import overpy
import math
import workers.val

def getOSM(lat, lon, distance = 1000):
 query = """
(
 node
  (around:%i,%f,%f)
  ["railway"~"tram_stop|station|subway"]
  [name];
 >;

 node
  (around:%i,%f,%f)
  ["highway"="bus_stop"]
  [name];
 >;);

out;
""" % (distance, lat, lon, distance, lat, lon)

 api = overpy.Overpass()
 res = api.query(query)

 return res.nodes

def cDistance(lat1, lon1, lat2, lon2):
 lat1, lon1, lat2, lon2 = map(math.radians, [lat1, lon1, lat2, lon2])

 dila = lat2 - lat1
 dilo = lon2 - lon1

 diff = 2 * math.asin(math.sqrt(math.sin(dila/2) ** 2 + math.cos(lat1) * math.cos(lat2) * math.sin(dilo/2) ** 2))

 dis = diff * 6371000

 return dis

def getStations(nodes, distance = 1000, lat = None, lon = None):
 unodes = list(set([node.tags["alt_name"].split(",")[0] if "alt_name" in node.tags and len(node.tags["alt_name"].split(",")[0]) > len(node.tags["name"]) else node.tags["name"] for node in nodes]))
 for node in unodes:
  for station in workers.val.validateName(node):
   if lat and lon:
    idistance = cDistance(station.lat(), station.lon(), lat, lon)
    if idistance < distance:
     station.distance = idistance
     yield station
     break
   else:
    yield station
    break

def findStations(lat, lon, distance = 1000, validate = True):
 stations = list(getStations(getOSM(lat, lon, distance), distance, lat if validate else None, lon if validate else None))

 if validate:
  return sorted(stations, key = lambda station: station.distance)

 return stations

def worker(lat, lon, distance = 1000):
 outtext = """<?xml version="1.0" encoding="UTF-8"?>
<stations>
"""

 for station in findStations(lat, lon, distance):
  try:
   idistance = int(station.distance)
  except:
   idistance = int(cDistance(station.lat(), station.lon(), lat, lon))
  outtext += "<station><name>%s</name><id>%s</id><distance>%i</distance></station>\n" % (station.name, station.useId(), idistance)

 outtext += "</stations>"

 return outtext