#!@python@/bin/python

import requests
from requests.exceptions import HTTPError
from requests.auth import HTTPBasicAuth
from datetime import *
from xdg import (BaseDirectory)
import configparser
from uritools import uricompose

from dateutil.easter import *
from dateutil.tz import *
from dateutil.parser import isoparse

from enum import Enum

from math import (copysign, ceil)

import calendar

import argparse

from copy import deepcopy

import sys

from tabulate import tabulate

class TogglAPISection(Enum):
    TOGGL = '/api/v8'
    REPORTS = '/reports/api/v2'

class TogglAPIError(Exception):
    def __init__(self, http_error, response):
        self.http_error = http_error
        self.response = response

    def __str__(self):
        if not self.http_error is None:
            return str(self.http_error)
        else:
            return self.response.text

class TogglAPI(object):
    def __init__(self, api_token, workspace_id):
        self._api_token = api_token
        self._workspace_id = workspace_id

    def _make_url(self, api=TogglAPISection.TOGGL, section=['time_entries', 'current'], params={}):
        if api is TogglAPISection.REPORTS:
          params.update({'user_agent': 'worktime', 'workspace_id': self._workspace_id})

        api_path = api.value
        section_path = '/'.join(section)
        uri = uricompose(scheme='https', host='api.track.toggl.com', path=f"{api_path}/{section_path}", query=params)

        return uri

    def _query(self, url, method):

        headers = {'content-type': 'application/json'}
        response = None

        if method == 'GET':
            response = requests.get(url, headers=headers, auth=HTTPBasicAuth(self._api_token, 'api_token'))
        elif method == 'POST':
            response = requests.post(url, headers=headers, auth=HTTPBasicAuth(self._api_token, 'api_token'))
        else:
            raise ValueError(f"Undefined HTTP method “{method}”")

        response.raise_for_status()

        return response

    def get_billable_hours(self, start_date, end_date=datetime.now(timezone.utc), rounding=False):
        billable_acc = timedelta(milliseconds = 0)
        step = timedelta(days = 365)

        for req_start in [start_date + x * step for x in range(0, ceil((end_date - start_date) / step))]:
          req_end = end_date
          if end_date > req_start + step:
            req_end = datetime.combine((req_start + step).astimezone(timezone.utc).date(), time(tzinfo=timezone.utc))
          elif req_start > start_date:
            req_start = datetime.combine(req_start.astimezone(timezone.utc).date(), time(tzinfo=timezone.utc)) + timedelta(days = 1)

          url = self._make_url(api = TogglAPISection.REPORTS, section = ['summary'], params={'since': req_start.astimezone(timezone.utc).isoformat(), 'until': req_end.astimezone(timezone.utc).isoformat(), 'rounding': rounding})
          r = self._query(url = url, method='GET')
          if not r or not r.json():
              raise TogglAPIError(r)
          billable_acc += timedelta(milliseconds=r.json()['total_billable']) if r.json()['total_billable'] else timedelta(milliseconds=0)

        return billable_acc

    def get_running_clock(self, now=datetime.now(timezone.utc)):
        url = self._make_url(api = TogglAPISection.TOGGL, section = ['time_entries', 'current'])
        r = self._query(url = url, method='GET')

        if not r or not r.json():
            raise TogglAPIError(r)

        if not r.json()['data'] or not r.json()['data']['billable']:
            return None

        start = isoparse(r.json()['data']['start'])

        return now - start if start <= now else None

class Worktime(object):
    time_worked = timedelta()
    running_entry = None
    now = datetime.now(tzlocal())
    time_pulled_forward = timedelta()
    is_workday = False
    include_running = True
    time_to_work = None
    force_day_to_work = True

    @staticmethod
    def holidays(year):
      holidays = dict()

      y_easter = datetime.combine(easter(year), time(), tzinfo=tzlocal())

