/*
    Copyright (C) 2002 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 <cmath>
#include <climits>
#include <string.h>

#include <cairo.h>
#include <gtkmm/menu.h>

#include "pbd/error.h"
#include "pbd/cartesian.h"
#include "ardour/panner.h"
#include <gtkmm2ext/gtk_ui.h>

#include "panner2d.h"
#include "keyboard.h"
#include "gui_thread.h"

#include "i18n.h"

using namespace std;
using namespace Gtk;
using namespace ARDOUR;
using namespace PBD;
using Gtkmm2ext::Keyboard;

Panner2d::Target::Target (const AngularVector& a, const char *txt)
	: position (a)
	, text (txt)
	, _selected (false)
{
}

Panner2d::Target::~Target ()
{
}

void
Panner2d::Target::set_text (const char* txt)
{
	text = txt;
}

Panner2d::Panner2d (boost::shared_ptr<Panner> p, int32_t h)
	: panner (p), width (0), height (h)
{
	panner->StateChanged.connect (state_connection, invalidator (*this), boost::bind (&Panner2d::handle_state_change, this), gui_context());
	panner->Changed.connect (change_connection, invalidator (*this), boost::bind (&Panner2d::handle_position_change, this), gui_context());

	drag_target = 0;
	set_events (Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::POINTER_MOTION_MASK);
}

Panner2d::~Panner2d()
{
	for (Targets::iterator i = targets.begin(); i != targets.end(); ++i) {
		delete *i;
	}
}

void
Panner2d::reset (uint32_t n_inputs)
{
	Targets::size_type existing_pucks = pucks.size();

	/* pucks */

	while (pucks.size() < n_inputs) {
		add_puck ("", AngularVector());
	}

	if (pucks.size() > n_inputs) {
		for (uint32_t i = pucks.size(); i < n_inputs; ++i) {
			delete pucks[i];
		}

		pucks.resize (n_inputs);
	}
						
	for (Targets::iterator x = pucks.begin(); x != pucks.end(); ++x) {
		(*x)->visible = false;
	}

	switch (n_inputs) {
	case 0:
		break;

	case 1:
		pucks[0]->set_text ("");
		break;

	case 2:
		pucks[0]->set_text ("R");
		pucks[1]->set_text ("L");
		break;

	default:
		for (uint32_t i = 0; i < n_inputs; ++i) {
			char buf[64];
			snprintf (buf, sizeof (buf), "%" PRIu32, i + 1);
			pucks[i]->set_text (buf);
		}
		break;
	}

	for (uint32_t i = existing_pucks; i < n_inputs; ++i) {
		pucks[i]->position = panner->streampanner (i).get_position ();
		pucks[i]->visible = true;
	}

	/* add all outputs */

	while (targets.size() < panner->nouts()) {
		add_target (AngularVector());
	}

	if (targets.size() > panner->nouts()) {
		for (uint32_t i = panner->nouts(); i < targets.size(); ++i) {
			delete targets[i];
		}

		targets.resize (panner->nouts ());
	}

	for (Targets::iterator x = targets.begin(); x != targets.end(); ++x) {
		(*x)->visible = false;
	}

	for (uint32_t n = 0; n < panner->nouts(); ++n) {
		char buf[16];

		snprintf (buf, sizeof (buf), "%d", n+1);
		targets[n]->set_text (buf);
		targets[n]->position = panner->output(n).position;
		targets[n]->visible = true;
	}

	queue_draw ();
}

void
Panner2d::on_size_allocate (Gtk::Allocation& alloc)
{
  	width = alloc.get_width();
  	height = alloc.get_height();

	if (height > 100) {
		width -= 20;
		height -= 20;
	}

	DrawingArea::on_size_allocate (alloc);
}

int
Panner2d::add_puck (const char* text, const AngularVector& a)
{
	Target* puck = new Target (a, text);
	pucks.push_back (puck);
	puck->visible = true;

