buses.py

#!/usr/bin/env python3
import enum, json
from sys import stderr
from datetime import date, time, datetime, timedelta
from copy import copy
from misc import *
from geometry import *

def transform_trip_reference(reference):
	return reference

class BusTrip:
	def __init__(self, reference, route, service, length):
		self.reference, self.route, self.service = reference, route, service
		self.length = length
		self.schedule = []
		self.name = transform_trip_reference(reference)
	def __repr__(self):
		return 'all_trips[%r]' % self.name
	def contains_stop(self, stop):
		for halt in self.schedule:
			if halt.stop is stop:
				return halt
		else:
			return None
	def is_served_at(self, day):
		try:
			return self.service in services_for_day[day]
		except KeyError:
			return False
	def concise_schedule(self, starting_stop = None):
		if starting_stop and starting_stop in self.schedule:
			schedule = copy(self.schedule)
			schedule = schedule[schedule.index(starting_stop):]
		else:
			schedule = self.schedule
		used_areas = set()
		result = []
		for halt in schedule:
			stop = halt.stop
			if stop.region and stop.region not in used_areas:
				used_areas.add(stop.region)
				result.append(stop.region)
		return result

class BusRoute:
	def __init__(self, entry):
		self.id = entry['route_id']
		self.reference = entry['route_short_name']
	def __repr__(self):
		return 'routes[%r]' % self.reference

class BusService:
	def __init__(self, reference):
		self.reference = reference
		self.dates = set()
	def __repr__(self):
		return 'services[%r]' % self.reference

class BusStop:
	def __init__(self, reference, name, location):
		self.reference, self.name, self.location = reference, name, location
		self.cluster = None
		self.pairs = set() # samannimiset lähellä olevat pysäkit
	def __repr__(self):
		return 'bus_stops[%r]' % self.reference
	def schedule(self, max_amount = 50):
		'''
			Hakee tämän pysäkin seuraavat `määrä` lähtöä. Päätepysäkille saapuvia busseja ei
			lasketa. Palauttaa pysähdykset listana jossa alkiot ovat muotoa (aika, halt),
			jossa:
			- `aika` on saapumishetki muotoa datetime ja
			- `halt` on vastaava BusHalt olio.
			
			Mikäli pysäkille ei ole määrätty riittävästi pysähdyksiä kalenterissa, tuloslista
			jää alimittaiseksi, mahdollisesti jopa tyhjäksi.
		'''
		result = []
		# -1 päivää yövuoroja varten
		date = today() - timedelta(days = 1)
		# Niin kauan kuin aikatauluja ei ole vielä tarpeeksi,
		while len(result) < max_amount:
			try:
				# hae nykyisen päivän aikataulut ja lisää ne,
				result += self.schedule_for_day(date)
			except ValueError:
				# paitsi jos mentiin kalenterin ulkopuolelle, jolloin lopetetaan,
				break
			# ja siirry seuraavaan päivään.
			date += timedelta(1)
		# Typistä lopputulos haluttuun tulosmäärään.
		return result[:max_amount]
	def schedule_for_day(self, date):
		'''
			Hakee pysäkin aikataulut tiettynä päivänä.
		'''
		# Jos päädyttiin aikataulukalenterin ulkopuolelle, niin tuotetaan virhe. Jos vain
		# palautettaisiin tyhjä result, niin algoritmi jatkaisi etsintää loputtomiin.
		if date > viimeinen_käyttöpäivä:
			raise ValueError('tried to retrieve schedule for date %s which is outside schedule data' % date)
		result = []
		# Jokaiselle ajovuorolle,
		for trip in all_trips.values():
			# jos tämä ajovuoro ajetaan tänä päivänä
			if trip.is_served_at(date):
				# ja jos tämä trip pysähtyy tällä pysäkillä, ei kuitenkaan saapuen
				# päätepysäkille,
				stop = trip.contains_stop(self)
				if stop and not stop.isArrival: # stop is not trip.schedule[-1]:
					# ja jos tämä halt on tulevaisuudessa,
					stop_time = datetime.combine(date, time()) + stop.arrival_time
					if stop_time >= now():
						# lisää halt listaan.
						result.append({
							'time': stop_time,
							'trip': trip,
							'stop': stop,
						})
		# Lajittele lopputulos saapumisajan mukaan.
		result.sort(key = lambda schedule_entry: schedule_entry['time'])
		return result

class BusHalt:
	def __init__(self, arrival_time, departure_time, stop, trip, traveled_distance):
		self.arrival_time, self.departure_time, self.stop, self.trip = arrival_time, departure_time, \
			stop, trip
		self.traveled_distance = traveled_distance
	@property
	def isArrival(self):
		if not hasattr(self, 'cachedIsArrival'):
			iterator = iter(self.trip.schedule)
			stop = next(iterator)
			while stop is not self:
				stop = next(iterator)
			for stop in iterator:
				if stop.stop.region != self.stop.region:
					self.cachedIsArrival = False
					break
			else:
				self.cachedIsArrival = True
		return self.cachedIsArrival
	def __repr__(self):
		return 'BusHalt(%r, %r, %r, %r)' % (self.arrival_time, self.departure_time, self.stop, self.trip)

