GameServer.py

"""
GameServer is the class responsible for spawning Pyro threads of the Game object.
Game objects themselves have an extremely limited lifetime as instances are
created whenever needed. That means that any data that needs to be stored must be
somewhere else. In this case, the Server object.

The GameServer is also responsible of relaying messages from the Game Pyro object
that is exposed to clients to the AdminGui. This works through QThreads.
"""
from __future__ import print_function
import sys, random
from copy import deepcopy
from socket import gethostbyname, gethostname

import Pyro.core
import Pyro.naming
from Pyro.errors import *

from PyQt4.QtCore import *
from PyQt4.QtGui import *

from Server import Server
from Game import Game

from PyQt4.QtGui import QColor


class GameServer(Server):
	"""
	GameServer class derived from Server. This is where most of the game's logic is implemented.

	Signals used to with Gui. Do not update interface elements, or
	perform non reentrant operations:
	calling B{self.gui.displayGrid()}can possibly cause a SIGSEGV
	use B{self.gridDisplayed.emit()} since inter-thread communication is sure to work
	"""
	playerConnected = pyqtSignal(tuple)
	playerReconnected = pyqtSignal(tuple)
	playerStatusChanged = pyqtSignal(tuple)

	playerBuzzed = pyqtSignal(str)
	questionSelected = pyqtSignal(int)
	accQuestion = pyqtSignal(int,str)

	labelTextSet = pyqtSignal(str)
	allGamesStarted = pyqtSignal()

	"""
	Concurrent access to the player table for modification (at login) could lead
	to a corrupt data structure. That's why a mutex must be obtained before
	modifying it.

	As for buzzing, since only one player can be the first to buzz, a lock is
	obtained immediately after the first buzz was recieved to prevent having
	multiple people answering at the same time.
	"""
	playerMutex = QMutex()
	buzzMutex = QMutex()

	"""
	   ***REIMPLEMENTED METHODS FROM BASECLASS***
	"""
	def __init__(self, gui, name, parent = None):
		Server.__init__(self, gui, name)

		self.rules = ''
		self.resources = []
		self.type = ''
		self.numRounds = 0
		self.numCategories = []
		self.numQuestions = []
		self.loginEnabled = True
		self.players = {}
		self.scores = {}
		self.gamesToStart = 0

		self.selectingPlayer = ''
		self.showAnsSender = ''

		self.roundNum = -1
		self.usedQuestions = set()

	def setupSignals(self):
		self.serverStarted.connect(self.enableLogin)
		self.playerConnected.connect(self.gui.playerAdmin.addPlayer)
		self.allGamesStarted.connect(self.choosePlayer)

	def setupGuiSignals(self):
		Server.setupGuiSignals(self)
		self.playerReconnected.connect(self.gui.getTable().updatePlayer)
		self.playerReconnected.connect(self.startPlayerGame)
		self.playerStatusChanged.connect(self.gui.getTable().updatePlayer)

		self.playerBuzzed.connect(self.gui.playerBuzzed)
		self.questionSelected.connect(self.gui.displayQuestion)
		self.accQuestion.connect(self.nameQuestion) 
		self.accQuestion.connect(self.gui.acceptQuestion) 


		self.labelTextSet.connect(self.gui.setLabelText)

	def connectDaemon(self):
		self.uri = self.daemon.connect(Game(self), self.name)

	"""
	***GAME FUNCTIONS***
	Methods for starting a new game.
	"""

	def startGame(self):
		"""
		Gui signals are not connected when this function is called.
		"""

		for name in self.players.keys():
			self.startPlayerGame((name, 0))
		self.setupGuiSignals()

	def startPlayerGame(self, player):
		"""
		Starting a player's client gui means:
		  - sending over the resources needed for the questions (image files, html templates, etc.)
		  - actually calling a startGame method so that the guis are loaded
		@param player: the name of the player for which to start the game.
		@type player: str
		"""
		name = player[0]
		try:
			self.players[name][0].loadResources()
			self.players[name][0].startGame()
		except (ConnectionClosedError, ProtocolError):
			self.changeStatus(name, 'Disconnected')

	def enableLogin(self):
		"""
		Without setting loginEnabled True, nobody is allowed to log in, unless they
		are marked as 'Disconnected'.
		 """
		self.log('Login enabled')
		self.loginEnabled = True


	def choosePlayer(self):
		"""
		When no answer was given last turn or the answer given was false, 
		a player is chosen at random to select the next question.
		Muted and disconnected players don't count.
		"""
		availablePlayers = []
		for player in self.players.items():
			if player[1][2] != 'Muted' and player[1][2] != 'Disconnected':
				availablePlayers.append(player)
				
