/*
    Copyright (C) 2011-2013 Paul Davis
    Author: Carl Hetherington <cth@carlh.net>

    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 "pbd/compose.h"
#include "pbd/stacktrace.h"
#include "pbd/convert.h"

#include "ardour/utils.h"

#include "canvas/canvas.h"
#include "canvas/debug.h"
#include "canvas/item.h"
#include "canvas/scroll_group.h"

using namespace std;
using namespace PBD;
using namespace ArdourCanvas;

int Item::default_items_per_cell = 64;

Item::Item (Canvas* canvas)
	: Fill (*this)
	, Outline (*this)
	,  _canvas (canvas)
	, _parent (0)
	, _scroll_parent (0)
	, _visible (true)
	, _bounding_box_dirty (true)
	, _lut (0)
	, _ignore_events (false)
{
	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));
}	

Item::Item (Item* parent)
	: Fill (*this)
	, Outline (*this)
	,  _canvas (parent->canvas())
	, _parent (parent)
	, _scroll_parent (0)
	, _visible (true)
	, _bounding_box_dirty (true)
	, _lut (0)
	, _ignore_events (false)
{
	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));

	if (parent) {
		_parent->add (this);
	}

	find_scroll_parent ();
}	

Item::Item (Item* parent, Duple const& p)
	: Fill (*this)
	, Outline (*this)
	,  _canvas (parent->canvas())
	, _parent (parent)
	, _scroll_parent (0)
	, _position (p)
	, _visible (true)
	, _bounding_box_dirty (true)
	, _lut (0)
	, _ignore_events (false)
{
	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));

	if (parent) {
		_parent->add (this);
	}

	find_scroll_parent ();

}	

Item::~Item ()
{
	if (_parent) {
		_parent->remove (this);
	}

	if (_canvas) {
		_canvas->item_going_away (this, _bounding_box);
	}

	clear_items (true);
	delete _lut;
}

Duple
Item::canvas_origin () const
{
	return item_to_canvas (Duple (0,0));
}

Duple
Item::window_origin () const 
{
	/* This is slightly subtle. Our _position is in the coordinate space of 
	   our parent. So to find out where that is in window coordinates, we
	   have to ask our parent.
	*/
	if (_parent) {
		return _parent->item_to_window (_position);
	} else {
		return _position;
	}
}

ArdourCanvas::Rect
Item::item_to_parent (ArdourCanvas::Rect const & r) const
{
	return r.translate (_position);
}

Duple
Item::scroll_offset () const
{
	if (_scroll_parent) {
		return _scroll_parent->scroll_offset();
	} 
	return Duple (0,0);
}

Duple
Item::position_offset() const
{
	Item const * i = this;
	Duple offset;

	while (i) {
		offset = offset.translate (i->position());
		i = i->parent();
	}

	return offset;
}

ArdourCanvas::Rect
Item::item_to_canvas (ArdourCanvas::Rect const & r) const
{
	return r.translate (position_offset());
}

ArdourCanvas::Duple
Item::item_to_canvas (ArdourCanvas::Duple const & d) const
{
	return d.translate (position_offset());
}

ArdourCanvas::Duple
Item::canvas_to_item (ArdourCanvas::Duple const & r) const
{
	return r.translate (-position_offset());
}

ArdourCanvas::Rect
Item::canvas_to_item (ArdourCanvas::Rect const & r) const
{
	return r.translate (-position_offset());
}

void
Item::item_to_canvas (Coord& x, Coord& y) const
{
	Duple d = item_to_canvas (Duple (x, y));
		
	x = d.x;
	y = d.y;
}

void
Item::canvas_to_item (Coord& x, Coord& y) const
{
	Duple d = canvas_to_item (Duple (x, y));

	x = d.x;
	y = d.y;
}


Duple
Item::item_to_window (ArdourCanvas::Duple const & d, bool rounded) const
{
	Duple ret = item_to_canvas (d).translate (-scroll_offset());

	if (rounded) {
		ret.x = round (ret.x);
		ret.y = round (ret.y);
	}

	return ret;
}

Duple
Item::window_to_item (ArdourCanvas::Duple const & d) const
{
	return canvas_to_item (d.translate (scroll_offset()));
}

