/* 

	Cadabra: a field-theory motivated computer algebra system.
	Copyright (C) 2001-2011  Kasper Peeters <kasper.peeters@aei.mpg.de>

   This program is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   This program 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/>.
 
*/

#ifndef window_hh__
#define window_hh__

#include <gtkmm/main.h>
#include <gtkmm/actiongroup.h>
#include <gtkmm/radioaction.h>
#include <gtkmm/uimanager.h>
#include <gtkmm/button.h>
#include <gtkmm/window.h>
#include <gtkmm/box.h>
#include <gtkmm/statusbar.h>
#include <gtkmm/textview.h>
#include <gtkmm/treeview.h>
#include <gtkmm/notebook.h>
#include <gtkmm/optionmenu.h>
#include <gtkmm/treestore.h>
#include <gtkmm/textbuffer.h>
#include <gtkmm/scrolledwindow.h>
#include <gtkmm/separator.h>
#include <gtkmm/menu.h>
#include <gtkmm/menubar.h>
#include <gtkmm/image.h>
#include <gtkmm/eventbox.h>
#include <gtkmm/expander.h>
#include <gtkmm/stock.h>
#include <gtkmm/paned.h>
#include <gtkmm/progressbar.h>
#include <gdkmm.h>
#include <modglue/main.hh>
#include <modglue/pipe.hh>
#include <modglue/ext_process.hh>

#include <stack>

#include "widgets.hh"
#include "help.hh"

class XCadabra;

/// A DataCell contains the information required to display a 
/// cell, but not the actual widget. Therefore, multiple widgets
/// can read from the data stored in this cell; multiple notebook
/// canvasses can therefore display the same notebook data.
///
/// DataCells are stored on the heap and reference counted since there
/// are too many objects with a pointer to them to keep track of 
/// proper de-allocation manually.

class DataCell : public Glib::Object {
	public:
		enum cell_t { c_input, c_output, c_comment, c_texcomment, c_tex, c_error };

		DataCell(cell_t, const std::string& str="", bool texhidden=false);

		cell_t                        cell_type;
		Glib::RefPtr<Gtk::TextBuffer> textbuf;
		Glib::RefPtr<TeXBuffer>       texbuf;
		std::string                   cdbbuf;             // c_output only: the output in cadabra input format
		bool                          tex_hidden;         // c_tex only
		bool                          sensitive;
		int                           sectioning;         // >0 for section header cells
		bool                          running;
};


/// A VisualCell contains pointers to the various cell widgets,
/// which in turn contain pointers to DataCell objects.

class VisualCell {
	public:
		union {
				ExpressionInput *inbox;
				TeXView         *outbox;
				TeXInput        *texbox;
		};
		Glib::RefPtr<DataCell> datacell;
};

/// The Action object is used to pass user action instructions around
/// and store them in the undo/redo stacks. All references to cells is
/// in terms of smart pointers to DataCells. 
///
/// This requires that if we delete a cell, its data cell together
/// with any TextBuffer and TeXBuffer objects should be kept in
/// memory, so that the pointer remains valid.  We keep a RefPtr.

class ActionBase : public Glib::Object {
	public:
		ActionBase(Glib::RefPtr<DataCell>);

		virtual void execute(XCadabra&)=0;
		virtual void revert(XCadabra&)=0;

		Glib::RefPtr<DataCell> cell;
};

/// As a general rule, objects derived from ActionBase are friends of XCadabra, 
/// so they really should be thought of as bits of functionality split off from
/// that large class.

class ActionAddCell : public ActionBase {
	public:
		ActionAddCell(Glib::RefPtr<DataCell>, Glib::RefPtr<DataCell> ref_, bool before_);