routes = {}
routes_per_id = {}
all_trips = {}
services = {}
bus_stops = {}
all_clusters = set()

print('Ladataan routes... ', file = stderr, end = '', flush = True)
with open('gtfs/routes.txt') as file:
	for row in read_csv(file):
		route = BusRoute(row)
		routes[route.reference] = route
		routes_per_id[route.id] = route
print('%d linjaa' % len(routes), file = stderr)

print('Ladataan ajovuorot... ', file = stderr, end = '', flush = True)

shape_distances = {}
with open('gtfs/shapes.txt') as file:
	for row in read_csv(file):
		shape_distances[row['shape_id']] = max(shape_distances.get(row['shape_id'], 0), float(row['shape_dist_traveled']))

with open('gtfs/trips.txt') as file:
	for row in read_csv(file):
		if row['service_id'] not in services:
			services[row['service_id']] = BusService(row['service_id'])
		route = routes_per_id[row['route_id']]
		trip = BusTrip(
			reference = row['trip_id'],
			route = route,
			service = services[row['service_id']],
			length = shape_distances[row['shape_id']]
		)
		assert trip.name not in all_trips
		all_trips[trip.name] = trip
print('%d ajoa' % len(all_trips), file = stderr)

def lue_päiväys(teksti):
	return date(int(teksti[:4]), int(teksti[4:6]), int(teksti[6:]))

def read_time(teksti):
	tunti, minuutti, sekunti = map(int, teksti.split(':'))
	return timedelta(hours = tunti, minutes = minuutti, seconds = sekunti)

print('Ladataan päiväykset... ', file = stderr, flush = True)

viimeinen_käyttöpäivä = date.today()
services_for_day = {}

with open('gtfs/calendar_dates.txt') as file:
	for row in read_csv(file):
		service = services[row['service_id']]
		day = lue_päiväys(row['date'])
		service.dates.add(day)
		if day not in services_for_day:
			services_for_day[day] = set()
		services_for_day[day].add(service)
		viimeinen_käyttöpäivä = max(day, viimeinen_käyttöpäivä)

def services_available_at(day):
	for service in services.values():
		if day in service.dates:
			yield service

print('Ladataan pysäkit... ', file = stderr, end = '', flush = True)
with open('gtfs/stops.txt') as file:
	for row in read_csv(file):
		location = Sijainti(float(row['stop_lat']), float(row['stop_lon']))
		stop = BusStop(row['stop_id'], row['stop_name'], location)
		bus_stops[stop.reference] = stop
with open('regions-per-stop.json') as file:
	for stop_reference, region in json.load(file).items():
		bus_stops[stop_reference].region = region
print('%d pysäkkiä' % len(bus_stops), file = stderr)


class BusStopCluster:
	def __init__(self):
		self.stops = set()
		self._center = None
		self.name = None
	@property
	def url_name(self):
		return self.name.lower().replace('(', '').replace(')', '').replace(' ', '-')
	def add_stop(self, stop):
		assert not stop.cluster
		stop.cluster = self
		self.stops.add(stop)
		self._center = None
	@property
	def center(self):
		if not self._center:
			if self.stops:
				from statistics import median
				pointtype = type(next(iter(self.stops)).location)
				self._center = pointtype(
					median(stop.location.x for stop in self.stops),
					median(stop.location.y for stop in self.stops),
				)
			else:
				raise ValueError('an empty cluster has no center point')
		return self._center
	def merge(self, other):
		for bus_stop in other.stops:
			bus_stop.cluster = self
		self.stops |= other.stops
		other.stops = set()
		other._center = None
	def schedule(self, max_amount = 50):
		result = []
		for stop in self.stops:
			result += stop.schedule(max_amount)
		result.sort(key = lambda schedule_entry: schedule_entry['time'])
		return result[:max_amount]

from collections import defaultdict
bus_stops_by_name = defaultdict(set)
for bus_stop in bus_stops.values():
	bus_stops_by_name[bus_stop.name].add(bus_stop)
bus_stops_by_name = dict(bus_stops_by_name)

