package jrummikub.control;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import jrummikub.control.turn.HumanTurnControl;
import jrummikub.control.turn.ITurnControl;
import jrummikub.model.Hand;
import jrummikub.model.IHand;
import jrummikub.model.IPlayer;
import jrummikub.model.IRoundState;
import jrummikub.model.ITable;
import jrummikub.model.Position;
import jrummikub.model.Score;
import jrummikub.model.Stone;
import jrummikub.model.StoneSet;
import jrummikub.util.Connection;
import jrummikub.util.Event;
import jrummikub.util.Event1;
import jrummikub.util.IEvent;
import jrummikub.util.IEvent1;
import jrummikub.util.IListener;
import jrummikub.util.Pair;
import jrummikub.view.IView;

/**
 * Controller that manages a single round of rummikub
 */
public class RoundControl {
	IRoundState roundState;
	private IView view;
	private ITable clonedTable;
	private Event restartRoundEvent = new Event();
	private Event1<Score> endOfRoundEvent = new Event1<Score>();
	private List<Connection> connections = new ArrayList<Connection>();
	private boolean roundFinished;

	/**
	 * Create a new RoundControl using the given gameState and view
	 * 
	 * @param roundState
	 *            initial round state
	 * @param view
	 *            view used for user interaction
	 */
	public RoundControl(IRoundState roundState, IView view) {
		this.roundState = roundState;
		this.view = view;
	}

	/**
	 * End the round
	 * 
	 * @return endOfRoundEvent
	 */
	public IEvent1<Score> getEndOfRoundEvent() {
		return endOfRoundEvent;
	}

	/**
	 * Begin the round
	 */
	public void startRound() {
		deal();

		connections.add(view.getStartTurnEvent().add(new IListener() {
			@Override
			public void handle() {
				startTurn();
			}
		}));

		prepareTurn();
	}

	private void prepareTurn() {
		clonedTable = (ITable) roundState.getTable().clone();
		view.enableStartTurnPanel(true);
		view.getTablePanel().setStoneSets(clonedTable);
		view.setCurrentPlayerName(roundState.getActivePlayer()
				.getPlayerSettings().getName());
		view.setCurrentPlayerColor(roundState.getActivePlayer()
				.getPlayerSettings().getColor());
		view.setHasLaidOut(roundState.getActivePlayer().getLaidOut());

	}

	private void startTurn() {
		boolean inspectOnly = roundState.getTurnNumber() < 1;
		boolean mayRedeal = inspectOnly
				&& roundState.getActivePlayer().getHand()
						.getIdenticalStoneCount() >= 3;

		view.getPlayerPanel().setEndTurnMode(inspectOnly, mayRedeal);

		ITurnControl turnControl = roundState.getActivePlayer()
				.getPlayerSettings().getTurnControlFactory().create();
		turnControl.setup(roundState.getActivePlayer().getHand(), clonedTable,
				view, inspectOnly, mayRedeal);
		turnControl.getEndOfTurnEvent().add(new IListener() {
			@Override
			public void handle() {
				endOfTurn();
			}
		});

		turnControl.getRedealEvent().add(new IListener() {
			@Override
			public void handle() {
				redeal();
			}
		});
		turnControl.startTurn();
	}

	void deal() {
		for (int i = 0; i < roundState.getPlayerCount(); i++) {
			IHand hand = roundState.getNthNextPlayer(i).getHand();
			for (int j = 0; j < 7; j++) {
				hand.drop(roundState.getGameHeap().drawStone(), new Position(j,
						0));
				hand.drop(roundState.getGameHeap().drawStone(), new Position(j,
						1));
			}
		}
	}

	private boolean laidOutValidPoints() {
		List<StoneSet> newSets = tableSetDifference(roundState.getTable(),
				clonedTable);

		int totalValue = 0;
		for (StoneSet set : newSets) {
			totalValue += set.classify().getSecond();
		}

		return totalValue == 0
				|| totalValue >= roundState.getGameSettings()
						.getInitialMeldThreshold();
	}

	private void endOfTurn() {
		if (roundState.getTurnNumber() >= 1) {
			checkTurn();
		}

		if (roundState.getLastPlayer() == null) {
			if (roundState.getGameHeap().getSize() == 0) {
				roundState.setLastPlayer(roundState.getNthNextPlayer(-1));
				roundState.nextTurn();
			} else {
				roundState.nextPlayer();
				roundState.nextTurn();
			}
		} else {
			if (roundState.getActivePlayer() == roundState.getLastPlayer()) {
				endOfRound();
			} else {
				roundState.nextPlayer();
				roundState.nextTurn();
			}
		}
		if (!roundFinished) {
			prepareTurn();
		}
	}