		/// Executing will also show the cell and grab its focus.
		virtual void execute(XCadabra&);
		virtual void revert(XCadabra&);

	private:
		// Keep track of the location where this cell is inserted into
		// the notebook. 
		Glib::RefPtr<DataCell> ref;
		bool                   before;
		std::vector<Glib::RefPtr<DataCell> > associated_cells; // output and comment cells
};

class ActionRemoveCell : public ActionBase {
	public:
		ActionRemoveCell(Glib::RefPtr<DataCell>);
		~ActionRemoveCell();

		virtual void execute(XCadabra&);
		virtual void revert(XCadabra&);

	private:
		// Keep track of the location where this cell was in the notebook. Since it is
		// not possible to delete the first cell, it is safe to keep a reference to the
		// cell just before the one we are deleting. 
		// Note that since we keep a RefPtr to this datacell, that cell will stay alive
		// even when a subsequent action will remove it. 
		Glib::RefPtr<DataCell>               prev_cell; 
		std::vector<Glib::RefPtr<DataCell> > associated_cells; // output and comment cells
};

class ActionAddText : public ActionBase {
	public:
		ActionAddText(Glib::RefPtr<DataCell>, int, const std::string&);

		virtual void execute(XCadabra&);
		virtual void revert(XCadabra&);
		
		int         insert_pos;
		std::string text;
};

class ActionRemoveText : public ActionBase {
	public:
		ActionRemoveText(Glib::RefPtr<DataCell>, int, int, const std::string&);

		virtual void execute(XCadabra&);
		virtual void revert(XCadabra&);

		int from_pos, to_pos;
		std::string removed_text;
};

typedef std::stack<Glib::RefPtr<ActionBase> > ActionStack;


/// NotebookCanvas is a view on notebook data. Any number of these
/// may be instantiated, and they all reflect the current status
/// of the document stored in the master XCadabra class.

class NotebookCanvas : public Gtk::VPaned {
	public:
		NotebookCanvas(XCadabra& doc);
		~NotebookCanvas();

//		bool handle_expression_input(std::string str);
//		bool handle_tex_update(const std::string&);
//		bool receive_output(std::string eqno, std::string eq);
//		bool receive_comment(std::string comment);

		bool handle_key_press_event(GdkEventKey*);

		/// Add a VisualCell corresponding to the given DataCell.
		/// The second and third element determine the position relative
		/// to another DataCell (or, by default, relative to the end marker).
		VisualCell* add_cell(Glib::RefPtr<DataCell>, Glib::RefPtr<DataCell> ref, bool before=true);
		
		void show_cell(Glib::RefPtr<DataCell>);

		/// Remove a VisualCell corresponding to the given DataCell.
		void         remove_cell(Glib::RefPtr<DataCell>);
		/// Make a cell grab focus. This will trigger a run of this cell, with various
		/// other side-effects before it returns.
		void         cell_grab_focus(VisualCell *);
		void         cell_grab_focus(Glib::RefPtr<DataCell>);
		void         select_first_input_cell();
		virtual void show();

//		void         scroll_to(Gtk::Allocation al);
		void         redraw_cells();
		bool         scroll_into_view_callback(VisualCell *);
		bool         scroll_into_view(VisualCell *, bool center=false);
		bool         scroll_into_view(Glib::RefPtr<DataCell>, bool center=false);
		void         scroll_to_start();
		void         scroll_to_end();
		void         scroll_up();
		void         scroll_down();

		XCadabra&                 doc;
		typedef std::list<VisualCell *> VisualCells_t;
		VisualCells_t             visualcells; // managed here
		Gtk::EventBox             ebox;
 		Gtk::ScrolledWindow       scroll;
		Gtk::VBox                 scrollbox;
		Gtk::HSeparator           bottomline;
};


/// Each notebook has one cadabra process associated to it, and one
/// main window to control it. 

class XCadabra : public Gtk::Window {
	public:
		XCadabra(modglue::ext_process&, const std::string& filename, modglue::main *);
		virtual ~XCadabra();

		/// Data coming from cadabra arrives here. This handles
		/// adding boxes to the document and propagating this to the
		/// notebooks.
		bool receive(modglue::ipipe& p);
		bool receive_err(modglue::ipipe& p);
		std::string accumulated_error;

