openlp/openlp/plugins/songs/lib/db.py

# -*- coding: utf-8 -*-
# vim: autoindent shiftwidth=4 expandtab textwidth=120 tabstop=4 softtabstop=4

###############################################################################
# OpenLP - Open Source Lyrics Projection                                      #
# --------------------------------------------------------------------------- #
# Copyright (c) 2008-2014 Raoul Snyman                                        #
# Portions copyright (c) 2008-2014 Tim Bentley, Gerald Britton, Jonathan      #
# Corwin, Samuel Findlay, Michael Gorven, Scott Guerrieri, Matthias Hub,      #
# Meinert Jordan, Armin Köhler, Erik Lundin, Edwin Lunando, Brian T. Meyer.   #
# Joshua Miller, Stevan Pettit, Andreas Preikschat, Mattias Põldaru,          #
# Christian Richter, Philip Ridout, Simon Scudder, Jeffrey Smith,             #
# Maikel Stuivenberg, Martin Thompson, Jon Tibble, Dave Warnock,              #
# Frode Woldsund, Martin Zibricky, Patrick Zimmermann                         #
# --------------------------------------------------------------------------- #
# This program is free software; you can redistribute it and/or modify it     #
# under the terms of the GNU General Public License as published by the Free  #
# Software Foundation; version 2 of the License.                              #
#                                                                             #
# This program is distributed in the hope that it will be useful, but WITHOUT #
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       #
# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for    #
# more details.                                                               #
#                                                                             #
# You should have received a copy of the GNU General Public License along     #
# with this program; if not, write to the Free Software Foundation, Inc., 59  #
# Temple Place, Suite 330, Boston, MA 02111-1307 USA                          #
###############################################################################
"""
The :mod:`db` module provides the database and schema that is the backend for
the Songs plugin
"""

import re

from sqlalchemy import Column, ForeignKey, Table, types
from sqlalchemy.orm import mapper, relation, reconstructor
from sqlalchemy.sql.expression import func, text

from openlp.core.lib.db import BaseModel, init_db
from openlp.core.utils import get_natural_key
from openlp.core.lib import translate


class Author(BaseModel):
    """
    Author model
    """
    def get_display_name(self, author_type=None):
        if author_type:
            return "%s (%s)" % (self.display_name, AuthorType.Types[author_type])
        return self.display_name


class AuthorSong(BaseModel):
    """
    Relationship between Authors and Songs (many to many).
    Need to define this relationship table explicit to get access to the
    Association Object (author_type).
    http://docs.sqlalchemy.org/en/latest/orm/relationships.html#association-object
    """
    pass


class AuthorType(object):
    """
    Enumeration for Author types.
    They are defined by OpenLyrics: http://openlyrics.info/dataformat.html#authors

    The 'words+music' type is not an official type, but is provided for convenience.
    """
    Words = 'words'
    Music = 'music'
    WordsAndMusic = 'words+music'
    Translation = 'translation'
    Types = {
        Words: translate('OpenLP.Ui', 'Words'),
        Music: translate('OpenLP.Ui', 'Music'),
        WordsAndMusic: translate('OpenLP.Ui', 'Words and Music'),
        Translation: translate('OpenLP.Ui', 'Translation')
    }


class Book(BaseModel):
    """
    Book model
    """
    def __repr__(self):
        return '<Book id="%s" name="%s" publisher="%s" />' % (str(self.id), self.name, self.publisher)


class MediaFile(BaseModel):
    """
    MediaFile model
    """
    pass


class Song(BaseModel):
    """
    Song model
    """

    def __init__(self):
        self.sort_key = []

    @reconstructor
    def init_on_load(self):
        """
        Precompute a natural sorting, locale aware sorting key.

        Song sorting is performance sensitive operation.
        To get maximum speed lets precompute the sorting key.
        """
        self.sort_key = get_natural_key(self.title)

    def add_author(self, author, author_type=None, ignore_type=False):
        """
        Add an author to the song if it not yet exists

        :return: True if the author has been added successfully. False if it was already there.
        """
        for author_song in self.authors_songs:
            if author_song.author == author and (ignore_type or author_song.author_type == author_type):
                return False
        new_author_song = AuthorSong()
        new_author_song.author = author
        new_author_song.author_type = author_type
        self.authors_songs.append(new_author_song)
        return True

    def remove_author(self, author, author_type=None, ignore_type=False):
        """
        Remove an existing author from the song

        :return: True if the author has been removed successfully. False if it could not be found.
        """
        for author_song in self.authors_songs:
            if author_song.author == author and (ignore_type or author_song.author_type == author_type):
                self.authors_songs.remove(author_song)
                return True
        return False


class Topic(BaseModel):
    """
    Topic model
    """
    pass


def init_schema(url):
    """
    Setup the songs database connection and initialise the database schema.

