server.py

from flask import Flask, g, request, url_for, redirect, session, render_template, flash, Response, make_response
from werkzeug.routing import Rule
from functools import wraps
from datetime import date, timedelta, datetime, time, MINYEAR
import threading
import os
import sys
import hashlib
import random
import sched
import traceback

app = Flask(__name__)

app.jinja_env.trim_blocks = True
app.jinja_env.lstrip_blocks = True
app.add_template_global(random.randint, name='randint')
app.add_template_global(datetime, name='datetime')
app.add_template_global(timedelta, name='timedelta')

scheduler = sched.scheduler()
def run_scheduler():
	import time
	time.sleep(1) # UWSGI does weird things on startup
	while True:
		scheduler.run()
		time.sleep(10)

def sched_func(delay, priority=0, firstdelay=None, args=[], kargs={}):
	if firstdelay == None:
		firstdelay = random.randint(1, 120)
	def wrapper(func):
		def sched_wrapper():
			with app.test_request_context():
				func(*args, **kargs)
			scheduler.enter(delay, priority, sched_wrapper)
		scheduler.enter(firstdelay, priority, sched_wrapper)
		return func
	return wrapper

threading.Thread(target=run_scheduler, daemon=True).start()

config = app.config
config.from_pyfile('config.py.example', silent=True)
if sys.argv[0].endswith('run.py'): 
	config['SQLITE_INIT_DATA'] = True
	config['DEBUG'] = True
config.from_pyfile('config.py', silent=True)
if config['DEBUG']:
	app.jinja_env.auto_reload = True
if not config.get('SECRET_KEY', None):
	config['SECRET_KEY'] = os.urandom(24)

from db import query, modify, searchquery, ldapauth, ldapget

mod_endpoints = []

@app.template_global()
def ismod(*args):
	return ('user' in session)

def mod_required(func):
	mod_endpoints.append(func.__name__)
	@wraps(func)
	def decorator(*args, **kwargs):
		if not ismod():
			flash('Diese Funktion ist nur für Moderatoren verfügbar!')
			return redirect(url_for('login', ref=request.url))
		else:
			return func(*args, **kwargs)
	return decorator

def evalauth(auths):
	cauths = []
	lauths = []
	vauths = []
	for auth in auths:
		if auth['course_id']:
			cauths.append(auth)
		elif auth['lecture_id']:
			lauths.append(auth)
		elif auth['video_id']:
			vauths.append(auth)
	if vauths:
		return vauths
	elif lauths:
	 	return lauths
	elif cauths:
		return cauths
	return [{'auth_type': 'public'}]

@app.template_filter()
def checkauth(auths, username=None, password=None):
	auths = evalauth(auths)
	for auth in auths:
		if auth['auth_type'] == 'public':
			return True
		elif auth['auth_type'] == 'password':
			if auth['auth_param'] == username and auth['auth_param2'] == password:
				return True
		elif auth['auth_type'] == 'l2p':
			if auth['auth_param'] in session.get('l2p_courses', []):
				return True
		elif auth['auth_type'] == 'rwth':
			if session.get('rwthintern', False):
				return True
	return False

@app.template_filter()
def authdescr(auths):
	auths = evalauth(auths)
	public = False
	password = False
	l2p_courses = []
	rwth_intern = False
	for auth in auths:
		if auth['auth_type'] == 'public':
			public = True
		elif auth['auth_type'] == 'password':
			password = True
		elif auth['auth_type'] == 'l2p':
			l2p_courses.append(auth['auth_param'])
		elif auth['auth_type'] == 'rwth':
			rwth_intern = True
	if public or not auths:
		return 'public', 'Öffentlich verfügbar'
	if rwth_intern:
		if password:
			return 'rwth', 'Nur für RWTH-Angehörige und Nutzer mit Passwort verfügbar'
		return 'rwth', 'Nur für RWTH-Angehörige verfügbar'
	if l2p_courses:
		if password:
			return 'l2p', 'Nur für Teilnehmer der Veranstaltung und Nutzer mit Passwort verfügbar'
		return 'l2p', 'Nur für Teilnehmer der Veranstaltung verfügbar'
	if password:
		return 'password', 'Nur für Nutzer mit Passwort verfügbar'
	return 'public', 'Öffentlich verfügbar'

