# puzzle_game.pyw  game by leonardo maffi, v.1.3, Sep 14 2005.
# Requires the Python interterpreter

import Tkinter, random, tkMessageBox

class GameButton(object):
    movesCount = 0 # class variables
    firstError = True
    hole = 0
    correctPositions = range(1, 16) + [hole]

    def __init__(self, parent, value):
        self.button = Tkinter.Button(parent, width=3, command=self.manageClick)
        self.set(value)
        self.button.grid(column=value%4, row=value/4)

    def set(self, value):
        self.value = value
        if value == GameButton.hole:
            self.label = ""
            relief = "flat"
        else:
            self.label = str(value)
            relief = "raised"
        self.button.configure(text=self.label, relief=relief)

    def _holeToMove(self, pos):
        posRow = pos // 4
        posCol = pos % 4
        for r,c in (posRow-1,posCol), (posRow+1,posCol), (posRow,posCol-1), (posRow,posCol+1):
            if 4>r>=0 and 4>c>=0 and buttons[c+r*4].value==GameButton.hole:
                return c+r*4

    def manageClick(self):
        moveFrom = buttons.index(self)
        moveTo = self._holeToMove(moveFrom)
        if moveTo is None and GameButton.firstError:
            tkMessageBox.Message(icon='error', type='ok', message=gameRules, title='Error').show()
            GameButton.firstError = False
        if moveTo is not None:
            GameButton.movesCount += 1
            oldLabel = self.label
            buttons[moveTo].set(self.value)
            self.set(GameButton.hole)

            if [b.value for b in buttons] == GameButton.correctPositions:
                endingMessage = "You completed the puzzle in %s moves" % GameButton.movesCount
                tkMessageBox.Message(type='ok', message=endingMessage, title='Game finished').show()
                scrambleButtonsAndReset()


def scrambleButtonsAndReset():
    # Generate a SOLVABLE random disposition (move parity must be correct)
    randomPositions = list(GameButton.correctPositions)
    holePosition = 15
    for i in xrange(500):
        posR = holePosition // 4
        posC = holePosition % 4
        positions = (posR-1,posC), (posR+1,posC), (posR,posC-1), (posR,posC+1)
        # Here a repeat-until can be quite useful:
        ro,co = random.choice( positions )
        while not( 4>ro>=0 and 4>co>=0 ):
            ro,co = random.choice( positions )
        move = co + ro*4
        # Swap
        randomPositions[holePosition], randomPositions[move] = randomPositions[move], randomPositions[holePosition]
        holePosition = move

    # randomPositions = range(1,15) + [0, 15] # For game end testing.
    for n,button in enumerate(buttons):
        button.set(randomPositions[n])
    GameButton.movesCount = 0


gameRules = """Click on a button next to the empty
space to move it into that space.
Do this until all buttons are in
order and the hole is the last one."""

root = Tkinter.Tk()
root.title("Puzzle game")
buttons = [GameButton(root, bu) for bu in range(16)]
root.resizable(0,0)
scrambleButtonsAndReset()
root.mainloop()