#!/usr/bin/env python

import exceptions
import mido
import svgwrite
import sys

def test():
    # http://www.orgues-de-barbarie.com/wp-content/uploads/2014/09/format-cartons.pdf
    conf = { 'notefile' : 'notes', 'pitch' : 5.5 }
    midi2note, note2midi = genmidi2note()
    note2slot = loadnote2slot(conf['notefile'], note2midi)
    midi2svg('test.midi', 'test%d.svg', conf['pitch'], midi2note, note2midi, note2slot)

# http://www.electronics.dit.ie/staff/tscarff/Music_technology/midi/midi_note_numbers_for_octaves.htm
def genmidi2note():
    '''Create forward & reverse tables for midi number to note name (assuming 69 == A440)'''
    names = ['C%d', 'C%d#', 'D%d', 'D%d#', 'E%d', 'F%d', 'F%d#', 'G%d', 'G%d#', 'A%d', 'A%d#', 'B%d']
    midi2note = {}
    note2midi = {}
    for midi in range(128):
        octave = midi / len(names)
        index = midi % len(names)
        name = names[index] % (octave)
        midi2note[midi] = name
        note2midi[name] = midi

    return midi2note, note2midi

def loadnote2slot(fname, note2midi):
    svg = svgwrite.Drawing(fname)

    note2slot = {}
    index = 0

    for note in file(fname):
        note = note.strip()
        if note[0] == '#':
            continue
        if note not in note2midi:
            raise exceptions.ValueError('Note \'%s\' not valid' % note)
        note2slot[note] = index
        index += 1

    return note2slot

def emitnote(svg, slot, start, notelen):
    # Let us say 185 ticks for a quaver and that is 5mm long
    tickscale = 185.0 / 5.0
    pitch = 5.5
    offset = 6
    x = start / tickscale
    y = offset + slot * pitch
    w = notelen / tickscale
    h = pitch
    print x, y, w, h
    svg.add(svgwrite.shapes.Rect(insert = ('%.3fcm' % (x / 10, '%.3fcm' % (y / 10)), size = (w, h), stroke = 'red', stroke_width = '1px', fill = 'red'))

def midi2svg(inf, outpat, pitch, midi2note, note2midi, note2slot):
    midi = mido.MidiFile(inf)
    svg = svgwrite.Drawing(outpat % (0))
    tnum = 0
    for t in midi.tracks:
        print "Track", tnum
        tnum += 1
        channels = []
        for i in range(16):
                channels.append({})
        ctime = 0
        for ev in t:
            ctime += ev.time
            if ev.type == 'note_on' and ev.velocity > 0:
                if ev.note in channels[ev.channel]:
                    print "Duplicate channel on message"
                else:
                    channels[ev.channel][ev.note] = ctime
            elif ev.type == 'note_off' or (ev.type == 'note_on' and ev.velocity == 0):
                    if ev.note not in channels[ev.channel]:
                        print 'Note_off with no corresponding note_on for track %d channel %d note %d' % (tnum, ev.channel, ev.note)
                    else:
                        note = midi2note[ev.note]
                        if note not in note2slot:
                            print 'Skipping unplayable note %s' % (note)
                        else:
                            notelen = ctime - channels[ev.channel][ev.note]
                            slot = note2slot[note]
                            print 'Note %s (%d) at %d length %d' % (note, slot, ctime, notelen)
                            emitnote(svg, slot, ctime, notelen)
                        del channels[ev.channel][ev.note]
        svg.save()

if __name__ == '__main__':
    main()