app.jinja_env.globals['navbar'] = []
# iconlib can be 'bootstrap'
# ( see: http://getbootstrap.com/components/#glyphicons )
# or 'fa'
# ( see: http://fontawesome.io/icons/ )
def register_navbar(name, iconlib='bootstrap', icon=None):
	def wrapper(func):
		endpoint = func.__name__
		app.jinja_env.globals['navbar'].append((endpoint, name, iconlib, icon, not endpoint in mod_endpoints))
		return func
	return wrapper

def render_endpoint(endpoint, flashtext=None, **kargs):
	if flashtext:
		flash(flashtext)
	# request.endpoint is used for navbar highlighting
	request.url_rule = Rule(request.path, endpoint=endpoint)
	return app.view_functions[endpoint](**kargs)

def handle_errors(endpoint, text, code, *errors, **epargs):
	def wrapper(func):
		@wraps(func)
		def decorator(*args, **kwargs):
			try:
				return func(*args, **kwargs)
			except errors:
				if endpoint:
					return make_response(render_endpoint(endpoint, text, **epargs), code)
				else:
					return text, code
		return decorator
	return wrapper

@app.errorhandler(404)
def handle_not_found(e):
	return render_endpoint('index', 'Diese Seite existiert nicht!'), 404

@app.errorhandler(500)
@app.errorhandler(Exception)
def handle_internal_error(e):
	traceback.print_exc()
	return render_template('500.html')

# debian ships jinja2 without this test...
@app.template_test(name='equalto')
def equalto(a,b):
	return a == b

@app.template_filter(name='semester')
def human_semester(s, long=False):
	if not s or s == 'zeitlos' or len(s) != 6:
		return 'Zeitlos'
	year = s[0:4]
	semester = s[4:6].upper()
	if not year.isdigit() or semester not in ['SS', 'WS']:
		print('Invalid semester string "%s"'%s)
		return '??'
	if not long:
		return semester+year[2:]
	elif semester == 'SS':
		return 'Sommersemester %s'%year
	else:
		return 'Wintersemester %s/%s'%(year, str(int(year)+1)[2:])

@app.template_filter(name='date')
def human_date(d):
	return d.strftime('%d.%m.%Y')

@app.template_filter(name='time')
def human_time(d):
	return d.strftime('%H:%M')

@app.template_filter()
def rfc3339(d):
	return d.strftime('%Y-%m-%dT%H:%M:%S+02:00')

@app.template_global()
def get_announcements(minlevel=0):
	offset = timedelta()
	if ismod():
		offset = timedelta(hours=24)
	return query('SELECT * FROM announcements WHERE NOT deleted AND ((time_expire = NULL) OR time_expire > ?) AND (? OR (visible AND time_publish < ?)) AND level >= ? ORDER BY level DESC', datetime.now()-offset, ismod(), datetime.now(), minlevel)

@app.template_filter()
def fixnl(s):
	# To be remove, as soon as db schema is cleaned-up
	return str(s).replace('\n', '<br>')

@app.route('/')
@register_navbar('Home', icon='home')
def index():
	start = date.today() - timedelta(days=1)
	end = start + timedelta(days=7)
	upcomming = query('''
		SELECT lectures.*, "course" AS sep, courses.*
		FROM lectures
		JOIN courses ON (lectures.course_id = courses.id)
		WHERE (time > ?) AND (time < ?) and lectures.visible and courses.visible and courses.listed
		ORDER BY time ASC LIMIT 30''',start,end)
	for i in upcomming:
		i['date'] = i['time'].date()
	latestvideos=query('''
		SELECT lectures.*, "course" AS sep, courses.*
		FROM lectures
		LEFT JOIN videos ON (videos.lecture_id = lectures.id)
		LEFT JOIN courses on (courses.id = lectures.course_id)
		WHERE (? OR (courses.visible AND courses.listed AND lectures.visible AND videos.visible))
		GROUP BY videos.lecture_id
		ORDER BY MAX(videos.time_updated) DESC
		LIMIT 6	''',ismod())
	featured = query('SELECT * FROM featured WHERE NOT deleted AND (? OR visible)', ismod())
	return render_template('index.html', latestvideos=latestvideos, upcomming=upcomming, featured=featured)

