/*
    Copyright (C) 2010 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 <iostream>
#include <cmath>
#include <algorithm>

#include <pangomm/layout.h>

#include "pbd/compose.h"
#include "pbd/error.h"

#include "gtkmm2ext/utils.h"
#include "gtkmm2ext/rgb_macros.h"
#include "gtkmm2ext/gui_thread.h"

#include "ardour_button.h"
#include "ardour_ui.h"
#include "global_signals.h"

#include "i18n.h"

using namespace Gdk;
using namespace Gtk;
using namespace Glib;
using namespace PBD;
using std::max;
using std::min;
using namespace std;

ArdourButton::Element ArdourButton::default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Text);
ArdourButton::Element ArdourButton::led_default_elements = ArdourButton::Element (ArdourButton::default_elements|ArdourButton::Indicator);
ArdourButton::Element ArdourButton::just_led_default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Indicator);

ArdourButton::ArdourButton (Element e)
	: _elements (e)
	, _act_on_release (true)
	, _text_width (0)
	, _text_height (0)
	, _diameter (11.0)
	, _corner_radius (9.0)
	, edge_pattern (0)
	, fill_pattern (0)
	, led_inset_pattern (0)
	, reflection_pattern (0)
	, _led_left (false)
	, _fixed_diameter (true)
	, _distinct_led_click (false)
{
	ColorsChanged.connect (sigc::mem_fun (*this, &ArdourButton::color_handler));
	StateChanged.connect (sigc::mem_fun (*this, &ArdourButton::state_handler));
}

ArdourButton::~ArdourButton()
{
}

void
ArdourButton::set_text (const std::string& str)
{
	_text = str;

	if (!_layout && !_text.empty()) {
		_layout = Pango::Layout::create (get_pango_context());
	} 
	
	_layout->set_text (str);

	queue_resize ();
}

void
ArdourButton::set_markup (const std::string& str)
{
	_text = str;

	if (!_layout) {
		_layout = Pango::Layout::create (get_pango_context());
	} 

	_layout->set_text (str);
	queue_resize ();
}

void
ArdourButton::render (cairo_t* cr)
{
	if (!_fixed_diameter) {
		_diameter = std::min (_width, _height);
	}

	/* background fill. use parent window style, so that we fit in nicely.
	 */
	
	Color c = get_parent_bg ();

	cairo_rectangle (cr, 0, 0, _width, _height);
	cairo_stroke_preserve (cr);
	cairo_set_source_rgb (cr, c.get_red_p(), c.get_green_p(), c.get_blue_p());
	cairo_fill (cr);

	if (_elements & Edge) {
		Gtkmm2ext::rounded_rectangle (cr, 0, 0, _width, _height, _corner_radius);
		cairo_set_source (cr, edge_pattern);
		cairo_fill (cr);
	}

	if (_elements & Body) {
		if (_elements & Edge) {
			Gtkmm2ext::rounded_rectangle (cr, 1, 1, _width-2, _height-2, _corner_radius - 1.0);
		} else {
			Gtkmm2ext::rounded_rectangle (cr, 0, 0, _width, _height, _corner_radius - 1.0);
		}
		cairo_set_source (cr, fill_pattern);
		cairo_fill (cr);
	}

	/* text, if any */

	float text_margin;

	if (_width < 75) {
		text_margin = 3;
	} else {
		text_margin = 10;
	}

	if ((_elements & Text) && !_text.empty()) {

		cairo_set_source_rgba (cr, text_r, text_g, text_b, text_a);

		if (_elements & Indicator) {
			if (_led_left) {
				cairo_move_to (cr, _width - text_margin - 4, _height/2.0 - _text_height/2.0);
			} else {
				cairo_move_to (cr, text_margin, _height/2.0 - _text_height/2.0);
			}
		} else {
			/* center text */
			cairo_move_to (cr, (_width - _text_width)/2.0, _height/2.0 - _text_height/2.0);
		}

		pango_cairo_show_layout (cr, _layout->gobj());
	} 

	if (_elements & Indicator) {

		/* move to the center of the indicator/led */

		cairo_save (cr);

		if (_elements & Text) {
			if (_led_left) {
				cairo_translate (cr, text_margin + (_diameter/2.0), _height/2.0);
			} else {
				cairo_translate (cr, _width - ((_diameter/2.0) + 4.0), _height/2.0);
			}
		} else {
			cairo_translate (cr, _width/2.0, _height/2.0);
		}
		
		//inset
		cairo_arc (cr, 0, 0, _diameter/2, 0, 2 * M_PI);
		cairo_set_source (cr, led_inset_pattern);
		cairo_fill (cr);
		