    :param url: The database to setup
    The song database contains the following tables:

        * authors
        * authors_songs
        * media_files
        * media_files_songs
        * song_books
        * songs
        * songs_topics
        * topics

    **authors** Table
        This table holds the names of all the authors. It has the following
        columns:

        * id
        * first_name
        * last_name
        * display_name

    **authors_songs Table**
        This is a bridging table between the *authors* and *songs* tables, which
        serves to create a many-to-many relationship between the two tables. It
        has the following columns:

        * author_id
        * song_id
        * author_type

    **media_files Table**
        * id
        * file_name
        * type

    **song_books Table**
        The *song_books* table holds a list of books that a congregation gets
        their songs from, or old hymnals now no longer used. This table has the
        following columns:

        * id
        * name
        * publisher

    **songs Table**
        This table contains the songs, and each song has a list of attributes.
        The *songs* table has the following columns:

        * id
        * song_book_id
        * title
        * alternate_title
        * lyrics
        * verse_order
        * copyright
        * comments
        * ccli_number
        * song_number
        * theme_name
        * search_title
        * search_lyrics

    **songs_topics Table**
        This is a bridging table between the *songs* and *topics* tables, which
        serves to create a many-to-many relationship between the two tables. It
        has the following columns:

        * song_id
        * topic_id

    **topics Table**
        The topics table holds a selection of topics that songs can cover. This
        is useful when a worship leader wants to select songs with a certain
        theme. This table has the following columns:

        * id
        * name
    """
    session, metadata = init_db(url)

    # Definition of the "authors" table
    authors_table = Table(
        'authors', metadata,
        Column('id', types.Integer(), primary_key=True),
        Column('first_name', types.Unicode(128)),
        Column('last_name', types.Unicode(128)),
        Column('display_name', types.Unicode(255), index=True, nullable=False)
    )

    # Definition of the "media_files" table
    media_files_table = Table(
        'media_files', metadata,
        Column('id', types.Integer(), primary_key=True),
        Column('song_id', types.Integer(), ForeignKey('songs.id'), default=None),
        Column('file_name', types.Unicode(255), nullable=False),
        Column('type', types.Unicode(64), nullable=False, default='audio'),
        Column('weight', types.Integer(), default=0)
    )

    # Definition of the "song_books" table
    song_books_table = Table(
        'song_books', metadata,
        Column('id', types.Integer(), primary_key=True),
        Column('name', types.Unicode(128), nullable=False),
        Column('publisher', types.Unicode(128))
    )

    # Definition of the "songs" table
    songs_table = Table(
        'songs', metadata,
        Column('id', types.Integer(), primary_key=True),
        Column('song_book_id', types.Integer(), ForeignKey('song_books.id'), default=None),
        Column('title', types.Unicode(255), nullable=False),
        Column('alternate_title', types.Unicode(255)),
        Column('lyrics', types.UnicodeText, nullable=False),
        Column('verse_order', types.Unicode(128)),
        Column('copyright', types.Unicode(255)),
        Column('comments', types.UnicodeText),
        Column('ccli_number', types.Unicode(64)),
        Column('song_number', types.Unicode(64)),
        Column('theme_name', types.Unicode(128)),
        Column('search_title', types.Unicode(255), index=True, nullable=False),
        Column('search_lyrics', types.UnicodeText, nullable=False),
        Column('create_date', types.DateTime(), default=func.now()),
        Column('last_modified', types.DateTime(), default=func.now(), onupdate=func.now()),
        Column('temporary', types.Boolean(), default=False)
    )

    # Definition of the "topics" table
    topics_table = Table(
        'topics', metadata,
        Column('id', types.Integer(), primary_key=True),
        Column('name', types.Unicode(128), index=True, nullable=False)
    )

    # Definition of the "authors_songs" table
    authors_songs_table = Table(
        'authors_songs', metadata,
        Column('author_id', types.Integer(), ForeignKey('authors.id'), primary_key=True),
        Column('song_id', types.Integer(), ForeignKey('songs.id'), primary_key=True),
        Column('author_type', types.String(), primary_key=True, nullable=False, server_default=text('""'))
    )

    # Definition of the "songs_topics" table
    songs_topics_table = Table(
        'songs_topics', metadata,
        Column('song_id', types.Integer(), ForeignKey('songs.id'), primary_key=True),
        Column('topic_id', types.Integer(), ForeignKey('topics.id'), primary_key=True)
    )

    mapper(Author, authors_table)
    mapper(AuthorSong, authors_songs_table, properties={
        'author': relation(Author)
    })
    mapper(Book, song_books_table)
    mapper(MediaFile, media_files_table)
    mapper(Song, songs_table, properties={
        # Use the authors_songs relation when you need access to the 'author_type' attribute
        # or when creating new relations
        'authors_songs': relation(AuthorSong, cascade="all, delete-orphan"),
        'authors': relation(Author, secondary=authors_songs_table, viewonly=True),
        'book': relation(Book, backref='songs'),
        'media_files': relation(MediaFile, backref='songs', order_by=media_files_table.c.weight),
        'topics': relation(Topic, backref='songs', secondary=songs_topics_table)
    })
    mapper(Topic, topics_table)

    metadata.create_all(checkfirst=True)
    return session