from PyQt5.QtWidgets import QMainWindow, QFrame, QDesktopWidget, QApplication
from PyQt5.QtCore import Qt, QBasicTimer, pyqtSignal
from PyQt5.QtGui import QPainter, QColor 
import sys, random

class Tetris(QMainWindow):
    
    def __init__(self):
        super().__init__()
        
        self.initUI()
        
        
    def initUI(self):    
        
 
'''initiates application UI'''

        self.tboard = Board(self)
        self.setCentralWidget(self.tboard)

        self.statusbar = self.statusBar()        
        self.tboard.msg2Statusbar[str].connect(self.statusbar.showMessage)
        
        self.tboard.start()
        
        self.resize(
 
180, 380)
        self.center()
        self.setWindowTitle('Tetris')        
        self.show()
        

    def center(self):
        '''centers the window on the screen'''
        
        screen = QDesktopWidget().screenGeometry()
        size = self.geometry()
        self.move((screen.width()-size.width())/2
 
, 
            (screen.height()-size.height())/2)
        

class Board(QFrame):
    
    msg2Statusbar = pyqtSignal(str)
    
    BoardWidth = 10
    BoardHeight = 22
    Speed = 300

    def __init__(self, parent):
        super().__init__(parent)
        
        self.initBoard()
        
        
    def initBoard(self):     
        '''initiates board'''

        self.timer = QBasicTimer()
        self.isWaitingAfterLine = False
        
        self.curX = 0
        self.curY = 0
        self.numLinesRemoved = 0
        self.board = []

        self.setFocusPolicy(Qt.StrongFocus)
        self.isStarted = False
        self.isPaused = False
        self.clearBoard()
        
        
    def shapeAt(self, x, y):
        '''determines shape at the board position'''
        
        return self.board[(y * Board.BoardWidth) + x]

        
    def setShapeAt(self, x, y, shape):
        '''sets a shape at the board'''
        
        self.board[(y * Board.BoardWidth) + x] = shape
        

    def squareWidth(self):
        '''returns the width of one square'''
        
        return self.contentsRect().width() // Board.BoardWidth
        

    def squareHeight(self):
        '''returns the height of one square'''
        
        return self.contentsRect().height() // Board.BoardHeight
        

    def start(self):
        '''starts game'''
        
        if self.isPaused:
            return

        self.isStarted = True
        self.isWaitingAfterLine = False
        self.numLinesRemoved = 0
        self.clearBoard()

        self.msg2Statusbar.emit(str(self.numLinesRemoved))

        self.newPiece()
        self.timer.start(Board.Speed, self)

        
    def pause(self):
        '''pauses game'''
        
        if not self.isStarted:
            return

        self.isPaused = not self.isPaused
        
        if self.isPaused:
            self.timer.stop()
            self.msg2Statusbar.emit("paused")
            
        else:
            self.timer.start(Board.Speed, self)
            self.msg2Statusbar.emit(str(self.numLinesRemoved))

        self.update()

        
    def paintEvent(self, event):
        '''paints all shapes of the game'''
        
        painter = QPainter(self)
        rect = self.contentsRect()

        boardTop = rect.bottom() - Board.BoardHeight * self.squareHeight()

        for i in range(Board.BoardHeight):
            for j in range(Board.BoardWidth):
                shape = self.shapeAt(j, Board.BoardHeight - i - 1)
                
                if shape != Tetrominoe.NoShape:
                    self.drawSquare(painter,
                        rect.left() + j * self.squareWidth(),
                        boardTop + i * self.squareHeight(), shape)

        if self.curPiece.shape() != Tetrominoe.NoShape:
            
            for i in range(4):
                
                x = self.curX + self.curPiece.x(i)
                y = self.curY - self.curPiece.y(i)
                self.drawSquare(painter, rect.left() + x * self.squareWidth(),
                    boardTop + (Board.BoardHeight - y - 1) * self.squareHeight(),
                    self.curPiece.shape())