	return 0;
}

int
Panner2d::add_target (const AngularVector& a)
{
	Target* target = new Target (a, "");
	targets.push_back (target);
	target->visible = true;
	queue_draw ();

	return targets.size() - 1;
}

void
Panner2d::handle_state_change ()
{
	ENSURE_GUI_THREAD (*this, &Panner2d::handle_state_change)

	queue_draw ();
}

void
Panner2d::handle_position_change ()
{
	uint32_t n;
	ENSURE_GUI_THREAD (*this, &Panner2d::handle_position_change)

	for (n = 0; n < pucks.size(); ++n) {
		pucks[n]->position = panner->streampanner(n).get_position ();
	}

	for (n = 0; n < targets.size(); ++n) {
		targets[n]->position = panner->output(n).position;
	}

	queue_draw ();
}

void
Panner2d::move_puck (int which, const AngularVector& a)
{
	if (which >= int (targets.size())) {
		return;
	}
	
	targets[which]->position = a;
	queue_draw ();
}

Panner2d::Target *
Panner2d::find_closest_object (gdouble x, gdouble y, int& which) const
{
	Target *closest = 0;
	Target *candidate;
	float distance;
	float best_distance = FLT_MAX;
	int pwhich;

	which = 0;
	pwhich = 0;

	cerr << "@ " << x << ", " << y << endl;

	for (Targets::const_iterator i = pucks.begin(); i != pucks.end(); ++i, ++pwhich) {
		candidate = *i;

		CartesianVector c;

		candidate->position.cartesian (c);
		cart_to_gtk (c);

		distance = sqrt ((c.x - x) * (c.x - x) +
		                 (c.y - y) * (c.y - y));

		cerr << "\tConsider candiate " << candidate->text << " @ " << c.x << ", " << c.y << ", " << c.z <<  " distance = " << distance << endl;

		if (distance < best_distance) {
			closest = candidate;
			best_distance = distance;
			which = pwhich;
		}
	}


	if (best_distance > 20) { // arbitrary 
		return 0;
	}

	cerr << "the winner is " << closest->text << endl;

	return closest;
}

bool
Panner2d::on_motion_notify_event (GdkEventMotion *ev)
{
	gint x, y;
	GdkModifierType state;

	if (ev->is_hint) {
		gdk_window_get_pointer (ev->window, &x, &y, &state);
	} else {
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;
	}

	return handle_motion (x, y, state);
}
bool
Panner2d::on_expose_event (GdkEventExpose *event)
{
	gint x, y;
	cairo_t* cr;

	cr = gdk_cairo_create (get_window()->gobj());

	cairo_set_line_width (cr, 1.0);

	cairo_rectangle (cr, event->area.x, event->area.y, event->area.width, event->area.height);
	if (!panner->bypassed()) {
		cairo_set_source_rgba (cr, 0.1, 0.1, 0.1, 1.0);
	} else {
		cairo_set_source_rgba (cr, 0.1, 0.1, 0.1, 0.2);
	}
	cairo_fill_preserve (cr);
	cairo_clip (cr);

	if (height > 100) {
		cairo_translate (cr, 10.0, 10.0);
	}

	/* horizontal line of "crosshairs" */

	cairo_set_source_rgb (cr, 0.0, 0.1, 0.7);
	cairo_move_to (cr, 0.5, height/2.0+0.5);
	cairo_line_to (cr, width+0.5, height/2+0.5);
	cairo_stroke (cr);

	/* vertical line of "crosshairs" */
	
	cairo_move_to (cr, width/2+0.5, 0.5);
	cairo_line_to (cr, width/2+0.5, height+0.5);
	cairo_stroke (cr);

