jam-cloud/ruby/lib/jam_ruby/models/lesson_booking.rb

# represenst the type of lesson package
module JamRuby
  class LessonBooking < ActiveRecord::Base

    include HtmlSanitize
    html_sanitize strict: [:description, :cancel_message]

    include ActiveModel::Dirty

    @@log = Logging.logger[LessonBooking]

    attr_accessor :accepting, :countering, :countered_slot, :countered_lesson

    STATUS_REQUESTED = 'requested'
    STATUS_CANCELED = 'canceled'
    STATUS_APPROVED = 'approved'
    STATUS_SUSPENDED = 'suspended'
    STATUS_COUNTERED = 'countered'

    STATUS_TYPES = [STATUS_REQUESTED, STATUS_CANCELED, STATUS_APPROVED, STATUS_SUSPENDED, STATUS_COUNTERED]

    LESSON_TYPE_FREE = 'single-free'
    LESSON_TYPE_TEST_DRIVE = 'test-drive'
    LESSON_TYPE_PAID = 'paid'

    LESSON_TYPES = [LESSON_TYPE_FREE, LESSON_TYPE_TEST_DRIVE, LESSON_TYPE_PAID]

    PAYMENT_STYLE_ELSEWHERE = 'elsewhere'
    PAYMENT_STYLE_SINGLE = 'single'
    PAYMENT_STYLE_WEEKLY = 'weekly'
    PAYMENT_STYLE_MONTHLY = 'monthly'


    PAYMENT_STYLES = [PAYMENT_STYLE_ELSEWHERE, PAYMENT_STYLE_SINGLE, PAYMENT_STYLE_WEEKLY, PAYMENT_STYLE_MONTHLY]

    belongs_to :user, class_name: "JamRuby::User"
    belongs_to :teacher, class_name: "JamRuby::User"
    belongs_to :accepter, class_name: "JamRuby::User"
    belongs_to :canceler, class_name: "JamRuby::User"
    belongs_to :default_slot, class_name: "JamRuby::LessonBookingSlot", foreign_key: :default_slot_id, inverse_of: :defaulted_booking
    belongs_to :counter_slot, class_name: "JamRuby::LessonBookingSlot", foreign_key: :counter_slot_id, inverse_of: :countered_booking

    has_many :lesson_booking_slots, class_name: "JamRuby::LessonBookingSlot"
    has_many :lesson_sessions, class_name: "JamRuby::LessonSession"
    has_many :lesson_package_purchases, class_name: "JamRuby::LessonPackagePurchase"

    validates :user, presence: true
    validates :teacher, presence: true
    validates :lesson_type, inclusion: {in: LESSON_TYPES}
    validates :status, presence: true, inclusion: {in: STATUS_TYPES}
    validates :recurring, inclusion: {in: [true, false]}
    validates :sent_notices, inclusion: {in: [true, false]}
    validates :card_presumed_ok, inclusion: {in: [true, false]}
    validates :active, inclusion: {in: [true, false]}
    validates :lesson_length, inclusion: {in: [30, 45, 60, 90, 120]}
    validates :payment_style, inclusion: {in: PAYMENT_STYLES}
    validates :booked_price, presence: true
    validates :description, no_profanity: true, length: {minimum: 10, maximum: 20000}

    validate :validate_user, on: :create
    validate :validate_recurring
    validate :validate_lesson_booking_slots
    validate :validate_lesson_length
    validate :validate_payment_style
    validate :validate_accepted, :if => :accepting


    before_save :before_save
    before_validation :before_validation
    after_create :after_create
    around_save :around_update

    scope :test_drive,  -> { where(lesson_type: LESSON_TYPE_TEST_DRIVE) }
    scope :active,      -> { where(active: true) }
    scope :approved,    -> { where(status: STATUS_APPROVED) }
    scope :requested,   -> { where(status: STATUS_REQUESTED) }
    scope :canceled,    -> { where(status: STATUS_CANCELED) }
    scope :suspended,   -> { where(status: STATUS_SUSPENDED) }
    scope :engaged,     -> { where("status = '#{STATUS_APPROVED}' OR status = '#{STATUS_REQUESTED}' OR status = '#{STATUS_SUSPENDED}'") }