	private void checkTurn() {
		if (!clonedTable.isValid()) {
			rejectMove();
			return;
		}
		if (!roundState.getActivePlayer().getLaidOut()) {
			// Player touched forbidden stones
			if (!tableSetDifference(clonedTable, roundState.getTable())
					.isEmpty()) {
				rejectMove();
				return;
			}
			if (!laidOutValidPoints()) {
				rejectMove();
				return;
			}
		}
		Set<Stone> tableDiff = tableDifference(roundState.getTable(),
				clonedTable);

		roundState.setTable(clonedTable);

		if (tableDiff.isEmpty()) {
			// Player hasn't made a move
			dealStone();
		} else {
			roundState.getActivePlayer().setLaidOut(true);
			if (roundState.getActivePlayer().getHand().getSize() == 0) {
				endOfRound();
			}
		}
	}

	private void rejectMove() {
		Set<Stone> tableDiff = tableDifference(roundState.getTable(),
				clonedTable);
		// deal penalty, reset
		roundState.getGameHeap().putBack(tableDiff);
		dealPenalty(tableDiff.size());

	}

	static Set<Stone> tableDifference(ITable oldTable, ITable newTable) {
		Set<Stone> ret = new HashSet<Stone>();

		for (Pair<StoneSet, Position> entry : newTable) {
			for (Stone stone : entry.getFirst()) {
				ret.add(stone);
			}
		}
		for (Pair<StoneSet, Position> entry : oldTable) {
			for (Stone stone : entry.getFirst()) {
				ret.remove(stone);
			}
		}
		return ret;
	}

	static List<StoneSet> tableSetDifference(ITable oldTable, ITable newTable) {
		List<StoneSet> ret = new ArrayList<StoneSet>();

		for (Pair<StoneSet, Position> entry : newTable) {
			ret.add(entry.getFirst());
		}
		for (Pair<StoneSet, Position> entry : oldTable) {
			ret.remove(entry.getFirst());
		}
		return ret;
	}

	void dealStones(int count) {
		IHand hand = roundState.getActivePlayer().getHand();
		int rowCount = hand.getRowCount();

		for (int i = 0; i < count; ++i) {
			if (hand.getFreeRowSpace(rowCount - 1) == 0) {
				rowCount++;
			}

			hand.drop(roundState.getGameHeap().drawStone(), new Position(
					Hand.WIDTH - 1, rowCount - 1));
		}
	}

	private void dealStone() {
		dealStones(1);
	}

	private void dealPenalty(int count) {
		dealStones(count + 3);
	}

	void endOfRound() {
		for (Connection c : connections) {
			c.remove();
		}
		Score roundScore = score();
		endOfRoundEvent.emit(roundScore);
		roundFinished = true;
	}

	private Score score() {
		List<Boolean> winners = new ArrayList<Boolean>();
		List<Integer> points = new ArrayList<Integer>();

		boolean foundRegularWinner = false;
		int winnerPlayerNumber = 0;
		Pair<Integer, Integer> bestScore = new Pair<Integer, Integer>(
				Integer.MIN_VALUE, Integer.MAX_VALUE);
		int pointSum = 0;
		for (int i = 0; i < roundState.getPlayerCount(); i++) {
			IPlayer player = roundState.getNthPlayer(i);
			IHand playerHand = player.getHand();
			boolean isWinner = playerHand.getSize() == 0;
			winners.add(isWinner);
			if (isWinner) {
				foundRegularWinner = true;
				winnerPlayerNumber = i;
			}
			int stonePoints = 0;

			if (!player.getLaidOut()) {
				stonePoints = playerHand.isInitialMeldPossible() ? 200 : 100;
			} else {
				stonePoints = playerHand.getStonePoints();
			}

			bestScore = updateBestScore(bestScore, -stonePoints,
					playerHand.getSize());

			points.add(-stonePoints);
			pointSum += stonePoints;
		}

		if (foundRegularWinner) {
			points.set(winnerPlayerNumber, pointSum);
		} else {
			for (int i = 0; i < roundState.getPlayerCount(); i++) {
				if (bestScore.equals(new Pair<Integer, Integer>(points.get(i),
						roundState.getNthPlayer(i).getHand().getSize()))) {
					winners.set(i, true);
				}
			}
		}
		return new Score(winners, points);
	}

	private static Pair<Integer, Integer> updateBestScore(
			Pair<Integer, Integer> bestScore, int stonePoints, int size) {
		if (bestScore.getFirst() == stonePoints) {
			return new Pair<Integer, Integer>(stonePoints, Math.min(
					bestScore.getSecond(), size));
		} else if (bestScore.getFirst() < stonePoints) {
			return new Pair<Integer, Integer>(stonePoints, size);
		}
		return bestScore;
	}

	/**
	 * Emitted when the round is aborted and needs to be restarted
	 * 
	 * @return the event
	 */
	public IEvent getRestartRoundEvent() {
		return restartRoundEvent;
	}

	private void redeal() {
		for (Connection c : new ArrayList<Connection>(connections)) {
			c.remove();
		}
		restartRoundEvent.emit();
	}
}