      # Legal holidays in munich, bavaria
      holidays[datetime(year, 1, 1, tzinfo=tzlocal()).date()] = 1
      holidays[datetime(year, 1, 6, tzinfo=tzlocal()).date()] = 1
      holidays[(y_easter+timedelta(days=-2)).date()] = 1
      holidays[(y_easter+timedelta(days=+1)).date()] = 1
      holidays[datetime(year, 5, 1, tzinfo=tzlocal()).date()] = 1
      holidays[(y_easter+timedelta(days=+39)).date()] = 1
      holidays[(y_easter+timedelta(days=+50)).date()] = 1
      holidays[(y_easter+timedelta(days=+60)).date()] = 1
      holidays[datetime(year, 8, 15, tzinfo=tzlocal()).date()] = 1
      holidays[datetime(year, 10, 3, tzinfo=tzlocal()).date()] = 1
      holidays[datetime(year, 11, 1, tzinfo=tzlocal()).date()] = 1
      holidays[datetime(year, 12, 25, tzinfo=tzlocal()).date()] = 1
      holidays[datetime(year, 12, 26, tzinfo=tzlocal()).date()] = 1

      return holidays

    @staticmethod
    def config():
        config = configparser.ConfigParser()
        config_dir = BaseDirectory.load_first_config('worktime')
        config.read(f"{config_dir}/worktime.ini")
        return config

    def __init__(self, start_datetime=None, end_datetime=None, now=None, include_running=True, force_day_to_work=True, **kwargs):
      self.include_running = include_running
      self.force_day_to_work = force_day_to_work
        
      if now:
        self.now = now
        
      config = Worktime.config()
      config_dir = BaseDirectory.load_first_config('worktime')
      api = TogglAPI(api_token=config['TOGGL']['ApiToken'], workspace_id=config['TOGGL']['Workspace'])
      date_format = config.get('WORKTIME', 'DateFormat', fallback='%Y-%m-%d')

      start_date = start_datetime or datetime.strptime(config['WORKTIME']['StartDate'], date_format).replace(tzinfo=tzlocal())
      end_date = end_datetime or self.now

      try:
          with open(f"{config_dir}/reset", 'r') as reset:
              for line in reset:
                  stripped_line = line.strip()
                  reset_date = datetime.strptime(stripped_line, date_format).replace(tzinfo=tzlocal())

                  if reset_date > start_date and reset_date < end_date:
                      start_date = reset_date
      except IOError as e:
          if e.errno != 2:
              raise e
              

      hours_per_week = float(config.get('WORKTIME', 'HoursPerWeek', fallback=40))
      workdays = set([int(d.strip()) for d in config.get('WORKTIME', 'Workdays', fallback='1,2,3,4,5').split(',')])
      time_per_day = timedelta(hours = hours_per_week) / len(workdays)

      holidays = dict()

      for year in range(start_date.year, end_date.year + 1):
          holidays |= {k: v * time_per_day for k, v in Worktime.holidays(year).items()}

      try:
          with open(f"{config_dir}/excused", 'r') as excused:
              for line in excused:
                  stripped_line = line.strip()
                  if stripped_line:
                      splitLine = stripped_line.split(' ')
                      if len(splitLine) == 2:
                          [hours, date] = splitLine
                          day = datetime.strptime(date, date_format).replace(tzinfo=tzlocal()).date()
                          holidays[day] = timedelta(hours = float(hours))
                      else:
                          holidays[datetime.strptime(stripped_line, date_format).replace(tzinfo=tzlocal()).date()] = time_per_day
      except IOError as e:
          if e.errno != 2:
              raise e

      pull_forward = dict()
      
      start_day = start_date.date()
      end_day = end_date.date()

      try:
          with open(f"{config_dir}/pull-forward", 'r') as excused:
              for line in excused:
                  stripped_line = line.strip()
                  if stripped_line:
                      [hours, date] = stripped_line.split(' ')
                      constr = date.split(',')
                      for d in [start_day + timedelta(days = x) for x in range(0, (end_day - start_day).days + 1 + int(timedelta(hours = float(hours)).total_seconds() / 60 * (7 / len(workdays)) * 2))]:
                          for c in constr:
                              if c in calendar.day_abbr:
                                  if not d.strftime('%a') == c: break
                              elif "--" in c:
                                  [fromDay,toDay] = c.split('--')
                                  if fromDay != "":
                                      fromDay = datetime.strptime(fromDay, date_format).replace(tzinfo=tzlocal()).date()
                                      if not fromDay <= d: break
                                  if toDay != "":
                                      toDay = datetime.strptime(toDay, date_format).replace(tzinfo=tzlocal()).date()
                                      if not d <= toDay: break
                              else:
                                  if not d == datetime.strptime(c, date_format).replace(tzinfo=tzlocal()).date(): break
                          else:
                              if d >= end_date.date():
                                  pull_forward[d] = min(timedelta(hours = float(hours)), time_per_day - (holidays[d] if d in holidays else timedelta())) 
      except IOError as e:
          if e.errno != 2:
              raise e