@app.route('/course')
@register_navbar('Videos', icon='film')
def courses():
	courses = query('SELECT * FROM courses WHERE (? OR (visible AND listed)) ORDER BY title', ismod())
	for course in courses:
		if course['semester'] == '':
			course['semester'] = 'zeitlos'
	groupedby = request.args.get('groupedby')
	if groupedby not in ['title', 'semester', 'organizer']:
		groupedby = 'semester'
	return render_template('courses.html', courses=courses, groupedby=groupedby)

@app.route('/course/<handle>')
@app.route('/course/<int:id>')
@handle_errors('courses', 'Diese Veranstaltung existiert nicht!', 404, IndexError)
def course(id=None, handle=None):
	if id:
		course = query('SELECT * FROM courses WHERE id = ? AND (? OR visible)', id, ismod())[0]
	else:
		course = query('SELECT * FROM courses WHERE handle = ? AND (? OR visible)', handle, ismod())[0]
	course['auth'] = query('SELECT * FROM auth WHERE course_id = ? ORDER BY auth_type', course['id'])
	auths = query('SELECT auth.* FROM auth JOIN lectures ON (auth.lecture_id = lectures.id) WHERE lectures.course_id = ? ORDER BY auth.auth_type', course['id'])
	lectures = query('SELECT * FROM lectures WHERE course_id = ? AND (? OR visible) ORDER BY time, duration DESC', course['id'], ismod())
	for lecture in lectures:
		lecture['auth'] = []
		lecture['course'] = course
		for auth in auths:
			if auth['lecture_id'] == lecture['id']:
				lecture['auth'].append(auth)
	videos = query('''
			SELECT videos.*, (videos.downloadable AND courses.downloadable) as downloadable, formats.description AS format_description, formats.player_prio, formats.prio
			FROM videos
			JOIN lectures ON (videos.lecture_id = lectures.id)
			JOIN formats ON (videos.video_format = formats.id)
			JOIN courses ON (lectures.course_id = courses.id)
			WHERE lectures.course_id= ? AND (? OR videos.visible)
			ORDER BY lectures.time, formats.prio DESC
			''', course['id'], ismod())
	return render_template('course.html', course=course, lectures=lectures, videos=videos)

@app.route('/faq')
@register_navbar('FAQ', icon='question-sign')
def faq():
	return render_template('faq.html')

@app.route('/play/<int:id>')
@app.route('/embed/<int:id>', endpoint='embed')
@handle_errors('course', 'Diese Vorlesung existiert nicht!', 404, IndexError)
def lecture(id):
	lecture = query('SELECT * FROM lectures WHERE id = ? AND (? OR visible)', id, ismod())[0]
	videos = query('''
			SELECT videos.*, (videos.downloadable AND courses.downloadable) as downloadable, formats.description AS format_description, formats.player_prio, formats.prio
			FROM videos
			JOIN formats ON (videos.video_format = formats.id)
			JOIN courses ON (courses.id = ?)
			WHERE videos.lecture_id = ? AND (? OR videos.visible)
			ORDER BY formats.prio DESC
			''', lecture['course_id'], lecture['id'], ismod())
	auths = query('SELECT auth.* FROM auth WHERE (auth.lecture_id = ? OR auth.course_id = ?)',
			lecture['id'], lecture['course_id'])
	if not videos:
		flash('Zu dieser Vorlesung wurden noch keine Videos veröffentlicht!')
	courses = query('SELECT * FROM courses WHERE id = ? AND (? OR visible)', lecture['course_id'], ismod())
	if not courses:
		return render_endpoint('courses', 'Diese Veranstaltung existiert nicht!'), 404
	chapters = query('SELECT * FROM chapters WHERE lecture_id = ? AND NOT deleted AND (? OR visible) ORDER BY time ASC', id, ismod())
	if not checkauth(auths):
		mode, text = authdescr(auths)
		if mode == 'rwth':
			flash(text+'. <a target="_blank" href="'+url_for('start_rwthauth')+'">Hier authorisieren</a>.')
		elif mode == 'l2p':
			flash(text+'. <a target="_blank" href="'+url_for('start_l2pauth')+'">Hier authorisieren</a>.')
		else:
			flash(text+'.')
	return render_template('embed.html' if request.endpoint == 'embed' else 'lecture.html', course=courses[0], lecture=lecture, videos=videos, chapters=chapters)


