// -*- C++ -*-
/**
 * \file Dialog.h
 * This file is part of LyX, the document processor.
 * Licence details can be found in the file COPYING.
 *
 * \author Angus Leeming
 *
 * Full author contact details are available in file CREDITS.
 */

#ifndef DIALOG_H
#define DIALOG_H

#include "lfuns.h"

#include "support/docstring.h"
#include <string>

namespace lyx {

class Buffer;
class BufferView;
class FuncRequest;

namespace frontend {

class LyXView;

/** \enum KernelDocType used to flag the different kinds of buffer
 *  without making the kernel header files available to the
 *  dialog's Controller or View.
 */
enum KernelDocType
{
	LATEX,
	LITERATE,
	DOCBOOK
};


/** \c Dialog collects the different parts of a Model-Controller-View
 *  split of a generic dialog together.
 */
class Dialog 
{
public:
	/// \param lv is the access point for the dialog to the LyX kernel.
	/// \param name is the identifier given to the dialog by its parent
	/// container.
	Dialog(LyXView & lv) : lyxview_(&lv) {}
	virtual ~Dialog();

	/** \name Container Access
	 *  These methods are publicly accessible because they are invoked
	 *  by the parent container acting on commands from the LyX kernel.
	 */
	//@{
	/// \param data is a string encoding of the data to be displayed.
	/// It is passed to the Controller to be translated into a useable form.
	virtual void showData(std::string const & /*data*/) {}
	virtual void updateData(std::string const & /*data*/) {}

	virtual void hide() {}

	// Override in GuiDialog
	virtual void slotOK() {}
	virtual void slotApply() {}
	virtual void slotRestore() {}
	virtual void slotClose() {}

	/** This function is called, for example, if the GUI colours
	 *  have been changed.
	 */
	virtual void redraw() {}
	//@}

	/** Check whether we may apply our data.
	 *
	 *  The buttons are disabled if not and (re-)enabled if yes.
	 */
	virtual void checkStatus() {}

	/** When applying, it's useful to know whether the dialog is about
	 *  to close or not (no point refreshing the display for example).
	 */
	virtual bool isClosing() const { return false; }


	/** \c Button controller part
	 */
	virtual void setButtonsValid(bool /*valid*/) {}


	/** \c View part
	 *  of a Model-Controller-View split of a generic dialog.
	 *  These few methods are all that a generic dialog needs of a
	 *  view.
	 */
	//@{
	/** A request to modify the data structures stored by the
	 *  accompanying Controller in preparation for their dispatch to
	 *  the LyX kernel.
	 */
	virtual void applyView() = 0;

	/// Hide the dialog from sight
	virtual void hideView() = 0;

	/// Redraw the dialog (e.g. if the colors have been remapped).
	virtual void redrawView() = 0;

	/// Create the dialog if necessary, update it and display it.
	virtual void showView() = 0;

	/// Update the display of the dialog whilst it is still visible.
	virtual void updateView() = 0;

	/// \return true if the dialog is visible.
	virtual bool isVisibleView() const = 0;
	//@}

	/** Defaults to nothing. Can be used by the Controller, however, to
	 *  indicate to the View that something has changed and that the
	 *  dialog therefore needs updating.
	 *  \param id identifies what should be updated.
	 */
	virtual void partialUpdateView(int /*id*/) = 0;

	///
	virtual std::string name() const = 0;

	//@{
	/** Enable the controller to initialise its data structures.
	 *  \param data is a string encoding of the parameters to be displayed.
	 *  \return true if the translation was successful.
	 */
	virtual bool initialiseParams(std::string const & data) = 0;

	/// Enable the controller to clean up its data structures.
	virtual void clearParams() = 0;

	/// Enable the Controller to dispatch its data back to the LyX kernel.
	virtual void dispatchParams() = 0;

	/** \return true if the dialog should be shown only when
	 *  a buffer is open.
	 */
	virtual bool isBufferDependent() const = 0;

	/** \return true if the dialog can apply data also
	 *  for ReadOnly buffers.
	 *  This has to be distinguished from isBufferDependent()
	 */
	virtual bool canApplyToReadOnly() const { return false; }

	/** The lfun that is sent for applying the data.
	 *
	 * This method is used by the default implementation of canApply()
	 * for buffer dependent dialogs that send one lfun when applying the
	 * data.
	 * It should be used in dispatchParams(), too for consistency reasons.
	 *  \returns the lfun that is sent for applying the data.
	 */
	virtual kb_action getLfun() const { return LFUN_INSET_APPLY; }

	/** Check whether we may apply our data.
	 *
	 * The default implementation works for all dialogs that send one
	 * lfun when applying the data. Dialogs that send none or more than
	 * one lfun need to reimplement it.
	 *  \returns whether the data can be applied or not.
	 */
	virtual bool canApply() const;

	/** \return true if the kernel should disconnect the dialog from
	 *  a particular inset after the data has been applied to it.
	 *  Clearly this makes sense only for dialogs modifying the contents
	 *  of an inset :-)
	 *  In practise, only a very few dialogs (e.g. the citation dialog)
	 *  return true.
	 */
	virtual bool disconnectOnApply() const { return false; }

	/** \return true if Dialog::View::show() should not display the dialog
	 *   after running update. Currently, only ControlSpellchecker
	 *   makes use of that.
	*/
	virtual bool exitEarly() const { return false; }
	//@}

	/** \c Kernel part: a wrapper making the LyX kernel available to the dialog.
	 * (Ie, it provides an interface to the Model part of the Model-Controller-
	 *  View split.
	 *  In an ideal world, it will shrink as more info is passed to the
	 *  Dialog::show() and Dialog::update() methods.
	 */


	/** This method is the primary purpose of the class. It provides
	 *  the "gateway" by which the dialog can send a request (of a
	 *  change in the data, for more information) to the kernel.
	 *  \param fr is the encoding of the request.
	 */
	void dispatch(FuncRequest const & fr) const;

	/** The dialog has received a request from the user
	 *  (who pressed the "Restore" button) to update contents.
	 *  It must, therefore, ask the kernel to provide this information.
	 *  \param name is used to identify the dialog to the kernel.
	 */
	void updateDialog(std::string const & name) const;

	/** A request from the Controller that future changes to the data
	 *  stored by the dialog are not applied to the inset currently
	 *  connected to the dialog. Instead, they will be used to generate
	 *  a new inset at the cursor position.
	 *  \param name is used to identify the dialog to the kernel.
	 */
	void disconnect(std::string const & name) const;

	/** \name Kernel Wrappers
	 *  Simple wrapper functions to Buffer methods.
	 */
	//@{
	bool isBufferAvailable() const;
	bool isBufferReadonly() const;
	std::string const bufferFilepath() const;
	//@}

	/// The type of the current buffer.
	KernelDocType docType() const;

	/** \name Kernel Nasties
	 *  Unpleasantly public internals of the LyX kernel.
	 *  We should aim to reduce/remove these from the interface.
	 */
	//@{
	LyXView & lyxview() { return *lyxview_; }
	LyXView const & lyxview() const { return *lyxview_; }

	Buffer & buffer();
	Buffer const & buffer() const;

	BufferView * bufferview();
	BufferView const * bufferview() const;
	//@}

protected:
	virtual void apply() {}

private:
	LyXView * lyxview_;

private:
	/// intentionally unimplemented, therefore uncopiable
	Dialog(Dialog const &);
	void operator=(Dialog const &);

};


} // namespace frontend
} // namespace lyx

#endif // DIALOG_H