import os
import re

from django.db import models
from django.db.models.fields.related import ForeignKey
from django.utils.translation import ugettext as _
from django.contrib.auth.models import User
from django.utils.safestring import mark_safe


############################# Helper Functions #######################################################


def space_to_camelcase(value):
    def camelcase(): 
        yield type(value).lower
        while True:
            yield type(value).capitalize

    c = camelcase()
    return "".join(c.next()(x) if x else '_' for x in value.split() )


def score_filename(score,original_name):
    fileExtension = os.path.splitext(original_name)[1]
    filename  = "scores/"
    filename += space_to_camelcase( score.piece.title ) + "/"
    filename += space_to_camelcase( score.score_type )
    filename += fileExtension
    return filename


def recordingFileName( recording, originalName ):
    fileExtension = os.path.splitext(originalName)[1]
    filename  = "recordings/"
    filename += space_to_camelcase( recording.piece.title ) + "/"
    filename += space_to_camelcase( recording.artist )
    filename += fileExtension
    return filename

_
#######################################################################################################


class Piece (models.Model):
    title         = models.CharField( max_length = 255, verbose_name = _("title"), unique=True )
    composer      = models.CharField( max_length = 255, blank = True, verbose_name = _("composer") ) 
    repertoire_nr = models.IntegerField( null = True, blank=True, unique=True, default = None )
    
    def __unicode__(self):
        res = self.title
        return res 
    
    def isInRepertoire(self):
        return self.repertoire_nr is not None

    def get_score_for_user(self, user):
        try:
            return ScoreUserMapping.objects.get( user=user, score__in = self.scores.all() ).score
        except Piece.DoesNotExist:
            if len( self.scores.all() ) > 0:
                return self.scores.all()[0]
            else:
                return None


    @staticmethod
    def getRepertoire():
        return Piece.objects.filter( repertoire_nr__isnull = False  ).order_by( 'repertoire_nr' )

    class Meta:
        permissions = (
            ("manage_scores", "Administrate and manage scores"),
        )



class BookLocation ( models.Model ):
    piece  = models.ForeignKey ( 'Piece' )
    book   = models.CharField( max_length = 100, blank = False, verbose_name = _("Buch") )
    page   = models.IntegerField( verbose_name = _("page") )
    
    def __unicode__(self):
        return  "%s, %d" % ( self.book, self.page )
        


class Score( models.Model ):
    piece = ForeignKey('Piece', related_name="scores")
    score_type = models.CharField(max_length=100, verbose_name="score type" ) # for example partitur, unterstimmen ...
    file = models.FileField(upload_to=score_filename, verbose_name = _("file") )
    uploaded_by = ForeignKey( User, verbose_name=_("uploaded_by") )

    @property
    def image_file_name(self):
        return os.path.splitext("image_cache/" + str(self.file))[0] + ".jpg"

    @staticmethod
    def pdf2jpg(source_file, target_file, resolution = 100, crop = 15):
        from wand.image import Image
        ret = True
        try:
            with Image(filename=source_file, resolution=(resolution,resolution)) as img:
                img.crop( crop,crop, width= img.width - 2*crop, height = int( 0.5 * img.height) - 2*crop )
                img.format = 'jpeg'
                img.save(filename = target_file)
        except Exception as e:
            print(e)
            ret = False

        return ret

    def get_image_file(self):
        from django.conf import settings

        inputFile = settings.MEDIA_ROOT + "/"  + str(self.file)
        cacheFile = settings.MEDIA_ROOT + "/" + str(self.image_file_name)
        # Create a jpg for this score, if it does not exist yet
        if not os.path.exists( cacheFile ):
            if not os.path.exists( os.path.dirname( cacheFile )):
                os.makedirs( os.path.dirname(cacheFile) )
            Score.pdf2jpg ( inputFile, cacheFile )

        return self.image_file_name

    def is_active_score(self,user):
        return len( ScoreUserMapping.objects.filter( score= self, user=user ) ) > 0

    class Meta:
        unique_together = (("piece", "score_type"),)
        ordering = ['score_type']



    
class Recording( models.Model ):
    piece = ForeignKey( 'Piece', related_name='recordings' )
    artist = models.CharField( max_length = 100, verbose_name = _("Artist") )
    file = models.FileField( upload_to = recordingFileName, verbose_name = _("file") )
    uploaded_by = ForeignKey( User, verbose_name=_("uploaded_by") )

    class Meta:
        unique_together = (("piece", "artist"),)
        ordering = ['artist']
    


class YoutubeRecording( models.Model ):
    piece = models.ForeignKey('Piece', related_name="youtubeLinks" )
    link  = models.CharField( max_length = 300, blank=False)
    uploaded_by = ForeignKey( User, verbose_name=_("uploaded_by") )

    youtubeRegex = re.compile( u'(?:https://)?(?:http://)?www.youtube.(?:com|de)/watch\?v=(?P<videoID>[-\w]*)' )

    @property
    def embed_html( self ):
        replacement = """
            <div class="embed-container"><iframe src="//www.youtube.de/embed/\g<videoID>" frameborder="0" allowfullscreen></iframe> </div>
        """
        return mark_safe( YoutubeRecording.youtubeRegex.sub( replacement, self.link ) )

    class Meta:
        unique_together = (("link", "piece" ))




class ScoreUserMapping( models.Model):
    score = ForeignKey( 'Score' )
    user = models.OneToOneField( User )
    piece = ForeignKey( 'Piece' )

    @staticmethod
    def add_user_score_mapping( score, user ):
        piece = score.piece
        ScoreUserMapping.objects.filter( user=user, piece=piece ).delete()
        ScoreUserMapping.objects.create( score=score, user=user, piece= piece )


    class Meta:
        unique_together = (("piece", "user" ))