    def before_validation
      if self.booked_price.nil?
        self.booked_price = compute_price
      end
    end

    def after_create
      if card_presumed_ok && !sent_notices
        send_notices
      end
    end

    def before_save
      automatically_default_slot
    end

    def around_update

      @default_slot_did_change = self.default_slot_id_changed?

      yield

      sync_lessons
      sync_remaining_test_drives

      @default_slot_did_change = nil
      @accepting = nil
      @countering = nil
    end

    # here for shopping_cart
    def product_info
      {price: booked_price, real_price: booked_price, total_price: booked_price}
    end
    # here for shopping_cart
    def price
      booked_price
    end


    def alt_slot
      found = nil
      lesson_booking_slots.each do |slot|
        if slot.id != default_slot.id
          found = slot
          break
        end
      end
      found
    end

    def student
      user
    end

    def next_lesson
      if recurring
        session = lesson_sessions.joins(:music_session).where("scheduled_start is not null").where("scheduled_start > ?", Time.now).order(:created_at).first
        LessonSession.find(session.id) if session
      else
        lesson_sessions[0]
      end
    end

    def accept(lesson_session, slot, accepter)
      if !is_active?
        self.accepting = true
      end

      self.active = true
      self.status = STATUS_APPROVED
      self.counter_slot = nil
      self.default_slot = slot
      self.accepter = accepter

      success = self.save

      if !success
        puts "unable to accept lesson booking #{errors.inspect}"
      end
      success
    end

    def counter(lesson_session, proposer, slot)
      self.countering = true
      self.lesson_booking_slots << slot
      self.counter_slot = slot
      #self.status = STATUS_COUNTERED
      self.save
    end

    def automatically_default_slot
      if is_requested?
        if lesson_booking_slots.length > 0
          self.default_slot = lesson_booking_slots[0]
        end
      end
    end

    def sync_remaining_test_drives
      if is_test_drive? || is_single_free?
        if card_presumed_ok && !user_decremented
          self.user_decremented = true
          self.save(validate: false)
          if is_single_free?
            user.remaining_free_lessons = user.remaining_free_lessons - 1
          elsif is_test_drive?
            user.remaining_test_drives = user.remaining_test_drives - 1
          end
          user.save(validate: false)
        end
      end
    end

    def create_minimum_booking_time
      # trying to be too smart
      #(Time.now + APP_CONFIG.minimum_lesson_booking_hrs * 60*60)
      Time.now
    end

    def sync_lessons

      if is_canceled?
        # don't create new sessions if cancelled
        return
      end


      if @default_slot_did_change

      end
      # Here we go; let's create a lesson(s) as needed

      # we need to make lessons into the future a bit, to give time for everyone involved
      minimum_start_time = create_minimum_booking_time

      # get all sessions that are already scheduled for this booking ahead of the minimum time
      sessions = MusicSession.joins(:lesson_session).where("lesson_sessions.lesson_booking_id = ?", id).where("scheduled_start is not null").where("scheduled_start > ?", minimum_start_time).order(:created_at)

      if @default_slot_did_change
        # # adjust all session times

        offset = 0
        sessions.each_with_index do |item, i|
          item.lesson_session.slot = default_slot
          result = item.lesson_session.update_next_available_time(offset)
          if result
            offset = result
            offset += 1
          end
        end
      end

      needed_sessions = determine_needed_sessions(sessions)

