# frozen_string_literal: true

# cannot delete program if there are events submitted

class Program < ApplicationRecord
  has_paper_trail on: [:update], ignore: [:updated_at], meta: { conference_id: :conference_id }

  belongs_to :conference

  has_many :cfps, dependent: :destroy
  has_many :event_types, dependent: :destroy
  has_many :tracks, dependent: :destroy
  has_many :difficulty_levels, dependent: :destroy
  has_many :schedules, dependent: :destroy
  has_many :event_schedules, through: :schedules
  belongs_to :selected_schedule, class_name: 'Schedule'
  has_many :events, dependent: :destroy do
    def require_registration
      where(require_registration: true, state: :confirmed)
    end

    def with_registration_open
      select { |e| e if e.registration_possible? }
    end

    # All confirmed events of the conference with attribute require_registration
    # excluding the events the user has already registered to
    def remaining_for_registration(registration)
      require_registration - registration.events
    end

    def confirmed
      where(state: :confirmed)
    end

    def scheduled(schedule_id)
      joins(:event_schedules).where('event_schedules.schedule_id = ?', schedule_id)
    end

    def highlights
      where(state: :confirmed, is_highlight: true)
    end
  end
  has_many :event_schedules, through: :events

  has_many :event_users, through: :events
  has_many :program_events_speakers, -> {where(event_role: 'speaker')}, through: :events, source: :event_users
  has_many :speakers, -> { distinct }, through: :program_events_speakers, source: :user do
    def confirmed
      joins(:events).where(events: { state: :confirmed })
    end

    def registered(conference)
      joins(:registrations).where('registrations.conference_id = ?', conference.id)
    end

    def unregistered(conference)
      self - registered(conference)
    end
  end

  accepts_nested_attributes_for :event_types, allow_destroy: true
  accepts_nested_attributes_for :tracks, reject_if: proc { |r| r['name'].blank? }, allow_destroy: true
  accepts_nested_attributes_for :difficulty_levels, allow_destroy: true

#   validates :conference_id, presence: true, uniqueness: true
  validates :rating, numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: 10, only_integer: true }
  validates :schedule_interval, numericality: { greater_than_or_equal_to: 5, less_than_or_equal_to: 60 }, presence: true
  validate :schedule_interval_divisor_60
  validate :voting_start_date_before_end_date
  validate :voting_dates_exist

  after_create :create_event_types
  after_create :create_difficulty_levels
  after_save :unschedule_unfit_events, if: :saved_change_to_schedule_interval?
  after_save :normalize_event_types_length, if: :saved_change_to_schedule_interval?
  validate :check_languages_format

  # Returns all event_schedules for the selected schedule ordered by start_time
  def selected_event_schedules(includes: [:event])
    event_schedules = []
    event_schedules = selected_schedule.event_schedules.includes(*includes).order(start_time: :asc) if selected_schedule
    tracks.self_organized.confirmed.includes(selected_schedule: { event_schedules: includes }).order(start_date: :asc).each do |track|
      next unless track.selected_schedule

      event_schedules += track.selected_schedule.event_schedules
    end
    event_schedules.sort_by(&:start_time)
  end

  ##
  # Checks if blind_voting is enabled and if voting period is over
  # ====Returns
  # * +true+ -> If we can show voting details
  # * +false+ -> If we cannot show voting details
  def show_voting?
    return true unless blind_voting

    Time.current > voting_end_date
  end

  ##
  # Checks if we are still in voting period
  # ====Returns
  # * +true+ -> If the voting period is not over yet (or if the voting dates are not set)
  # * +false+ -> If the voting period is over
  def voting_period?
    return true unless voting_start_date && voting_end_date

    (voting_start_date.to_datetime..voting_end_date.to_datetime).cover? Time.current
  end

  ##
  # Checks if both voting_start_date and voting_end_date are set
  # ====Returns
  # Errors when the condition is not true
  def voting_dates_exist
    errors.add(:voting_start_date, 'must be set, when blind voting is enabled') if blind_voting && !voting_start_date && !voting_end_date

    errors.add(:voting_end_date, 'must be set, when blind voting is enabled') if blind_voting && !voting_start_date && !voting_end_date

    errors.add(:voting_end_date, 'must be set, when voting_start_date is set') if voting_start_date && !voting_end_date

    errors.add(:voting_start_date, 'must be set, when voting_end_date is set') if voting_end_date && !voting_start_date
  end

  ##
  # Checks if voting_start_date is before voting_end_date
  # ====Returns
  # Errors when the condition is not true
  def voting_start_date_before_end_date
    errors.add(:voting_start_date, 'must be before voting end date') if voting_start_date && voting_end_date && voting_start_date > voting_end_date
  end

