/*
    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 (float xa, float ya, const char *txt)
	: x (xa, 0.0, 1.0, 0.01, 0.1)
	, y (ya, 0.0, 1.0, 0.01, 0.1)
	, azimuth (M_PI/2.0, 0.0, 2.0 * M_PI, 0.1, 0.5)
	, text (txt)
        , _selected (false)
{
	azimuth.set_value ((random() / (double) INT_MAX) * (2.0 * M_PI));
}

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)
{
	allow_x = false;
	allow_y = false;
	allow_target = false;

	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 ("", 0.0, 0.0);
	}

	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) {
		float x, y;
                double dx, dy;

		panner->streampanner (i).get_position (x, y);

                dx = x;
                dy = y;
                clamp_to_circle (dx, dy);

		pucks[i]->x.set_value (dx);
		pucks[i]->y.set_value (dy);

		pucks[i]->visible = true;
	}

	/* add all outputs */

	while (targets.size() < panner->nouts()) {
		add_target (0.0, 0.0);
	}

	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]->x.set_value (panner->output(n).x);
		targets[n]->y.set_value (panner->output(n).y);
		targets[n]->visible = true;
	}

	allow_x_motion (true);
	allow_y_motion (true);
	allow_target_motion (true);

	queue_draw ();
}

Gtk::Adjustment&
Panner2d::azimuth (uint32_t which)
{
	assert (which < pucks.size());
	return pucks[which]->azimuth;
}

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, float x, float y)
{
        double dx, dy;
        
        dx = x;
        dy = y;
        
        clamp_to_circle (dx, dy);

	Target* puck = new Target (dx, dy, text);
	pucks.push_back (puck);
	puck->visible = true;

	return 0;
}

int
Panner2d::add_target (float x, float y)
{
	Target* target = new Target (x, y, "");
	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) {
		float x, y;
		panner->streampanner(n).get_position (x, y);
		pucks[n]->x.set_value (x);
		pucks[n]->y.set_value (y);
	}

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

	queue_draw ();
}

void
Panner2d::move_puck (int which, float x, float y)
{
	if (which >= int (targets.size())) {
		return;
	}
	
	targets[which]->x.set_value (x);
	targets[which]->y.set_value (y);
	queue_draw ();
}

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

	efx = x/(width-1.0);
        efy = 1.0 - (y/(height-1.0)); /* convert from X Window origin */

	which = 0;
	pwhich = 0;

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

		cx = candidate->x.get_value();
		cy = candidate->y.get_value();

		distance = sqrt ((cx - efx) * (cx - efx) +
				 (cy - efy) * (cy - efy));

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

        if (best_distance > 0.05) { // arbitrary 
                return 0;
        }

	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;
	float fx, fy;
	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 */

				fx = min (puck->x.get_value(), 1.0);
				fx = max (fx, -1.0f);
				x = (gint) floor (width * fx - 4);

				fy = min (fy, 1.0f);
				fy = max (fy, -1.0f);

                                /* translate back to X Window abomination coordinates */
                                fy = -(puck->y.get_value() - 1.0);

				y = (gint) floor (height * fy - 4);
                                
				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);
				cairo_show_text (cr, puck->text.c_str());
			}
		}

		/* 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) {

				fx = min (target->x.get_value(), 1.0);
				fx = max (fx, -1.0f);
				x = (gint) floor (width  * fx);

				fy = min (target->y.get_value(), 1.0);
				fy = max (fy, -1.0f);
				y = (gint) floor (height * fy);

				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)) {

                double fx = evx;
                double fy = evy;
                bool need_move = false;

                clamp_to_circle (fx, fy);

                if ((fx != drag_target->x.get_value()) || (fy != drag_target->y.get_value())) {
                        need_move = true;
                }

                if (need_move) {
                        drag_target->x.set_value (fx);
                        drag_target->y.set_value (fy);
                        
                        panner->streampanner (drag_index).set_position (drag_target->x.get_value(), drag_target->y.get_value(), false);
			queue_draw ();
		}

	} else if ((state & GDK_BUTTON2_MASK) && !(state & GDK_BUTTON1_MASK)) {

		int xdelta = drag_x - evx;
		int ydelta = drag_x - evy;

		drag_target->azimuth.set_value (drag_target->azimuth.get_value() + (2 * M_PI) * ((float)ydelta)/height * ((float) -xdelta)/height);
		queue_draw ();
	}

	return true;
}

void
Panner2d::cart_to_azi_ele (double x, double y, double& azi, double& ele)
{
        x = min (x, (double) width);
        x = max (x, 0.0);
        x = x / (width-1.0);

        y = min (y, (double) height);
        y = max (y, 0.0);
        y = y / (height-1.0);

        /* at this point, new_x and new_y are in the range [ 0.0 .. 1.0 ], with
           (0,0) at the upper left corner (thank you, X Window)
           
           we need to translate to (0,0) at center
        */
        
        x -= 0.5;
        y  = (1.0 - y) - 0.5;

        PBD::cart_to_azi_ele (x, y, 0.0, azi, ele);
}

void
Panner2d::azi_ele_to_cart (double azi, double ele, double& x, double& y)
{
        double z;

        PBD::azi_ele_to_cart (azi, ele, x, y, z);
        
        /* xp,yp,zp use a (0,0) == center and 2.0 unit dimension. so convert
           back to (0,0) and 1.0 unit dimension
        */
        
        x /= 2.0;
        y /= 2.0;
        z /= 2.0;
        
        /* and now convert back to (0,0) == upper left corner */
        
        x += 0.5;
        y += 0.5;
        z += 0.5;
}

void
Panner2d::clamp_to_circle (double& x, double& y)
{
        double azi, ele;

        cart_to_azi_ele (x, y, azi, ele);
        azi_ele_to_cart (azi, ele, x, y);
}

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

void
Panner2d::allow_x_motion (bool yn)
{
	allow_x = yn;
}

void
Panner2d::allow_target_motion (bool yn)
{
	allow_target = yn;
}

void
Panner2d::allow_y_motion (bool yn)
{
	allow_y = yn;
}

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);

	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());
	}
}