Initial commit

.gitignore

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+__pycache__
+balises.ini

README.md

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+Radio Balises is a local radio that broadcasts in the Lorient area in
+France. The website of the radio offers a list of the last 10 songs, no
+more. There is no way to search for a song that was broadcast on a
+particular date, except for those last 10 songs.
+
+The goals for this toy project are:
+
+* parse the 'last 10 songs' page and store them in a database ;
+* offer a simple web interface to search songs played on a particular
+  date, if they are stored in the database.
+
+Ideally, the 'last 10 songs' list should be regularly retrieved, so that
+the database is complete enough to be useful. Then, I may be able to
+find out what was that song that I heard 3 days ago while I was driving.
+
+
+# Requirements
+
+This project is written in Python and uses the following libraries:
+
+* requests: to retrieve the 'last 10 songs' page;
+* beautiful soup: to parse that page;
+* peewee: a simple ORM, to store and query the data in a SQL database;
+* bottle: a micro web framework.
+
+Those libraries are all packaged in Debian and can be installed with:
+
+```
+apt install python3-request python3-bs4 python3-peewee python3-bottle
+```
+
+It also needs a MySQL server (although switching to another database
+should be easy).
+
+
+# Installation
+
+We suppose the repository is cloned under `/opt/balises`.
+
+Create a `balises.py` config file, and fill in MySQL credentials. You
+can use `balises.ini.example as a starting point.
+
+To update the database every 15 minutes, the following line can be
+installed as a cronjob:
+
+```
+*/15 * * * * /opt/balises/balises.py update
+```
+
+To launch the server automatically, you can install and use the systemd
+service file :
+
+```
+ln -s /opt/balises/balises.service /etc/systemd/system/balises.service
+systemctl enable balises.service
+systemctl start balises.service
+```
+
+The server listens to port 9980 on localhost by default, unless
+otherwise specified in the config file. Setting up a reverse proxy and
+ssl is left as an exercise to the reader.

balises.ini.example

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+[mysql]
+database = balises
+user = please change me
+password = please change me
+host = localhost
+port = 3306
+
+[server]
+host = localhost
+port = 9980
+debug = false