  ##
  # Checks if the program has rating enabled
  #
  # ====Returns
  # * +false+ -> If rating is not enabled
  # * +true+ -> If rating is enabled
  def rating_enabled?
    rating && rating > 0
  end

  ##
  # Checks if the call for papers for the conference is currently open
  #
  # ====Returns
  # * +false+ -> If the CFP is not set or today isn't in the CFP period.
  # * +true+ -> If today is in the CFP period.
  def cfp_open?
    cfp = self.cfp

    cfp.present? && (cfp.start_date..cfp.end_date).cover?(Date.current)
  end

  def notify_on_schedule_public?
    return false unless conference.email_settings.send_on_program_schedule_public
    # do not notify if the schedule is not public
    return false unless schedule_public

    # do not notify unless the mail content is set up
    (!conference.email_settings.program_schedule_public_subject.blank? && !conference.email_settings.program_schedule_public_body.blank?)
  end

  def languages_list
    languages.split(',').map {|l| ISO_639.find(l).english_name} if languages.present?
  end

  ##
  # Checks if there is any event in the program that starts in the given date
  #
  # ====Returns
  # * +True+ -> If there is any event for the given date
  # * +False+ -> If there is not any event for the given date
  def any_event_for_this_date?(date)
    return false unless selected_schedule.present?

    parsed_date = DateTime.parse("#{date} 00:00").utc
    range = parsed_date..(parsed_date + 1.day)
    selected_schedule.event_schedules.any? { |es| range.cover?(es.start_time) }
  end

  ##
  # Provides backwards compatibility for when the program had one cfp
  #
  # ====Returns
  # * +ActiveRecord+ -> The program's cfp with cfp_type == 'events'
  def cfp
    return nil if cfps.for_events.blank?

    cfps.for_events
  end

  ##
  # ====Returns
  # * +Array+ -> The types of cfps for which a cfp doesn't exist yet
  def remaining_cfp_types
    Cfp::TYPES - cfps.pluck(:cfp_type)
  end

  private

  ##
  # Creates default EventTypes for this Conference. Used as before_create.
  #
  def create_event_types
    EventType.create(title: 'Talk', length: 30, color: '#FF0000', description: 'Presentation in lecture format',
                     minimum_abstract_length: 0,
                     maximum_abstract_length: 500, program_id: id)
    EventType.create(title: 'Workshop', length: 60, color: '#0000FF', description: 'Interactive hands-on practice',
                     minimum_abstract_length: 0,
                     maximum_abstract_length: 500, program_id: id)
  end

  ##
  # Creates default DifficultyLevels for this Conference. Used as before_create.
  #
  def create_difficulty_levels
    DifficultyLevel.create(title: 'Easy',
                           description: 'Events are understandable for everyone without knowledge of the topic.',
                           color: '#32CB2A', program_id: id)
    DifficultyLevel.create(title: 'Medium',
                           description: 'Events require a basic understanding of the topic.',
                           color: '#E6B65B', program_id: id)
    DifficultyLevel.create(title: 'Hard',
                           description: 'Events require expert knowledge of the topic.',
                           color: '#EF6E69', program_id: id)
  end

  ##
  # Check if languages string has the right format. Used as validation.
  #
  def check_languages_format
    return unless languages.present?

    # All white spaces are removed to allow languages to be separated by ',' and ', '. The languages string without spaces is saved
    self.languages = languages.delete(' ').downcase
    errors.add(:languages, 'must be two letters separated by commas') && return unless
    languages.match(/^$|(\A[a-z][a-z](,[a-z][a-z])*\z)/).present?
    languages_array = languages.split(',')
    # We check that languages are not repeated
    errors.add(:languages, "can't be repeated") && return unless languages_array.uniq!.nil?
    # We check if every language is a valid ISO 639-1 language
    errors.add(:languages, 'must be ISO 639-1 valid codes') unless languages_array.select{ |x| ISO_639.find(x).nil? }.empty?
  end

  ##
  # Check if schedule_interval is a divisor of 60 minutes
  #
  def schedule_interval_divisor_60
    errors.add(:schedule_interval, 'must be a divisor of 60') if schedule_interval > 0 && 60 % schedule_interval > 0
  end

  ##
  # Unschedule all the events which don't fit
  #
  def unschedule_unfit_events
    unfit_schedules = event_schedules.select do |event_schedule|
      event_schedule.start_time.min % schedule_interval > 0
    end
    EventSchedule.where(id: unfit_schedules.map(&:id)).destroy_all
  end

  ##
  # Change event type length according schedule interval
  #
  def normalize_event_types_length
    event_types.each do |event_type|
      new_length = event_type.length > schedule_interval ? event_type.length - (event_type.length % schedule_interval) : schedule_interval
      event_type.update_attribute(:length, new_length)
    end
  end
end