/*
    mephi-tasks — a client to NRNU MEPhI Redmine server

    Copyright (C) 2015  Dmitry Yu Okunev <dyokunev@ut.mephi.ru> 0x8E30679C

    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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "redmineitemtree.h"

RedmineItemTree::RedmineItemTree()
{
	this->displayRetryTimer.setSingleShot ( true );
	connect ( &this->displayRetryTimer, SIGNAL ( timeout() ), this, SLOT ( display_retry() ) );
	this->filterRetryTimer.setSingleShot ( true );
	connect ( &this->filterRetryTimer,  SIGNAL ( timeout() ), this, SLOT ( filter_retry() ) );
}

void RedmineItemTree::clear()
{
	this->real.clear();
}

void RedmineItemTree::add ( QJsonObject jsonObj )
{
	this->real.add ( jsonObj );
}

QList<QJsonObject> RedmineItemTree::get()
{
	return this->real.get();
}
QJsonObject RedmineItemTree::get ( int item_id )
{
	return this->real.get ( item_id );
}
QJsonObject RedmineItemTree::get ( QTreeWidgetItem *widgetItem )
{
	return this->widgetItem2item[widgetItem];
}

bool RedmineItemTree::isDescendant ( int descendant_id, int ancestor_id )
{
	QJsonObject descendant = this->get ( descendant_id );
	int parent_id = 0;

	//qDebug("RedmineItemTree::isDescendant(%i, %i)", descendant_id, ancestor_id);

	while ( true ) {
		parent_id  = descendant["parent"].toObject() ["id"].toInt();

		if ( parent_id == 0 )
			break;

		//qDebug("%i <> %i", parent_id, ancestor_id);

		if ( parent_id == ancestor_id )
			return true;

		descendant = this->get ( parent_id );
	};

	return false;
}

void RedmineItemTree::set ( QJsonArray array )
{
	/* refilling this->list */
	this->clear();
	foreach ( const QJsonValue & val, array )
	this->add ( val.toObject() );
	/* rebuilding this->real.hierarchy */
	QList<QJsonObject> item_list;
	item_list = this->get();
	foreach ( const QJsonObject & item, item_list ) {
		int parent_id;

		if ( item.contains ( "parent" ) )
			parent_id = item["parent"].toObject() ["id"].toInt();
		else
			parent_id = 0;

		this->real.hierarchy[parent_id].append ( item );
	}
	return;
}

void RedmineItemTree::filter ( QWidget *initiator, itemFilterFunct_t filterFunct )
{
	if ( !this->displayMutex.tryLock() ) {
		if ( !this->displayExceptionMutex.tryLock() )
			return;

		this->filterRetryArgs.initiator   = initiator;
		this->filterRetryArgs.filterFunct = filterFunct;
		this->filterRetryTimer.start ( 70 );
		this->displayExceptionMutex.unlock();
		return;
	}

	QList<QJsonObject> item_list = this->real.get();
	QHash<int, bool> filtered_hash;
	this->filtered_old = this->filtered;
	this->filtered.clear();
	foreach ( const QJsonObject & item, item_list )

	if ( filterFunct ( initiator, item ) ) {
		this->filtered.add ( item );
		filtered_hash.insert ( item["id"].toInt(), true );
	}

	QList<QJsonObject> filtered_list = this->filtered.get();
	foreach ( const QJsonObject & item, filtered_list ) {
		int parent_id;

		if ( item.contains ( "parent" ) )
			parent_id = item["parent"].toObject() ["id"].toInt();
		else
			parent_id = 0;

		while ( !filtered_hash.contains ( parent_id ) ) {
			QJsonObject parent = this->real.get ( parent_id ) ["parent"].toObject();

			if ( parent.contains ( "id" ) )
				parent_id = parent["id"].toInt();
			else
				parent_id = 0;

			if ( parent_id == 0 )
				break;
		}

		this->filtered.parent.insert ( item["id"].toInt(), parent_id );
		this->filtered.hierarchy[parent_id].append ( item );
	}
	this->displayMutex.unlock();
	return;
}

void RedmineItemTree::filter_retry()
{
	this->filter ( this->filterRetryArgs.initiator,
	               this->filterRetryArgs.filterFunct );
	return;
}

void RedmineItemTree::widgetItemReset ( int item_id )
{
	if ( !this->id2widgetItem.contains ( item_id ) )
		return;

	QTreeWidgetItem *widgetItem = this->id2widgetItem[item_id];
	this->id2widgetItem.remove ( item_id );
	this->widgetItem2item.remove ( widgetItem );
	//this->filtered.removechild(item_id);
	return;
}

void RedmineItemTree::widgetItemResetRecursive ( int item_id )
{
	QList<QJsonObject> children = this->real.getchildren ( item_id );

	if ( !this->id2widgetItem.contains ( item_id ) )
		return;

	foreach ( const QJsonObject & child, children ) {
		int child_id = child["id"].toInt();
		this->widgetItemResetRecursive ( child_id );
		this->widgetItemReset ( child_id );
	}
	QTreeWidgetItem *widgetItem = this->id2widgetItem[item_id];
	this->widgetItemReset ( item_id );
	delete widgetItem;
	return;
}


void RedmineItemTree::widgetItemsResetIfUpdated ( int item_id, QJsonObject item )
{
	/*
	 *  Remove the project from list if it had been updated
	 */
	QJsonObject item_old      = this->get ( item_id );
	int         parent_id     = this->filtered.parent[item_id];
	int         parent_old_id = this->filtered_old.parent[item_id];

