#!/usr/bin/env python

import exceptions
import itertools
import math
import mido
import os
import reportlab.lib.colors
from reportlab.lib.units import mm
import sys

CUT_COLOUR = reportlab.lib.colors.red
ENGRAVE_COLOUR = reportlab.lib.colors.black


## XXX: PDF origin bottom left, SVG origin top left
def test(filename = None):
    if filename == None:
        filename = 'test.midi'
    # Card layout from http://www.orgues-de-barbarie.com/wp-content/uploads/2014/09/format-cartons.pdf
    m = Midi2PDF('notes', 200, 155, 5.5, 6.0, 10, 'Helvetica', 12)
    base, ext = os.path.splitext(filename)
    m.processMidi(filename, base + '-%02d.pdf')

class Midi2PDF(object):
    def __init__(self, notefile, pagewidth, pageheight, pitch, offset, timescale, fontname, fontsize):
        self.midi2note, self.note2midi = Midi2PDF.genmidi2note()
        self.note2slot = Midi2PDF.loadnote2slot(notefile, self.note2midi)
        self.pagewidth = pagewidth # Dimensions are in millimetres
        self.pageheight = pageheight
        self.pitch = pitch
        self.offset = offset
        self.timescale = timescale
        self.fontname = fontname
        self.fontsize = fontsize

    def processMidi(self, midifile, outpat):
        playablecount = 0
        unplayablecount = 0
        midi = mido.MidiFile(midifile)
        ctime = 0
        channels = []
        for i in range(16):
            channels.append({})

        npages = int(math.ceil(midi.length * self.timescale / self.pagewidth))
        print 'npages', npages
        pdfs = []
        for i in range(npages):
            pdf = reportlab.pdfgen.canvas.Canvas(file(outpat % (i + 1), 'w'), pagesize = (self.pagewidth * mm, self.pageheight * mm))
            pdfs.append(pdf)

        title = midifile
        for ev in midi:
            if ev.type == 'text' and ctime == 0:
                title = ev.text

            ctime += ev.time
            if ev.type == 'note_on' or ev.type == 'note_off':
                note = self.midi2note[ev.note]
            #print ctime, ev
            if ev.type == 'note_on' and ev.velocity > 0:
                if ev.note in channels[ev.channel]:
                    print 'Duplicate note_on message %d (%s)' % (ev.note, note)
                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 channel %d note %d' % (ev.channel, ev.note)
                    else:
                        if note not in self.note2slot:
                            print 'Skipping unplayable note %s' % (note)
                            unplayablecount += 1
                        else:
                            start = channels[ev.channel][ev.note]
                            notelen = ctime - start
                            slot = self.note2slot[note]
                            print 'Note %s (%d) at %.2f length %.2f' % (note, slot, start, notelen)
                            self.emitnote(pdfs, slot, start, notelen)
                            playablecount += 1
                        del channels[ev.channel][ev.note]
            elif ev.type == 'end_of_track':
                print 'EOT, not flushing, check for missed notes'
                for chan in channels:
                    for ev in chan:
                        print ev

        print 'Playable count:', playablecount
        print 'Unplayable count:', unplayablecount

        for i in range(len(pdfs)):
            pdf = pdfs[i]
            tobj = pdf.beginText()
            tobj.setTextOrigin(2 * mm, 1 * mm)
            tobj.setFont(self.fontname, self.fontsize)
            tobj.setFillColor(ENGRAVE_COLOUR)
            tobj.setStrokeColor(ENGRAVE_COLOUR)
            tobj.textLine('%s (%d / %d)' % (title, i + 1, npages))
            pdf.drawText(tobj)
            pdf.save()

    # http://www.electronics.dit.ie/staff/tscarff/Music_technology/midi/midi_note_numbers_for_octaves.htm
    @staticmethod
    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

    @staticmethod
    def loadnote2slot(fname, note2midi):
        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(self, pdfs, slot, start, notelen):
        x = start * self.timescale
        pageidx = int(x / self.pagewidth)
        x = x % self.pagewidth
        y = self.offset + slot * self.pitch
        w = notelen * self.timescale
        h = self.pitch

        print 'page = %d x = %.3f y = %.3f w = %.3f h = %.3f' % (pageidx, x, y, w, h)
        w1 = w
        # Check if the note crosses a page
        if x + w > self.pagewidth:
            w1 = x - self.pagewidth # Crop first note
            w2 = w - w1
            assert w1 <= self.pagewidth, 'note extends for more than a page'
            # Emit second half of note
            print 'split note, page %d w2 = %.3f' % (pageidx + 1, w2)
            Midi2PDF._emitnote(pdfs[pageidx + 1], 0, y, w2, h)

        Midi2PDF._emitnote(pdfs[pageidx], x, y, w1, h)

    @staticmethod
    def _emitnote(pdf, x, y, w, h):
        pdf.saveState()
        pdf.setStrokeColor(CUT_COLOUR)
        pdf.setLineWidth(0)
        pdf.rect(x * mm, y * mm, w * mm, h * mm, fill = False, stroke = True)
        pdf.restoreState()

if __name__ == '__main__':
    main()