#!/usr/bin/python3
# -*- coding: utf-8 -*-
"""
Agenda module for Inky-Calendar Project
Copyright by aceisace
"""

from inkycal.modules.template import inkycal_module
from inkycal.custom import *
from inkycal.modules.ical_parser import iCalendar

import calendar as cal
import arrow

filename = os.path.basename(__file__).split('.py')[0]
logger = logging.getLogger(filename)
logger.setLevel(level=logging.ERROR)


class Agenda(inkycal_module):
  """Agenda class
  Create agenda and show events from given icalendars
  """

  def __init__(self, section_size, section_config):
    """Initialize inkycal_agenda module"""

    super().__init__(section_size, section_config)
    # Module specific parameters
    required = ['week_starts_on', 'ical_urls']
    for param in required:
      if not param in section_config:
        raise Exception('config is missing {}'.format(param))

    # class name
    self.name = self.__class__.__name__

    # module specific parameters
    self.date_format = 'ddd D MMM'
    self.time_format = "HH:mm"
    self.language = self.config['language']
    self.timezone = get_system_tz()
    self.ical_urls = self.config['ical_urls']
    self.ical_files = []

    # give an OK message
    print('{0} loaded'.format(self.name))

  def _validate(self):
    """Validate module-specific parameters"""

    if not isinstance(self.date_format, str):
      print('date_format has to be an arrow-compatible token')

    if not isinstance(self.time_format, str):
      print('time_format has to be an arrow-compatible token')

    if not isinstance(self.language, str):
      print('language has to be a string: "en" ')

    if not isinstance(self.timezone, str):
      print('The timezone has bo be a string.')

    if not isinstance(self.ical_urls, list):
      print('ical_urls has to be a list ["url1", "url2"] ')

    if not isinstance(self.ical_files, list):
      print('ical_files has to be a list ["path1", "path2"] ')

  def generate_image(self):
    """Generate image for this module"""

    # Define new image size with respect to padding
    im_width = int(self.width - (self.width * 2 * self.margin_x))
    im_height = int(self.height - (self.height * 2 * self.margin_y))
    im_size = im_width, im_height

    logger.info('Image size: {0}'.format(im_size))

    # Create an image for black pixels and one for coloured pixels
    im_black = Image.new('RGB', size = im_size, color = 'white')
    im_colour = Image.new('RGB', size = im_size, color = 'white')

    # Calculate the max number of lines that can fit on the image
    line_spacing = 1
    line_height = int(self.font.getsize('hg')[1]) + line_spacing
    line_width = im_width
    max_lines = im_height // line_height
    logger.debug(('max lines:',max_lines))

    # Create timeline for agenda
    now = arrow.now()
    today = now.floor('day')

    # Create a list of dates for the next days
    agenda_events = [
      {'begin':today.shift(days=+_),
       'title': today.shift(days=+_).format(
         self.date_format,locale=self.language)}
      for _ in range(max_lines)]

    # Load icalendar from config
    self.ical = iCalendar()
    parser = self.ical

    if self.ical_urls:
      parser.load_url(self.ical_urls)
    if self.ical_files:
      parser.load_from_file(self.ical_files)

    # Load events from all icalendar in timerange
    upcoming_events = parser.get_events(today, agenda_events[-1]['begin'],
                                        self.timezone)

    # Sort events by beginning time
    parser.sort()
    # parser.show_events()

    # Set the width for date, time and event titles
    date_width = int(max([self.font.getsize(
          dates['begin'].format(self.date_format, locale=self.language))[0]
          for dates in agenda_events]) * 1.2)
    logger.debug(('date_width:', date_width))

    # Check if any events were filtered
    if upcoming_events:

      # Find out how much space the event times take
      time_width = int(max([self.font.getsize(
          events['begin'].format(self.time_format, locale=self.language))[0]
          for events in upcoming_events]) * 1.2)
      logger.debug(('time_width:', time_width))

      # Calculate x-pos for time
      x_time = date_width
      logger.debug(('x-time:', x_time))

      # Find out how much space is left for event titles
      event_width = im_width - time_width - date_width
      logger.debug(('width for events:', event_width))

      # Calculate x-pos for event titles
      x_event = date_width + time_width
      logger.debug(('x-event:', x_event))

      # Calculate positions for each line
      line_pos = [(0, int(line * line_height)) for line in range(max_lines)]
      logger.debug(('line_pos:', line_pos))

      # Merge list of dates and list of events
      agenda_events += upcoming_events

      # Sort the combined list in chronological order of dates
      by_date = lambda event: event['begin']
      agenda_events.sort(key = by_date)

      # Delete more entries than can be displayed (max lines)
      del agenda_events[max_lines:]

      self._agenda_events = agenda_events

      cursor = 0
      for _ in agenda_events:
        title = _['title']

        # Check if item is a date
        if not 'end' in _:
          ImageDraw.Draw(im_colour).line(
            (0, line_pos[cursor][1], im_width, line_pos[cursor][1]),
          fill = 'black')

          write(im_black, line_pos[cursor], (date_width, line_height),
              title, font = self.font, alignment='left')

          cursor += 1

        # Check if item is an event
        if 'end' in _:
          time = _['begin'].format(self.time_format)

          # Check if event is all day, if not, add the time
          if parser.all_day(_) == False:
            write(im_black, (x_time, line_pos[cursor][1]),
                (time_width, line_height), time,
                font = self.font, alignment='left')

          write(im_black, (x_event, line_pos[cursor][1]),
                (event_width, line_height),
                '• '+title, font = self.font, alignment='left')
          cursor += 1

    # If no events were found, write only dates and lines
    else:
      cursor = 0
      for _ in agenda_events:
        title = _['title']
        ImageDraw.Draw(im_colour).line(
            (0, line_pos[cursor][1], im_width, line_pos[cursor][1]),
            fill = 'black')

        write(im_black, line_pos[cursor], (date_width, line_height),
              title, font = self.font, alignment='left')

        cursor += 1

      logger.info('no events found')

    # Save image of black and colour channel in image-folder
    im_black.save(images+self.name+'.png')
    im_colour.save(images+self.name+'_colour.png')

if __name__ == '__main__':
  print('running {0} in standalone mode'.format(filename))