      days_to_work = dict()

      if pull_forward:
          end_day = max(end_day, max(list(pull_forward)))
          
      for day in [start_day + timedelta(days = x) for x in range(0, (end_day - start_day).days + 1)]:
          if day.isoweekday() in workdays:
              time_to_work = time_per_day
              if day in holidays.keys():
                time_to_work -= holidays[day]
              if time_to_work > timedelta():
                days_to_work[day] = time_to_work

      extra_days_to_work = dict()

      try:
          with open(f"{config_dir}/days-to-work", 'r') as extra_days_to_work_file:
              for line in extra_days_to_work_file:
                  stripped_line = line.strip()
                  if stripped_line:
                      splitLine = stripped_line.split(' ')
                      if len(splitLine) == 2:
                          [hours, date] = splitLine
                          day = datetime.strptime(date, date_format).replace(tzinfo=tzlocal()).date()
                          extra_days_to_work[day] = timedelta(hours = float(hours))
                      else:
                          extra_days_to_work[datetime.strptime(stripped_line, date_format).replace(tzinfo=tzlocal()).date()] = time_per_day
      except IOError as e:
          if e.errno != 2:
              raise e


      self.is_workday = self.now.date() in days_to_work or self.now.date() in extra_days_to_work

      self.time_worked = timedelta()

      if self.include_running:
          self.running_entry = api.get_running_clock(self.now)

      if self.running_entry:
          self.time_worked += self.running_entry

      if self.running_entry and self.include_running and self.force_day_to_work and not (self.now.date() in days_to_work or self.now.date() in extra_days_to_work):
          extra_days_to_work[self.now.date()] = timedelta()

      self.time_to_work = sum([days_to_work[day] for day in days_to_work.keys() if day <= end_date.date()], timedelta())
      for day in [d for d in list(pull_forward) if d > end_date.date()]:
          days_forward = set([d for d in days_to_work.keys() if d >= end_date.date() and d < day and (not d in pull_forward or d == end_date.date())])
          extra_days_forward = set([d for d in extra_days_to_work.keys() if d >= end_date.date() and d < day and (not d in pull_forward or d == end_date.date())])
          days_forward = days_forward.union(extra_days_forward)

          extra_day_time_left = timedelta()
          for extra_day in extra_days_forward:
              day_time = max(timedelta(), time_per_day - extra_days_to_work[extra_day])
              extra_day_time_left += day_time
          extra_day_time = min(extra_day_time_left, pull_forward[day])
          time_forward = pull_forward[day] - extra_day_time
          if extra_day_time_left > timedelta():
            for extra_day in extra_days_forward:
                day_time = max(timedelta(), time_per_day - extra_days_to_work[extra_day])
                extra_days_to_work[extra_day] += extra_day_time * (day_time / extra_day_time_left)
          
          hours_per_day_forward = time_forward / len(days_forward) if len(days_forward) > 0 else timedelta()
          days_forward.discard(end_date.date())

          self.time_pulled_forward += time_forward - hours_per_day_forward * len(days_forward)

      if end_date.date() in extra_days_to_work:
          self.time_pulled_forward += extra_days_to_work[end_date.date()]
          
      self.time_to_work += self.time_pulled_forward

      self.time_worked += api.get_billable_hours(start_date, self.now, rounding = config.getboolean('WORKTIME', 'rounding', fallback=True))

def worktime(**args):
    worktime = Worktime(**args)

    def format_worktime(worktime):
      def difference_string(difference):
        total_minutes_difference = round(difference / timedelta(minutes = 1))
        (hours_difference, minutes_difference) = divmod(abs(total_minutes_difference), 60)
        sign = '' if total_minutes_difference >= 0 else '-'

        difference_string = f"{sign}"
        if hours_difference != 0:
            difference_string += f"{hours_difference}h"
        if hours_difference == 0 or minutes_difference != 0:
            difference_string += f"{minutes_difference}m"

        return difference_string

      difference = worktime.time_to_work - worktime.time_worked
      total_minutes_difference = 5 * ceil(difference / timedelta(minutes = 5))

      if worktime.running_entry and abs(difference) < timedelta(days = 1) and (total_minutes_difference > 0 or abs(worktime.running_entry) >= abs(difference)) :
          clockout_time = worktime.now + difference
          clockout_time += (5 - clockout_time.minute % 5) * timedelta(minutes = 1)
          clockout_time = clockout_time.replace(second = 0, microsecond = 0)