		#numActivePlayers = the number of unmuted players still ingame
		numActivePlayers = len(availablePlayers)
			
		if numActivePlayers > 0:
			pass
		else:
			alertMsg = QMessageBox()
			alertMsg.setText("Please wait for the players to " + 
				"reconnect or unmute existing players")
			alertMsg.exec_()

		n = random.randint(0, numActivePlayers - 1)
		self.changeStatus(availablePlayers[n][0], 'Selecting')
		self.selectingPlayer = availablePlayers[n][0]
		print ('randomly selected player is: ' + self.selectingPlayer)

	def nameQuestion(self, i):
		(c,q) = self.toLineCol(self.round, i)
		category = self.round['categories'][c]
		self.question = deepcopy(category['questions'][q])
		self.question['category'] = category['title']

	def selectQuestion(self, i):
		"""
		When a question is selected (by the admin, requested by a player)
		  - it's loaded into the question variable to not do any more lookups
		  - the game prepares to recieve a buzz
		  - player statuses are changed to Waiting
		  - player guis are signaled to display the ButtonGrid
		"""
		self.nameQuestion(i)
		#(c, q) = self.toLineCol(self.round, i)

		#category = self.round['categories'][c]
		#self.question = deepcopy(category['questions'][q])
		#self.question['category'] = category['title']
		self.buzzed = False

		for player in self.players.items():
			if player[1][2] == 'Selecting':
				self.changeStatus(player[0], 'Waiting')
			try:
				player[1][0].displayQuestion(i)
			except (ConnectionClosedError, ProtocolError):
				self.changeStatus(player[0], 'Disconnected')


		numActivePlayers = len(self.players)
		for player in self.players.values():
			if player[2] == 'Muted' or player[2] == 'Disconnected':
				numActivePlayers -= 1

		if numActivePlayers > 0:
			self.usedQuestions.add(i)
			self.questionSelected.emit(i)
		else:
			alertMsg = QMessageBox()
			alertMsg.setText("Please wait for the players to reconnect or unmute existing players")
			alertMsg.exec_()

	def checkAnswer(self, name, ans):
		"""
		Once the admin has validated the answer through the messagebox in the AdminGui
		this function, that calculates the new score is called.
		Afterwards, the correct answer is displayed.
		"""
		name = str(name)
		player = self.players[name]

		score = player[3]
		if ans == True:
			score += self.question['value']
			self.selectingPlayer = name
			self.changeScore(name, score)
		else:
			score -= self.question['value']
			self.selectingPlayer = ''
			self.changeScore(name, score)
		self.changeStatus(name, 'Waiting')
		self.showAnswer()

	def showAnswer(self):
		"""
		Displays the answer to all players and updates the scores array.
		The scores array is required to draw the final plot at the end of the game.
		"""
		for player in self.players.items():
			try:
				player[1][0].disableBuzz()
				player[1][0].displayAnswer()
			except (ConnectionClosedError, ProtocolError):
				self.changeStatus(player[0], 'Disconnected')

			self.scores[player[0]][0].append(player[1][3])

		# used to be self.gui.displayAnswer()... I wonder if this caused the SIGSEGV
		self.answerDisplayed.emit()

	def nextQuestion(self):
		"""
		The game continues by waiting for another question to be selected.
		  1. we must find out if there are any more questions this round, 
		     or if there are any more questions at all.
		  2. a player must be chosen to select a question - if the last 
		    answer was correct, then the player who gave that answer gets 
		    to pick, otherwise, a player is chosen at random.
		  3. the players are signaled to display the ButtonGrids and 
		     the AdminGui itself displays its grid.
		"""
		if len(self.usedQuestions) == self.numQuestions:
			if not self.nextRound():
				return