      # if the latest scheduled session is after the minimum start time, then bump up minimum start time
      last_session = sessions.last
      last_session.reload if last_session # because of @default_slot_did_change logic above, this can be necessary

      if last_session && last_session.scheduled_start && last_session.scheduled_start > minimum_start_time
        minimum_start_time = last_session.scheduled_start
      end
      times = default_slot.scheduled_times(needed_sessions, minimum_start_time)

      scheduled_lessons(times)
    end

    # sensitive to current time
    def predicted_times_for_month(year, month)
      first_day = Date.new(year, month, 1)
      last_day = Date.new(year, month, -1)
      sessions = MusicSession.joins(:lesson_session).where("lesson_sessions.lesson_booking_id = ?", id).where("scheduled_start >= ?", first_day).where("scheduled_start <= ?", last_day).order(:created_at)

      times = []

      sessions.each do |session|
        times << session.scheduled_start
      end
      last_session = sessions.last

      start_day = first_day
      if last_session
        start_day = last_session.scheduled_start.to_date + 1
      end

      # now flesh out the rest of the month with predicted times

      more_times = default_slot.scheduled_times(5, start_day)

      more_times.each do |time|
        if time.to_date >= first_day && time.to_date <= last_day
          times << time
        end
      end
      times
    end

    def determine_needed_sessions(sessions)
      needed_sessions = 0
      if is_requested?
        # in the case of a requested booking (not approved) only make one, even if it's recurring.   This is for UI considerations
        if sessions.count == 0
          needed_sessions = 1
        end
      elsif is_active?
        expected_num_sessions = recurring ? 2 : 1
        needed_sessions = expected_num_sessions - sessions.count
      end
      needed_sessions
    end

    def scheduled_lessons(times)
      times.each do |time|

        lesson_session = LessonSession.create(self)

        if lesson_session.errors.any?
          puts "JamClass lesson session creation errors #{lesson_session.errors.inspect}"
          @@log.error("JamClass lesson session creation errors #{lesson_session.errors.inspect}")
          raise ActiveRecord::Rollback
        end
        ms_tz = ActiveSupport::TimeZone.new(default_slot.timezone)
        ms_tz = "#{ms_tz.name},#{default_slot.timezone}"

        rsvps = [{instrument_id: 'other', proficiency_level: 0, approve: true}]

        music_session = MusicSession.create(student, {
                                                       name: "#{display_type2} JamClass taught by #{teacher.name}",
                                                       description: "This is a #{lesson_length}-minute #{display_type2} lesson with #{teacher.name}.",
                                                       musician_access: false,
                                                       fan_access: false,
                                                       genres: ['other'],
                                                       approval_required: false,
                                                       fan_chat: false,
                                                       legal_policy: "standard",
                                                       language: 'eng',
                                                       duration: lesson_length,
                                                       recurring_mode: false,
                                                       timezone: ms_tz,
                                                       create_type: MusicSession::CREATE_TYPE_LESSON,
                                                       is_unstructured_rsvp: true,
                                                       scheduled_start: time,
                                                       invitations: [teacher.id],
                                                       lesson_session: lesson_session,
                                                       rsvp_slots: rsvps
                                                   })

        if music_session.errors.any?
          puts "JamClass lesson scheduling errors #{music_session.errors.inspect}"
          @@log.error("JamClass lesson scheduling errors #{music_session.errors.inspect}")
          raise ActiveRecord::Rollback
        end

        if lesson_session.is_active?
          # send out email to student to act as something they can add to their calendar
          Notification.send_student_jamclass_invitation(music_session, student)
        end

      end
    end

    def is_weekly_payment?
      payment_style == PAYMENT_STYLE_WEEKLY
    end

    def is_monthly_payment?
      payment_style == PAYMENT_STYLE_MONTHLY
    end

    def requires_per_session_billing?
      is_normal? && !is_monthly_payment?
    end

    def requires_teacher_distribution?(target)
      if target.is_a?(JamRuby::LessonSession)
        is_test_drive? || (is_normal? && !is_monthly_payment?)
      elsif target.is_a?(JamRuby::LessonPackagePurchase)
        is_monthly_payment?
      else
        raise "unable to determine object type of #{target}"
      end
    end

