/*
 * barrier -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2002 Chris Schoeneman
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include "barrier/clipboard_types.h"
#include "barrier/IClipboard.h"
#include "common/stdmap.h"
#include "common/stdlist.h"
#include "common/stdvector.h"
#include "XWindowsImpl.h"

#include <X11/Xlib.h>

class IXWindowsClipboardConverter;

//! X11 clipboard implementation
class XWindowsClipboard : public IClipboard {
public:
    /*!
    Use \c window as the window that owns or interacts with the
    clipboard identified by \c id.
    */
    XWindowsClipboard(IXWindowsImpl* impl, Display*, Window window,
                      ClipboardID id);
    virtual ~XWindowsClipboard();

    //! Notify clipboard was lost
    /*!
    Tells clipboard it lost ownership at the given time.
    */
    void                lost(Time);

    //! Add clipboard request
    /*!
    Adds a selection request to the request list.  If the given
    owner window isn't this clipboard's window then this simply
    sends a failure event to the requestor.
    */
    void                addRequest(Window owner,
                            Window requestor, Atom target,
                            ::Time time, Atom property);

    //! Process clipboard request
    /*!
    Continues processing a selection request.  Returns true if the
    request was handled, false if the request was unknown.
    */
    bool                processRequest(Window requestor,
                            ::Time time, Atom property);

    //! Cancel clipboard request
    /*!
    Terminate a selection request.  Returns true iff the request
    was known and handled.
    */
    bool                destroyRequest(Window requestor);

    //! Get window
    /*!
    Returns the clipboard's window (passed the c'tor).
    */
    Window                getWindow() const;

    //! Get selection atom
    /*!
    Returns the selection atom that identifies the clipboard to X11
    (e.g. XA_PRIMARY).
    */
    Atom                getSelection() const;

    // IClipboard overrides
    virtual bool        empty();
    virtual void add(EFormat, const std::string& data);
    virtual bool        open(Time) const;
    virtual void        close() const;
    virtual Time        getTime() const;
    virtual bool        has(EFormat) const;
    virtual std::string get(EFormat) const;

private:
    // remove all converters from our list
    void                clearConverters();

    // get the converter for a clipboard format.  returns NULL if no
    // suitable converter.  iff onlyIfNotAdded is true then also
    // return NULL if a suitable converter was found but we already
    // have data of the converter's clipboard format.
    IXWindowsClipboardConverter*
                        getConverter(Atom target,
                            bool onlyIfNotAdded = false) const;

    // convert target atom to clipboard format
    EFormat                getFormat(Atom target) const;

    // add a non-MULTIPLE request.  does not verify that the selection
    // was owned at the given time.  returns true if the conversion
    // could be performed, false otherwise.  in either case, the
    // reply is inserted.
    bool                addSimpleRequest(
                            Window requestor, Atom target,
                            ::Time time, Atom property);

    // if not already checked then see if the cache is stale and, if so,
    // clear it.  this has the side effect of updating m_timeOwned.
    void                checkCache() const;

    // clear the cache, resetting the cached flag and the added flag for
    // each format.
    void                clearCache() const;
    void                doClearCache();

    // cache all formats of the selection
    void                fillCache() const;
    void                doFillCache();

    //
    // helper classes
    //

    // read an ICCCM conforming selection
    class CICCCMGetClipboard {
    public:
        CICCCMGetClipboard(Window requestor, Time time, Atom property);
        ~CICCCMGetClipboard();

        // convert the given selection to the given type.  returns
        // true iff the conversion was successful or the conversion
        // cannot be performed (in which case *actualTarget == None).
        bool            readClipboard(Display* display,
                            Atom selection, Atom target,
                            Atom* actualTarget, std::string* data);

    private:
        bool            processEvent(Display* display, XEvent* event);

    private:
        Window            m_requestor;
        Time            m_time;
        Atom            m_property;
        bool            m_incr;
        bool            m_failed;
        bool            m_done;

        // atoms needed for the protocol
        Atom            m_atomNone;        // NONE, not None
        Atom            m_atomIncr;

        // true iff we've received the selection notify
        bool            m_reading;

        // the converted selection data
        std::string* m_data;

        // the actual type of the data.  if this is None then the
        // selection owner cannot convert to the requested type.
        Atom*            m_actualTarget;

    public:
        // true iff the selection owner didn't follow ICCCM conventions
        bool            m_error;
    };

    // Motif structure IDs
    enum { kMotifClipFormat = 1, kMotifClipItem, kMotifClipHeader };

    // _MOTIF_CLIP_HEADER structure
    class MotifClipHeader {
    public:
        SInt32            m_id;            // kMotifClipHeader
        SInt32            m_pad1[3];
        SInt32            m_item;
        SInt32            m_pad2[4];
        SInt32            m_numItems;
        SInt32            m_pad3[3];
        SInt32            m_selectionOwner;    // a Window
        SInt32            m_pad4[2];
    };

    // Motif clip item structure
    class MotifClipItem {
    public:
        SInt32            m_id;            // kMotifClipItem
        SInt32            m_pad1[5];
        SInt32            m_size;
        SInt32            m_numFormats;
        SInt32            m_numDeletedFormats;
        SInt32            m_pad2[6];
    };