	/* the circle on which signals live */

	cairo_arc (cr, width/2, height/2, height/2, 0, 2.0 * M_PI);
	cairo_stroke (cr);

	if (!panner->bypassed()) {
		float arc_radius;

		cairo_select_font_face (cr, "sans", CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);

		if (height < 100) {
			cairo_set_font_size (cr, 10);
			arc_radius = 2.0;
		} else {
			cairo_set_font_size (cr, 16);
			arc_radius = 4.0;
		}

		for (Targets::iterator i = pucks.begin(); i != pucks.end(); ++i) {

			Target* puck = *i;

			if (puck->visible) {
				/* redraw puck */

				CartesianVector c;
                                
				puck->position.cartesian (c);
				cart_to_gtk (c);
                                
				x = (gint) floor (c.x);
				y = (gint) floor (c.y);

				/* XXX need to shift circles so that they are centered on the circle */
                                        
				cairo_arc (cr, x, y, arc_radius, 0, 2.0 * M_PI);
				cairo_set_source_rgb (cr, 0.8, 0.2, 0.1);
				cairo_close_path (cr);
				cairo_fill (cr);

				cairo_move_to (cr, x + 6, y + 6);

				char buf[256];
				snprintf (buf, sizeof (buf), "%s:%d", puck->text.c_str(), (int) lrint (puck->position.azi));
				cairo_show_text (cr, buf);
			}
		}

		/* redraw any visible targets */

		int n = 0;

		for (Targets::iterator i = targets.begin(); i != targets.end(); ++i) {
			Target *target = *i;
			char buf[256];
			++n;

			if (target->visible) {

				CartesianVector c;
                                
				target->position.cartesian (c);
				cart_to_gtk (c);

				x = (int) floor (c.x);
				y = (int) floor (c.y);
                                
				snprintf (buf, sizeof (buf), "%d", n);

				cairo_set_source_rgb (cr, 0.0, 0.8, 0.1);
				cairo_rectangle (cr, x-2, y-2, 4, 4);
				cairo_fill (cr);
				cairo_move_to (cr, x+6, y+6);
				cairo_show_text (cr, buf);

			}
		}
	}

	cairo_destroy (cr);

	return TRUE;
}

bool
Panner2d::on_button_press_event (GdkEventButton *ev)
{
	GdkModifierType state;

	if (ev->type == GDK_2BUTTON_PRESS && ev->button == 1) {
		return false;
	}

	switch (ev->button) {
	case 1:
	case 2:
		if ((drag_target = find_closest_object (ev->x, ev->y, drag_index)) != 0) {
			drag_target->set_selected (true);
		}

		drag_x = (int) floor (ev->x);
		drag_y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;

		return handle_motion (drag_x, drag_y, state);
		break;

	default:
		break;
	}

	return FALSE;
}

bool
Panner2d::on_button_release_event (GdkEventButton *ev)
{
	gint x, y;
	GdkModifierType state;
	bool ret = false;

	switch (ev->button) {
	case 1:
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;

		if (Keyboard::modifier_state_contains (state, Keyboard::TertiaryModifier)) {
                        
			for (Targets::iterator i = pucks.begin(); i != pucks.end(); ++i) {
				//Target* puck = i->second;
				/* XXX DO SOMETHING TO SET PUCK BACK TO "normal" */
			}

			queue_draw ();
			PuckMoved (-1);
			ret = true;

		} else {
			ret = handle_motion (x, y, state);
		}

		drag_target = 0;
		break;

	case 2:
		x = (int) floor (ev->x);
		y = (int) floor (ev->y);
		state = (GdkModifierType) ev->state;

		if (Keyboard::modifier_state_contains (state, Keyboard::TertiaryModifier)) {
			toggle_bypass ();
			ret = true;
		} else {
			ret = handle_motion (x, y, state);
		}

		drag_target = 0;
		break;

	case 3:
		break;

