#This script generates a xml file of all the train stations in the Netherlands
#using Lines.xml outputed by get_all_lines.py.


import xml.etree.cElementTree as ET
from retrieve_station import retrieve_station


#It reads in the Lines.xml file to construct
#a set of stations
line_tree = ET.parse("../data/Lines.xml")
lines_element = line_tree.getroot()

station_links = set()

for line_element in lines_element:
    for station in line_element[1]:
        station_links.add(station.attrib["Link"])

stations_element = None 

#It now tries to read Stations.xml and removes all the stations from the set 
#that are already downloaded in the file
try:
    tree = tree = ET.parse("Stations.xml")
    stations_element = tree.getroot()
    for station_element in stations_element:
        link = station_element[1].text
        station_links.discard(link)
        print(f"Discarded {link}")
except:
    print("Could not open Stations.xml")
    stations_element = ET.Element("Stations")

print(f"Still need retrieve {len(station_links)} stations")
n = 0
for station_link in station_links:
    print(f"{n}:{station_link}")
    try:
        station_element = retrieve_station(station_link)
    except:
        print(f"failed to read {station_element}")
        break
    stations_element.append(station_element.toXML())
    n+=1

tree = ET.ElementTree(stations_element)
ET.indent(tree,'\t')
tree.write("Stations.xml")