    def is_requested?
      status == STATUS_REQUESTED
    end

    def is_canceled?
      status == STATUS_CANCELED
    end

    def is_approved?
      status == STATUS_APPROVED
    end

    def is_suspended?
      status == STATUS_SUSPENDED
    end

    def is_active?
      active
    end

    def validate_accepted
      # accept is multipe purpose; either accept the initial request, or a counter slot
      if self.status_was != STATUS_REQUESTED && counter_slot.nil? # && self.status_was != STATUS_COUNTERED
        self.errors.add(:status, "This lesson is already #{self.status}.")
      end

      self.accepting = false
    end

    def send_notices
      UserMailer.student_lesson_request(self).deliver
      UserMailer.teacher_lesson_request(self).deliver
      Notification.send_lesson_message('requested', lesson_sessions[0], false) # TODO: this isn't quite an 'accept'
      self.sent_notices = true
      self.save
    end

    def lesson_package_type
      if is_single_free?
        LessonPackageType.single_free
      elsif is_test_drive?
        LessonPackageType.test_drive
      elsif is_normal?
        LessonPackageType.single
      end
    end

    def display_type2
      if is_single_free?
        "Free"
      elsif is_test_drive?
        "TestDrive"
      elsif is_normal?
        "Single"
      end
    end

    def display_type
      if is_single_free?
        "Free"
      elsif is_test_drive?
        "TestDrive"
      elsif is_normal?
        if recurring
          "recurring"
        else
          "single"
        end

      end
    end

    # determine the price of this booking based on what the user wants, and the teacher's pricing

    def compute_price
      if is_single_free?
        0
      elsif is_test_drive?
        LessonPackageType.test_drive.price
      elsif is_normal?
        teacher.teacher.booking_price(lesson_length, payment_style != PAYMENT_STYLE_MONTHLY)
      end
    end

    def distribution_price_in_cents
      if is_single_free?
        0
      elsif is_test_drive?
        10 * 100
      elsif is_normal?
        booked_price * 100
      end
    end

    def is_single_free?
      lesson_type == LESSON_TYPE_FREE
    end

    def is_test_drive?
      lesson_type == LESSON_TYPE_TEST_DRIVE
    end

    def is_normal?
      lesson_type == LESSON_TYPE_PAID
    end

    def dayWeekDesc(slot = default_slot)
      day = case slot.day_of_week
        when 0 then "Sunday"
        when 1 then "Monday"
        when 2 then "Tuesday"
        when 3 then "Wednesday"
        when 4 then "Thursday"
        when 5 then "Friday"
        when 6 then "Saturday"
      end


      if slot.hour > 11
        hour = slot.hour - 12
        if hour == 0
          hour = 12
        end
        am_pm = 'pm'
      else
        hour = slot.hour
        if hour == 0
          hour = 12
        end
        am_pm = 'am'
      end

      "#{day} at #{hour}:#{slot.minute}#{am_pm}"

    end

    def approved_before?
      !self.accepter_id.nil?
    end
    def cancel(canceler, other, message)

      self.active = false
      self.status = STATUS_CANCELED
      self.cancel_message = message
      self.canceler = canceler
      success = save
      if success
        if approved_before?
            # just tell both people it's cancelled, to act as confirmation
            Notification.send_lesson_message('canceled', next_lesson, false)
            Notification.send_lesson_message('canceled', next_lesson, true)
            UserMailer.student_lesson_booking_canceled(self, message).deliver
            UserMailer.teacher_lesson_booking_canceled(self, message).deliver
            chat_message_prefix = "Lesson Canceled"
        else
          if canceler == student
            # if it's the first time acceptance student canceling, we call it a 'cancel'
            Notification.send_lesson_message('canceled', next_lesson, false)
            UserMailer.teacher_lesson_booking_canceled(self, message).deliver
            chat_message_prefix = "Lesson Canceled"
          else
            # if it's the first time acceptance teacher, it was declined
            UserMailer.student_lesson_booking_declined(self, message).deliver
            Notification.send_lesson_message('declined', next_lesson, true)
            chat_message_prefix = "Lesson Declined"
          end
        end