ArdourCanvas::Rect
Item::item_to_window (ArdourCanvas::Rect const & r) const
{
	Rect ret = item_to_canvas (r).translate (-scroll_offset());

	ret.x0 = round (ret.x0);
	ret.x1 = round (ret.x1);
	ret.y0 = round (ret.y0);
	ret.y1 = round (ret.y1);

	return ret;
}

ArdourCanvas::Rect
Item::window_to_item (ArdourCanvas::Rect const & r) const
{
	return canvas_to_item (r.translate (scroll_offset()));
}

/** Set the position of this item in the parent's coordinates */
void
Item::set_position (Duple p)
{
	if (p == _position) {
		return;
	}

	boost::optional<ArdourCanvas::Rect> bbox = bounding_box ();
	boost::optional<ArdourCanvas::Rect> pre_change_parent_bounding_box;

	if (bbox) {
		/* see the comment in Canvas::item_moved() to understand
		 * why we use the parent's bounding box here.
		 */
		pre_change_parent_bounding_box = item_to_parent (bbox.get());
	}
	
	_position = p;

	_canvas->item_moved (this, pre_change_parent_bounding_box);

	if (_parent) {
		_parent->child_changed ();
	}
}

void
Item::set_x_position (Coord x)
{
	set_position (Duple (x, _position.y));
}

void
Item::set_y_position (Coord y)
{
	set_position (Duple (_position.x, y));
}

void
Item::raise_to_top ()
{
	if (_parent) {
		_parent->raise_child_to_top (this);
	}
}

void
Item::raise (int levels)
{
	if (_parent) {
		_parent->raise_child (this, levels);
	}
}

void
Item::lower_to_bottom ()
{
	if (_parent) {
		_parent->lower_child_to_bottom (this);
	}
}

void
Item::hide ()
{
	if (_visible) {
		_visible = false;

		/* recompute parent bounding box, which may alter now that this
		 * child is hidden.
		 */

		if (_parent) {
			_parent->child_changed ();
		}

		_canvas->item_shown_or_hidden (this);
	}
}

void
Item::show ()
{
	if (!_visible) {
		_visible = true;

		/* bounding box may have changed while we were hidden */

		if (_parent) {
			_parent->child_changed ();
		}

		_canvas->item_shown_or_hidden (this);
	}
}

Duple
Item::item_to_parent (Duple const & d) const
{
	return d.translate (_position);
}

Duple
Item::parent_to_item (Duple const & d) const
{
	return d.translate (- _position);
}

ArdourCanvas::Rect
Item::parent_to_item (ArdourCanvas::Rect const & d) const
{
	return d.translate (- _position);
}

void
Item::unparent ()
{
	_parent = 0;
	_scroll_parent = 0;
}

void
Item::reparent (Item* new_parent)
{
	if (new_parent == _parent) {
		return;
	}

	assert (_canvas == new_parent->canvas());

	if (_parent) {
		_parent->remove (this);
	}

	assert (new_parent);

	_parent = new_parent;
	_canvas = _parent->canvas ();

	find_scroll_parent ();

	_parent->add (this);
}

void
Item::find_scroll_parent ()
{
	Item const * i = this;
	ScrollGroup const * last_scroll_group = 0;

	/* Don't allow a scroll group to find itself as its own scroll parent
	 */

	i = i->parent ();

	while (i) {
		ScrollGroup const * sg = dynamic_cast<ScrollGroup const *> (i);
		if (sg) {
			last_scroll_group = sg;
		}
		i = i->parent();
	}
	
	_scroll_parent = const_cast<ScrollGroup*> (last_scroll_group);
}

bool
Item::common_ancestor_within (uint32_t limit, const Item& other) const
{
	uint32_t d1 = depth();
	uint32_t d2 = other.depth();
	const Item* i1 = this;
	const Item* i2 = &other;
	
	/* move towards root until we are at the same level
	   for both items
	*/

	while (d1 != d2) {
		if (d1 > d2) {
			if (!i1) {
				return false;
			}
			i1 = i1->parent();
			d1--;
			limit--;
		} else {
			if (!i2) {
				return false;
			}
			i2 = i2->parent();
			d2--;
			limit--;
		}
		if (limit == 0) {
			return false;
		}
	}

