/*
 * Repr transaction logging
 *
 * Authors:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *   MenTaLguY  <mental@rydia.net>
 *
 * Copyright (C) 2004-2005 MenTaLguY
 * Copyright (C) 1999-2003 authors
 * Copyright (C) 2001-2002 Ximian, Inc.
 * g++ port Copyright (C) 2003 Nathan Hurst
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include <glib.h> // g_assert()

#include "event.h"
#include "event-fns.h"
#include "util/reverse-list.h"
#include "xml/document.h"
#include "xml/node-observer.h"
#include "debug/event-tracker.h"
#include "debug/simple-event.h"

using Inkscape::Util::List;
using Inkscape::Util::reverse_list;

int Inkscape::XML::Event::_next_serial=0;

void
sp_repr_begin_transaction (Inkscape::XML::Document *doc)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("begin-transaction");

	g_assert(doc != NULL);
	doc->beginTransaction();
}

void
sp_repr_rollback (Inkscape::XML::Document *doc)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("rollback");

	g_assert(doc != NULL);
	doc->rollback();
}

void
sp_repr_commit (Inkscape::XML::Document *doc)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("commit");

	g_assert(doc != NULL);
	doc->commit();
}

Inkscape::XML::Event *
sp_repr_commit_undoable (Inkscape::XML::Document *doc)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("commit");

	g_assert(doc != NULL);
	return doc->commitUndoable();
}

namespace {

class LogPerformer : public Inkscape::XML::NodeObserver {
public:
	typedef Inkscape::XML::Node Node;

	static LogPerformer &instance() {
		static LogPerformer singleton;
		return singleton;
	}

	void notifyChildAdded(Node &parent, Node &child, Node *ref) {
		parent.addChild(&child, ref);
	}

	void notifyChildRemoved(Node &parent, Node &child, Node *old_ref) {
		parent.removeChild(&child);
	}

	void notifyChildOrderChanged(Node &parent, Node &child,
			             Node *old_ref, Node *new_ref)
	{
		parent.changeOrder(&child, new_ref);
	}

	void notifyAttributeChanged(Node &node, GQuark name,
			            Inkscape::Util::ptr_shared<char> old_value,
				    Inkscape::Util::ptr_shared<char> new_value)
	{
		node.setAttribute(g_quark_to_string(name), new_value);
	}

	void notifyContentChanged(Node &node,
			          Inkscape::Util::ptr_shared<char> old_value,
				  Inkscape::Util::ptr_shared<char> new_value)
	{
		node.setContent(new_value);
	}
};

}

void Inkscape::XML::undo_log_to_observer(
	Inkscape::XML::Event const *log,
	Inkscape::XML::NodeObserver &observer
) {
	for ( Event const *action = log ; action ; action = action->next ) {
		action->undoOne(observer);
	}
}

void
sp_repr_undo_log (Inkscape::XML::Event *log)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("undo-log");

	if (log && log->repr) {
		g_assert(!log->repr->document()->inTransaction());
	}

	Inkscape::XML::undo_log_to_observer(log, LogPerformer::instance());
}

void Inkscape::XML::EventAdd::_undoOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildRemoved(*this->repr, *this->child, this->ref);
}

void Inkscape::XML::EventDel::_undoOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildAdded(*this->repr, *this->child, this->ref);
}

void Inkscape::XML::EventChgAttr::_undoOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyAttributeChanged(*this->repr, this->key, this->newval, this->oldval);
}

void Inkscape::XML::EventChgContent::_undoOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyContentChanged(*this->repr, this->newval, this->oldval);
}

void Inkscape::XML::EventChgOrder::_undoOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildOrderChanged(*this->repr, *this->child, this->newref, this->oldref);
}

void Inkscape::XML::replay_log_to_observer(
	Inkscape::XML::Event const *log,
	Inkscape::XML::NodeObserver &observer
) {
	List<Inkscape::XML::Event const &> reversed =
	  reverse_list<Inkscape::XML::Event::ConstIterator>(log, NULL);
	for ( ; reversed ; ++reversed ) {
		reversed->replayOne(observer);
	}
}

void
sp_repr_replay_log (Inkscape::XML::Event *log)
{
	using Inkscape::Debug::SimpleEvent;
	using Inkscape::Debug::EventTracker;
	using Inkscape::Debug::Event;

