"""And that's my cue to exit(0)..."""

from time import time

class Cue:

    """Cues are groups of fades.  They can tell you the current levels at a 

    given time.  They contain Fades, which are actually children of Cue,

    meaning that Cues can contain Cues.  This is similar to the Light9 concept

    of Cues and Fades, but without all the Nodes."""

    def __init__(self, name, starttime, dur, *fades):

        'Create a cue'

        endtime = starttime + dur

        dur = endtime - starttime

        self.name = name

        self.starttime = starttime

        self.dur = dur

        self.endtime = endtime

        self.fades = fades

        self.cuestart = None

        self.init_levels = None

    def channels_involved(self):

        'Return which channels are involved.  This is important for marking.'

        c = {}

        for fade in self.fades:

            for f_chan in fade.channels_involved():

        self.param = param

    def start(self, levels, time):

        'Mark the beginning of the fade'

        # print "fade", self.name, "marked with", levels

        self.init_levels = levels

        self.init_level = levels[self.channel]

        self.init_time = time

    def channels_involved(self):

        'Speaks for itself, I hope'

        return [self.channel]

    def get_levels(self, curtime):

        elapsed = curtime - self.init_time

        if elapsed <= self.starttime:

            return self.init_levels

        elif elapsed >= self.endtime:

            return {self.channel : self.endlevel}

        else:

            percent = float((curtime - self.init_time) - self.starttime) / \

                        self.dur

            return {self.channel : self.init_level + 

                percent * (self.endlevel - self.init_level)}

    def get_end_levels(self):

        return {self.channel : self.endlevel}

if __name__ == '__main__':

    f1 = Fade('red', 0, 2, 100)

    f2 = Fade('green', 1, 3, 50)

    f3 = Fade('blue', 0, 4, 0)

    f4 = Fade('clear', 0, 8, 75) 

    c = Cue("Color shift", 0, 10, f1, f2, f3, f4)

    tstart = time()

    # note how green is not mentioned -- it goes to 0

    c.start({'red' : 0, 'blue' : 100, 'clear' : 25}, tstart)

    while time() - tstart < 15:

        curtime = time()

        levs = c.get_levels(curtime)

        s = '\t'.join(["%s: %d" % (k[0], v) for k, v, in levs.items()])

        print "%.1f" % (curtime - tstart), s