package com.game.AI;



import java.util.Iterator;

import java.util.Vector;



import com.game.Constants;

import com.game.Cursor;

import com.game.Map;

import com.game.Tile;

import com.game.Vec2;



/**

 * Task to calculate a path along the border of the nearest enemy

 * army.

 * @author Ying

 *

 */

public class CalculateCirclePathTask extends LeafTask 

{

	/**

	 * Max length of the path we want

	 */

	private static final int pathLen = 10;

	

	/**

	 * Minimum distance at which we attempt to circle

	 * TODO: Calculate from map size.

	 */

	private static final float minDistance = 40;



	/**

	 * Creates a new instance of the CalculateCirclePathTask class 

	 * @param blackboard Reference to the AI Blackboard data

	 */

	public CalculateCirclePathTask(Blackboard blackboard) 

	{

		super(blackboard);

	}



	/**

	 * Creates a new instance of the CalculateCirclePathTask class 

	 * @param blackboard Reference to the AI Blackboard data

	 * @param name Name of the class, used for debugging

	 */

	public CalculateCirclePathTask(Blackboard blackboard, String name) 

	{

		super(blackboard, name);

	}



	/**

	 * Confirms the data we need exists and that we are not

	 * too far away to circle.

	 */

	@Override

	public boolean CheckConditions()

	{

		LogTask("Checking conditions");

		if(bb.path == null && bb.closestEnemyCursor == null)

		{

			return false;

		}

		

		float distanceToEnemy = (float) bb.player.GetCursor().GetPosition().GetVectorTo(bb.closestEnemyCursor.GetPosition()).Length();

		if(distanceToEnemy > minDistance)

		{

			return false;

		}

		

		return true;

	}



	/**

	 * Calculates a path of tiles around the enemy army

	 * and stores it in the Blackboard

	 */

	@Override

	public void DoAction() 

	{

		LogTask("Doing action");

		

		

		Cursor chosenEnemy = bb.closestEnemyCursor;

		Vec2 lineToEnemy = bb.player.GetCursor().GetPosition().GetVectorTo(chosenEnemy.GetPosition());

		

		//Log.i("CircleStrategy", "Start: Selected enemy " + chosenEnemy.GetID());

		

		// Get the last empty tile before the cursor density

		Map mapRef = Blackboard.map;

		Tile curTile = mapRef.AtWorld(

				(int)chosenEnemy.GetPosition().X(), 

				(int)chosenEnemy.GetPosition().Y());

		

		lineToEnemy.Normalize();

		lineToEnemy.Scale(Constants.TileWidth);

		

		// If no starting tile, we're done here.

		if(curTile == null)

		{

			LogTask("Not found initial tile, bailing out");

			this.control.FinishWithFailure();

			return;

		}

		

		//curTile.GetPos().Print("CircleStrategy", "Start: Enemy cursor closest tile is ");

		//lineToEnemy.Print("CircleStrategy", "Start: Line to enemy is ");

		

		while( curTile != null && curTile.GetMaxCapacity() > 0 && !curTile.HasEnemyDensity(chosenEnemy.GetPlayer().GetID()))

		{

			//curTile.GetPos().Print("CircleStrategy", "Start: Checking tile ");

			

			int x = (int)Math.round((curTile.GetRealPos().X()-lineToEnemy.X() ));

			int y = (int)Math.round((curTile.GetRealPos().Y()-lineToEnemy.Y()) );

			

			//curTile.GetRealPos().Print("CircleStrategy", "Start: (" + x+", " +y +") Checking tile ");

			Tile nextTile = mapRef.AtWorld( x , y);

			

			// To avoid infinite loops caused by float precision, if we're stuck on the same tile twice

			// Just jump to the closest in that direction.

			if(curTile == nextTile)

			{

				curTile = mapRef.AtWorld( 

						(int)(curTile.GetRealPos().X()-(Math.signum(lineToEnemy.X()) * Constants.TileWidth) ) , 

						(int)(curTile.GetRealPos().Y()-(Math.signum(lineToEnemy.Y()) * Constants.TileWidth) ));

			}

			else

			{

				curTile = nextTile;

			}

					

		}

		//Log.i("CircleStrategy", "Start: Finished looking for initial tile");

		

		

		// If no starting tile, we're done here.

		if(curTile == null)

		{

			LogTask("Not found initial tile, bailing out");

			this.control.FinishWithFailure();

			return;

		}	

		

		//curTile.GetPos().Print("CircleStrategy", "Start: Initial selected tile is ");

		

		// In the direction of the cursor, find the emptiest tile of the surrounding ones		

		Vector<Tile> path= new Vector<Tile>();

		path.add(curTile);		

		//Log.i("CircleStrategy", "Start: Looking for tile path");

		for(int i = 0; i < pathLen; i++)

		{		

			Tile toAdd = null;

			curTile = mapRef.AtWorld(

					(int)(path.lastElement().GetRealPos().X()+lineToEnemy.X()), 

					(int)(path.lastElement().GetRealPos().Y()+lineToEnemy.Y()));

			

			for(int j = 0; j < 9; j++)

			{

				Tile next = Blackboard.map.GetNeighbour(curTile, j);

				if(next != null)

				{

					if(toAdd == null)

					{

						if(next.GetCurrentCapacity() > 0)

						{

							if(NotInPath(next,path))

							{

								toAdd = next;

							}

						}

					}

					else

					{

						if(next.GetCurrentCapacity() > toAdd.GetCurrentCapacity())

						{

							if(NotInPath(next,path))

							{

								toAdd = next;

							}

						}

					}

				}

			}

			

			if(toAdd != null)

			{

				//toAdd.GetPos().Print("CircleStrategy", "Start: -- Adding tile ");

				path.add(toAdd);

			}

			else

			{

				//Log.i("CircleStrategy", "Start: No more tiles to add. Path ended");

				break;

			}

		}

		

		bb.path = path;

		this.control.FinishWithSuccess();

		

	}



	/**

	 * Ends the task

	 */

	@Override

	public void End() 

	{

		LogTask("Ending");



	}



	/**

	 * Starts the task

	 */

	@Override

	public void Start() 

	{

		LogTask("Starting");



	}

	

	/**

	 * Checks if a said tile is not in the path so far

	 * @param tile Tile to check against.

	 * @return True if it's not on the path, false if it is

	 */

	private boolean NotInPath(Tile tile, Vector<Tile> path)

	{

		boolean found = false;

		for (Iterator<Tile> iterator = path.iterator(); iterator.hasNext();) 

		{

			if(tile == (Tile) iterator.next())

			{

				found = true;

				break;

			}			

		}

		

		return !found;

	}

}