                    
    def keyPressEvent(self, event):
        '''processes key press events'''
        
        if not self.isStarted or self.curPiece.shape() == Tetrominoe.NoShape:
            super(Board, self).keyPressEvent(event)
            return

        key = event.key()
        
        if key == Qt.Key_P:
            self.pause()
            return
            
        if self.isPaused:
            return
                
        elif key == Qt.Key_Left:
            self.tryMove(self.curPiece, self.curX - 1, self.curY)
            
        elif key == Qt.Key_Right:
            self.tryMove(self.curPiece, self.curX + 1, self.curY)
            
        elif key == Qt.Key_Down:
            self.tryMove(self.curPiece.rotateRight(), self.curX, self.curY)
            
        elif key == Qt.Key_Up:
            self.tryMove(self.curPiece.rotateLeft(), self.curX, self.curY)
            
        elif key == Qt.Key_Space:
            self.dropDown()
            
        elif key == Qt.Key_D:
            self.oneLineDown()
            
        else:
            super(Board, self).keyPressEvent(event)
                

    def timerEvent(self, event):
        '''handles timer event'''
        
        if event.timerId() == self.timer.timerId():
            
            if self.isWaitingAfterLine:
                self.isWaitingAfterLine = False
                self.newPiece()
            else:
                self.oneLineDown()
                
        else:
            super(Board, self).timerEvent(event)

            
    def clearBoard(self):
        '''clears shapes from the board'''
        
        for i in range(Board.BoardHeight * Board.BoardWidth):
            self.board.append(Tetrominoe.NoShape)

        
    def dropDown(self):
        '''drops down a shape'''
        
        newY = self.curY
        
        while newY > 0:
            
            if not self.tryMove(self.curPiece, self.curX, newY - 1):
                break
                
            newY -= 1

        self.pieceDropped()
        

    def oneLineDown(self):
        '''goes one line down with a shape'''
        
        if not self.tryMove(self.curPiece, self.curX, self.curY - 1):
            self.pieceDropped()
            

    def pieceDropped(self):
        '''after dropping shape, remove full lines and create new shape'''
        
        for i in range(4):
            
            x = self.curX + self.curPiece.x(i)
            y = self.curY - self.curPiece.y(i)
            self.setShapeAt(x, y, self.curPiece.shape())

        self.removeFullLines()

        if not self.isWaitingAfterLine:
            self.newPiece()
            

    def removeFullLines(self):
        '''removes all full lines from the board'''
        
        numFullLines = 0
        rowsToRemove = []

        for i in range(Board.BoardHeight):
            
            n = 0
            for j in range(Board.BoardWidth):
                if not self.shapeAt(j, i) == Tetrominoe.NoShape:
                    n = n + 1

            if n == 10:
                rowsToRemove.append(i)

        rowsToRemove.reverse()
        

        for m in rowsToRemove:
            
            for k in range(m, Board.BoardHeight):
                for l in range(Board.BoardWidth):
                        self.setShapeAt(l, k, self.shapeAt(l, k + 1))

        numFullLines = numFullLines + len(rowsToRemove)

        if numFullLines > 0:
            
            self.numLinesRemoved = self.numLinesRemoved + numFullLines
            self.msg2Statusbar.emit(str(self.numLinesRemoved))
                
            self.isWaitingAfterLine = True
            self.curPiece.setShape(Tetrominoe.NoShape)
            self.update()
            

    def newPiece(self):
        '''creates a new shape'''
        
        self.curPiece = Shape()
        self.curPiece.setRandomShape()
        self.curX = Board.BoardWidth // 2 + 1
        self.curY = Board.BoardHeight - 1 + self.curPiece.minY()
        
        if not self.tryMove(self.curPiece, self.curX, self.curY):
            
            self.curPiece.setShape(Tetrominoe.NoShape)
            self.timer.stop()
            self.isStarted = False
            self.msg2Statusbar.emit("Game over")



    def tryMove(self, newPiece, newX, newY):
        '''tries to move a shape'''
        
        for i in range(4):
            
            x = newX + newPiece.x(i)
            y = newY - newPiece.y(i)
            
            if x < 0 or x >= Board.BoardWidth or y < 0 or y >= Board.BoardHeight:
                return False
                
            if self.shapeAt(x, y) != Tetrominoe.NoShape:
                return False

        self.curPiece = newPiece
        self.curX = newX
        self.curY = newY
        self.update()
        
        return True
        

    def drawSquare(self, painter, x, y, shape):
        '''draws a square of a shape'''        
        
