from xml.dom import minidom
import sys

# This program is a very simple text adventure game
# It reads from the file gamefile.xml, parses the xml
# and acts like a command line game.

# The main class
class Game:
	chapters = [] # All chapter objects are stored here
	
	# Constructor
	def __init__(self):
		print "Welcome! Please type '-1' at any time to quit the game. Enjoy!"
		self.parseXml()
		self.show_chapter()

	# This function displays the chapter, your options and
	# takes input from the command line
	def show_chapter(self, idno = 1):
		print ""
		chapter = 0

		for chapt in self.chapters:
			if(chapt.get_idno() == idno):
				chapter = chapt

		if(chapter == 0):
			print "Error: no chapter found!"
			self.quit()

		chapter.show()
		print ""
		chapter.show_options()
		print ""

		try:
			selection = input('Please enter a number: ')
		except SyntaxError:
			selection = 9999 # Out of range
		
		if(selection == -1):
			self.quit()

		next_chapter = chapter.get_option(selection)
		
		while(next_chapter == 0): # The user typed an invalid number
			try:
				selection = input("Wrong number selected. Please type another one:")
				if(selection == -1):
					self.quit()
				next_chapter= chapter.get_option(selection)
			except SyntaxError:
				selection= 9999 # Out of range

		self.show_chapter(next_chapter)

	# Quit the game
	def quit(self):
		print "Thank you for playing. Have a nice day!"
		sys.exit(0)

	# Parse the game xml file, and initialize the game
	def parseXml(self):
		xmldoc = minidom.parse('gamefile.xml')
		game = xmldoc.documentElement

		for chapter in game.childNodes:
			idno = 0
			text = ""
			goto = 0
			optiontext = ""

			if(chapter.nodeName == "chapter"):
				options = [] # Empty option list
				for chapterinfo in chapter.childNodes:
					if(chapterinfo.nodeName == "id"):
						for info in chapterinfo.childNodes:
							idno = int(info.nodeValue)
					if(chapterinfo.nodeName == "text"):
						for info in chapterinfo.childNodes:
							text = info.nodeValue
					if(chapterinfo.nodeName == "option"):
						for info in chapterinfo.childNodes:
							if(info.nodeName == "goto"):
								for optioninfo in info.childNodes:
									goto = int(optioninfo.nodeValue)
							if(info.nodeName == "text"):
								for optioninfo in info.childNodes:
									optiontext = optioninfo.nodeValue

						# Create an option object for each parsed option
						option_obj = Option(goto, optiontext)
						options.append(option_obj)

				# Create a chapter object for each parsed chapter
				chapter_obj = Chapter(idno, text)
				chapter_obj.set_options(options)
				self.chapters.insert(idno, chapter_obj)



class Chapter:
	idno = 0
	text = ""
	options = []

	# Constructor
	def __init__(self, idno, text):
		self.idno = idno
		self.text = text

	def set_options(self, options):
		self.options = options
	
	def show(self):
		print self.text
	
	def show_options(self):
		selection = 0 # The number the user types to choose this option
		for option in self.options:
			option.show(selection)
			selection = selection + 1

	# Get the selected option id
	def get_option(self, selection):
		if(selection + 1 > len(self.options)):
			return 0
		return self.options[selection].get_goto()

	def get_idno(self):
		return self.idno


class Option:
	goto = 0
	text = ""

	# Constructor
	def __init__(self, goto, text):
		self.goto = goto
		self.text = text

	def show(self, selection):
		print self.text+": type "+str(selection)

	def get_goto(self):
		return self.goto


# Start the game!
game = Game()