        chat_message = message.nil? ? chat_message_prefix : "#{chat_message_prefix}: #{message}"
        msg = ChatMessage.create(canceler, nil, chat_message, ChatMessage::CHANNEL_LESSON, nil, other, self)

      end

      success
    end

    def card_approved
      self.card_presumed_ok = true
      if self.save && !sent_notices
        send_notices
      end
    end

    def validate_user
      if card_presumed_ok && is_single_free?
        if !user.has_free_lessons?
          errors.add(:user, 'have no remaining free lessons')
        end

        #if !user.has_stored_credit_card?
        #  errors.add(:user, 'has no credit card stored')
        #end
      elsif is_test_drive?
        if user.has_requested_test_drive?(teacher) && !user.admin
          errors.add(:user, "has a requested TestDrive with this teacher")
        end
        if !user.has_test_drives? && !user.can_buy_test_drive?
          errors.add(:user, "have no remaining test drives")
        end
      elsif is_normal?
        #if !user.has_stored_credit_card?
        #  errors.add(:user, 'has no credit card stored')
        #end
      end
    end

    def validate_teacher
      # shouldn't we check if the teacher already has a booking in this time slot, or at least warn the user
    end

    def validate_recurring
      if is_single_free? || is_test_drive?
        if recurring
          errors.add(:recurring, "can not be true for this type of lesson")
        end
      end

      false
    end

    def validate_lesson_booking_slots
      if lesson_booking_slots.length == 0 || lesson_booking_slots.length == 1
        errors.add(:lesson_booking_slots, "must have two times specified")
      end
    end

    def validate_lesson_length
      if is_single_free? || is_test_drive?
        if lesson_length != 30
          errors.add(:lesson_length, "must be 30 minutes")
        end
      end
    end

    def validate_payment_style
      if is_normal?
        if payment_style.nil?
          errors.add(:payment_style, "can't be blank")
        end
      end
    end


    def self.book_free(user, teacher, lesson_booking_slots, description)
      self.book(user, teacher, LessonBooking::LESSON_TYPE_FREE, lesson_booking_slots, false, 30, PAYMENT_STYLE_ELSEWHERE, description)
    end

    def self.book_test_drive(user, teacher, lesson_booking_slots, description)
      self.book(user, teacher, LessonBooking::LESSON_TYPE_TEST_DRIVE, lesson_booking_slots, false, 30, PAYMENT_STYLE_ELSEWHERE, description)
    end

    def self.book_normal(user, teacher, lesson_booking_slots, description, recurring, payment_style, lesson_length)
      self.book(user, teacher, LessonBooking::LESSON_TYPE_PAID, lesson_booking_slots, recurring, lesson_length, payment_style, description)
    end

    def self.book(user, teacher, lesson_type, lesson_booking_slots, recurring, lesson_length, payment_style, description)

      lesson_booking = nil
      LessonBooking.transaction do

        lesson_booking = LessonBooking.new
        lesson_booking.user = user
        lesson_booking.card_presumed_ok = user.has_stored_credit_card?
        lesson_booking.sent_notices = false
        lesson_booking.teacher = teacher
        lesson_booking.lesson_type = lesson_type
        lesson_booking.recurring = recurring
        lesson_booking.lesson_length = lesson_length
        lesson_booking.payment_style = payment_style
        lesson_booking.description = description
        lesson_booking.status = STATUS_REQUESTED