		if self.selectingPlayer == '' or self.players[self.selectingPlayer][2] == 'Disconnected':
			self.choosePlayer()
		else:
			self.changeStatus(self.selectingPlayer, 'Selecting')

		for player in self.players.items():
			try:
				player[1][0].displayGrid()
			except (ConnectionClosedError, ProtocolError):
				self.changeStatus(player[0], 'Disconnected')

		self.gridDisplayed.emit()

	def nextRound(self):
		"""
		When progressing to the next round:
			- the round variable of the GameServer needs to be updated
			- the usedQuestions array needs to be emptied
			- the numQuestions needs to be recalculated
			- gui events need to be trigerred to replace the ButtonGrid with a new one
		 """
		self.roundNum += 1

		if self.roundNum >= self.numRounds:
			self.endGame()
			return False

		# updating game state
		self.round = self.rules['rounds'][self.roundNum]
		self.usedQuestions = set()
		self.numQuestions = 0
		for c in self.round['categories']:
			self.numQuestions += len(c['questions'])

		# trigerring gui events (Player.nextRound emits a signal)
		if self.roundNum > 0:
			for player in self.players.items():
				try:
					player[1][0].nextRound()
				except (ConnectionClosedError, ProtocolError):
					self.changeStatus(player[0], 'Disconnected')
			self.roundChanged.emit()
		return True

	def endGame(self):
		"""
		At the end of the game, when there are no more questions and no more rounds,
		this function gets called to trigger the drawing of the score plots.
		Also, assigns a color to each player in the game.
		"""
		hue = 0
		hueInc = 360 / len(self.scores.items())

		for e in self.scores.items():
			color = QColor()
			color.setHsv(hue, 255, 240)
			hue += hueInc - 1
			self.scores[e[0]] = (e[1][0], color.getRgbF())

		# actually ending the game here...
		for player in self.players.values():
				player[0].endGame()
		self.gameEnded.emit()

	"""
	   ***UTILITY FUNCTIONS***
	"""
	def toLineCol(self, round, index):
		"""
		When selecting a question through the ButtonGrid, the position of the item in
		the grid is emitted. That is not however the actual number of the question.
		From that index, category and question number can be determined.
		This function supports categories with a different number of questions.
		"""
		n = len(round['categories'])
		maxIndex = 0
		for i in range(n):
			maxIndex += len(round['categories'][i]['questions']) + 1
			if index <= maxIndex:
				break
		j = index - (maxIndex - len(round['categories'][i]['questions']))
		return (i, j)

	def mutePlayers(self, names):
		"""
		Players are muted/unmuted through these functions as long as the players in
		the names array are not Selecting. A Selecting player cannot be muted.
		@param names: the names of the players to be muted
		@type names: array
		"""
		for name in names:
			if name == self.selectingPlayer:
				continue
			if name in self.players.keys() and self.players[name][2] == 'Waiting':
				self.changeStatus(name, 'Muted')

	def unmutePlayers(self, names):
		for name in names:
			if name in self.players.keys() and self.players[name][2] == 'Muted':
				self.changeStatus(name, 'Waiting')



	def changeStatus(self, name, status):
		"""
		Changing a player's status or score works in pretty much the same way.
		The player entry in the players table is copied and the required field is
		modified. The entry is then put back in the dictionary and the proper signals
		are emitted.
		@param name: name of the player whose status is to change
		@type name: str
		@param status: the player's new status
		@type status: str
		"""
		player = self.players[name]
		self.players[name] = (player[0], player[1], status, player[3])
		self.playerStatusChanged.emit((name, player[1], status, player[3]))
		if status != 'Disconnected':
			try:
				player[0].changeStatus(status)
			except (ConnectionClosedError, ProtocolError):
				self.changeStatus(name, 'Disconnected')

	def changeScore(self, name, score):
		"""
		@param name: name of the player whose status is to change
		@type name: str
		@param score: the player's new score
		@type score: int
		"""
		player = self.players[name]
		self.players[name] = (player[0], player[1], player[2], score)
		self.playerScoreChanged.emit((name, player[1], player[2], score))
		for player in self.players.items():
			try:
				player[1][0].changeScore(name, score)
			except (ConnectionClosedError, ProtocolError):
				self.changeStatus(player[0], 'Disconnected')