	EventTracker<SimpleEvent<Event::XML> > tracker("replay-log");

	if (log) {
		if (log->repr->document()) {
			g_assert(!log->repr->document()->inTransaction());
		}
	}

	Inkscape::XML::replay_log_to_observer(log, LogPerformer::instance());
}

void Inkscape::XML::EventAdd::_replayOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildAdded(*this->repr, *this->child, this->ref);
}

void Inkscape::XML::EventDel::_replayOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildRemoved(*this->repr, *this->child, this->ref);
}

void Inkscape::XML::EventChgAttr::_replayOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyAttributeChanged(*this->repr, this->key, this->oldval, this->newval);
}

void Inkscape::XML::EventChgContent::_replayOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyContentChanged(*this->repr, this->oldval, this->newval);
}

void Inkscape::XML::EventChgOrder::_replayOne(
	Inkscape::XML::NodeObserver &observer
) const {
	observer.notifyChildOrderChanged(*this->repr, *this->child, this->oldref, this->newref);
}

Inkscape::XML::Event *
sp_repr_coalesce_log (Inkscape::XML::Event *a, Inkscape::XML::Event *b)
{
	Inkscape::XML::Event *action;
	Inkscape::XML::Event **prev_ptr;

	if (!b) return a;
	if (!a) return b;

	/* find the earliest action in the second log */
	/* (also noting the pointer that references it, so we can
	 *  replace it later) */
	prev_ptr = &b;
	for ( action = b ; action->next ; action = action->next ) {
		prev_ptr = &action->next;
	}

	/* add the first log after it */
	action->next = a;

	/* optimize the result */
	*prev_ptr = action->optimizeOne();

	return b;
}

void
sp_repr_free_log (Inkscape::XML::Event *log)
{
	while (log) {
		Inkscape::XML::Event *action;
		action = log;
		log = action->next;
		delete action;
	}
}

namespace {

template <typename T> struct ActionRelations;

template <>
struct ActionRelations<Inkscape::XML::EventAdd> {
	typedef Inkscape::XML::EventDel Opposite;
};

template <>
struct ActionRelations<Inkscape::XML::EventDel> {
	typedef Inkscape::XML::EventAdd Opposite;
};

template <typename A>
Inkscape::XML::Event *cancel_add_or_remove(A *action) {
	typedef typename ActionRelations<A>::Opposite Opposite;
	Opposite *opposite=dynamic_cast<Opposite *>(action->next);

	if ( opposite && opposite->repr == action->repr &&
	     opposite->child == action->child &&
	     opposite->ref == action->ref )
	{
		Inkscape::XML::Event *remaining=opposite->next;

		delete opposite;
		delete action;

		return remaining;
	} else {
		return action;
	}
}

}

Inkscape::XML::Event *Inkscape::XML::EventAdd::_optimizeOne() {
	return cancel_add_or_remove(this);
}

Inkscape::XML::Event *Inkscape::XML::EventDel::_optimizeOne() {
	return cancel_add_or_remove(this);
}

Inkscape::XML::Event *Inkscape::XML::EventChgAttr::_optimizeOne() {
	Inkscape::XML::EventChgAttr *chg_attr=dynamic_cast<Inkscape::XML::EventChgAttr *>(this->next);

	/* consecutive chgattrs on the same key can be combined */
	if ( chg_attr && chg_attr->repr == this->repr &&
	     chg_attr->key == this->key )
	{
		/* replace our oldval with the prior action's */
		this->oldval = chg_attr->oldval;

		/* discard the prior action */
		this->next = chg_attr->next;
		delete chg_attr;
	}

	return this;
}

Inkscape::XML::Event *Inkscape::XML::EventChgContent::_optimizeOne() {
	Inkscape::XML::EventChgContent *chg_content=dynamic_cast<Inkscape::XML::EventChgContent *>(this->next);