	if ( item_old["id"].toInt() > 0 ) // If exists
		if ( ( item_old != item ) || ( parent_id != parent_old_id ) ) // If changed
			this->widgetItemResetRecursive ( item_id );

	return;
}

void RedmineItemTree::display_recursive ( QTreeWidgetItem *widgetItem, QWidget *initiator, widgetItemSetTextFunct_t setTextFunct, QJsonObject item, int level, QHash<int, int> &toremove_ids )
{
	int item_id = item["id"].toInt();
	toremove_ids.remove ( item_id );
	setTextFunct ( initiator, widgetItem, item, this, level );
	foreach ( const QJsonObject & child, this->filtered.getchildren ( item_id ) ) {
		this->display_child ( widgetItem, initiator, setTextFunct, child, level + 1, toremove_ids );
	}
}

void RedmineItemTree::display_child ( QTreeWidgetItem *parent, QWidget *initiator, widgetItemSetTextFunct_t setTextFunct, QJsonObject child, int level, QHash<int, int> &toremove_ids )
{
	int item_id = child["id"].toInt();
	QTreeWidgetItem *widgetItem;
	this->widgetItemsResetIfUpdated ( item_id, child );

	if ( this->id2widgetItem.contains ( item_id ) )
		widgetItem = this->id2widgetItem[item_id];
	else {
		widgetItem = new QTreeWidgetItem ( parent );
		this->id2widgetItem.insert ( item_id, widgetItem );
		this->widgetItem2item.insert ( widgetItem, child );
	}

	this->display_recursive ( widgetItem, initiator, setTextFunct, child, level, toremove_ids );
}

void RedmineItemTree::display_topOne ( QTreeWidget *widget, QWidget *initiator, widgetItemSetTextFunct_t setTextFunct, int pos, QHash<int, int> &toremove_ids )
{
	QJsonObject item    = this->row2item[pos];
	int         item_id = item["id"].toInt();
	QTreeWidgetItem *widgetItem;
	this->widgetItemsResetIfUpdated ( item_id, item );

	if ( this->id2widgetItem.contains ( item_id ) )
		widgetItem = this->id2widgetItem[item_id];
	else {
		widgetItem = new QTreeWidgetItem ( widget );
		this->id2widgetItem.insert ( item_id, widgetItem );
		this->widgetItem2item.insert ( widgetItem, item );
	}

	this->display_recursive ( widgetItem, initiator, setTextFunct, item, 0, toremove_ids );
}

void RedmineItemTree::display ( QTreeWidget *widget, QWidget *initiator, widgetItemSetTextFunct_t setTextFunct )
{
	//qDebug("RedmineItemTree::display()");
	if ( !this->displayMutex.tryLock() ) {
		if ( !this->displayExceptionMutex.tryLock() )
			return;

		this->displayRetryArgs.widget       = widget;
		this->displayRetryArgs.initiator    = initiator;
		this->displayRetryArgs.setTextFunct = setTextFunct;
		this->displayRetryTimer.start ( 100 );
		this->displayExceptionMutex.unlock();
		return;
	}

	/*\
	 *  Preparing
	\*/
	widget->setSortingEnabled ( false );
	/*\
	 *  Building a table of items' id
	\*/
	QHash <int, int> toremove_ids;
	foreach ( const QJsonObject & item, this->widgetItem2item )
	toremove_ids.insert ( item["id"].toInt(), item["id"].toInt() );
	/*\
	 *  Displaying new items
	\*/
	this->row2item.clear();
	int topitems_count = 0;
	foreach ( const QJsonObject & item, this->filtered.getchildren ( 0 ) ) {
		this->row2item.insert ( topitems_count, item );
		this->display_topOne ( widget, initiator, setTextFunct, topitems_count, toremove_ids );
		topitems_count++;
	}
	/*\
	 *  Removing stale items
	\*/
	foreach ( const int &item_id, toremove_ids )
	this->widgetItemResetRecursive ( item_id );
	/*\
	 *  Redisplaying lost items (due to ascentor removing)
	\*/
	topitems_count = 0;
	foreach ( const QJsonObject & item, this->filtered.getchildren ( 0 ) )
	this->display_topOne ( widget, initiator, setTextFunct, topitems_count++, toremove_ids );
	/*\
	 *  Finishing
	\*/
	widget->setSortingEnabled ( true );
	this->displayMutex.unlock();
	return;
}



void RedmineItemTree::display ( QComboBox *widget, QWidget *initiator, comboBoxAddItemFunct_t addItemFunct )
{
	( void ) initiator;

	qDebug ( "RedmineItemTree::display()" );
	this->displayMutex.lock();
	/*\
	 *  Building a table of items' id
	\*/
	QHash <int, int> toremove_ids;
	foreach ( const QJsonObject & item, this->widgetItem2item )
	toremove_ids.insert ( item["id"].toInt(), item["id"].toInt() );
	/*\
	 *  Displaying new items
	\*/
	int itemIdx = 0;
	this->row2item.clear();
	foreach ( const QJsonObject & item, this->filtered.get() ) {
		this->row2item.insert ( itemIdx++, item );
		addItemFunct ( widget, item );
		// display item
		//this->display_topOne(widget, initiator, setTextFunct, topitems_count, toremove_ids);
	}
	/*\
	 *  Removing stale items
	\*/
	foreach ( const int &item_id, toremove_ids )
	this->widgetItemResetRecursive ( item_id );
	/*\
	 *  Finishing
	\*/
	this->displayMutex.unlock();
	return;
}


void RedmineItemTree::display_retry()
{
	this->display ( this->displayRetryArgs.widget,
	                this->displayRetryArgs.initiator,
	                this->displayRetryArgs.setTextFunct );
	return;
}