balises.py

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+#!/usr/bin/env python3
+
+from argparse import ArgumentParser
+from configparser import ConfigParser
+from datetime import datetime, timedelta
+
+import bs4
+import requests
+
+from peewee import *
+from bottle import hook, request, route, run, view
+
+# ------------------------------------------------------------
+conf = ConfigParser()
+conf.read('balises.ini')
+
+db = MySQLDatabase(conf['mysql'].get('database'),
+                   user=conf['mysql'].get('user'),
+                   password=conf['mysql'].get('password'),
+                   host=conf['mysql'].get('host', 'localhost'),
+                   port=conf['mysql'].getint('port', 3306))
+
+class BaseModel(Model):
+    class Meta:
+        database = db
+
+class Song(BaseModel):
+    id = AutoField()
+    artist = CharField(default='')
+    title = CharField(default='')
+
+    class Meta:
+        indexes = (
+            (('artist', 'title'), True),  # Unique on artist + title
+        )
+
+class AirCast(BaseModel):
+    id = AutoField()
+    date = DateTimeField()
+    song = ForeignKeyField(Song, backref='dates')
+
+
+# ----------------------------------------------------------------------
+# Util functions
+
+def http_get(url):
+    response = requests.get(url);
+    if response.status_code == 200:
+        pass
+    else:
+        print('Uh, oh, unable to fetch', url)
+        print('Http status code:', response.status_code)
+        raise Error('Download error')
+    return response
+
+
+# ----------------------------------------------------------------------
+# Get song informations
+
+last_ten_url = 'https://radiobalises.com/Play-list/last10.html'
+
+def get_last_ten():
+    response = http_get(last_ten_url)
+    soup = bs4.BeautifulSoup(response.content, 'html5lib')
+    dates = soup.select('p.rldj-cell span.post-date')
+    for elem in dates:
+        dt = datetime.fromisoformat(elem.text)
+        artist, title = [x.strip() for x in elem.previous.previous.split(' - ', 1)]
+        song, _ = Song.get_or_create(artist=artist, title=title)
+        # get_or_create does not play nice with the unique constraint on the date
+        # so we use a simple try/except instead
+        try:
+            aircast = AirCast.get(date=dt, song=song)
+        except DoesNotExist:
+            aircast = AirCast.create(date=dt, song=song)
+
+        line_template = '{:<10} | {:<25} {:<40}'
+        print(line_template.format(str(dt), artist, title))
+
+
+# ----------------------------------------------------------------------
+# Search song
+
+def search_song(query):
+    # query must be a datetime
+    delta = timedelta(minutes=30)
+
+    query = AirCast.select().order_by(AirCast.date).where(
+        (AirCast.date > query - delta) &
+        (AirCast.date < query + delta))
+    results = [x for x in query]
+
+    return results
+
+def print_aircast(x):
+    line_template = '{:<10} | {:<25} {:<40}'
+    print(line_template.format(str(x.date), x.song.artist, x.song.title))
+
+
+# ----------------------------------------------------------------------
+# Web application
+#
+# Very simple, just a page with an input for a date/time, a query button and a
+# list of results
+
+@route('/', method='GET')
+@view('search_form')
+def main_page():
+    now = datetime.now()
+    date = '{}'.format(now.date())
+    time = '{}:{}'.format(now.hour, now.minute)
+    return dict(title='', date=date, time=time)
+
+@route('/', method='POST')
+@view('search_results')
+def results_page():
+    date = request.forms.date
+    time = request.forms.time
+    dt = datetime.fromisoformat('{} {}'.format(date, time))
+    results = search_song(dt)
+    return dict(results=[x for x in results], date=date, time=time)
+
+@hook('before_request')
+def connect_to_db():
+    db.connect()
+
+@hook('after_request')
+def close_db_connection():
+    db.close()
+
+# ----------------------------------------------------------------------
+# Argument parsing
+# use a decorator to simplify argparse usage, as suggested by
+# https://mike.depalatis.net/blog/simplifying-argparse.html
+
+cli = ArgumentParser(description='Balises')
+subparsers = cli.add_subparsers(dest="subcommand")
+
+def subcommand(args=[], parent=subparsers):
+    def decorator(func):
+        parser = parent.add_parser(func.__name__, description=func.__doc__)
+        for arg in args:
+            parser.add_argument(*arg[0], **arg[1])
+        parser.set_defaults(func=func)
+    return decorator
+
+def argument(*name_or_flags, **kwargs):
+    return ([*name_or_flags], kwargs)
+
+
+@subcommand([argument('query', help='Search query')])
+def search(args):
+    results = search_song(datetime.fromisoformat(args.query))
+    for res in results:
+        print_aircast(res)
+
+
+@subcommand()
+def update(args):
+    get_last_ten()
+
+
+@subcommand()
+def serve(args):
+    run(host=conf['server'].get('host', 'localhost'),
+        port=conf['server'].getint('port', 9980),
+        debug=conf['server'].getboolean('debug', False))
+
+
+# ----------------------------------------------------------------------
+# Main
+
+def main():
+    args = cli.parse_args()
+    if args.subcommand is None:
+        cli.print_help()
+    else:
+        args.func(args)
+
+if __name__ == '__main__':
+    main()

balises.service

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+[Unit]
+Description=Radio Balises titles fetcher
+After=syslog.target
+After=network.target
+Requires=mysql.service
+#Requires=mariadb.service
+
+[Service]
+RestartSec=2s
+Type=simple
+User=balises
+Group=balises
+WorkingDirectory=/opt/balises
+ExecStart=/opt/balises/balises.py serve
+Restart=always
+
+[Install]
+WantedBy=multi-user.target

views/base.tpl

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+<html>
+<head>
+  <title>{{title or 'No title'}}</title>
+</head>
+<body>
+    <form action="/" method="post">
+      <label for="date">Date:</label>
+      <input name="date" type="date" value="{{date or ''}}"/>
+      <label for="time">Heure:</label>
+      <input name="time" type="time" value="{{time or ''}}"/>
+      <input value="Chercher" type="submit" />
+  </form>
+  {{!base}}
+</body>
+</html>

views/search_form.tpl

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+% rebase('base.tpl', title='Radio Balises')

views/search_results.tpl

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+% rebase('base.tpl', title='Radio Balises - Résultats')
+<h1>Liste des chansons</h1>
+<ul>
+  % for x in results:
+    <li>[{{str(x.date)}}] {{x.song.artist}} - {{x.song.title}}
+  % end
+</ul>