#!/usr/bin/env python
### spianostaff.py -- 
"""\
StevePianoStaff -- Spreads notes of a single melody over two staves.
"""

from abjad import *


def sum_durations( measure ):
    """\
    Add the "duration.written" of all the notes, rests, skips in a measure.
    It looks like there's an Abjad call for not only this, but also for what
    I *should have* done.
    """
    return sum( item.duration.written for item in measure )


def voice_measures_append( voice, meter, item ):
    """\
    Add item to last measure in voice, adding a measure if necessary.
    voice actually only need be a Container, but it must contain measures. """
    if len( voice ) == 0:
        last_measure_fullness = meter.duration
    else:
        last_measure_fullness = sum_durations( voice[ -1 ] )
    if last_measure_fullness == meter.duration:
        voice.append( AnonymousMeasure( ) )
    voice[ -1 ].append( item )


class StevePianoStaff:
    """\
    Contains a PianoStaff with treble and bass cleffs, with a fixed meter (time signature),
    and a single melody line that moves between the staves, or at least looks as if
    it does.
    """

    def __init__( self, meter, notes ):
        self.meter = Meter( meter )
        self.voices = [ Voice( [ RigidMeasure(meter) ] ) for i in range(2) ]
        self.p = PianoStaff( [ Staff( [v] ) for v in self.voices ] )
        self.p[1].clef.forced = Clef('bass')
        self.notes = []
        self.midc = Pitch( 0 )
        self.extend( notes )
        self.currently_bottom = False

    def extend( self, notes ):
        for note in notes:
            self.append( note )

    def append( self, note ):
        skip = Skip( note.duration.written )
        if note.pitch < self.midc  or  note.pitch == self.midc and self.currently_bottom:
            self.append_top_bottom( [ skip, note ] )
            self.currently_bottom = True
        else:
            self.append_top_bottom( [ note, skip ] )
            self.currently_bottom = False
        self.notes.append( note )

    def append_top_bottom( self, items ):
        for voice, item in zip( self.voices, items ):
            voice_measures_append( voice, self.meter, item )

    def show( self, **kwargs ):
        show( self.p, **kwargs )

    def play( self, **kwargs ):
        play( self.p, **kwargs )


def demo_StevePianoStaff():
    length = 128
    sp = StevePianoStaff( (4,4), [ Note( randint( -19, 19 ), (1,8) ) for i in range( length ) ] )
    sp.show( title="Random Melody" )
    # sp.play( )


if __name__ == "__main__":
    from random import *
    demo_StevePianoStaff()