import re

class Demo:
    def __init__(self, demo="0:0"):
        self.set(demo)

    def __delitem__(self, key):
        if isinstance(key, int):
            start, stop = key, key+1
        elif isinstance(key, slice):
            start, stop = key.start, key.stop
        self.demo = self.demo[:start] + self.demo[stop:]
        self.length = len(self.demo)

    def __iter__(self):
        return iter(map(lambda n: int(n, 16), list(self.demo)))

    def __getitem__(self, key):
        return self.demo[key]

    def __len__(self):
        return self.length

    def __nonzero__(self):
        return self.length != 0

    def __setitem__(self, key, value):
        if isinstance(key, int):
            start, stop = key, key+1
        elif isinstance(key, slice):
            start, stop = key.start, key.stop
        self.demo = self.demo[:start] + value + self.demo[stop:]
        self.length = len(self.demo)

    def __str__(self):
        return self.demo

    def decode(self, demo=None):
        if demo == None:
            demo = self.demo
        # self.demo pads to 7 characters, so dividing its length
        # by 7 will always yield an integer
        fragment_count = len(demo) / 7
        fragment_list = [str(int(demo[i*7:(i+1)*7][::-1], 16))
                         for i in range(fragment_count)]
        return str(self.length) + ':' + '|'.join(fragment_list)

    def set(self, demo):
        if self.validate(demo):
            if ':' in demo:
                # format is 18:0|35782656|35791394|0
                self.length = int(demo.split(':')[0])
                self.demo = ''.join(
                    [("%07X" % (int(fragment)))[::-1]
                     for fragment in demo.split(":")[1].split("|")])
            else:
                # format is 0111C5540
                self.length = len(demo)
                self.demo = demo
        else:
            raise Exception("Failed to set demo data: " + demo)

    def validate(self, demo):
        return re.match("^\d+:\d+(\|\d+)*$", demo) or \
               re.match("^[0-9A-Fa-f]+$", demo)


if __name__ == "__main__":
    # Demonstration

    mydemo = Demo("148:35791392|107405858|107374182|71582788|71582788|89408580|89478485|17895765|17895697|17895697|17895697|17895697|17895697|17895697|17895697|17895697|219222289|219223381|89478485|18175317|17|0")
    print mydemo,          '\n\n', \
          mydemo.length,   '\n\n', \
          mydemo.decode(), '\n\n', \
          list(mydemo),    '\n\n', \
          mydemo[5],       '\n\n', \
          mydemo[5:40],    '\n'

    # Use bitwise AND to see if each frame has the player holding jump
    print ''.join(['j' if frame & 4 else '.' for frame in mydemo])

    mydemo[15:25] = '0000000000'
    print mydemo[5:40]

    del mydemo[15:25]
    print mydemo.length
    print mydemo[5:40]

    print 'Not null' if mydemo else 'Null'
    mydemo.set('0:0')
    print 'Not null' if mydemo else 'Null'