    // Motif clip format structure
    class MotifClipFormat {
    public:
        SInt32            m_id;            // kMotifClipFormat
        SInt32            m_pad1[6];
        SInt32            m_length;
        SInt32            m_data;
        SInt32            m_type;            // an Atom
        SInt32            m_pad2[1];
        SInt32            m_deleted;
        SInt32            m_pad3[4];
    };

    // stores data needed to respond to a selection request
    class Reply {
    public:
        Reply(Window, Atom target, ::Time);
        Reply(Window, Atom target, ::Time, Atom property, const std::string& data,
              Atom type, int format);

    public:
        // information about the request
        Window            m_requestor;
        Atom            m_target;
        ::Time            m_time;
        Atom            m_property;

        // true iff we've sent the notification for this reply
        bool            m_replied;

        // true iff the reply has sent its last message
        bool            m_done;

        // the data to send and its type and format
        std::string m_data;
        Atom            m_type;
        int                m_format;

        // index of next byte in m_data to send
        UInt32            m_ptr;
    };
    typedef std::list<Reply*> ReplyList;
    typedef std::map<Window, ReplyList> ReplyMap;
    typedef std::map<Window, long> ReplyEventMask;

    // ICCCM interoperability methods
    void                icccmFillCache();
    bool icccmGetSelection(Atom target, Atom* actualTarget, std::string* data) const;
    Time                icccmGetTime() const;

    // motif interoperability methods
    bool                motifLockClipboard() const;
    void                motifUnlockClipboard() const;
    bool                motifOwnsClipboard() const;
    void                motifFillCache();
    bool motifGetSelection(const MotifClipFormat*, Atom* actualTarget, std::string* data) const;
    Time                motifGetTime() const;

    // reply methods
    bool                insertMultipleReply(Window, ::Time, Atom);
    void                insertReply(Reply*);
    void                pushReplies();
    void                pushReplies(ReplyMap::iterator&,
                            ReplyList&, ReplyList::iterator);
    bool                sendReply(Reply*);
    void                clearReplies();
    void                clearReplies(ReplyList&);
    void                sendNotify(Window requestor, Atom selection,
                            Atom target, Atom property, Time time);
    bool                wasOwnedAtTime(::Time) const;

    // data conversion methods
    Atom getTargetsData(std::string&, int* format) const;
    Atom getTimestampData(std::string&, int* format) const;

private:
    typedef std::vector<IXWindowsClipboardConverter*> ConverterList;
    IXWindowsImpl*       m_impl;

    Display*            m_display;
    Window                m_window;
    ClipboardID            m_id;
    Atom                m_selection;
    mutable bool        m_open;
    mutable Time        m_time;
    bool                m_owner;
    mutable Time        m_timeOwned;
    Time                m_timeLost;

    // true iff open and clipboard owned by a motif app
    mutable bool        m_motif;

    // the added/cached clipboard data
    mutable bool        m_checkCache;
    bool                m_cached;
    Time                m_cacheTime;
    bool                m_added[kNumFormats];
    std::string m_data[kNumFormats];

    // conversion request replies
    ReplyMap            m_replies;
    ReplyEventMask        m_eventMasks;

    // clipboard format converters
    ConverterList        m_converters;

    // atoms we'll need
    Atom                m_atomTargets;
    Atom                m_atomMultiple;
    Atom                m_atomTimestamp;
    Atom                m_atomInteger;
    Atom                m_atomAtom;
    Atom                m_atomAtomPair;
    Atom                m_atomData;
    Atom                m_atomINCR;
    Atom                m_atomMotifClipLock;
    Atom                m_atomMotifClipHeader;
    Atom                m_atomMotifClipAccess;
    Atom                m_atomGDKSelection;
};

//! Clipboard format converter interface
/*!
This interface defines the methods common to all X11 clipboard format
converters.
*/
class IXWindowsClipboardConverter : public IInterface {
public:
    //! @name accessors
    //@{

    //! Get clipboard format
    /*!
    Return the clipboard format this object converts from/to.
    */
    virtual IClipboard::EFormat
                        getFormat() const = 0;

    //! Get X11 format atom
    /*!
    Return the atom representing the X selection format that
    this object converts from/to.
    */
    virtual Atom        getAtom() const = 0;

    //! Get X11 property datum size
    /*!
    Return the size (in bits) of data elements returned by
    toIClipboard().
    */
    virtual int            getDataSize() const = 0;

    //! Convert from IClipboard format
    /*!
    Convert from the IClipboard format to the X selection format.
    The input data must be in the IClipboard format returned by
    getFormat().  The return data will be in the X selection
    format returned by getAtom().
    */
    virtual std::string fromIClipboard(const std::string&) const = 0;

    //! Convert to IClipboard format
    /*!
    Convert from the X selection format to the IClipboard format
    (i.e., the reverse of fromIClipboard()).
    */
    virtual std::string toIClipboard(const std::string&) const = 0;

    //@}
};