	/* now see if there is a common parent */

	while (i1 != i2) {
		if (i1) {
			i1 = i1->parent();
		}
		if (i2) {
			i2 = i2->parent ();
		}

		limit--;
		if (limit == 0) {
			return false;
		}
	}
	
	return true;
}

const Item*
Item::closest_ancestor_with (const Item& other) const
{
	uint32_t d1 = depth();
	uint32_t d2 = other.depth();
	const Item* i1 = this;
	const Item* i2 = &other;

	/* move towards root until we are at the same level
	   for both items
	*/

	while (d1 != d2) {
		if (d1 > d2) {
			if (!i1) {
				return 0;
			}
			i1 = i1->parent();
			d1--;
		} else {
			if (!i2) {
				return 0;
			}
			i2 = i2->parent();
			d2--;
		}
	}

	/* now see if there is a common parent */

	while (i1 != i2) {
		if (i1) {
			i1 = i1->parent();
		}
		if (i2) {
			i2 = i2->parent ();
		}
	}
	
	return i1;
}

bool
Item::is_descendant_of (const Item& candidate) const
{
	Item const * i = _parent;

	while (i) {
		if (i == &candidate) {
			return true;
		}
		i = i->parent();
	}

	return false;
}

void
Item::grab_focus ()
{
	/* XXX */
}

/** @return Bounding box in this item's coordinates */
boost::optional<ArdourCanvas::Rect>
Item::bounding_box () const
{
	if (_bounding_box_dirty) {
		compute_bounding_box ();
		assert (!_bounding_box_dirty);
		add_child_bounding_boxes ();
	}

	return _bounding_box;
}

Coord
Item::height () const 
{
	boost::optional<ArdourCanvas::Rect> bb  = bounding_box();

	if (bb) {
		return bb->height ();
	}
	return 0;
}

Coord
Item::width () const 
{
	boost::optional<ArdourCanvas::Rect> bb = bounding_box().get();

	if (bb) {
		return bb->width ();
	}

	return 0;
}

void
Item::redraw () const
{
	if (_visible && _bounding_box && _canvas) {
		_canvas->request_redraw (item_to_window (_bounding_box.get()));
	}
}	

void
Item::begin_change ()
{
	_pre_change_bounding_box = bounding_box ();
}

void
Item::end_change ()
{
	if (_visible) {
		_canvas->item_changed (this, _pre_change_bounding_box);
		
		if (_parent) {
			_parent->child_changed ();
		}
	}
}

void
Item::begin_visual_change ()
{
}

void
Item::end_visual_change ()
{
	if (_visible) {
		_canvas->item_visual_property_changed (this);
	}
}

void
Item::move (Duple movement)
{
	set_position (position() + movement);
}

void
Item::grab ()
{
	assert (_canvas);
	_canvas->grab (this);
}

void
Item::ungrab ()
{
	assert (_canvas);
	_canvas->ungrab ();
}

void
Item::set_data (string const & key, void* data)
{
	_data[key] = data;
}

void *
Item::get_data (string const & key) const
{
	map<string, void*>::const_iterator i = _data.find (key);
	if (i == _data.end ()) {
		return 0;
	}
	
	return i->second;
}

void
Item::set_ignore_events (bool ignore)
{
	_ignore_events = ignore;
}

std::string
Item::whatami () const 
{
	std::string type = demangle (typeid (*this).name());
	return type.substr (type.find_last_of (':') + 1);
}

uint32_t
Item::depth () const
{
	Item* i = _parent;
	int d = 0;
	while (i) {
		++d;
		i = i->parent();
	}
	return d;
}

bool
Item::covers (Duple const & point) const
{
	Duple p = window_to_item (point);

	if (_bounding_box_dirty) {
		compute_bounding_box ();
	}

	boost::optional<Rect> r = bounding_box();

	if (!r) {
		return false;
	}

	return r.get().contains (p);
}

/* nesting/grouping API */

void
Item::render_children (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
{
	if (_items.empty()) {
		return;
	}

	ensure_lut ();
	std::vector<Item*> items = _lut->get (area);