        colorTable = [0x000000, 0xCC6666, 0x66CC66, 0x6666CC,
                      0xCCCC66, 0xCC66CC, 0x66CCCC, 0xDAAA00]

        color = QColor(colorTable[shape])
        painter.fillRect(x + 1, y + 1, self.squareWidth() - 2, 
            self.squareHeight() - 2, color)

        painter.setPen(color.lighter())
        painter.drawLine(x, y + self.squareHeight() - 1, x, y)
        painter.drawLine(x, y, x + self.squareWidth() - 1, y)

        painter.setPen(color.darker())
        painter.drawLine(x + 1, y + self.squareHeight() - 1,
            x + self.squareWidth() - 1, y + self.squareHeight() - 1)
        painter.drawLine(x + self.squareWidth() - 1, 
            y + self.squareHeight() - 1, x + self.squareWidth() - 1, y + 1)


class Tetrominoe(object):
    
    NoShape = 0
    ZShape = 1
    SShape = 2
    LineShape = 3
    TShape = 4
    SquareShape = 5
    LShape = 6
    MirroredLShape = 7


class Shape(object):
    
    coordsTable = (
        ((0, 0),     (0, 0),     (0, 0),     (0, 0)),
        ((0, -1),    (0, 0),     (-1, 0),    (-1, 1)),
        ((0, -1),    (0, 0),     (1, 0),     (1, 1)),
        ((0, -1),    (0, 0),     (0, 1),     (0, 2)),
        ((-1, 0),    (0, 0),     (1, 0),     (0, 1)),
        ((0, 0),     (1, 0),     (0, 1),     (1, 1)),
        ((-1, -1),   (0, -1),    (0, 0),     (0, 1)),
        ((1, -1),    (0, -1),    (0, 0),     (0, 1))
    )

    def __init__(self):
        
        self.coords = [[0,0] for i in range(4)]
        self.pieceShape = Tetrominoe.NoShape

        self.setShape(Tetrominoe.NoShape)
        

    def shape(self):
        '''returns shape'''
        
        return self.pieceShape
        

    def setShape(self, shape):
        '''sets a shape'''
        
        table = Shape.coordsTable[shape]
        
        for i in range(4):
            for j in range(2):
                self.coords[i][j] = table[i][j]

        self.pieceShape = shape
        

    def setRandomShape(self):
        '''chooses a random shape'''
        
        self.setShape(random.randint(1, 7))

        
    def x(self, index):
        '''returns x coordinate'''
        
        return self.coords[index][0]

        
    def y(self, index):
        '''returns y coordinate'''
        
        return self.coords[index][1]

        
    def setX(self, index, x):
        '''sets x coordinate'''
        
        self.coords[index][0] = x

        
    def setY(self, index, y):
        '''sets y coordinate'''
        
        self.coords[index][1] = y

        
    def minX(self):
        '''returns min x value'''
        
        m = self.coords[0][0]
        for i in range(4):
            m = min(m, self.coords[i][0])

        return m

        
    def maxX(self):
        '''returns max x value'''
        
        m = self.coords[0][0]
        for i in range(4):
            m = max(m, self.coords[i][0])

        return m

        
    def minY(self):
        '''returns min y value'''
        
        m = self.coords[0][1]
        for i in range(4):
            m = min(m, self.coords[i][1])

        return m

        
    def maxY(self):
        '''returns max y value'''
        
        m = self.coords[0][1]
        for i in range(4):
            m = max(m, self.coords[i][1])

        return m

        
    def rotateLeft(self):
        '''rotates shape to the left'''
        
        if self.pieceShape == Tetrominoe.SquareShape:
            return self

        result = Shape()
        result.pieceShape = self.pieceShape
        
        for i in range(4):
            
            result.setX(i, self.y(i))
            result.setY(i, -self.x(i))

        return result

        
    def rotateRight(self):
        '''rotates shape to the right'''
        
        if self.pieceShape == Tetrominoe.SquareShape:
            return self

        result = Shape()
        result.pieceShape = self.pieceShape
        
        for i in range(4):
            
            result.setX(i, -self.y(i))
            result.setY(i, self.x(i))

        return result


if __name__ == '__main__':
    
    app = QApplication([])
    tetris = Tetris()    
    sys.exit(app.exec_())