# Copyright 2021 (c) Anna Schumaker.
#
# Table: genres
# +---------+------+------+
# | genreid | name | sort |
# +---------+------+------+
#
# Index: genre_index
# +-----------------+
# | name -> genreid |
# +-----------------+
#
# Map: genre_map
# +---------+---------+
# | genreid | trackid |
# +---------+---------+
from . import execute
from . import objects
from . import track

class Genre(objects.Tag):
    def do_get_column(self, column):
        return execute(f"SELECT {column} FROM genres "
                        "WHERE genreid=?", [ self.rowid ])


class GenreTable(objects.Table):
    def __init__(self):
        objects.Table.__init__(self, "genres", Genre)

    def do_create(self):
        execute("CREATE TABLE IF NOT EXISTS genres "
                    "(genreid INTEGER PRIMARY KEY, "
                    " name TEXT UNIQUE, "
                    " sort TEXT)")
        execute("CREATE INDEX IF NOT EXISTS genre_index "
                "ON genres(name)")

    def do_insert(self, name):
        return execute("INSERT INTO genres (name, sort) "
                       "VALUES (?, ?)", (name, name.casefold()))

    def do_delete(self, genre):
        return execute("DELETE FROM genres WHERE genreid=?", [ int(genre) ])

    def do_get(self, rowid):
        return execute("SELECT genreid FROM genres "
                       "WHERE genreid=?", [ rowid ])

    def do_lookup(self, name):
        return execute("SELECT genreid FROM genres "
                       "WHERE name=?", [ name ])


class GenreMap(objects.Map):
    def __init__(self):
        objects.Map.__init__(self, "genre_map", Genre, track.Track)
        self.lookup_tracks = self.lookup_rhs
        self.lookup_genres = self.lookup_lhs

    def do_create(self):
        execute("CREATE TABLE IF NOT EXISTS genre_map "
                    "(genreid INTEGER, "
                    " trackid INTEGER, "
                    " FOREIGN KEY(genreid) REFERENCES genres(genreid), "
                    " FOREIGN KEY(trackid) REFERENCES tracks(trackid), "
                    " UNIQUE(genreid, trackid))")

    def do_insert(self, genre, track):
        execute("INSERT INTO genre_map (genreid, trackid) "
                "VALUES (?, ?)", [ int(genre), int(track) ])

    def do_delete(self, genre, track):
        return execute("DELETE FROM genre_map WHERE genreid=? AND trackid=?",
                       [ int(genre), int(track) ])

    def do_lookup_rhs(self, genre):
        return execute("SELECT trackid FROM genre_map "
                       "WHERE genreid=?", [ int(genre) ])

    def do_lookup_lhs(self, track):
        return execute("SELECT genreid FROM genre_map "
                       "WHERE trackid=?", [ int(track) ])

    def delete_track(self, track):
        for genre in self.lookup_genres(track):
            self.delete(genre, track)


Table = GenreTable()
Map   = GenreMap()