#ifdef CANVAS_DEBUG
	if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
		cerr << string_compose ("%1%7 %2 @ %7 render %5 @ %6 %3 items out of %4\n", 
					_canvas->render_indent(), (name.empty() ? string ("[unnamed]") : name), items.size(), _items.size(), area, _position, this,
					whatami());
	}
#endif

	++render_depth;
		
	for (std::vector<Item*>::const_iterator i = items.begin(); i != items.end(); ++i) {

		if (!(*i)->visible ()) {
#ifdef CANVAS_DEBUG
			if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
				cerr << _canvas->render_indent() << "Item " << (*i)->whatami() << " [" << (*i)->name << "] invisible - skipped\n";
			}
#endif
			continue;
		}
		
		boost::optional<Rect> item_bbox = (*i)->bounding_box ();

		if (!item_bbox) {
#ifdef CANVAS_DEBUG
			if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
				cerr << _canvas->render_indent() << "Item " << (*i)->whatami() << " [" << (*i)->name << "] empty - skipped\n";
			}
#endif
			continue;
		}
		
		Rect item = (*i)->item_to_window (item_bbox.get());
		boost::optional<Rect> d = item.intersection (area);
		
		if (d) {
			Rect draw = d.get();
			if (draw.width() && draw.height()) {
#ifdef CANVAS_DEBUG
				if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
					if (dynamic_cast<Container*>(*i) == 0) {
						cerr << _canvas->render_indent() << "render "
						     << ' ' 
						     << (*i)
						     << ' '
						     << (*i)->whatami()
						     << ' '
						     << (*i)->name
						     << " item "
						     << item_bbox.get()
						     << " window = " 
						     << item
						     << " intersect = "
						     << draw
						     << " @ " 
						     << _position
						     << endl;
					}
				}
#endif

				(*i)->render (area, context);
				++render_count;
			}

		} else {

#ifdef CANVAS_DEBUG
			if (DEBUG_ENABLED(PBD::DEBUG::CanvasRender)) {
				cerr << string_compose ("%1skip render of %2 %3, no intersection between %4 and %5\n", _canvas->render_indent(), (*i)->whatami(),
							(*i)->name, item, area);
			}
#endif

		}
	}

	--render_depth;
}

void
Item::add_child_bounding_boxes() const
{
	boost::optional<Rect> self;
	Rect bbox;
	bool have_one = false;

	if (_bounding_box) {
		bbox = _bounding_box.get();
		have_one = true;
	}

	for (list<Item*>::const_iterator i = _items.begin(); i != _items.end(); ++i) {

		boost::optional<Rect> item_bbox = (*i)->bounding_box ();

		if (!item_bbox) {
			continue;
		}

		Rect group_bbox = (*i)->item_to_parent (item_bbox.get ());
		if (have_one) {
			bbox = bbox.extend (group_bbox);
		} else {
			bbox = group_bbox;
			have_one = true;
		}
	}

	if (!have_one) {
		_bounding_box = boost::optional<Rect> ();
	} else {
		_bounding_box = bbox;
	}
}

void
Item::add (Item* i)
{
	/* XXX should really notify canvas about this */

	_items.push_back (i);
	i->reparent (this);
	invalidate_lut ();
	_bounding_box_dirty = true;
}

void
Item::remove (Item* i)
{

	if (i->parent() != this) {
		return;
	}

	/* we cannot call bounding_box() here because that will iterate over
	   _items, one of which (the argument, i) may be in the middle of
	   deletion, making it impossible to call compute_bounding_box()
	   on it.
	*/

	if (_bounding_box) {
		_pre_change_bounding_box = _bounding_box;
	} else {
		_pre_change_bounding_box = Rect();
	}

	i->unparent ();
	_items.remove (i);
	invalidate_lut ();
	_bounding_box_dirty = true;
	
	end_change ();
}

void
Item::clear (bool with_delete)
{
	begin_change ();

	clear_items (with_delete);

	invalidate_lut ();
	_bounding_box_dirty = true;

	end_change ();
}

void
Item::clear_items (bool with_delete)
{
	for (list<Item*>::iterator i = _items.begin(); i != _items.end(); ) {

		list<Item*>::iterator tmp = i;
		Item *item = *i;