        # two-way association slots, for before_validation loic in slot to work
        lesson_booking.lesson_booking_slots = lesson_booking_slots
        lesson_booking_slots.each do |slot|
          slot.lesson_booking = lesson_booking
          slot.message = description
        end if lesson_booking_slots

        if lesson_booking.save
          msg = ChatMessage.create(user, lesson_booking.lesson_sessions[0], description, ChatMessage::CHANNEL_LESSON, nil, teacher, lesson_booking)
        end
      end
      lesson_booking
    end

    def self.unprocessed(current_user)
      LessonBooking.where(user_id: current_user.id).where(card_presumed_ok: false)
    end

    def self.requested(current_user)
      LessonBooking.where(user_id: current_user.id).where(status: STATUS_REQUESTED)
    end


    def self.find_bookings_needing_sessions(minimum_start_time)
      MusicSession.select([:lesson_booking_id]).joins(:lesson_session => :lesson_booking).where("lesson_bookings.active = true").where('lesson_bookings.recurring = true').where("scheduled_start is not null").where("scheduled_start > ?", minimum_start_time).group(:lesson_booking_id).having('count(lesson_booking_id) < 2')
    end

    # check for any recurring sessions where there are not at least 2 sessions into the future.  If not, we need to make sure they get made
    def self.hourly_check
      schedule_upcoming_lessons
      bill_monthlies
    end

    def self.bill_monthlies
      now = Time.now
      billable_monthlies(now).each do |lesson_booking|
        lesson_booking.bill_monthly(now)
      end

      today = now.to_date
      seven_days_in_future = today + 7


      is_different_month = seven_days_in_future.month != today.month
      if is_different_month
        next_month = seven_days_in_future.to_time
        billable_monthlies(next_month).each do |lesson_booking|
          lesson_booking.bill_monthly(next_month)
        end
      end
    end

    def self.billable_monthlies(now)
      current_month_first_day = Date.new(now.year, now.month, 1)
      current_month_last_day = Date.new(now.year, now.month, -1)
      #next_month_last_day = now.month == 12 ? Date.new(now.year + 1, 1, -1) : Date.new(now.year, now.month + 1, -1)

      LessonBooking
          .joins(:lesson_sessions => :music_session)
          .joins("LEFT JOIN lesson_package_purchases ON (lesson_package_purchases.lesson_booking_id = lesson_bookings.id AND (lesson_package_purchases.year = #{current_month_first_day.year} AND lesson_package_purchases.month = #{current_month_first_day.month}))")
          .where("lesson_package_purchases.id IS NULL OR (lesson_package_purchases.id IS NOT NULL AND lesson_package_purchases.post_processed = false)")
          .where(payment_style: PAYMENT_STYLE_MONTHLY)
          .active
          .where('music_sessions.scheduled_start >= ?', current_month_first_day)
          .where('music_sessions.scheduled_start <= ?', current_month_last_day).uniq

=begin
      today = now.to_date
      seven_days_in_future = today + 7

      is_different_month = seven_days_in_future.month != today.month
      if is_different_month
        condition = "(((lesson_package_purchases.year = #{current_month_first_day.year} AND lesson_package_purchases.month = #{current_month_first_day.month}) AND (  (EXTRACT(YEAR FROM lesson_sessions.created_at)) = #{current_month_first_day.year} AND (EXTRACT(MONTH FROM lesson_sessions.created_at)) = #{current_month_first_day.month} ) )
                      OR ((lesson_package_purchases.year = #{seven_days_in_future.year} AND lesson_package_purchases.month = #{seven_days_in_future.month}) AND ( (EXTRACT(YEAR FROM lesson_sessions.created_at)) = #{seven_days_in_future.year} AND (EXTRACT(MONTH FROM lesson_sessions.created_at)) = #{seven_days_in_future.month} ) ) )"
      else
        condition = "((lesson_package_purchases.year = #{current_month_first_day.year} AND lesson_package_purchases.month = #{current_month_first_day.month}) AND (  (EXTRACT(YEAR FROM lesson_sessions.created_at)) = #{current_month_first_day.year} AND (EXTRACT(MONTH FROM lesson_sessions.created_at)) = #{current_month_first_day.month} ) )"
      end


