/* 
 * Copyright (C) 2005-2008 MaNGOS <http://www.mangosproject.org/>
 *
 * Copyright (C) 2008 Trinity <http://www.trinitycore.org/>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "Creature.h"
#include "CreatureGroups.h"
#include "ObjectMgr.h"
#include "ProgressBar.h"
#include "Policies/SingletonImp.h"

#define MAX_DESYNC 5.0f
//TODO: Create group manager for each map
INSTANTIATE_SINGLETON_1(CreatureGroupManager);

UNORDERED_MAP<uint32, CreatureGroup*> CreatureGroupHolder;
UNORDERED_MAP<uint32, FormationMember*> CreatureGroupMap;

void CreatureGroupManager::UpdateCreatureGroup(uint32 group_id, Creature *member)
{
	if(CreatureGroupHolder.find(group_id) != CreatureGroupHolder.end())
	{	
		sLog.outDebug("Group found: %u, inserting creature GUID: %u", group_id, member->GetGUIDLow());
		CreatureGroupHolder[group_id]->AddMember(member);
	}
	else
	{
		sLog.outDebug("Group not found: %u. Creating new group.", group_id);
		CreatureGroup* formation = new CreatureGroup;
		CreatureGroupHolder[group_id] = formation;
		formation->AddMember(member);
	}
}

void CreatureGroupManager::DestroyGroup(uint32 group_id, uint64 guid)
{
	if(CreatureGroupHolder.find(group_id) != CreatureGroupHolder.end())
	{
		sLog.outDebug("Deleting member pointer to GUID: %u from group %u", group_id, guid);
		CreatureGroupHolder[group_id]->RemoveMember(guid);

		if(CreatureGroupHolder[group_id]->isEmpty())
		{
			sLog.outDebug("Deleting group %u", group_id);
			delete CreatureGroupHolder[group_id];
			CreatureGroupHolder.erase(group_id);
		}
	}
}

void CreatureGroupManager::LoadCreatureFormations()
{
	//Clear existing map
	CreatureGroupMap.clear();
	
	//Check Integrity of the table
	QueryResult *result = WorldDatabase.PQuery("SELECT MAX(`leaderGUID`) FROM `creature_formations`");
    
	if(!result)
    {
        sLog.outErrorDb(" an error occured while loading the table `creature_formations` ( maybe it doesn't exist ?)\n");
        return;
    }
	delete result;

	//Get group data
	result = WorldDatabase.PQuery("SELECT `leaderGUID`, `memberGUID`, `dist`, `angle`, `groupAI` FROM `creature_formations` ORDER BY `leaderGUID`");
    
	if(!result)
    {
        sLog.outErrorDb("The table `creature_formations` is empty or corrupted");
        return;
    }

    uint32 total_records = result->GetRowCount(), lastLeaderGUID = 0;
	barGoLink bar( total_records);
    Field *fields;
    
	FormationMember *group_member;
	//Loading data...
	do
    {
        fields = result->Fetch();
        
		bar.step();
        //Load group member data
		group_member						= new FormationMember;
		group_member->leaderGUID			= fields[0].GetUInt32();
		group_member->memberGUID			= fields[1].GetUInt32();
		group_member->groupAI				= fields[4].GetUInt8();
		//If creature is group leader we may skip loading of dist/angle
		if(group_member->leaderGUID != group_member->memberGUID)
		{
			group_member->follow_dist			= fields[2].GetUInt32();
			group_member->follow_angle			= fields[3].GetUInt32();
		}
		
		CreatureGroupMap[group_member->memberGUID] = group_member;
		
		if(lastLeaderGUID != group_member->leaderGUID)
			lastLeaderGUID = group_member->leaderGUID;
	} 
	while(result->NextRow()) ;
	
	sLog.outString();
	sLog.outString( ">> Loaded %u creatures in formations", total_records );
    sLog.outString();
	//Free some heap
	delete result;
}

void CreatureGroup::AddMember(Creature *member)
{
	sLog.outDebug("Adding unit GUID: %u.", member->GetGUIDLow());
	
	uint64 guid = member->GetGUID();
	//We first search creature member if exist
	if(CreatureGroupMembers.find(guid) != CreatureGroupMembers.end())
		return;
	//Check is that shit is a leader
	if(member->IsFormationLeader())
	{	
		sLog.outDebug("Unit GUID: %u is formation leader. Adding group.", member->GetGUIDLow());
		m_leader = member;
	}
	//Add to the club
	CreatureGroupMembers[guid] = member;
	sLog.outDebug("Unit GUID: %u added.", member->GetGUID());
}

void CreatureGroup::RemoveMember(uint64 guid)
{
	if(CreatureGroupMembers.find(guid) != CreatureGroupMembers.end())
		CreatureGroupMembers.erase(guid);	
}

void CreatureGroup::MemberHasAttacked(Creature *member)
{
	uint8 groupAI = CreatureGroupMap[member->GetDBTableGUIDLow()]->groupAI;;

	for(UNORDERED_MAP<uint64, Creature*>::iterator itr = CreatureGroupMembers.begin(); itr != CreatureGroupMembers.end(); itr++)
	{
		sLog.outDebug("AI:%u:Group member found: %u, attacked by %s.", groupAI, itr->second->GetGUIDLow(), member->getVictim()->GetName());
		if(itr->second)
		{
			switch(groupAI)
			{
				case 0:
					return;
				case 1:
					if(!member->IsFormationLeader())
						return;
			}	
			//Attack if everything is OK
			itr->second->AI()->AttackStart(member->getVictim());	
		}
	}
}

void CreatureGroup::LeaderMovedInEvade()
{
	for(UNORDERED_MAP<uint64, Creature*>::iterator itr = CreatureGroupMembers.begin(); itr != CreatureGroupMembers.end(); itr++)
	{
		if(itr->second && itr->second->isAlive() && !itr->second->isInCombat() && !itr->second->getVictim())
			SetMemberDestination(itr->second);		
	}
}
		
void CreatureGroup::SetMemberDestination(Creature *member)
{
	if(!member || !m_leader || member->IsFormationLeader())
		return;
	
	float x,y,z;
	uint32 lowguid = member->GetGUIDLow();
	
	UNORDERED_MAP<uint32, FormationMember*>::iterator itr2 = CreatureGroupMap.find(lowguid);
			
	if(m_leader->GetMotionMaster()->GetDestination(x,y,z) && itr2 != CreatureGroupMap.end())
	{	
		float dist, angle, pathangle;
		
		angle		= CreatureGroupMap[lowguid]->follow_angle;	
		dist		= CreatureGroupMap[lowguid]->follow_dist;	
		pathangle	= atan2(m_leader->GetPositionY()-y, m_leader->GetPositionX()-x);
								
		x = x+cos(angle+pathangle)*dist;
		y = y+sin(angle+pathangle)*dist;
		
		member->GetMotionMaster()->Clear();

		if(member->GetDistance(m_leader) < dist+MAX_DESYNC)
			member->SetUnitMovementFlags(m_leader->GetUnitMovementFlags());
		else
			member->RemoveUnitMovementFlag(MOVEMENTFLAG_WALK_MODE);

		member->GetMotionMaster()->MovePoint(0, x, y, z);
	}
}