@app.route('/search')
def search():
	if 'q' not in request.args:
		return redirect(url_for('index'))
	q = request.args['q']
	courses = searchquery(q, '*', ['title', 'short', 'organizer', 'subject', 'description'],
			'courses', 'WHERE (? OR (visible AND listed)) GROUP BY id ORDER BY _score DESC, semester DESC LIMIT 20', ismod())
	#lectures = searchquery(q, 'lectures.*, courses.visible AS coursevisible, courses.listed, "course" AS sep, courses.*',
	#			['lectures.title', 'lectures.comment', 'lectures.speaker', 'courses.short'],
	#			'lectures LEFT JOIN courses on (courses.id = lectures.course_id)',
	#			'WHERE (? OR (coursevisible AND listed AND visible)) GROUP BY id ORDER BY _score DESC, time DESC LIMIT 30', ismod())
	lectures = searchquery(q, 'lectures.*, courses.visible AS coursevisible, courses.listed, courses.id AS courses_id, courses.visible AS courses_visible, courses.listed AS courses_listed, courses.title AS courses_title, courses.short AS courses_short, courses.handle AS courses_handle, courses.organizer AS courses_organizer, courses.subject AS courses_subject, courses.credits AS courses_credits, courses.created_by AS courses_created_by, courses.time_created AS courses_time_created, courses.time_updated AS courses_time_updated, courses.semester AS courses_semester, courses.downloadable AS courses_downloadable, courses.embedinvisible AS courses_embedinvisible, courses.description AS courses_description, courses.internal AS courses_internal, courses.responsible AS courses_responsible',
			['lectures.title', 'lectures.comment', 'lectures.speaker', 'courses.short'],
			'lectures LEFT JOIN courses on (courses.id = lectures.course_id)',
			'WHERE (? OR (coursevisible AND listed AND visible)) GROUP BY id ORDER BY _score DESC, time DESC LIMIT 30', ismod())
	for lecture in lectures:
		lecture['course'] = {}
		for key in lecture:
			if key.startswith('courses_'):
				lecture['course'][key[8:]] = lecture[key]
	return render_template('search.html', searchtext=request.args['q'], courses=courses, lectures=lectures)

def check_mod(user, groups):
	return user and 'users' in groups

@app.route('/login', methods=['GET', 'POST'])
def login():
	if request.method == 'GET':
		return render_template('login.html')
	user, groups = ldapauth(request.form.get('user'), request.form.get('password'))
	if not check_mod(user, groups):
		flash('Login fehlgeschlagen!')
		return render_template('login.html')
	session['user'] = ldapget(user)
	dbuser = query('SELECT * FROM users WHERE name = ?', user)
	if not dbuser:
		modify('INSERT INTO users (name, realname, fsacc, level, calendar_key, rfc6238) VALUES (?, ?, ?, 1, "", "")', user, session['user']['givenName'], user)
		dbuser = query('SELECT * FROM users WHERE name = ?', user)
	session['user']['dbid'] = dbuser[0]['id']
	return redirect(request.values.get('ref', url_for('index')))

@app.route('/logout', methods=['GET', 'POST'])
def logout():
	session.pop('user')
	return redirect(request.values.get('ref', url_for('index')))

