OpenMensa parser for STW Potsdam after canteen website redesign

stw_potsdam/__init__.py

@@ -0,0 +1 @@
+# -*- encoding: utf-8 -*-

stw_potsdam/__main__.py

@@ -0,0 +1,4 @@
+# -*- encoding: utf-8 -*-
+from views import app
+
+app.run()

stw_potsdam/canteen.py

@@ -0,0 +1,5 @@
+# -*- encoding: utf-8 -*-
+
+from collections import namedtuple
+
+Canteen = namedtuple('Canteen', ('name', 'street', 'city', 'id', 'chash'))

stw_potsdam/canteen_api.py

@@ -0,0 +1,33 @@
+# -*- encoding: utf-8 -*-
+
+import json
+import requests
+from collections import namedtuple
+
+MenuParams = namedtuple('MenuParams', ('canteen_id', 'chash'))
+
+URL = 'https://www.studentenwerk-potsdam.de/essen/unsere-mensen-cafeterien/detailinfos/'
+
+
+def _param_json(it):
+    return json.dumps(it, separators=(',', ':'))
+
+
+def download_menu(menu_params):
+    context = {
+        'record': 'pages_66',
+        'path': 'tt_content.list.20.ddfmensa_ddfmensajson'
+    }
+
+    params = {
+        'tx_typoscriptrendering[context]': _param_json(context),
+        'tx_ddfmensa_ddfmensajson[mensa]': menu_params.canteen_id,
+        'cHash': menu_params.chash
+    }
+
+    body = {
+        'data': False
+    }
+
+    request = requests.post(URL, params=params, json=body)
+    return request.json()

stw_potsdam/canteens.ini

@@ -0,0 +1,41 @@
+[neues_palais]
+name = Mensa Am Neuen Palais
+street = Am Neuen Palais 10, Haus 12
+city = 14469 Potsdam
+id = 1
+cHash = 677e69a0122d1ccca57a6c30dd149cc8
+
+[golm]
+name = Mensa Golm
+street = Karl-Liebknecht-Straße 24/25
+city = 14476 Potsdam / OT Golm
+id = 4
+cHash = b14a1168346e0b7db67da056660d3a0e
+
+[griebnitzsee]
+name = Mensa Griebnitzsee
+street = August-Bebel-Straße 69, Haus 6
+city = 14482 Potsdam
+id = 6
+cHash = 0c7f1095dcc78ff74b6cd32cd231c75f
+
+[kiepenheuerallee]
+name = Mensa Kiepenheuerallee
+street = Kiepenheuerallee 5
+city =  14469 Potsdam
+id = 7
+cHash = 3900afbd3d9b776e947708b7dfd2378c
+
+[wildau]
+name = Mensa Wildau
+street = Hochschulring 1
+city = 15745 Wildau
+id = 33
+cHash = 2ba7ac17766ceec4a35dac29b593378f
+
+[brandenburg]
+name = Mensa Brandenburg an der Havel
+street = Magdeburger Straße 50
+city = 14770 Brandenburg an der Havel
+id = 38
+cHash = 0843fa029901bdfc0e76d8f31eee7f56

stw_potsdam/config.py

@@ -0,0 +1,29 @@
+# -*- encoding: utf-8 -*-
+
+import ConfigParser
+import io
+import os
+from functools import partial
+from canteen import Canteen
+
+
+def _get_config(filename):
+    config = ConfigParser.SafeConfigParser()
+    path = os.path.join('stw_potsdam', filename)
+    with io.open(path, encoding='utf-8') as f:
+        config.readfp(f)
+    return config
+
+
+def _parse_canteen(config, canteen_name):
+    get = partial(config.get, canteen_name)
+    return Canteen(name=get('name'),
+                   street=get('street'),
+                   city=get('city'),
+                   id=get('id'),
+                   chash=get('cHash'))
+
+
+def read_canteen_config():
+    config = _get_config('canteens.ini')
+    return {name: _parse_canteen(config, name) for name in config.sections()}

stw_potsdam/feed.py

@@ -0,0 +1,65 @@
+# -*- encoding: utf-8 -*-
+
+from pyopenmensa.feed import LazyBuilder
+
+PRICE_ROLE_MAPPING = {
+    'student': 'preis_s',
+    'other': 'preis_g',
+    'employee': 'preis_m'
+}
+
+
+def _active_days(menu):
+    for container in menu['wochentage']:
+        day = container['datum']
+        active = 'angebote' in day
+        if active:
+            yield day
+
+
+def _notes(offer):
+    result = []
+    for label in offer['labels']:
+        result.append(label['name'].capitalize())
+    return result
+
+
+def _prices(offer):
+    result = {}
+    for role, api_role in PRICE_ROLE_MAPPING.items():
+        if api_role not in offer:
+            continue
+
+        price = offer[api_role]
+        # When no price is set, this can be empty dict
+        if (isinstance(price, unicode) or isinstance(price, str)) and price.strip():
+            result[role] = str(price)  # Convert unicode to str for PyOpenMensa -> misses type check
+
+    return result
+
+
+def _process_day(builder, day):
+    for offer in day['angebote']:
+        builder.addMeal(date=day['data'],
+                        category=offer['titel'],
+                        name=offer['beschreibung'],
+                        notes=_notes(offer),
+                        prices=_prices(offer),
+                        roles=None)
+
+
+def _create_builder(canteen):
+    builder = LazyBuilder()
+    builder.name = canteen.name
+    builder.address = canteen.street
+    builder.city = canteen.city
+    return builder
+
+
+def render(canteen, menu):
+    builder = _create_builder(canteen)
+
+    for day in _active_days(menu):
+        _process_day(builder, day)
+
+    return builder.toXMLFeed()

stw_potsdam/views.py

@@ -0,0 +1,56 @@
+# -*- encoding: utf-8 -*-
+
+from flask import Flask, make_response
+from werkzeug.contrib.cache import SimpleCache
+
+import feed
+from config import read_canteen_config
+from canteen_api import MenuParams, download_menu
+
+CACHE_TIMEOUT = 45 * 60
+
+app = Flask(__name__)
+
+cache = SimpleCache()
+
+
+def canteen_not_found(config, canteen_name):
+    app.logger.warn('Canteen %s not found', canteen_name)
+    configured = ', '.join("'{}'".format(c) for c in config.keys())
+    message = "Canteen '{canteen}' not found, available: {configured}".format(canteen=canteen_name,
+                                                                              configured=configured)
+    return make_response(message, 404)
+
+
+def get_menu_cached(canteen):
+    params = MenuParams(canteen_id=canteen.id, chash=canteen.chash)
+    menu = cache.get(params)
+    if menu:
+        app.logger.info('Using cached menu for %s', canteen)
+    return menu or get_menu(canteen, params)
+
+
+def get_menu(canteen, params):
+    app.logger.info('Downloading menu for %s', canteen)
+    menu = download_menu(params)
+    cache.set(params, menu, timeout=CACHE_TIMEOUT)
+    return menu
+
+
+def canteen_feed_xml(canteen, menu):
+    xml = feed.render(canteen, menu)
+    response = make_response(xml)
+    response.mimetype = 'text/xml'
+    return response
+
+
+@app.route('/canteen/<canteen_name>')
+def canteen_feed(canteen_name):
+    config = read_canteen_config()
+
+    if canteen_name not in config:
+        return canteen_not_found(config, canteen_name)
+
+    canteen = config[canteen_name]
+    menu = get_menu_cached(canteen)
+    return canteen_feed_xml(canteen, menu)