		++tmp;

		/* remove from list before doing anything else, because we
		 * don't want to find the item in _items during any activity
		 * driven by unparent-ing or deletion.
		 */

		_items.erase (i);
		item->unparent ();
		
		if (with_delete) {
			delete item;
		}

		i = tmp;
	}
}

void
Item::raise_child_to_top (Item* i)
{
	if (!_items.empty()) {
		if (_items.back() == i) {
			return;
		}
	}

	_items.remove (i);
	_items.push_back (i);
	invalidate_lut ();
}

void
Item::raise_child (Item* i, int levels)
{
	list<Item*>::iterator j = find (_items.begin(), _items.end(), i);
	assert (j != _items.end ());

	++j;
	_items.remove (i);

	while (levels > 0 && j != _items.end ()) {
		++j;
		--levels;
	}

	_items.insert (j, i);
	invalidate_lut ();
}

void
Item::lower_child_to_bottom (Item* i)
{
	if (!_items.empty()) {
		if (_items.front() == i) {
			return;
		}
	}
	_items.remove (i);
	_items.push_front (i);
	invalidate_lut ();
}

void
Item::ensure_lut () const
{
	if (!_lut) {
		_lut = new DumbLookupTable (*this);
	}
}

void
Item::invalidate_lut () const
{
	delete _lut;
	_lut = 0;
}

void
Item::child_changed ()
{
	invalidate_lut ();
	_bounding_box_dirty = true;

	if (_parent) {
		_parent->child_changed ();
	}
}

void
Item::add_items_at_point (Duple const point, vector<Item const *>& items) const
{
	boost::optional<Rect> const bbox = bounding_box ();

	/* Point is in window coordinate system */

	if (!bbox || !item_to_window (bbox.get()).contains (point)) {
		return;
	}

	/* recurse and add any items within our group that contain point.
	   Our children are only considered visible if we are 
	*/

	vector<Item*> our_items;

	if (!_items.empty() && visible()) {
		ensure_lut ();
		our_items = _lut->items_at_point (point);
	}

	if (!our_items.empty() || covers (point)) {
		/* this adds this item itself to the list of items at point */
		items.push_back (this);
	}

	for (vector<Item*>::iterator i = our_items.begin(); i != our_items.end(); ++i) {
		(*i)->add_items_at_point (point, items);
	}
}

void
Item::dump (ostream& o) const
{
	boost::optional<ArdourCanvas::Rect> bb = bounding_box();

	o << _canvas->indent() << whatami() << ' ' << this << " Visible ? " << _visible;
	o << " @ " << position();
	
#ifdef CANVAS_DEBUG
	if (!name.empty()) {
		o << ' ' << name;
	}
#endif

	if (bb) {
		o << endl << _canvas->indent() << "\tbbox: " << bb.get();
		o << endl << _canvas->indent() << "\tCANVAS bbox: " << item_to_canvas (bb.get());
	} else {
		o << " bbox unset";
	}

	o << endl;

	if (!_items.empty()) {

#ifdef CANVAS_DEBUG
		o << _canvas->indent();
		o << " @ " << position();
		o << " Items: " << _items.size();
		o << " Visible ? " << _visible;
		
		boost::optional<Rect> bb = bounding_box();
		
		if (bb) {
			o << endl << _canvas->indent() << "  bbox: " << bb.get();
			o << endl << _canvas->indent() << "  CANVAS bbox: " << item_to_canvas (bb.get());
		} else {
			o << "  bbox unset";
		}
		
		o << endl;
#endif
		
		ArdourCanvas::dump_depth++;
		
		for (list<Item*>::const_iterator i = _items.begin(); i != _items.end(); ++i) {
			o << **i;
		}
		
		ArdourCanvas::dump_depth--;
	}
}

ostream&
ArdourCanvas::operator<< (ostream& o, const Item& i)
{
	i.dump (o);
	return o;
}