	/* consecutive content changes can be combined */
	if ( chg_content && chg_content->repr == this->repr ) {
		/* replace our oldval with the prior action's */
		this->oldval = chg_content->oldval;

		/* get rid of the prior action*/
		this->next = chg_content->next;
		delete chg_content;
	}

	return this;
}

Inkscape::XML::Event *Inkscape::XML::EventChgOrder::_optimizeOne() {
	Inkscape::XML::EventChgOrder *chg_order=dynamic_cast<Inkscape::XML::EventChgOrder *>(this->next);

	/* consecutive chgorders for the same child may be combined or
	 * canceled out */
	if ( chg_order && chg_order->repr == this->repr &&
	     chg_order->child == this->child )
	{
		if ( chg_order->oldref == this->newref ) {
			/* cancel them out */
			Inkscape::XML::Event *after=chg_order->next;

			delete chg_order;
			delete this;

			return after;
		} else {
			/* combine them */
			this->oldref = chg_order->oldref;

			/* get rid of the other one */
			this->next = chg_order->next;
			delete chg_order;

			return this;
		}
	} else {
		return this;
	}
}

namespace {

class LogPrinter : public Inkscape::XML::NodeObserver {
public:
	typedef Inkscape::XML::Node Node;

	static LogPrinter &instance() {
		static LogPrinter singleton;
		return singleton;
	}

	static Glib::ustring node_to_string(Node const &node) {
		Glib::ustring result;
		char const *type_name=NULL;
		switch (node.type()) {
		case Inkscape::XML::DOCUMENT_NODE:
			type_name = "Document";
			break;
		case Inkscape::XML::ELEMENT_NODE:
			type_name = "Element";
			break;
		case Inkscape::XML::TEXT_NODE:
			type_name = "Text";
			break;
		case Inkscape::XML::COMMENT_NODE:
			type_name = "Comment";
			break;
		default:
			g_assert_not_reached();
		}
		char buffer[40];
		result.append("#<");
		result.append(type_name);
		result.append(":");
		snprintf(buffer, 40, "0x%p", &node);
		result.append(buffer);
		result.append(">");

		return result;
	}

	static Glib::ustring ref_to_string(Node *ref) {
		if (ref) {
			return node_to_string(*ref);
		} else {
			return "beginning";
		}
	}

	void notifyChildAdded(Node &parent, Node &child, Node *ref) {
		g_warning("Event: Added %s to %s after %s", node_to_string(parent).c_str(), node_to_string(child).c_str(), ref_to_string(ref).c_str());
	}

	void notifyChildRemoved(Node &parent, Node &child, Node *ref) {
		g_warning("Event: Removed %s from %s", node_to_string(parent).c_str(), node_to_string(child).c_str());
	}

	void notifyChildOrderChanged(Node &parent, Node &child,
	                             Node *old_ref, Node *new_ref)
	{
		g_warning("Event: Moved %s after %s in %s", node_to_string(child).c_str(), ref_to_string(new_ref).c_str(), node_to_string(parent).c_str());
	}

	void notifyAttributeChanged(Node &node, GQuark name,
	                            Inkscape::Util::ptr_shared<char> old_value,
				    Inkscape::Util::ptr_shared<char> new_value)
	{
		if (new_value) {
			g_warning("Event: Set attribute %s to \"%s\" on %s", g_quark_to_string(name), new_value.pointer(), node_to_string(node).c_str());
		} else {
			g_warning("Event: Unset attribute %s on %s", g_quark_to_string(name), node_to_string(node).c_str());
		}
	}

	void notifyContentChanged(Node &node,
			          Inkscape::Util::ptr_shared<char> old_value,
				  Inkscape::Util::ptr_shared<char> new_value)
	{
		if (new_value) {
			g_warning("Event: Set content of %s to \"%s\"", node_to_string(node).c_str(), new_value.pointer());
		} else {
			g_warning("Event: Unset content of %s", node_to_string(node).c_str());
		}
	}
};

}

void
sp_repr_debug_print_log(Inkscape::XML::Event const *log) {
	Inkscape::XML::replay_log_to_observer(log, LogPrinter::instance());
}

