/*
  Copyright (C) 2011 Paul Davis

  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 2 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, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <algorithm>
#include <cmath>
#include <iostream>

#include "gtkmm2ext/cairocell.h"
#include "gtkmm2ext/utils.h"

using std::string;
using std::map;
using std::cerr;
using std::endl;
using namespace Gtkmm2ext;

CairoCell::CairoCell ()
	: _visible (true)
	, _xpad (5)
{
	bbox.x = 0;
	bbox.y = 0;
	bbox.width = 0;
	bbox.height = 0;
}

void
CairoColonCell::render (Cairo::RefPtr<Cairo::Context>& context)
{
	/* two very small circles */
	context->arc (bbox.x, bbox.y + (bbox.height/3.0), bbox.width/2.0, 0.0, M_PI*2.0);
	context->fill ();
	context->arc (bbox.x, bbox.y + (2.0 * bbox.height/3.0), bbox.width/2.0, 0.0, M_PI*2.0);
	context->fill ();
}

void 
CairoColonCell::set_size (Glib::RefPtr<Pango::Context>& context, const Pango::FontDescription& font)
{
	Pango::FontMetrics metrics = context->get_metrics (font);
	bbox.width = std::max (3.0, (0.25 * metrics.get_approximate_char_width() / PANGO_SCALE));
	bbox.height = (metrics.get_ascent() + metrics.get_descent()) / PANGO_SCALE;
}

CairoTextCell::CairoTextCell (double wc)
	: _width_chars (wc)
{
}

void
CairoTextCell::set_text (const std::string& txt)
{
	layout->set_text (txt); 
}

void
CairoTextCell::render (Cairo::RefPtr<Cairo::Context>& context)
{
	if (!_visible || _width_chars == 0) {
		return;
	}

	context->move_to (bbox.x, bbox.y);
	pango_cairo_update_layout (context->cobj(), layout->gobj());
	pango_cairo_show_layout (context->cobj(), layout->gobj());
}

void
CairoTextCell::set_size (Glib::RefPtr<Pango::Context>& context, const Pango::FontDescription& font)
{
	if (!layout) {
		layout = Pango::Layout::create (context);
	}

        layout->set_font_description (font);

	Pango::FontMetrics metrics = context->get_metrics (font);

	bbox.width = (_width_chars * metrics.get_approximate_digit_width ()) / PANGO_SCALE;
	bbox.height = (metrics.get_ascent() + metrics.get_descent()) / PANGO_SCALE;
}

CairoCell*
CairoEditableText::get_cell (uint32_t id)
{
	CellMap::iterator i = cells.find (id);
	if (i == cells.end()) {
		return 0;
	}
	return i->second;
}

CairoEditableText::CairoEditableText ()
        : editing_id (0)
        , width (0)
        , max_cell_height (0)
        , height (0)
        , corner_radius (18)
        , xpad (10)
        , ypad (5)
{
        add_events (Gdk::POINTER_MOTION_HINT_MASK | Gdk::SCROLL_MASK | Gdk::KEY_PRESS_MASK | Gdk::KEY_RELEASE_MASK |
                    Gdk::BUTTON_PRESS_MASK | Gdk::BUTTON_RELEASE_MASK | Gdk::SCROLL_MASK);
        set_flags (Gtk::CAN_FOCUS);

        set_can_default (true);
        set_receives_default (true);
}

CairoEditableText::~CairoEditableText ()
{
	for (CellMap::iterator i = cells.begin(); i != cells.end(); ++i) {
		delete i->second;
	}
}

bool
CairoEditableText::on_scroll_event (GdkEventScroll* ev)
{
	uint32_t id;
	CairoCell* cell = find_cell (ev->x, ev->y, id);

	if (cell) {
		return scroll (ev, id);
	}

	return false;
}

bool
CairoEditableText::on_focus_in_event (GdkEventFocus* ev)
{
	return false;
}

bool
CairoEditableText::on_focus_out_event (GdkEventFocus* ev)
{
        if (editing_id) {
                CairoCell* cell = get_cell (editing_id);
                queue_draw_cell (cell);
                editing_id = 0;
        }
	return false;
}

void
CairoEditableText::add_cell (uint32_t id, CairoCell* cell)
{
	if (id > 0) {
		Glib::RefPtr<Pango::Context> context = get_pango_context ();
		cell->set_size (context, font);