# ryhmittele bus_stops nimen mukaan
all_clusters = []
def cluster_bus_stops():
	sorted_bus_stops = sorted(bus_stops.values(), key = lambda bus_stop: bus_stop.name)
	for bus_stop in sorted_bus_stops:
		if not bus_stop.cluster:
			stops_to_cluster = {bus_stop}
			# etsi pysäkin samannimiset vastaparit
			for pair_candidate in bus_stops_by_name[bus_stop.name]:
				distance = pair_candidate.location.etäisyys(bus_stop.location)
				if pair_candidate is not bus_stop and distance <= 0.3:
					stops_to_cluster.add(pair_candidate)
			for stop_to_cluster in stops_to_cluster:
				if stop_to_cluster.cluster:
					cluster = stop_to_cluster.cluster
					break
			else:
				cluster = BusStopCluster()
				all_clusters.append(cluster)
			for stop_to_cluster in stops_to_cluster:
				if not stop_to_cluster.cluster:
					cluster.add_stop(stop_to_cluster)
	# Merkitse muistiin pysäkkien vastaparit käyttäen hyväksi tämänhetkistä ryhmittelytietoa
	for bus_stop in bus_stops.values():
		if bus_stop.cluster:
			bus_stop.pairs = bus_stop.cluster.stops - {bus_stop}
	# Ryhmitä ne bus_stops, joilla ei ollut omaa vastaparia, muiden pysäkkien kanssa
	for bus_stop in sorted_bus_stops:
		if len(bus_stop.cluster.stops) == 1:
			possibilities = set()
			for cluster in all_clusters:
				if cluster is not bus_stop.cluster:
					distance = cluster.center.etäisyys(bus_stop.location)
					if distance <= 0.3:
						possibilities.add((distance, cluster))
			if possibilities:
				best = min(possibilities)[1]
				all_clusters.remove(bus_stop.cluster)
				best.merge(bus_stop.cluster)

def shared_elements_in_n_sets(sets):
	from itertools import combinations
	result = set()
	for pair in combinations(sets, 2):
		result |= pair[0] & pair[1]
	return result

def name_clusters():
	from collections import defaultdict
	from pprint import pprint
	clusters_per_name = defaultdict(set)
	for cluster in all_clusters:
		name_representing_stop = min((len(stop.reference), stop.reference, stop) for stop in cluster.stops)[2]
		clusters_per_name[name_representing_stop.name].add(cluster)
	for name, clusters in clusters_per_name.items():
		if len(clusters) == 1:
			# Ryhmä on ainoa jolla on varaus tälle nimelle. Sen kuin vaan.
			next(iter(clusters)).name = name
		else:
			# Olisiko kaikki klusterit eri alueilla?
			common_regions = shared_elements_in_n_sets({stop.region for stop in cluster.stops} for cluster in clusters)
			# Esitys: ryhmä -> ne alueet jotka ovat tälle ryhmälle ainutlaatuisia
			proposal = {
				cluster: {stop.region for stop in cluster.stops} - common_regions - {None}
				for cluster in clusters
			}
			# Jos enintään yksi klusteri tässä esityksessä on kokonaan ilman omaa aluetta, jolla se voisi eritellä,
			# niin nimetään klusterit näiden alueiden mukaan.
			# Se klusteri jolla ei ole omaa aluetta (jos on) jätetään ilman aluepäätettä.
			if sum([1 for unique_areas in proposal.values() if not unique_areas]) <= 1:
				for cluster, unique_areas in proposal.items():
					individual_cluster_name = name
					if unique_areas:
						individual_cluster_name += ' (' + min(unique_areas) + ')'
					cluster.name = individual_cluster_name
			else:
				# Typerä reunatapaus. Indeksoidaan numeroin...
				for n, (_, cluster) in enumerate(sorted(
					min((stop.reference.lower(), cluster) for stop in cluster.stops)
					for cluster in clusters
				), 1):
					individual_cluster_name = name + '-' + str(n)
					cluster.name = individual_cluster_name

print('Ryhmitellään pysäkit...')
cluster_bus_stops()
name_clusters()

clusters_by_name = {}
for cluster in all_clusters:
	assert cluster.url_name not in clusters_by_name
	clusters_by_name[cluster.url_name] = cluster

print('Ladataan aikataulut... ', end = '', flush = True, file = stderr)
with open('gtfs/stop_times.txt') as file:
	rivimäärä = sum(line.count('\n') for line in file)
	progress = 0
	file.seek(0)
	for row in read_csv(file):
		trip = all_trips[transform_trip_reference(row['trip_id'])]
		arrival_time = read_time(row['arrival_time'])
		departure_time = read_time(row['departure_time'])
		stop = bus_stops[row['stop_id']]
		traveled_distance = float(row['shape_dist_traveled'])
		trip.schedule.append(BusHalt(arrival_time, departure_time, stop, trip, traveled_distance))
		progress += 1
		if progress % 1000 == 0:
			print('\rLadataan aikataulut... %.1f%%' % (progress * 100 / rivimäärä), end = ' ', file = stderr)
print('\rLadataan aikataulut... ladattu', file = stderr)