# coding: utf-8

import config

from sqlalchemy import create_engine, Table, Column, ForeignKey, func
from sqlalchemy import Integer, String, Boolean, DateTime
from sqlalchemy.orm import scoped_session, sessionmaker, relationship, backref
from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy.types import TypeDecorator, BINARY
from sqlalchemy.dialects.postgresql import UUID as pgUUID

import uuid, datetime, time
import os.path

def _unique(session, cls, hashfunc, queryfunc, constructor, arg, kw):
	cache = getattr(session, '_unique_cache', None)
	if cache is None:
		session._unique_cache = cache = {}

	key = (cls, hashfunc(*arg, **kw))
	if key in cache:
		return cache[key]
	else:
		with session.no_autoflush:
			q = session.query(cls)
		q = queryfunc(q, *arg, **kw)
		obj = q.first()
		if not obj:
			obj = constructor(*arg, **kw)
			session.add(obj)
		cache[key] = obj
		return obj

class UniqueMixin(object):
	@classmethod
	def unique_hash(cls, *arg, **kw):
		raise NotImplementedError()

	@classmethod
	def unique_filter(cls, query, *arg, **kw):
		raise NotImplementedError()

	@classmethod
	def as_unique(cls, session, *arg, **kw):
		return _unique(
				session,
				cls,
				cls.unique_hash,
				cls.unique_filter,
				cls,
				arg, kw
				)

class UUID(TypeDecorator):
	"""Platform-somewhat-independent UUID type

	Uses Postgresql's UUID type, otherwise uses BINARY(16),
	should be more efficient than a CHAR(32).

	Mix of http://stackoverflow.com/a/812363
	and http://www.sqlalchemy.org/docs/core/types.html#backend-agnostic-guid-type
	"""

	impl = BINARY

	def load_dialect_impl(self, dialect):
		if dialect.name == 'postgresql':
			return dialect.type_descriptor(pgUUID())
		else:
			return dialect.type_descriptor(BINARY(16))

	def process_bind_param(self, value, dialect):
		if value and isinstance(value, uuid.UUID):
			if dialect.name == 'postgresql':
				return str(value)
			return value.bytes
		if value and not isinstance(value, uuid.UUID):
			raise ValueError, 'value %s is not a valid uuid.UUID' % value
		return None

	def process_result_value(self, value, dialect):
		if value:
			if dialect.name == 'postgresql':
				return uuid.UUID(value)
			return uuid.UUID(bytes = value)
		return None

	def is_mutable(self):
		return False

	@staticmethod
	def gen_id_column():
		return Column(UUID, primary_key = True, default = uuid.uuid4)

def now():
	return datetime.datetime.now().replace(microsecond = 0)

engine = create_engine(config.get('base', 'database_uri'), convert_unicode = True)
session = scoped_session(sessionmaker(autoflush = False, bind = engine))

Base = declarative_base()
Base.query = session.query_property()

class User(Base):
	__tablename__ = 'user'

	id = UUID.gen_id_column()
	name = Column(String(64), unique = True)
	mail = Column(String(256))
	password = Column(String(40))
	salt = Column(String(6))
	admin = Column(Boolean, default = False)
	lastfm_session = Column(String(32), nullable = True)
	lastfm_status = Column(Boolean, default = True) # True: ok/unlinked, False: invalid session

	last_play_id = Column(UUID, ForeignKey('track.id'), nullable = True)
	last_play = relationship('Track')
	last_play_date = Column(DateTime, nullable = True)

	def as_subsonic_user(self):
		return {
			'username': self.name,
			'email': self.mail,
			'scrobblingEnabled': self.lastfm_session is not None and self.lastfm_status,
			'adminRole': self.admin,
			'settingsRole': True,
			'downloadRole': True,
			'uploadRole': False,
			'playlistRole': True,
			'coverArtRole': False,
			'commentRole': False,
			'podcastRole': False,
			'streamRole': True,
			'jukeboxRole': False,
			'shareRole': False
		}

class Folder(Base):
	__tablename__ = 'folder'

	id = UUID.gen_id_column()
	root = Column(Boolean, default = False)
	name = Column(String(256))
	path = Column(String(4096)) # should be unique, but mysql don't like such large columns
	created = Column(DateTime, default = now)
	has_cover_art = Column(Boolean, default = False)
	last_scan = Column(Integer, default = 0)

