import datetime
import dateutil
import logging
import json
import re
import requests


def init(CONFIG, logger):
  return Mod(CONFIG, logger)


class Mod:
  def __init__(self, CONFIG, logging):
    self.URL     = "https://www.e-license.jp/el25/pc/"
    self.CONFIG  = CONFIG

    self.logging  = logging
    self.targets  = []
    self.calender = None

    self.ss = self.authenticate()

  def __del__(self):
    res = self.ss.get(
      url    = self.URL+"logout.action",
      params = {
        "b.schoolCd": self.CONFIG["school"],
        "senisakiCd": 4,
      })
    res.encoding = "shift_jis"
    self.calender = Calender(res.text)

    self.logging.info("logout succeeded")

  def cycle(self):
    if len(self.targets) == 0:
      return

    res = self.ss.post(
      url  = self.URL+"p04a.action",
      data = {
        "b.processCd": "A",
        "b.kamokuCd" : self.calender.params["kamokuCd"],
        "b.page"     : 1,
        "b.schoolCd" : self.CONFIG["school"],
      })
    res.encoding = "shift_jis"
    self.calender = Calender(res.text)

    now   = datetime.datetime.utcnow() + datetime.timedelta(hours=9)
    today = now.strftime("%Y%m%d")

    for target in self.targets:
      for slot in target[1]:
        begins = now.combine(now.date(), TIMETABLE[slot])
        border = begins - datetime.timedelta(hours=2)

        if target[0] != today or now < border:
          if self.calender.checkAvailable(target[0], slot):
            self.make_reserve(target[0], slot)
            target[2]()
            break
    self.targets = []

  def watch(self, date, slots, cb):
    self.logging.debug("watch request accepted, {} {}".format(date, slots))
    self.targets.append((date, slots, cb))

  def make_reserve(self, date, slot):
    res = self.ss.post(
      url  = self.URL+"p03a.action",
      data = {
        "b.schoolCd"           : self.CONFIG["school"],
        "b.processCd"          : "V",
        "b.kamokuCd"           : self.calender.params["kamokuCd"],
        "b.instructorTypeCd"   : self.calender.params["instructorTypeCd"],
        "b.dateInformationType": date,
        "b.infoPeriodNumber"   : slot,
        "b.carModelCd"         : self.calender.params["carModelCd"],
        "b.instructorCd"       : self.calender.params["instructorCd"],
        "b.page"               : 1,
        "b.groupCd"            : self.calender.group,
      })
    res.encoding = "shift_jis"
    self.calender = Calender(res.text)

    self.logging.info("reservation made, {}:{}".format(date, slots))

  def authenticate(self):
    ss = requests.Session()
    try:
      res = ss.post(
        url  = self.URL+"p01a.action",
        data = {
          "b.studentId"    : self.CONFIG["username"],
          "b.password"     : self.CONFIG["password"],
          "b.schoolCd"     : self.CONFIG["school"],
          "b.processCd"    : "",
          "b.kamokuCd"     : "",
          "method:doLogin" : "ログイン".encode("shift_jis"),
        })
      res.encoding  = "shift_jis"
      self.calender = Calender(res.text)
      self.logging.info("authenticated")
      return ss
    except Exception as e:
      self.logging.error("authentication failure ({})".format(e))
      return None


class Calender:
  def __init__(self, text):
    m = re.search(RE_ERROR, text)
    if m is None:
      m = re.search(RE_ALERT, text)
    if m is not None:
      raise Exception(m[1])

    self.avails = re.findall(RE_AVAIL_SLOT, text)

    self.params = {}
    for name in RE_PARAMS:
      m = re.search(RE_PARAMS[name], text)
      if m is not None:
        self.params[name] = m[1]

  def checkAvailable(self, date, slot):
    for avail in self.avails:
      if avail[0] == date and avail[1] == str(slot):
        return True
    return False


TIMETABLE = {
   1: datetime.time( 9,20),
   2: datetime.time(10,20),
   3: datetime.time(11,20),
   4: datetime.time(12,20),
   5: datetime.time(14,10),
   6: datetime.time(15,10),
   7: datetime.time(16,10),
   8: datetime.time(17,10),
   9: datetime.time(18,10),
  10: datetime.time(19,10),
}

RE_ALERT      = re.compile(r"window\.alert\('(.*)'\)")
RE_ERROR      = re.compile(r"<.*? class=\"errorTitle\">メッセージ<\/.*?>\s*<.*? class=\"errorDisp\">(.*?)<\/.*?>", re.MULTILINE)
RE_AVAIL_SLOT = re.compile(r"^\s*<a href=\"#\" onclick=\"sendContent\('(\d+)','(\d+)','V',document\.getElementById\('formId'\)\)\">$")

RE_PARAMS = {
  "kamokuCd"        : None,
  "instructorTypeCd": None,
  "carModelCd"      : None,
  "instructorCd"    : None,
  "groupCd"         : None,
}
for name in RE_PARAMS:
  RE_PARAMS[name] = re.compile(
    r"<input type=\"hidden\" name=\"b.{0}\" value=\"(.*?)\" id=\"".format(name))