          if total_minutes_difference >= 0:
            difference_string = difference_string(total_minutes_difference * timedelta(minutes = 1))
            return "{difference_string}/{clockout_time}".format(difference_string = difference_string, clockout_time = clockout_time.strftime("%H:%M"))
          else:
            difference_string = difference_string(abs(total_minutes_difference) * timedelta(minutes = 1))
            return "{clockout_time}/{difference_string}".format(difference_string = difference_string, clockout_time = clockout_time.strftime("%H:%M"))
      else:
          if worktime.running_entry:
              difference_string = difference_string(abs(total_minutes_difference) * timedelta(minutes = 1))
              indicator = '↓' if total_minutes_difference >= 0 else '↑' # '\u25b6'

              return f"{indicator}{difference_string}"
          else:
              difference_string = difference_string(total_minutes_difference * timedelta(minutes = 1))
              if worktime.is_workday:
                  return difference_string
              else:
                  return f"({difference_string})"

    if worktime.time_pulled_forward >= timedelta(minutes = 15):
        worktime_no_pulled_forward = deepcopy(worktime)
        worktime_no_pulled_forward.time_to_work -= worktime_no_pulled_forward.time_pulled_forward
        worktime_no_pulled_forward.time_pulled_forward = timedelta()

        difference_string = format_worktime(worktime)
        difference_string_no_pulled_forward = format_worktime(worktime_no_pulled_forward)

        print(f"{difference_string_no_pulled_forward}…{difference_string}")
    else:
        print(format_worktime(worktime))

def time_worked(now, **args):
    then = now.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
    if now.time() == time():
        now = now + timedelta(days = 1)

    then = Worktime(**dict(args, now = then))
    now = Worktime(**dict(args, now = now))

    worked = now.time_worked - then.time_worked

    if args['do_round']:
      total_minutes_difference = 5 * ceil(worked / timedelta(minutes = 5))
      (hours_difference, minutes_difference) = divmod(abs(total_minutes_difference), 60)
      sign = '' if total_minutes_difference >= 0 else '-'

      difference_string = f"{sign}"
      if hours_difference != 0:
        difference_string += f"{hours_difference}h"
      if hours_difference == 0 or minutes_difference != 0:
        difference_string += f"{minutes_difference}m"

      print(difference_string)
    else:
      print(worked)

def diff(now, **args):
    now = now.replace(hour = 0, minute = 0, second = 0, microsecond = 0)
    then = now - timedelta.resolution

    then = Worktime(**dict(args, now = then, include_running = False))
    now = Worktime(**dict(args, now = now, include_running = False))

    print(now.time_to_work - then.time_to_work)

def holidays(now, **args):
    config = Worktime.config()
    date_format = config.get('WORKTIME', 'DateFormat', fallback='%Y-%m-%d')

    table_data = []
    
    holidays = Worktime.holidays(now.year)
    for k, v in holidays.items():
        kstr = k.strftime(date_format)
        
        table_data += [[kstr, v]]
    print(tabulate(table_data, tablefmt="plain"))
          
def main():
    parser = argparse.ArgumentParser(prog = "worktime", description = 'Track worktime using toggl API')
    parser.add_argument('--time', dest = 'now', metavar = 'TIME', type = lambda s: datetime.fromisoformat(s).replace(tzinfo=tzlocal()), help = 'Time to calculate status for (default: current time)', default = datetime.now(tzlocal()))
    parser.add_argument('--no-running', dest = 'include_running', action = 'store_false')
    parser.add_argument('--no-force-day-to-work', dest = 'force_day_to_work', action = 'store_false')
    subparsers = parser.add_subparsers(help = 'Subcommands')
    parser.set_defaults(cmd = worktime)
    time_worked_parser = subparsers.add_parser('time_worked', aliases = ['time', 'worked', 'today'])
    time_worked_parser.add_argument('--no-round', dest = 'do_round', action = 'store_false')
    time_worked_parser.set_defaults(cmd = time_worked)
    diff_parser = subparsers.add_parser('diff')
    diff_parser.set_defaults(cmd = diff)
    holidays_parser = subparsers.add_parser('holidays')
    holidays_parser.set_defaults(cmd = holidays)
    args = parser.parse_args()

    args.cmd(**vars(args))

if __name__ == "__main__":
    sys.exit(main())