      # .where("(lesson_package_purchases.year = #{current_month_first_day.year} AND lesson_package_purchases.month = #{current_month_first_day.month}) OR (lesson_package_purchases.year = #{next_month_last_day.year} AND lesson_package_purchases.month = #{next_month_last_day.month})")

      # find any monthly-billed bookings that have a session coming up within 7 days, and if so, attempt to bill them
      LessonBooking
          .joins(:lesson_sessions)
          .joins("LEFT JOIN lesson_package_purchases ON (lesson_package_purchases.lesson_booking_id = lesson_bookings.id AND #{condition})")
          .where("lesson_package_purchases.id IS NULL OR (lesson_package_purchases.id IS NOT NULL AND lesson_package_purchases.post_processed = false)")
          .where(payment_style: PAYMENT_STYLE_MONTHLY)
          .where(status: STATUS_APPROVED)
          .where('lesson_sessions.created_at >= ?', current_month_first_day)
          .where('lesson_sessions.created_at <= ?', seven_days_in_future).uniq

=end
    end

    def self.bookings(student, teacher, since_at = nil)
      bookings = LessonBooking.where(user_id: student.id, teacher_id: teacher.id)

      if since_at
        bookings = bookings.where('created_at >= ?', since_at)
      end

      bookings
    end

    def self.engaged_bookings(student, teacher, since_at = nil)
      bookings = bookings(student, teacher, since_at)
      bookings.engaged
    end

    def bill_monthly(now)
      LessonBooking.transaction do
        self.lock!

        current_month = Date.new(now.year, now.month, 1)

        bill_for_month(current_month)

        today = now.to_date
        seven_days_in_future = today + 7
        is_different_month = seven_days_in_future.month != today.month
        if is_different_month
          bill_for_month(seven_days_in_future)
        end
      end
    end

    def bill_for_month(day_in_month)
      # try to find lesson package purchase for this month, and last month, and see if they need processing
      current_month_purchase = lesson_package_purchases.where(lesson_booking_id: self.id, user_id: student.id, year: day_in_month.year, month: day_in_month.month).first
      if current_month_purchase.nil?
        current_month_purchase = LessonPackagePurchase.create(user, self, lesson_package_type, day_in_month.year, day_in_month.month)
      end
      current_month_purchase.bill_monthly
    end

    def suspend!
      # when this is called, the calling code sends out a email to let the student and teacher know (it feels unnatural it's not here, though)
      self.status = STATUS_SUSPENDED
      self.active = false
      if self.save
        future_sessions.each do |lesson_session|
          LessonSession.find(lesson_session.id).suspend!
        end
      end
    end

    def unsuspend!
      if self.status == STATUS_SUSPENDED
        self.status = STATUS_APPROVED
        self.active = true
        if self.save
          future_sessions.each do |lesson_session|
            LessonSession.find(lesson_session.id).unsuspend!
          end
        end
      end
    end

    def future_sessions
      lesson_sessions.joins(:music_session).where('scheduled_start > ?', Time.now).order(:created_at)
    end

    def self.schedule_upcoming_lessons
      minimum_start_time = (Time.now + APP_CONFIG.minimum_lesson_booking_hrs * 60*60)

      lesson_bookings = find_bookings_needing_sessions(minimum_start_time)

      lesson_bookings.each do |data|
        lesson_booking = LessonBooking.find(data["lesson_booking_id"])
        lesson_booking.sync_lessons
      end
    end


    def home_url
      APP_CONFIG.external_root_url + "/client#/jamclass"
    end

    def web_url
      APP_CONFIG.external_root_url + "/client#/jamclass/lesson-booking/" + id
    end

    def update_payment_url
      APP_CONFIG.external_root_url + "/client#/jamclass/update-payment"
    end

    def admin_url
      APP_CONFIG.admin_root_url + "/admin/lesson_bookings/" + id
    end
  end
end