# name: (tablename, idcolumn, [editable_fields], [fields_to_set_at_creation_time])
tabs = {
	'courses': ('courses_data', 'id', ['visible', 'listed', 'title', 'short',
			'handle', 'organizer', 'subject', 'semester', 'downloadable',
			'internal', 'responsible','deleted','description'],
			['created_by', 'time_created', 'time_updated']),
	'lectures': ('lectures_data', 'id', ['visible', 'title', 'comment',
			'internal', 'speaker', 'place', 'time', 'duration', 'jumplist','deleted'],
			['course_id', 'time_created', 'time_updated']),
	'videos': ('videos_data', 'id', ['visible','deleted'],
			['created_by', 'time_created', 'time_updated']),
	'chapters': ('chapters', 'id', ['time', 'text', 'visible', 'deleted'],
			['created_by', 'time_created', 'time_updated']),
	'announcements': ('announcements', 'id', ['text', 'level', 'visible',
			'deleted', 'time_publish', 'time_expire'],
			['created_by', 'time_created', 'time_updated']),
	'featured': ('featured', 'id', ['title', 'text', 'internal', 'visible', 'deleted'],
			['created_by', 'time_created', 'time_updated']),
	'auth': ('auth_data', 'auth_id', ['auth_type', 'auth_param', 'auth_param2', 'deleted'],
			['course_id', 'lecture_id', 'video_id', 'created_by', 'time_created', 'time_updated']),
	'sorterrorlog': ('sorterrorlog_data', 'id', ['deleted'],
			['time_created', 'time_updated'])
}

@app.route('/edit', methods=['GET', 'POST'])
@mod_required
def edit(prefix='', ignore=[]):
	# All editable tables are expected to have a 'time_updated' field
	ignore.append('ref')
	ignore.append('prefix')
	if not prefix and 'prefix' in request.args:
		prefix = request.args['prefix']
	modify('BEGIN')
	changes = request.values.items()
	if (request.method == 'POST') and (request.get_json()):
		changes = request.get_json().items()
	for key, val in changes:
		if key in ignore:
			continue
		key = prefix+key
		table, id, column = key.split('.', 2)
		assert table in tabs
		assert column in tabs[table][2]
		modify('INSERT INTO changelog (`table`,id_value, id_key, field, value_new, value_old, `when`, who, executed) VALUES (?,?,?,?,?,(SELECT %s FROM %s WHERE %s = ?),?,?,1)'%(column, tabs[table][0], tabs[table][1]),
				table, id, tabs[table][1], column, val, id, datetime.now(), session['user']['dbid'])
		modify('UPDATE %s SET %s = ?, time_updated = ? WHERE %s = ?'%(tabs[table][0], column, tabs[table][1]), val, datetime.now(), id)
	modify('COMMIT')
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return "OK", 200

@app.route('/new/<table>', methods=['GET', 'POST'])
@mod_required
def create(table):
	assert table in tabs
	defaults = {'created_by': session['user']['dbid'], 'time_created': datetime.now(), 'time_updated': datetime.now()}
	columns = []
	values = []
	for column, val in defaults.items():
		if column in tabs[table][3]:
			columns.append(column)
			values.append(val)
	args = request.values
	if (request.method == 'POST') and (request.get_json()):
		args = request.get_json()
	for column, val in args.items():
		if column == 'ref':
			continue
		assert column in tabs[table][2]+tabs[table][3]
		assert column not in defaults
		columns.append(column)
		values.append(val)
	id = modify('INSERT INTO %s (%s) VALUES (%s)'%(tabs[table][0],
				','.join(columns), ','.join(['?']*len(values))), *values)
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return str(id), 200