		/// Data from the NotebookCanvas objects arrives here.
		bool handle_editbox_output(std::string str, NotebookCanvas *, VisualCell *);
		void on_my_insert(const Gtk::TextIter& pos, const Glib::ustring& text, int bytes, Glib::RefPtr<DataCell>);
		void on_my_erase(const Gtk::TextIter& start, const Gtk::TextIter& end, Glib::RefPtr<DataCell>);

		/// Events from the notebook cells arrive here.
		void handle_on_grab_focus(NotebookCanvas *, VisualCell *);
		bool handle_visibility_toggle(GdkEventButton *, NotebookCanvas *, VisualCell *);
		bool handle_outbox_select(GdkEventButton *, NotebookCanvas *, VisualCell *);
		bool handle_tex_update_request(std::string, NotebookCanvas *, VisualCell *);

		/// Toplevel keyboard handling.
		virtual bool on_key_press_event(GdkEventKey *);

		/// All the menu routines.
		void on_file_new();
		void on_file_open();
		void on_file_save();
		void on_file_save_as();
		void on_file_print();
		void on_file_export_text();
		void on_file_quit();
		bool quit_safeguard(bool quit=true);
		void on_edit_copy();
		void on_edit_paste();
		void on_edit_insert_tex_above();
		void on_edit_insert_tex_below();
		void on_edit_insert_input_above();
		void on_edit_insert_input_below();
		void on_edit_insert_section_above();
		void on_edit_remove_cell();
		void on_edit_divide_cell();
		void on_view_split();
		void on_view_close();
		void on_settings_font_size(int);
		void on_settings_brain(int);
		void on_tutorial_open(unsigned int);
		void on_help_about();
		void on_help_citing();
		void on_help_properties(const std::string&);
		void on_help_algorithms(const std::string&);
		void on_help_reserved(const std::string&);
		bool on_autocomplete();
		void on_help_context();
		void on_stop();
		void on_kill();
		void on_run();
		void on_run_to();
		void on_run_from();

		bool current_objtype_and_name(CadabraHelp::objtype_t&, std::string&);
		void insert_at_mark(const std::string instxt);

		/// Saving and loading to/from disk. If the return string is
		/// non-empty, it contains an error message.
		void clear();
		std::string save(const std::string&) const;
		std::string load(const std::string&, bool ignore_nonexistence=false); 
		std::string expo(const std::string&) const; 

		/// Handling starting/restarting of the kernel.
		bool on_kernel_exit(modglue::ext_process&);

		/// Clipboard handling
		void on_clipboard_get(Gtk::SelectionData&, guint info);
		void on_clipboard_clear();
		std::string clipboard_txt, clipboard_cdb;

		/// Adding and removing cells from the current document.
		/// These routines also update all NotebookCanvas objects
		/// so that they reflect the current structure of the document.
		/// The DataCell ownership is handled by the XCadabra class once
		/// it has been added here. 
		/// These functions do _not_ grab focus or make the new cell active.
		/// The add_cell member also does _not_ call show_cell: cells will not
		/// automatically become visible.
		Glib::RefPtr<DataCell> add_cell(Glib::RefPtr<DataCell>, Glib::RefPtr<DataCell> ref, bool before=true);

		/// Show the datacell in all canvasses.
		void         show_cell(Glib::RefPtr<DataCell>);

		/// Add another notebook canvas to the window.
		void         add_canvas();

		/// Call this to determine which cell will scroll into view as soon as the Gtk main loop
		/// regains control.
		void         set_next_into_view(VisualCell *);

		/// Signals from Gtk, such as closing windows or changing the text
		/// of an input cell.
		virtual bool on_delete_event(GdkEventAny*);
		virtual bool on_configure_event(GdkEventConfigure*);
		void         on_signal_exception();
		void         input_cell_modified();
		void         tex_cell_modified();


		/// Display of error messages.
		void         generic_error_popup(const std::string&) const;

		void         connect_io_signals();
		void         disconnect_io_signals();	

		int          font_step;
		int          brain_wired;
	private:
		/// Variables for the undo/redo mechanism.
		ActionStack      undo_stack, redo_stack;
		bool             disable_stacks; // for changes which should not be recorded on the stack
		bool             action_add(Glib::RefPtr<ActionBase>); // takes ownership and fills the stacks 
		void             action_undo();
		void             action_redo();

