# Generates fourTwentyTz.js from time zone csv files
# get latest files from https://timezonedb.com/download
import csv,json,time,os,math
countries = {}
for r in csv.reader(open("country.csv")):
  countries[r[0]] = r[1]
zones = {}
for r in csv.reader(open("zone.csv")):
  parts = r[2].replace('_',' ').split('/')
  city = parts[-1]
  if len(parts)>2: # e.g. America/North_Dakota/New_Salem
    country = parts[1] # e.g. North Dakota
  else: # e.g. America/Denver
    country = countries[r[1]] # e.g. United States
  if country==city: # Avoid awkward searches like "Anguilla, Anguilla"
    country = r[1] # Use code instead
  zones[int(r[0])] = {"name":', '.join((city,country))}
now = int(time.time())
for r in csv.reader(open("timezone.csv")):
  code = int(r[0])
  if code not in zones:
    continue
  starttime = int(r[2] or "0") # Bugger. They're feeding us blanks for UTC now
  offs = int(r[3])
  if offs < 0:
    offs += 60*60*24
  d = zones[code]
  if starttime<now and ("starttime" not in d or d["starttime"]<starttime):
    d["starttime"] = starttime
    d["offs"] = math.floor(offs/60)
offsdict = {}
for k in zones:
  d = zones[k]
  if d["offs"]%60: # One a dem funky timezone. Ignore.
      continue
  offsdict[d["offs"]] = offsdict.get(d["offs"],[])+[d["name"]]
res = sorted([[k,sorted(offsdict[k])] for k in offsdict],key=lambda x:-x[0])
js = open("fourTwentyTz.js","w")
js.write("// Generated by mk420tz.py - see https://github.com/thedod/BangleApps/420clock\n")
js.write("//              (version: {0})\n".format(time.ctime(time.time())))
js.write("// Data source: https://timezonedb.com/files/timezonedb.csv.zip\n")
js.write("//              (version: {0})\n".format(time.ctime(os.stat("zone.csv").st_mtime)))
js.write("exports.timezones = ")
json.dump(res,js,indent=1)
js.write(";\n")
js.close()