		//black ring
		cairo_set_source_rgb (cr, 0, 0, 0);
		cairo_arc (cr, 0, 0, _diameter/2-2, 0, 2 * M_PI);
		cairo_fill(cr);
		
		//led color
		cairo_set_source_rgba (cr, led_r, led_g, led_b, led_a);
		cairo_arc (cr, 0, 0, _diameter/2-3, 0, 2 * M_PI);
		cairo_fill(cr);
		
		//reflection
		cairo_scale(cr, 0.7, 0.7);
		cairo_arc (cr, 0, 0, _diameter/2-3, 0, 2 * M_PI);
		cairo_set_source (cr, reflection_pattern);
		cairo_fill (cr);

		cairo_restore (cr);

	}

	/* a partially transparent gray layer to indicate insensitivity */

	if ((visual_state() & Insensitive)) {
		cairo_rectangle (cr, 0, 0, _width, _height);
		cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.5);
		cairo_fill (cr);
	}
}

void
ArdourButton::state_handler ()
{
	set_colors ();
}

void
ArdourButton::set_diameter (float d)
{
	_diameter = (d*2) + 5.0;

	if (_diameter != 0.0) {
		_fixed_diameter = true;
	}

	set_colors ();
}

void
ArdourButton::set_corner_radius (float r)
{
	_corner_radius = r;
	set_dirty ();
}

void
ArdourButton::on_size_request (Gtk::Requisition* req)
{
	int xpad = 0;
	int ypad = 6;

	CairoWidget::on_size_request (req);

	if ((_elements & Text) && !_text.empty()) {
		_layout->get_pixel_size (_text_width, _text_height);
		if (_text_width + _diameter < 75) {
			xpad = 7;
		} else {
			xpad = 20;
		}
	} else {
		_text_width = 0;
		_text_height = 0;
	}

        if ((_elements & Indicator) && _fixed_diameter) {
                req->width = _text_width + lrint (_diameter) + xpad;
                req->height = max (_text_height, (int) lrint (_diameter)) + ypad;
        } else {
                req->width = _text_width + xpad;
                req->height = _text_height + ypad;
	}
}

void
ArdourButton::set_colors ()
{
	uint32_t start_color;
	uint32_t end_color;
	uint32_t r, g, b, a;
	uint32_t text_color;
	uint32_t led_color;

	/* we use the edge of the button to show Selected state, so the
	 * color/pattern used there will vary depending on that
	 */
	
	if (edge_pattern) {
		cairo_pattern_destroy (edge_pattern);
	}

	if (_elements & Edge) {

		edge_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _height);
		if (visual_state() & CairoWidget::Selected) {
			start_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 border start selected", get_name()));
			end_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 border end selected", get_name()));
		} else {
			start_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 border start", get_name()));
			end_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 border end", get_name()));
		}
		UINT_TO_RGBA (start_color, &r, &g, &b, &a);
		cairo_pattern_add_color_stop_rgba (edge_pattern, 0, r/255.0,g/255.0,b/255.0, 0.7);
		UINT_TO_RGBA (end_color, &r, &g, &b, &a);
		cairo_pattern_add_color_stop_rgba (edge_pattern, 1, r/255.0,g/255.0,b/255.0, 0.7);
	}


	/* the fill pattern is used to indicate Normal/Active/Mid state
	 */

	if (fill_pattern) {
		cairo_pattern_destroy (fill_pattern);
	}

	if (_elements & Body) {
		fill_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _height);
		
		if (active_state() == Mid) {
			start_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill start mid", get_name()));
			end_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill end mid", get_name()));
		} else if (active_state() == Active) {
			start_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill start active", get_name()));
			end_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill end active", get_name()));
		} else {
			start_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill start", get_name()));
			end_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 fill end", get_name()));
		}
		UINT_TO_RGBA (start_color, &r, &g, &b, &a);
		cairo_pattern_add_color_stop_rgba (fill_pattern, 0, r/255.0,g/255.0,b/255.0, a/255.0);
		UINT_TO_RGBA (end_color, &r, &g, &b, &a);
		cairo_pattern_add_color_stop_rgba (fill_pattern, 1, r/255.0,g/255.0,b/255.0, a/255.0);
	}

	if (led_inset_pattern) {
		cairo_pattern_destroy (led_inset_pattern);
	}
	
	if (reflection_pattern) {
		cairo_pattern_destroy (reflection_pattern);
	}

	if (_elements & Indicator) {
		led_inset_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _diameter);
		cairo_pattern_add_color_stop_rgba (led_inset_pattern, 0, 0,0,0, 0.4);
		cairo_pattern_add_color_stop_rgba (led_inset_pattern, 1, 1,1,1, 0.7);

		reflection_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _diameter/2-3);
		cairo_pattern_add_color_stop_rgba (reflection_pattern, 0, 1,1,1, active_state() ? 0.4 : 0.2);
		cairo_pattern_add_color_stop_rgba (reflection_pattern, 1, 1,1,1, 0.0);
	}
	
