package com.netbeetle.minesweeper;

public class Cell
{
    private Cell[] neighbors = null;
    private double mineProbability = .5;
    private int probabilityQuality = 0;
    private boolean neighborsKnown = false;
    private boolean known = false;
    private boolean mine;
    private boolean guess = false;
    private boolean mineGuess = false;
    private int mines = 0;

    public Cell(boolean mine)
    {
        this.mine = mine;
    }

    public void setNeighbors(Cell[] neighbors)
    {
        this.neighbors = neighbors;
        updateMines();
    }

    public Cell[] getNeighbors()
    {
        return neighbors;
    }

    public void setMineProbability(double probability)
    {
        mineProbability = probability;
        probabilityQuality = 0;
        normalizeProbability();
    }

    public void adjustMineProbability(double probability)
    {
        mineProbability = ((mineProbability * probabilityQuality) + probability) / (probabilityQuality + 1);
        probabilityQuality++;
        normalizeProbability();
    }

    private void normalizeProbability()
    {
        if (mineProbability > 1)
            mineProbability = 1;
        else if (mineProbability < 0)
            mineProbability = 0;
    }

    public double getMineProbability()
    {
        return mineProbability;
    }

    public boolean isKnown()
    {
        return known;
    }

    public boolean isMine()
    {
        return known && mine;
    }

    public boolean isEmpty()
    {
        return known && !mine;
    }

    public int getMines()
    {
        if (isEmpty())
            return mines;
        return -1;
    }

    public void updateMines()
    {
        if (neighbors == null)
            return;

        mines = 0;
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (neighbors[i].mine)
                mines++;
        }
    }

    public void guess(boolean mine)
    {
        if (known)
            return;
        guess = true;
        mineGuess = mine;
    }

    public void clearGuess()
    {
        guess = false;
    }

    public boolean hasGuess()
    {
        return guess;
    }

    public boolean getGuess()
    {
        return mineGuess;
    }

    public boolean reveal()
    {
        if (known)
            return !mine;
        guess = false;
        known = true;
        if (!mine && mines == 0)
            return revealNeighbors();
        return !mine;
    }

    public boolean revealNeighbors()
    {
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (neighbors[i].known)
                continue;

            if (neighbors[i].guess && neighbors[i].mineGuess)
                continue;

            if (!neighbors[i].reveal())
                return false;
        }
        return true;
    }

    public boolean isSatisfiable()
    {
        if (neighbors == null)
            return false;

        if (!isEmpty())
            return true;

        int existingMines = 0;
        int unknownCells = 0;
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (neighbors[i].isMine())
                existingMines++;
            else if (neighbors[i].guess)
            {
                if (neighbors[i].mineGuess)
                    existingMines++;
            }
            else if (!neighbors[i].isKnown())
            {
                unknownCells++;
            }
        }

        int minesNeeded = mines - existingMines;

        if (minesNeeded < 0 || minesNeeded > unknownCells)
            return false;

        return true;
    }

    public boolean isSatisfied()
    {
        if (neighbors == null)
            return false;

        if (!isEmpty())
            return true;

        int existingMines = 0;
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (neighbors[i].isMine())
                existingMines++;
            else if (neighbors[i].guess)
            {
                if (neighbors[i].mineGuess)
                    existingMines++;
            }
        }

        return mines - existingMines == 0;
    }

    public boolean areNeighborsSatisfiable()
    {
        if (neighbors == null)
            return false;

        //if (known)
        //    return true;

        int existingMines = 0;
        int unknownCells = 0;
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (!neighbors[i].isSatisfiable())
                return false;
        }

        return true;
    }

    public boolean areNeighborsSatisfied()
    {
        if (neighbors == null)
            return false;

        //if (known)
        //    return true;

        int existingMines = 0;
        int unknownCells = 0;
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (!neighbors[i].isSatisfied())
                return false;
        }

        return true;
    }

    public boolean hasEmptyNeighbors()
    {
        for (int i = 0; i < neighbors.length; i++)
        {
            if (neighbors[i] == null)
                continue;

            if (neighbors[i].isEmpty())
                return true;
        }

        return false;
    }

}