		cells[id] = cell; /* we own it */
	}
}

void
CairoEditableText::set_text (uint32_t id, const string& text)
{
	CellMap::iterator i = cells.find (id);

	if (i == cells.end()) {
		return;
	}

	CairoTextCell* textcell = dynamic_cast<CairoTextCell*> (i->second);

        if (textcell) {
                set_text (textcell, text);
        } 
}            

void
CairoEditableText::set_text (CairoTextCell* cell, const string& text)
{
	cell->set_text (text);
	queue_draw_cell (cell);
}

bool
CairoEditableText::on_expose_event (GdkEventExpose* ev)
{
	Cairo::RefPtr<Cairo::Context> context = get_window()->create_cairo_context();
	
	if (cells.empty()) {
		return true;
	}

	context->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
	context->clip ();

	context->set_source_rgba (bg_r, bg_g, bg_b, bg_a);
	rounded_rectangle (context, 0, 0, width, height, corner_radius);
	context->fill ();
	
	for (CellMap::iterator i = cells.begin(); i != cells.end(); ++i) {
		
		uint32_t id = i->first;
		CairoCell* cell = i->second;
		
		/* is cell inside the expose area?
		 */

                if (cell->intersects (ev->area)) {		
			if (id == editing_id) {
				context->set_source_rgba (edit_r, edit_b, edit_g, edit_a);
			} else {
				context->set_source_rgba (r, g, b, a);
			}
			
			cell->render (context);
		}
	}

        return true;
}

void
CairoEditableText::queue_draw_cell (CairoCell* cell)
{
	Glib::RefPtr<Gdk::Window> win = get_window();

	if (!win) {
		return;
	}

	Gdk::Rectangle r;

	r.set_x (cell->x());
	r.set_y (cell->y());
	r.set_width (cell->width());
	r.set_height (cell->height());

	Gdk::Region rg (r);
	win->invalidate_region (rg, true);
}

CairoCell*
CairoEditableText::find_cell (uint32_t x, uint32_t y, uint32_t& id)
{
	for (CellMap::iterator i = cells.begin(); i != cells.end(); ++i) {
		if (i->second->covers (x, y)) {
			id = i->first;
			return i->second;
		}
	}

	return 0;
}

bool
CairoEditableText::on_button_press_event (GdkEventButton* ev)
{
        uint32_t id;         
        CairoCell* cell = find_cell (ev->x, ev->y, id);
		
	if (!cell) {
		return false;
	}
		
	return button_press (ev, id);
}

bool
CairoEditableText::on_button_release_event (GdkEventButton* ev)
{
        uint32_t id;         
        CairoCell* cell = find_cell (ev->x, ev->y, id);
		
	if (!cell) {
		return false;
	}
		
	return button_release (ev, id);
}

void
CairoEditableText::start_editing (uint32_t id)
{
	CairoCell* cell = get_cell (id);

	stop_editing ();

	if (cell) {
		editing_id = id;
		queue_draw_cell (cell);
		grab_focus ();
	}
}

void
CairoEditableText::stop_editing ()
{
	if (editing_id) {
		CairoCell* cell;
		if ((cell = get_cell (editing_id))) {
			queue_draw_cell (cell);
		}
		editing_id = 0;
	}
}

void
CairoEditableText::on_size_request (GtkRequisition* req)
{
	double x = 0;

	max_cell_height = 0;

	x = xpad;

	for (CellMap::iterator i = cells.begin(); i != cells.end(); ++i) {
		CairoCell* cell = i->second;

		if (cell->visible()) {
			cell->set_position (x, ypad);
		}

		x += cell->width() + cell->xpad();
		max_cell_height = std::max ((double) cell->height(), max_cell_height);
	}

	x += xpad;

	req->width = x;
	req->height = max_cell_height + (ypad * 2);
}

void
CairoEditableText::on_size_allocate (Gtk::Allocation& alloc)
{
	Misc::on_size_allocate (alloc);

	width = alloc.get_width();
	height = alloc.get_height();
}

void
CairoEditableText::set_font (const std::string& str)
{
	set_font (Pango::FontDescription (str));
}

void
CairoEditableText::set_font (const Pango::FontDescription& fd)
{
	Glib::RefPtr<Pango::Context> context = get_pango_context ();

        for (CellMap::iterator i = cells.begin(); i != cells.end(); ++i) {
		i->second->set_size (context, fd);
	}

	queue_resize ();
	queue_draw ();
}