		/// Various assorted other variables related to communicating with the kernel.
		Gdk::Cursor      hglass;
		bool             load_file; // used by main to indicate a load should occur after start
		bool             have_received;
		modglue::main   *cmm;
		std::map<int, sigc::connection> connections;
		std::string      name;
		bool             modified;
		bool             running;
		Glib::RefPtr<DataCell> running_last;
		bool             restarting_kernel;
		bool             callmm(Glib::IOCondition, int fd);
		void             update_title();
		bool             make_backup(const std::string&) const;
		void             remove_noninput_below(Glib::RefPtr<DataCell>);
		void             kernel_idle();
		/// A map to keep track of identifiers of input cells. These are used to associated input
		/// data to the kernel to output data from the kernel, and hence can be used to associate
		/// the output to the right input cell.
		std::map<long, Glib::RefPtr<DataCell> > id_to_datacell;
		long             last_used_id;

		/// Boxes and widgets.
		std::vector<NotebookCanvas *>  canvasses;   // managed by gtk
		CadabraHelp                    help_window;
		NotebookCanvas                *active_canvas;
		VisualCell                    *active_cell;
		Gtk::VBox                      topbox;
		Gtk::HBox                      supermainbox;
		Gtk::VBox                      mainbox;
		Gtk::HBox                      buttonbox;
		Gtk::HBox                      statusbarbox;
		Gtk::VBox                      progressbarvbox;
		Gtk::ProgressBar               progressbar1,progressbar2;
		Glib::RefPtr<Gtk::ActionGroup> actiongroup;
		Glib::RefPtr<Gtk::Action>      undo_action_menu, redo_action_menu;
		Glib::RefPtr<Gtk::UIManager>   uimanager;
		Glib::RefPtr<Gtk::RadioAction> font_action0, font_action1, font_action2, font_action3;
		Glib::RefPtr<Gtk::RadioAction> brain_wired_action0, brain_wired_action1;
		Gtk::HBox                      statusbox;
		Gtk::Label                     b_cdbstatus, b_kernelversion;
		Gtk::Button                    b_kill, b_run, b_run_to, b_run_from, b_help, b_stop, b_undo, b_redo;
		int                            last_configure_width;

		/// Storage of document data. This data is not managed by smart
		/// pointers and should thus be deleted by the XCadabra
		/// destructor.
		/// The order in which pointers to datacells appear reflects the
		/// order in the document. We never use iterators directly in this
		/// list to refer to a cell (always use the RefPtr<DataCell> pointers).
		typedef std::list<Glib::RefPtr<DataCell> > DataCells_t;
		DataCells_t                   datacells;

		/// Data concerning the interaction with the externally started
		/// cadabra process.
		modglue::ext_process&     cdb;
		enum parse_mode_t         { m_status, m_eqno, m_eq, m_property, m_algorithm, m_reserved,
											 m_discard, m_comment, m_texcomment, m_error,
		                            m_progress, m_plain };
		std::vector<parse_mode_t> parse_mode;
		std::string               eqno, eq, status, progress, plain, algorithm, property, reserved;
		int                       progress_todo, progress_done, progress_count;

		/// Collection of all known algorithm and property names, as extracted from the kernel.
		void add_property_help(const std::string&);
		void add_algorithm_help(const std::string&);
		void add_reserved_help(const std::string&);
		std::set<std::string> property_set, algorithm_set;
		static const char * const autocomplete_strings[];
		std::string duplicate_underscores(const std::string& str) const;

		/// Cut-n-paste data
		VisualCell  *selected;

		/// Configuration data saving/loading
		std::string save_config() const;
		std::string load_config();

		TeXEngine tex_engine;

		friend class ActionRemoveCell;
		friend class ActionAddCell;

		/// When the main loop is idle, this function will get called and will check
		/// all 'to_scroll_to' cells of the canvasses.
		bool         on_idle();

		/// Cell to scroll into view as soon as the main loop is idle. 
		VisualCell  *to_scroll_to;
};


#endif