# Copyright (C) 2012-2014 Zammad Foundation, http://zammad-foundation.org/

class Calendar < ApplicationModel
  store :business_hours
  store :public_holidays

  after_create   :sync_default, :min_one_check
  after_update   :sync_default, :min_one_check
  after_destroy  :min_one_check

=begin

get default calendar

  calendar = Calendar.default

returns calendar object

=end

  def self.default
    find_by(default: true)
  end

=begin

returnes preset of ical feeds

  feeds = Calendar.ical_feeds

returns

  {
    'US Holidays' => 'http://www.google.com/calendar/ical/en.usa%23holiday%40group.v.calendar.google.com/public/basic.ics',
    ...
  }

=end

  def self.ical_feeds
    gfeeds = {
      'Australian Holidays' => 'en.australian',
      'Austrian Holidays' => 'de.austrian',
      'Brazilian Holidays' => 'en.brazilian',
      'Canadian Holidays' => 'en.canadian',
      'China Holidays' => 'en.china',
      'Switzerland Holidays' => 'de.ch',
      'Christian Holidays' => 'en.christian',
      'Danish Holidays' => 'da.danish',
      'Dutch Holidays' => 'nl.dutch',
      'Finnish Holidays' => 'en.finnish',
      'French Holidays' => 'fe.french',
      'German Holidays' => 'de.german',
      'Greek Holidays' => 'en.greek',
      'Hong Kong Holidays' => 'en.hong_kong',
      'Indian Holidays' => 'en.indian',
      'Indonesian Holidays' => 'en.indonesian',
      'Iranian Holidays' => 'en.iranian',
      'Irish Holidays' => 'en.irish',
      'Islamic Holidays' => 'en.islamic',
      'Italian Holidays' => 'it.italian',
      'Japanese Holidays' => 'en.japanese',
      'Jewish Holidays' => 'en.jewish',
      'Malaysian Holidays' => 'en.malaysia',
      'Mexican Holidays' => 'en.mexican',
      'New Zealand Holidays' => 'en.new_zealand',
      'Norwegian Holidays' => 'en.norwegian',
      'Philippines Holidays' => 'en.philippines',
      'Polish Holidays' => 'en.polish',
      'Portuguese Holidays' => 'en.portuguese',
      'Russian Holidays' => 'en.russian',
      'Singapore Holidays' => 'en.singapore',
      'South Africa Holidays' => 'en.sa',
      'South Korean Holidays' => 'en.south_korea',
      'Spain Holidays' => 'en.spain',
      'Swedish Holidays' => 'en.swedish',
      'Taiwan Holidays' => 'en.taiwan',
      'Thai Holidays' => 'en.thai',
      'UK Holidays' => 'en.uk',
      'US Holidays' => 'en.usa',
      'Vietnamese Holidays' => 'en.vietnamese',
    }
    all_feeds = {}
    gfeeds.each {|key, name|
      all_feeds["http://www.google.com/calendar/ical/#{name}%23holiday%40group.v.calendar.google.com/public/basic.ics"] = key
    }
    all_feeds
  end

=begin

get list of available timezones and UTC offsets

  list = Calendar.timezones

returns

  {
    'America/Los_Angeles' => -7
    ...
  }

=end

  def self.timezones
    list = {}
    TZInfo::Timezone.all_country_zone_identifiers.each { |timezone|
      t = TZInfo::Timezone.get(timezone)
      diff = t.current_period.utc_total_offset / 60 / 60
      list[ timezone ] = diff
    }
    list
  end

=begin

syn all calendars with ical feeds

  success = Calendar.sync

returns

  true # or false

=end

  def self.sync
    Calendar.all.each(&:sync)
    true
  end

=begin

syn one calendars with ical feed

  calendar = Calendar.find(4711)
  success = calendar.sync

returns

  true # or false

=end

  def sync
    return if !ical_url
    events = Calendar.parse(ical_url)

    # sync with public_holidays
    if !public_holidays
      self.public_holidays = {}
    end
    events.each {|day, summary|
      if !public_holidays[day]
        public_holidays[day] = {}
      end

      # ignore if already added or changed
      next if public_holidays[day].key?('active')

      # create new entry
      public_holidays[day] = {
        active: true,
        summary: summary,
      }
    }
    self.last_log = ''
    self.last_sync = Time.zone.now
    save
    true
  end

  def self.parse(location)
    if location =~ /^http/i
      result = UserAgent.get(location)
      cal_file = result.body
    else
      cal_file = File.open(location)
    end

    cals = Icalendar.parse(cal_file)
    cal = cals.first
    events = {}
    cal.events.each {|event|
      next if event.dtstart < Time.zone.now - 1.year
      next if event.dtstart > Time.zone.now + 3.year
      day = "#{event.dtstart.year}-#{format('%02d', event.dtstart.month)}-#{format('%02d', event.dtstart.day)}"
      comment = event.summary || event.description
      comment = Encode.conv( 'utf8', comment.to_s.force_encoding('utf-8') )
      if !comment.valid_encoding?
        comment = comment.encode('utf-8', 'binary', invalid: :replace, undef: :replace, replace: '?')
      end

      # ignore daylight saving time entries
      next if comment =~ /(daylight saving|sommerzeit|summertime)/i
      events[day] = comment
    }
    events.sort.to_h
  end

  private

  # if changed calendar is default, set all others default to false
  def sync_default
    return if !default
    Calendar.all.each {|calendar|
      next if calendar.id == id
      next if !calendar.default
      calendar.default = false
      calendar.save
    }
  end

  # check if min one is set to default true
  def min_one_check
    Calendar.all.each {|calendar|
      return true if calendar.default
    }
    first = Calendar.order(:created_at, :id).limit(1).first
    first.default = true
    first.save
  end
end