buffer);
    bool WriteMem(soc_addr_t addr, size_t length, void *buffer);

protected:
    bool Probe();

    bool m_valid;
    struct libusb_device *m_dev;
    libusb_device_handle *m_handle;
    struct hwstub_device_t *m_hwdev;
    struct hwstub_version_desc_t m_hwdev_ver;
    struct hwstub_target_desc_t m_hwdev_target;
    struct hwstub_stmp_desc_t m_hwdev_stmp;
};

/** NOTE the HWStub backend is never dirty: all writes are immediately committed */
class HWStubIoBackend : public IoBackend
{
    Q_OBJECT
public:
    HWStubIoBackend(HWStubDevice *dev);
    virtual ~HWStubIoBackend();

    virtual bool SupportAccess(AccessType type) { return type == ByAddress; }
    virtual QString GetSocName();
    virtual bool ReadRegister(const QString& name, soc_word_t& value)
        { (void) name; (void) value; return false; }
    virtual bool ReadRegister(soc_addr_t addr, soc_word_t& value);
    virtual bool Reload();
    virtual bool IsReadOnly() { return false; }
    virtual bool WriteRegister(const QString& name, soc_word_t value)
        { (void) name; (void) value; return false; }
    virtual bool WriteRegister(soc_addr_t addr, soc_word_t value);
    virtual bool IsDirty() { return false; }
    virtual bool Commit() { return true; }

protected:
    QString m_soc;
    HWStubDevice *m_dev;
};

#if LIBUSB_API_VERSION < 0x01000102
#define LIBUSB_NO_HOTPLUG
#endif

class HWStubBackendHelper : public QObject
{
    Q_OBJECT
public:
    HWStubBackendHelper();
    ~HWStubBackendHelper();
    bool HasHotPlugSupport();
    QList< HWStubDevice* > GetDevList();

signals:
    void OnDevListChanged(bool arrived, struct libusb_device *dev);

protected:
#ifndef LIBUSB_NO_HOTPLUG
    void OnHotPlug(bool arrived, struct libusb_device *dev);
    static int HotPlugCallback(struct libusb_context *ctx, struct libusb_device *dev,
        libusb_hotplug_event event, void *user_data);
    libusb_hotplug_callback_handle m_hotplug_handle;
#endif
    bool m_hotplug;
};
#endif

class SocRef
{
public:
    SocRef():m_soc(0) {}
    SocRef(const soc_t *soc):m_soc(soc) {}
    const soc_t& GetSoc() const { return *m_soc; }
protected:
    const soc_t *m_soc;
};

class SocDevRef : public SocRef
{
public:
    SocDevRef() {}
    SocDevRef(const SocRef& soc, int dev_idx, int dev_addr_idx)
        :SocRef(soc), m_dev_idx(dev_idx), m_dev_addr_idx(dev_addr_idx) {}
    int GetDevIndex() const { return m_dev_idx; }
    const soc_dev_t& GetDev() const { return GetSoc().dev[GetDevIndex()]; }
    int GetDevAddrIndex() const { return m_dev_addr_idx; }
    const soc_dev_addr_t& GetDevAddr() const { return GetDev().addr[GetDevAddrIndex()]; }
protected:
    int m_dev_idx, m_dev_addr_idx;
};

class SocRegRef : public SocDevRef
{
public:
    SocRegRef() {}
    SocRegRef(const SocDevRef& dev, int reg_idx, int reg_addr_idx)
        :SocDevRef(dev), m_reg_idx(reg_idx), m_reg_addr_idx(reg_addr_idx) {}
    int GetRegIndex() const { return m_reg_idx; }
    const soc_reg_t& GetReg() const { return GetDev().reg[GetRegIndex()]; }
    int GetRegAddrIndex() const { return m_reg_addr_idx; }
    const soc_reg_addr_t& GetRegAddr() const { return GetReg().addr[GetRegAddrIndex()]; }
protected:
    int m_reg_idx, m_reg_addr_idx;
};

class SocFieldRef : public SocRegRef
{
public:
    SocFieldRef(){}
    SocFieldRef(const SocRegRef& reg, int field_idx)
        :SocRegRef(reg), m_field_idx(field_idx) {}
    int GetFieldIndex() const { return m_field_idx; }
    const soc_reg_field_t& GetField() const { return GetReg().field[GetFieldIndex()]; }
protected:
    int m_field_idx;
};

class Backend : public QObject
{
    Q_OBJECT
public:
    Backend();

    QStringList GetSocNameList();
    bool LoadSocDesc(const QString& filename);
    bool GetSocByName(const QString& name, SocRef& s);
    IoBackend *CreateDummyIoBackend();
    IoBackend *CreateFileIoBackend(const QString& filename);
#ifdef HAVE_HWSTUB
    IoBackend *CreateHWStubIoBackend(HWStubDevice *dev);
#endif

signals:
    void OnSocListChanged();
private:
    std::list< soc_t > m_socs;
};

class BackendHelper
{
public:
    BackendHelper(IoBackend *io_backend, const SocRef& soc);
    bool ReadRegister(const QString& dev, const QString& reg, soc_word_t& v);
    bool ReadRegisterField(const QString& dev, const QString& reg,
        const QString& field, soc_word_t& v);
    bool GetDevRef(const QString& dev, SocDevRef& ref);
    bool GetRegRef(const SocDevRef& dev, const QString& reg, SocRegRef& ref);
    bool GetFieldRef(const SocRegRef& reg, const QString& field, SocFieldRef& ref);
    bool GetRegisterAddress(const QString& dev, const QString& reg, soc_addr_t& addr);
private:
    IoBackend *m_io_backend;
    const SocRef& m_soc;
};

#endif /* __BACKEND_H__ */