	parent_id = Column(UUID, ForeignKey('folder.id'), nullable = True)
	children = relationship('Folder', backref = backref('parent', remote_side = [ id ]))

	def as_subsonic_child(self, user):
		info = {
			'id': str(self.id),
			'isDir': True,
			'title': self.name,
			'album': self.name,
			'created': self.created.isoformat()
		}
		if not self.root:
			info['parent'] = str(self.parent_id)
			info['artist'] = self.parent.name
		if self.has_cover_art:
			info['coverArt'] = str(self.id)

		starred = StarredFolder.query.get((user.id, self.id))
		if starred:
			info['starred'] = starred.date.isoformat()

		rating = RatingFolder.query.get((user.id, self.id))
		if rating:
			info['userRating'] = rating.rating
		avgRating = RatingFolder.query.filter(RatingFolder.rated_id == self.id).value(func.avg(RatingFolder.rating))
		if avgRating:
			info['averageRating'] = avgRating

		return info

class Artist(UniqueMixin, Base):
	__tablename__ = 'artist'

	id = UUID.gen_id_column()
	name = Column(String(256), unique = True, nullable=False)
	albums = relationship('Album', backref = 'artist')

	@classmethod
	def unique_hash(cls, name):
		return name

	@classmethod
	def unique_filter(cls, query, name):
		return query.filter(Artist.name == name)

	def as_subsonic_artist(self, user):
		info = {
			'id': str(self.id),
			'name': self.name,
			# coverArt
			'albumCount': len(self.albums)
		}

		starred = StarredArtist.query.get((user.id, self.id))
		if starred:
			info['starred'] = starred.date.isoformat()

		return info

class Album(Base):
	__tablename__ = 'album'

	id = UUID.gen_id_column()
	name = Column(String(256))
	artist_id = Column(UUID, ForeignKey('artist.id'))
	tracks = relationship('Track', backref = 'album')

	def as_subsonic_album(self, user):
		info = {
			'id': str(self.id),
			'name': self.name,
			'artist': self.artist.name,
			'artistId': str(self.artist_id),
			'songCount': len(self.tracks),
			'duration': sum(map(lambda t: t.duration, self.tracks)),
			'created': min(map(lambda t: t.created, self.tracks)).isoformat()
		}
		if self.tracks[0].folder.has_cover_art:
			info['coverArt'] = str(self.tracks[0].folder_id)

		starred = StarredAlbum.query.get((user.id, self.id))
		if starred:
			info['starred'] = starred.date.isoformat()

		return info

	def sort_key(self):
		year = min(map(lambda t: t.year if t.year else 9999, self.tracks))
		return '%i%s' % (year, self.name.lower())

class Track(Base):
	__tablename__ = 'track'

	id = UUID.gen_id_column()
	disc = Column(Integer)
	number = Column(Integer)
	title = Column(String(256))
	year = Column(Integer, nullable = True)
	genre = Column(String(256), nullable = True)
	duration = Column(Integer)
	album_id = Column(UUID, ForeignKey('album.id'))
	bitrate = Column(Integer)

	path = Column(String(4096)) # should be unique, but mysql don't like such large columns
	content_type = Column(String(32))
	created = Column(DateTime, default = now)
	last_modification = Column(Integer)

	play_count = Column(Integer, default = 0)
	last_play = Column(DateTime, nullable = True)

	root_folder_id = Column(UUID, ForeignKey('folder.id'))
	root_folder = relationship('Folder', primaryjoin = Folder.id == root_folder_id)
	folder_id = Column(UUID, ForeignKey('folder.id'))
	folder = relationship('Folder', primaryjoin = Folder.id == folder_id, backref = 'tracks')

	def as_subsonic_child(self, user):
		info = {
			'id': str(self.id),
			'parent': str(self.folder.id),
			'isDir': False,
			'title': self.title,
			'album': self.album.name,
			'artist': self.album.artist.name,
			'track': self.number,
			'size': os.path.getsize(self.path),
			'contentType': self.content_type,
			'suffix': self.suffix(),
			'duration': self.duration,
			'bitRate': self.bitrate,
			'path': self.path[len(self.root_folder.path) + 1:],
			'isVideo': False,
			'discNumber': self.disc,
			'created': self.created.isoformat(),
			'albumId': str(self.album.id),
			'artistId': str(self.album.artist.id),
			'type': 'music'
		}

