/*
 * RoadCarrier.cs
 * Authors: Mike Dapiran
 * Copyright (c) 2007-2008 Cornell University

 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.
*/

using System.Collections.Generic;
using ColonySim.Structures;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;

namespace ColonySim
{
	class RoadCarrier : Carrier
	{
		private int mCurrentDistance;
		bool mTowardsResidential;

		bool mInitialTowardsResidential;

		public bool TowardsResidential
		{
			get { return mTowardsResidential; }
			set { mTowardsResidential = value; }
		}

		public bool InitialTowardsResidential
		{
			get { return mInitialTowardsResidential; }
			set { mInitialTowardsResidential = value; }
		}

		public RoadCarrier(bool GotoResidential, ContentManager pContent, string pModelName, string pTextureName, Grid pGridReference)
			:base(pContent, pModelName, pTextureName, pGridReference)
		{
			mInitialTowardsResidential = GotoResidential;
			mTowardsResidential = mInitialTowardsResidential;

		}

		public void UpdateDirection()
		{
			// If we've moved outside the bounds of the grid, destroy us
			Structure contents = GridReference.GridContents(GridPosition);
			if (GridPosition.X < GridReference.GridBounds.Left || GridPosition.X > GridReference.GridBounds.Right ||
				GridPosition.Y < GridReference.GridBounds.Top || GridPosition.Y > GridReference.GridBounds.Bottom)
			{
				// Purge this carrier
				Destroy();
				return;
			}
			else
			{
				Dictionary<Directions, Structure> neighbors = GridReference.GetNeighborsForRoad(GridPosition);
				if (mInitialTowardsResidential)
				{
					if (contents != null &&
						contents.mDistanceFromResidential == 1
						&& Util.Random.Bool())
					{
						Destroy();
						return;
					}
				}
				else
				{
					foreach (Structure v in neighbors.Values)
					{
						if (!(v is Residential || v is Tube || v is Road)
							&& Util.Random.NextDouble() <= .2)
						{
							Destroy();
							return;
						}
					}
				}

				if (contents is RoadTubeCrossing)
				{
					neighbors = GridReference.GetNeighborsForIntersection(GridPosition, typeof(Road));
				}
				else
				{
					neighbors = GridReference.GetNeighborsForRoad(GridPosition, typeof(Road));
					Dictionary<Directions, Structure> temp = GridReference.GetNeighborsForRoad(GridPosition, typeof(RoadTubeCrossing));
					foreach (Directions d in temp.Keys)
					{
						if (GridReference.GetNeighborsForIntersection(temp[d].GridPosition, typeof(Road)).ContainsValue(contents))
						{
							neighbors.Add(d, temp[d]);
						}
					}
				}

				if (neighbors.Count == 0)
				{
					Destroy();
				}
				else
				{
					mTowardsResidential = mInitialTowardsResidential;

					List<Directions> possibleDirections = new List<Directions>();
					foreach (Directions d in neighbors.Keys)
					{
						if (mTowardsResidential && neighbors[d].mDistanceFromResidential < mCurrentDistance)
						{
							possibleDirections.Add(d);
						}
						else if (!mTowardsResidential && neighbors[d].mDistanceFromResidential > mCurrentDistance)
						{
							possibleDirections.Add(d);
						}
					}
					if (possibleDirections.Count == 0)
					{
						foreach (Directions d in neighbors.Keys)
						{
							possibleDirections.Add(d);
						}
					}
					Direction = possibleDirections[Util.Random.Next(0, possibleDirections.Count)];
				}
			}
		}

		public override bool UpdatePosition()
		{
			if (!base.UpdatePosition())
			{
				return false;
			}
			Structure contents = GridReference.GridContents(GridPosition);

			// If we've moved outside the bounds of the grid, destroy us
			if (GridPosition.X < GridReference.GridBounds.Left || GridPosition.X > GridReference.GridBounds.Right ||
				GridPosition.Y < GridReference.GridBounds.Top || GridPosition.Y > GridReference.GridBounds.Bottom)
			{
				// Purge this carrier
				Destroy();
			}
			else
			{
				Dictionary<Directions, Structure> neighbors = GridReference.GetNeighborsForRoad(GridPosition);
				if (mInitialTowardsResidential)
				{
						if (contents.mDistanceFromResidential == 1 && Util.Random.Bool())
						{
							Destroy();
							return false;
						}
				}
				else
				{
					foreach (Structure s in neighbors.Values)
					{
						if (!(s is Residential || s is TransportStructure)
							&& Util.Random.NextDouble() <= .2)
						{
							Destroy();
							return false;
						}
					}
				}

				if (contents is RoadTubeCrossing)
				{
					neighbors = GridReference.GetNeighborsForIntersection(GridPosition, typeof(Road));
				}
				else
				{
					neighbors = GridReference.GetNeighborsForRoad(GridPosition, typeof(Road));
					Dictionary<Directions, Structure> temp = GridReference.GetNeighborsForRoad(GridPosition, typeof(RoadTubeCrossing));
					foreach (Directions d in temp.Keys)
					{
						if (GridReference.GetNeighborsForIntersection(temp[d].GridPosition, typeof(Road)).ContainsValue(contents))
						{
							neighbors.Add(d, temp[d]);
						}
					}
				}

				if (neighbors.Count == 0)
				{
					Destroy();
					return false;
				}
				else if (neighbors.Count == 1)
				{
					Dictionary<Directions, Structure>.KeyCollection.Enumerator temp = neighbors.Keys.GetEnumerator();
					temp.MoveNext();
					Direction = temp.Current;
					mTowardsResidential = !mTowardsResidential;
					if (bumps >= 4)
					{
						Destroy();
						return false;
					}
					bumps++;
				}
				else if (neighbors.Count == 2)
				{
					foreach (Directions d in neighbors.Keys)
					{
						if (d != Opposite(Direction))
						{
							Direction = d;
							break;
						}
					}
				}
				else
				{
					mTowardsResidential = mInitialTowardsResidential;

					List<Directions> possibleDirections = new List<Directions>();
					foreach (Directions d in neighbors.Keys)
					{
						if (mTowardsResidential && neighbors[d].mDistanceFromResidential < mCurrentDistance)
						{
							possibleDirections.Add(d);
						}
						else if (!mTowardsResidential && neighbors[d].mDistanceFromResidential > mCurrentDistance)
						{
							possibleDirections.Add(d);
						}
					}
					if (possibleDirections.Count == 0)
					{
						foreach (Directions d in neighbors.Keys)
						{
							if(d != Opposite(Direction))
								possibleDirections.Add(d);
						}
					}
					Direction = possibleDirections[Util.Random.Next(0, possibleDirections.Count)];
				}
			}

			return true;
		}
	}
}