module JamRuby
  class MusicSession < ActiveRecord::Base

    NO_RECURRING = 'once'
    RECURRING_WEEKLY = 'weekly'

    RECURRING_MODES = [NO_RECURRING, RECURRING_WEEKLY]

    attr_accessor :legal_terms, :recurring_mode

    self.table_name = "music_sessions"

    self.primary_key = 'id'

    belongs_to :creator,:class_name => 'JamRuby::User', :foreign_key => :user_id, :inverse_of => :music_session_histories

    belongs_to :band, :class_name => 'JamRuby::Band',  :foreign_key => :band_id, :inverse_of => :music_sessions

    belongs_to :active_music_session, :class_name => 'JamRuby::ActiveMusicSession', foreign_key: :music_session_id

    has_many :music_session_user_histories, :class_name => "JamRuby::MusicSessionUserHistory", :foreign_key => "music_session_id", :dependent => :delete_all
    has_many :comments, :class_name => "JamRuby::MusicSessionComment", :foreign_key => "music_session_id"
    has_many :likes, :class_name => "JamRuby::MusicSessionLiker", :foreign_key => "session_id"
    has_many :plays, :class_name => "JamRuby::PlayablePlay", :as => :playable, :dependent => :destroy
    has_one :share_token, :class_name => "JamRuby::ShareToken", :inverse_of => :shareable, :foreign_key => 'shareable_id'
    has_one :feed, :class_name => "JamRuby::Feed", :inverse_of => :music_session, :foreign_key => 'music_session_id', :dependent => :destroy
    belongs_to :genre, :class_name => "JamRuby::Genre", :inverse_of => :music_sessions, :foreign_key => 'genre_id'
    has_many :join_requests, :foreign_key => "music_session_id", :inverse_of => :music_session, :class_name => "JamRuby::JoinRequest", :foreign_key => "music_session_id"
    has_many :invitations, :foreign_key => "music_session_id", :inverse_of => :music_session, :class_name => "JamRuby::Invitation", :foreign_key => "music_session_id"
    has_many :invited_musicians, :through => :invitations, :class_name => "JamRuby::User", :foreign_key => "receiver_id", :source => :receiver
    has_many :fan_invitations, :foreign_key => "music_session_id", :inverse_of => :music_session, :class_name => "JamRuby::FanInvitation", :foreign_key => "music_session_id"
    has_many :invited_fans, :through => :fan_invitations, :class_name => "JamRuby::User", :foreign_key => "receiver_id", :source => :receiver

    validates :genre, :presence => true
    validates :description, :presence => true, :no_profanity => true
    validates :fan_chat, :inclusion => {:in => [true, false]}
    validates :fan_access, :inclusion => {:in => [true, false]}
    validates :approval_required, :inclusion => {:in => [true, false]}
    validates :musician_access, :inclusion => {:in => [true, false]}
    validates :legal_terms, :inclusion => {:in => [true]}, :on => :create
    validates :creator, :presence => true
    # validates :recurring_mode, :inclusion => {:in => RECURRING_MODES}, :on => :create
    validate :creator_is_musician

    before_create :generate_share_token
    before_create :add_to_feed

    SHARE_TOKEN_LENGTH = 8

    SEPARATOR = '|'

    def add_to_feed
      feed = Feed.new
      feed.music_session = self
    end

    def comment_count
      self.comments.size
    end

    def grouped_tracks
      tracks = []
      self.music_session_user_histories.each do |msuh|
        user = User.find(msuh.user_id)
        t = Track.new
        t.musician = user
        t.instrument_ids = []
        # this treats each track as a "user", which has 1 or more instruments in the session
        unless msuh.instruments.blank?
          instruments = msuh.instruments.split(SEPARATOR)
          instruments.each do |instrument|
            if !t.instrument_ids.include? instrument
              t.instrument_ids << instrument
            end
          end
        end
        tracks << t
      end
      tracks
    end

    def self.index(current_user, user_id, band_id = nil, genre = nil)
      hide_private = false
      if current_user.id != user_id
        hide_private = false # TODO: change to true once public flag exists
      end

      query = MusicSession
        .joins(
          %Q{
            LEFT OUTER JOIN
              music_sessions_user_history
            ON
              music_sessions.id = music_sessions_user_history.music_session_id
          }
        )
        .where(
          %Q{
              music_sessions.user_id = '#{user_id}'
          }
        )