	}

	return ret;
}

gint
Panner2d::handle_motion (gint evx, gint evy, GdkModifierType state)
{
	if (drag_target == 0) {
		return false;
	}

	if ((state & (GDK_BUTTON1_MASK|GDK_BUTTON2_MASK)) == 0) {
		return false;
	}


	if (state & GDK_BUTTON1_MASK && !(state & GDK_BUTTON2_MASK)) {
		CartesianVector c;
		bool need_move = false;
                
		drag_target->position.cartesian (c);
		cart_to_gtk (c);

		if ((evx != c.x) || (evy != c.y)) {
			need_move = true;
		}

		if (need_move) {
			CartesianVector cp (evx, evy, 0.0);

			/* canonicalize position */

			gtk_to_cart (cp);

			/* position actual signal on circle */

			clamp_to_circle (cp.x, cp.y);
                        
			/* generate an angular representation and set drag target (GUI) position */

			cp.angular (drag_target->position); /* sets drag target position */

			panner->streampanner (drag_index).set_position (drag_target->position);
                        
			queue_draw ();
		}
	} 

	return true;
}

void
Panner2d::cart_to_gtk (CartesianVector& c) const
{
	/* "c" uses a coordinate space that is:
            
	   center = 0.0
	   dimension = 2.0 * 2.0
	   so max values along each axis are -1..+1

	   GTK uses a coordinate space that is:

	   top left = 0.0
	   dimension = width * height
	   so max values along each axis are 0,width and
	   0,height
	*/

	c.x = (width / 2) * (c.x + 1);
	c.y = (height / 2) * (1 - c.y);

	/* XXX z-axis not handled - 2D for now */
}

void
Panner2d::gtk_to_cart (CartesianVector& c) const
{
	c.x = (c.x / (width / 2.0)) - 1.0;
	c.y = -((c.y / (height / 2.0)) - 1.0);

	/* XXX z-axis not handled - 2D for now */
}

void
Panner2d::clamp_to_circle (double& x, double& y)
{
	double azi, ele;
	double z = 0.0;
        
	PBD::cart_to_azi_ele (x, y, z, azi, ele);
	PBD::azi_ele_to_cart (azi, ele, x, y, z);
}

void
Panner2d::toggle_bypass ()
{
	panner->set_bypassed (!panner->bypassed());
}

Panner2dWindow::Panner2dWindow (boost::shared_ptr<Panner> p, int32_t h, uint32_t inputs)
	: widget (p, h)
	, reset_button (_("Reset"))
	, bypass_button (_("Bypass"))
	, mute_button (_("Mute"))
{
	widget.set_name ("MixerPanZone");

	set_title (_("Panner"));
	widget.set_size_request (h, h);

	button_box.set_spacing (6);
	button_box.pack_start (reset_button, false, false);
	button_box.pack_start (bypass_button, false, false);
	button_box.pack_start (mute_button, false, false);

	spinner_box.set_spacing (6);
	left_side.set_spacing (6);

	left_side.pack_start (button_box, false, false);
	left_side.pack_start (spinner_box, false, false);

	reset_button.show ();
	bypass_button.show ();
	mute_button.show ();
	button_box.show ();
	spinner_box.show ();
	left_side.show ();

	hpacker.set_spacing (6);
	hpacker.set_border_width (12);
	hpacker.pack_start (widget, false, false);
	hpacker.pack_start (left_side, false, false);
	hpacker.show ();

	add (hpacker);
	reset (inputs);
	widget.show ();
}

void
Panner2dWindow::reset (uint32_t n_inputs)
{
	widget.reset (n_inputs);

#if 0
	while (spinners.size() < n_inputs) {
		// spinners.push_back (new Gtk::SpinButton (widget.azimuth (spinners.size())));
		//spinner_box.pack_start (*spinners.back(), false, false);
		//spinners.back()->set_digits (4);
		spinners.back()->show ();
	}

	while (spinners.size() > n_inputs) {
		spinner_box.remove (*spinners.back());
		delete spinners.back();
		spinners.erase (--spinners.end());
	}
#endif
}