@app.route('/auth')
def auth(): # For use with nginx auth_request
	if 'X-Original-Uri' not in request.headers:
		return 'Internal Server Error', 500
	url = request.headers['X-Original-Uri'].lstrip(config['VIDEOPREFIX'])
	ip = request.headers.get('X-Real-IP', '')
	if url.endswith('jpg'):
		return "OK", 200
	videos = query('''SELECT videos.path, videos.id, auth.*
      FROM videos
      JOIN lectures ON (videos.lecture_id = lectures.id)
      JOIN courses ON (lectures.course_id = courses.id)
			LEFT JOIN auth ON (videos.id = auth.video_id OR lectures.id = auth.lecture_id OR courses.id = auth.course_id)
      WHERE videos.path = ?
      AND (? OR (courses.visible AND lectures.visible AND videos.visible))
			ORDER BY auth.video_id DESC, auth.lecture_id DESC, auth.course_id DESC''',
			url, ismod())

	if not videos:
		return "Not allowed", 403
	auth = request.authorization
	username = password = None
	if auth:
		username = auth.username
		password = auth.password
	if checkauth(videos, username=username, password=password):
		return 'OK', 200
		modify('INSERT INTO log VALUES (?, "", ?, "video", ?, ?)', ip, datetime.now(), videos[0]['id'], url)
	password_auth = False
	for video in videos:
		if video['auth_type'] == 'password':
			password_auth = True
			break
	if password_auth:
		return Response("Login required", 401, {'WWW-Authenticate': 'Basic realm="Login Required"'})
	return "Not allowed", 403

@app.route('/stats')
@register_navbar('Statistiken', icon='stats')
@mod_required
def stats():
	return render_template('stats.html')

@app.route('/changelog')
@register_navbar('Changelog', icon='book')
@mod_required
def changelog():
	changelog = query('SELECT * FROM changelog LEFT JOIN users ON (changelog.who = users.id) ORDER BY `when` DESC LIMIT 50')
	for entry in changelog:
		entry['path'] = '.'.join([entry['table'], entry['id_value'], entry['field']])
	return render_template('changelog.html', changelog=changelog)

@app.route('/files/<filename>')
def files(filename):
	return redirect(config['VIDEOPREFIX']+'/'+filename)

@app.route('/newchapter/<int:lectureid>', methods=['POST', 'GET'])
def suggest_chapter(lectureid):
	time = request.values['time']
	text = request.values['text']
	assert(time and text)
	try:
		x = datetime.strptime(time,'%H:%M:%S')
		time= timedelta(hours=x.hour,minutes=x.minute,seconds=x.second).total_seconds()
		time = int(time)
	except ValueError:
		flash('Falsches Zeitformat, "%H:%M:%S" wird erwartet. Z.B. "01:39:42" für eine Kapitel bei Stunde 1, Minute 39, Sekunde 42')
		
	submitter = None
	if not ismod():
		submitter = request.environ['REMOTE_ADDR']
	id = modify('INSERT INTO chapters (lecture_id, time, text, time_created, time_updated, created_by, submitted_by) VALUES (?, ?, ?, ?, ?, ?, ?)',
				lectureid, time, text, datetime.now(), datetime.now(), session.get('user', {'dbid':None})['dbid'], submitter)
	if 'ref' in request.values:
		return redirect(request.values['ref'])
	return 'OK',  200

@app.route('/chapters/<int:lectureid>')
def chapters(lectureid):
	chapters = query("SELECT * FROM chapters WHERE lecture_id = ? and visible ORDER BY time DESC", lectureid)
	last = None
	for c in chapters:
		c['start'] = c['time']
		c['end'] = last['start'] if last else 9999
		last = c
	return Response(render_template('chapters.srt',chapters=chapters), 200, {'Content-Type':'text/vtt'})

@app.route('/sitemap.xml')
def sitemap():
	pages=[]
	# static pages
	for rule in app.url_map.iter_rules():
		if 'GET' in rule.methods and len(rule.arguments)==0:
			if rule.endpoint not in mod_endpoints:
				pages.append([rule.rule])
	for i in query('select * from courses where visible and listed'):
		pages.append([url_for('course',handle=i['handle'])])
		for j in query('select * from lectures where (course_id = ? and visible)',i['id']):
			pages.append([url_for('lecture',id=j['id'])])


	return Response(render_template('sitemap.xml', pages=pages), 200, {'Content-Type': 'application/atom+xml'} )

import feeds
import importer
import sorter
if 'ICAL_URL' in config:
	import meetings
if 'L2P_APIKEY' in config:
	import l2pauth
import jobs
import timetable