		if self.year:
			info['year'] = self.year
		if self.genre:
			info['genre'] = self.genre
		if self.folder.has_cover_art:
			info['coverArt'] = str(self.folder_id)

		starred = StarredTrack.query.get((user.id, self.id))
		if starred:
			info['starred'] = starred.date.isoformat()

		rating = RatingTrack.query.get((user.id, self.id))
		if rating:
			info['userRating'] = rating.rating
		avgRating = RatingTrack.query.filter(RatingTrack.rated_id == self.id).value(func.avg(RatingTrack.rating))
		if avgRating:
			info['averageRating'] = avgRating

		if self.suffix() == 'flac':
			info['transcodedContentType'] = 'audio/ogg'
			info['transcodedSuffix'] = 'ogg'

		return info

	def duration_str(self):
		ret = '%02i:%02i' % ((self.duration % 3600) / 60, self.duration % 60)
		if self.duration >= 3600:
			ret = '%02i:%s' % (self.duration / 3600, ret)
		return ret

	def suffix(self):
		return os.path.splitext(self.path)[1][1:].lower()

	def sort_key(self):
		return (self.album.artist.name + self.album.name + ("%02i" % self.disc) + ("%02i" % self.number) + str(self.title)).lower()

class StarredFolder(Base):
	__tablename__ = 'starred_folder'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	starred_id = Column(UUID, ForeignKey('folder.id'), primary_key = True)
	date = Column(DateTime, default = now)

	user = relationship('User')
	starred = relationship('Folder')

class StarredArtist(Base):
	__tablename__ = 'starred_artist'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	starred_id = Column(UUID, ForeignKey('artist.id'), primary_key = True)
	date = Column(DateTime, default = now)

	user = relationship('User')
	starred = relationship('Artist')

class StarredAlbum(Base):
	__tablename__ = 'starred_album'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	starred_id = Column(UUID, ForeignKey('album.id'), primary_key = True)
	date = Column(DateTime, default = now)

	user = relationship('User')
	starred = relationship('Album')

class StarredTrack(Base):
	__tablename__ = 'starred_track'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	starred_id = Column(UUID, ForeignKey('track.id'), primary_key = True)
	date = Column(DateTime, default = now)

	user = relationship('User')
	starred = relationship('Track')

class RatingFolder(Base):
	__tablename__ = 'rating_folder'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	rated_id = Column(UUID, ForeignKey('folder.id'), primary_key = True)
	rating = Column(Integer)

	user = relationship('User')
	rated = relationship('Folder')

class RatingTrack(Base):
	__tablename__ = 'rating_track'

	user_id = Column(UUID, ForeignKey('user.id'), primary_key = True)
	rated_id = Column(UUID, ForeignKey('track.id'), primary_key = True)
	rating = Column(Integer)

	user = relationship('User')
	rated = relationship('Track')

class ChatMessage(Base):
	__tablename__ = 'chat_message'

	id = UUID.gen_id_column()
	user_id = Column(UUID, ForeignKey('user.id'))
	time = Column(Integer, default = lambda: int(time.time()))
	message = Column(String(512))

	user = relationship('User')

	def responsize(self):
		return {
			'username': self.user.name,
			'time': self.time * 1000,
			'message': self.message
		}

playlist_track_assoc = Table('playlist_track', Base.metadata,
	Column('playlist_id', UUID, ForeignKey('playlist.id')),
	Column('track_id', UUID, ForeignKey('track.id'))
)

class Playlist(Base):
	__tablename__ = 'playlist'

	id = UUID.gen_id_column()
	user_id = Column(UUID, ForeignKey('user.id'))
	name = Column(String(256))
	comment = Column(String(256), nullable = True)
	public = Column(Boolean, default = False)
	created = Column(DateTime, default = now)

	user = relationship('User')
	tracks = relationship('Track', secondary = playlist_track_assoc)

	def as_subsonic_playlist(self, user):
		info = {
			'id': str(self.id),
			'name': self.name if self.user_id == user.id else '[%s] %s' % (self.user.name, self.name),
			'owner': self.user.name,
			'public': self.public,
			'songCount': len(self.tracks),
			'duration': sum(map(lambda t: t.duration, self.tracks)),
			'created': self.created.isoformat()
		}
		if self.comment:
			info['comment'] = self.comment
		return info

def init_db():
	Base.metadata.create_all(bind = engine)

def recreate_db():
	Base.metadata.drop_all(bind = engine)
	Base.metadata.create_all(bind = engine)