app.py

from flask import Flask, redirect, render_template
from flask_debugtoolbar import DebugToolbarExtension

from models import db, connect_db, Playlist, Song, PlaylistSong
from forms import NewSongForPlaylistForm, SongForm, PlaylistForm

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'postgresql:///playlist-app'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_ECHO'] = True

connect_db(app)
db.create_all()

app.config['SECRET_KEY'] = "I'LL NEVER TELL!!"

# Having the Debug Toolbar show redirects explicitly is often useful;
# however, if you want to turn it off, you can uncomment this line:
#
# app.config['DEBUG_TB_INTERCEPT_REDIRECTS'] = False

debug = DebugToolbarExtension(app)


@app.route("/")
def root():
    """Homepage: redirect to /playlists."""

    return redirect("/playlists")


##############################################################################
# Playlist routes


@app.route("/playlists")
def show_all_playlists():
    """Return a list of playlists."""

    playlists = Playlist.query.all()
    return render_template("playlists.html", playlists=playlists)


@app.route("/playlists/<int:playlist_id>")
def show_playlist(playlist_id):
    """Show detail on specific playlist.""" # ADD THE NECESSARY CODE HERE FOR THIS ROUTE TO WORK

    playlist=Playlist.query.get_or_404(playlist_id)
    return render_template('playlist.html', playlist=playlist)


@app.route("/playlists/add", methods=["GET", "POST"])
def add_playlist():
    """Handle add-playlist form:

    - if form not filled out or invalid: show form
    - if valid: add playlist to SQLA and redirect to list-of-playlists
    """

    # ADD THE NECESSARY CODE HERE FOR THIS ROUTE TO WORK
    form = PlaylistForm()

    if form.validate_on_submit():
        name = form.playlist_name.data
        description = form.playlist_description.data 

        new_playlist = Playlist(playlist_name=name, playlist_description=description)
        db.session.add(new_playlist)
        db.session.commit()
        flash('new playlist created!', 'success')
        return redirect('/playlist')
    return render_template('new_playlist.html', form=form)


##############################################################################
# Song routes


@app.route("/songs")
def show_all_songs():
    """Show list of songs."""

    songs = Song.query.all()
    return render_template("songs.html", songs=songs)


@app.route("/songs/<int:song_id>")
def show_song(song_id):
    """return a specific song"""

    # ADD THE NECESSARY CODE HERE FOR THIS ROUTE TO WORK
    song = Song.query.get_or_404(song_id)
    return render_template('song.html', song=song)


@app.route("/songs/add", methods=["GET", "POST"])
def add_song():
    """Handle add-song form:

    - if form not filled out or invalid: show form
    - if valid: add playlist to SQLA and redirect to list-of-songs
    """

    # ADD THE NECESSARY CODE HERE FOR THIS ROUTE TO WORK
    form = SongForm()
    if form.validate_on_submit():
        song_title = form.song_title.data
        song_artist = form.song_artist.data
        new_song=Song(song_title=song_title, song_artist=song_artist)

        db.session.add(song)
        db.session.commit()
        flash('New song added!')
        return redirect('/songs')
    return render_template('new_song.html', form=form)


@app.route("/playlists/<int:playlist_id>/add-song", methods=["GET", "POST"])
def add_song_to_playlist(playlist_id):
    """Add a playlist and redirect to list."""

    # BONUS - ADD THE NECESSARY CODE HERE FOR THIS ROUTE TO WORK

    playlist = Playlist.query.get_or_404(playlist_id)
    form = NewSongForPlaylistForm()

  # Restrict form to songs not already on this playlist

    curr_on_playlist = [s.id for s in playlist.songs]
    form.song.choices = (db.session.query(Song.id, Song.title)
                      .filter(Song.id.notin_(curr_on_playlist))
                      .all())

    if form.validate_on_submit():

      # This is one way you could do this ...
      playlist_song = PlaylistSong(song_id=form.song.data,
                                  playlist_id=playlist_id)
      db.session.add(playlist_song)

      # Here's another way you could that is slightly more ORM-ish:
      #
      # song = Song.query.get(form.song.data)
      # playlist.songs.append(song)

      # Either way, you have to commit:
      db.session.commit()

      return redirect(f"/playlists/{playlist_id}")

    return render_template("add_song_to_playlist.html",
                         playlist=playlist,
                         form=form)