	/* text and LED colors depend on Active/Normal/Mid */

	if (active_state() == Active) {
		text_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 text active", get_name()));
		led_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 led active", get_name()));
	} else if (active_state() == Mid) {
		text_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 text mid", get_name()));
		led_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 led active", get_name()));
	} else {
		text_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 text", get_name()));
		led_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1 led", get_name()));
	}

	UINT_TO_RGBA (text_color, &r, &g, &b, &a);
	text_r = r/255.0;
	text_g = g/255.0;
	text_b = b/255.0;
	text_a = a/255.0;
	UINT_TO_RGBA (led_color, &r, &g, &b, &a);
	led_r = r/255.0;
	led_g = g/255.0;
	led_b = b/255.0;
	led_a = a/255.0;

	set_dirty ();
}

void
ArdourButton::set_led_left (bool yn)
{
	_led_left = yn;
}

bool
ArdourButton::on_button_press_event (GdkEventButton *ev)
{
	if ((_elements & Indicator) && _distinct_led_click) {
		/* if within LED, swallow event */
		
		int top = lrint (_height/2.0 - _diameter/2.0);
		int bottom = lrint (_height/2.0 + _diameter/2.0);
		int left;
		int right;
		
		if (_elements & Text) {
			if (_led_left) {
				left = 4;
				right = left + _diameter;
			} else {
				left = lrint (_width - 4 - _diameter/2.0);
				right = left + _diameter;
			}
		} else {
			left = _width/2.0 - (_diameter/2.0);
			right = _width/2.0 + (_diameter/2.0);
		}

		if (ev->x >= left && ev->x <= right && ev->y <= bottom && ev->y >= top) {
			return true;
		}
	}

	if (binding_proxy.button_press_handler (ev)) {
		return true;
	}

	if (!_act_on_release) {
		if (_action) {
			_action->activate ();
			return true;
		}
	}

	return false;
}

bool
ArdourButton::on_button_release_event (GdkEventButton *ev)
{
	if ((_elements & Indicator) && _distinct_led_click) {

		/* if within LED, emit signal */

		int top = lrint (_height/2.0 - _diameter/2.0);
		int bottom = lrint (_height/2.0 + _diameter/2.0);
		int left;
		int right;
		if (_led_left) {
			left = 4;
			right = left + _diameter;
		} else {
			left = lrint (_width - 4 - _diameter/2.0);
			right = left + _diameter;
		}
		
		if (ev->x >= left && ev->x <= right && ev->y <= bottom && ev->y >= top) {
			signal_led_clicked(); /* EMIT SIGNAL */
			return true;
		}
	}

	if (_act_on_release) {
		if (_action) {
			_action->activate ();
			return true;
		}
	}

	return false;
}

void
ArdourButton::set_distinct_led_click (bool yn)
{
	_distinct_led_click = yn;
}

void
ArdourButton::color_handler ()
{
	set_colors ();
	set_dirty ();
}

void
ArdourButton::on_size_allocate (Allocation& alloc)
{
	CairoWidget::on_size_allocate (alloc);
	set_colors ();
}

void
ArdourButton::set_controllable (boost::shared_ptr<Controllable> c)
{
        watch_connection.disconnect ();
        binding_proxy.set_controllable (c);
}

void
ArdourButton::watch ()
{
        boost::shared_ptr<Controllable> c (binding_proxy.get_controllable ());

        if (!c) {
                warning << _("button cannot watch state of non-existing Controllable\n") << endmsg;
                return;
        }

        c->Changed.connect (watch_connection, invalidator(*this), boost::bind (&ArdourButton::controllable_changed, this), gui_context());
}

void
ArdourButton::controllable_changed ()
{
        float val = binding_proxy.get_controllable()->get_value();

	if (fabs (val) >= 0.5f) {
		set_active_state (CairoWidget::Active);
	} else {
		unset_active_state ();
	}
}

void
ArdourButton::set_related_action (RefPtr<Action> act)
{
	_action = act;

	Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
	if (tact) {
		tact->signal_toggled().connect (sigc::mem_fun (*this, &ArdourButton::action_toggled));
	}
}

void
ArdourButton::action_toggled ()
{
	Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);

	if (tact) {
		if (tact->get_active()) {
			set_active_state (CairoWidget::Active);
		} else {
			unset_active_state ();
		}
	}
}