      #query = query.where("public = false") unless !hide_private
      query = query.where("music_sessions.band_id = '#{band_id}") unless band_id.nil?
      query = query.where("music_sessions.genres like '%#{genre}%'") unless genre.nil?
      return query
    end

    def self.create user, params
      band = Band.find(params[:band]) unless params[:band].nil?

      ms                    = MusicSession.new
      ms.name               = params[:description][0..40]
      ms.description        = params[:description]
      ms.musician_access    = params[:musician_access]
      ms.approval_required  = params[:approval_required]
      ms.fan_access         = params[:fan_access]
      ms.fan_chat           = params[:fan_chat]
      ms.band               = band
      ms.legal_policy       = params[:legal_policy]
      ms.language           = params[:language]
      ms.genre_id           = (params[:genres].length > 0 ? params[:genres][0] : nil) if params[:genres]
      ms.legal_terms        = true
      ms.creator            = user

      ms.save
    end

    def unique_users
      User
      .joins(:music_session_user_histories)
      .group("users.id")
      .order("users.id")
      .where(%Q{ music_sessions_user_history.music_session_id = '#{id}'})
    end

    # returns one user history per user, with instruments all crammed together, and with total duration
    def unique_user_histories
      MusicSessionUserHistory
      .joins(:user)
      .select("STRING_AGG(instruments, '|') AS total_instruments,
               SUM(date_part('epoch', COALESCE(music_sessions_user_history.session_removed_at, music_sessions_user_history.created_at) - music_sessions_user_history.created_at)) AS total_duration,
               music_sessions_user_history.user_id, music_sessions_user_history.music_session_id, users.first_name, users.last_name, users.photo_url")
      .group("music_sessions_user_history.user_id, music_sessions_user_history.music_session_id, users.first_name, users.last_name, users.photo_url")
      .order("music_sessions_user_history.user_id")
      .where(%Q{ music_sessions_user_history.music_session_id = '#{id}'})
    end

    def duration_minutes
      end_time = self.session_removed_at || Time.now
      (end_time - self.created_at) / 60.0
    end

    def music_session_user_histories
      @msuh ||= JamRuby::MusicSessionUserHistory
        .where(:music_session_id => self.id)
        .order('created_at DESC')
    end

    def comments
      @comments ||= JamRuby::MusicSessionComment
        .where(:music_session_id => self.id)
        .order('created_at DESC')
    end

    def likes
      @likes ||= JamRuby::MusicSessionLiker
        .where(:music_session_id => self.music_session_id)
    end

    # these are 'users that are a part of this session'
    # which means are currently in the music_session, or, rsvp'ed, or creator
    def part_of_session? user
      # XXX check RSVP'ed
      user == self.creator || (active_music_session ? active_music_session.users.exists?(user) : false)
    end

    def is_over?
      active_music_session.nil?
    end

    def has_mount?
      active_music_session && active_music_session.mount
    end

    def recordings
      Recording.where(music_session_id: self.id)
    end

    def end_history
      self.update_attribute(:session_removed_at, Time.now)


      # ensure all user histories are closed
      music_session_user_histories.each do |music_session_user_history|
        music_session_user_history.end_history

        # then update any users that need their user progress updated
        if music_session_user_history.duration_minutes > 15 && music_session_user_history.max_concurrent_connections >= 3
          music_session_user_history.user.update_progression_field(:first_real_music_session_at)
        end
      end

    end

    def self.removed_music_session(session_id)
      hist = self
        .where(:id => session_id)
        .limit(1)
        .first

      hist.end_history if hist

      Notification.send_session_ended(session_id)
    end

    def remove_non_alpha_num(token)
      token.gsub(/[^0-9A-Za-z]/, '')
    end

    private

    def generate_share_token

      token = loop do
        token = SecureRandom.urlsafe_base64(SHARE_TOKEN_LENGTH, false)
        token = remove_non_alpha_num(token)
        token.upcase!
        break token unless ShareToken.exists?(token: token)
      end

      self.share_token = ShareToken.new
      self.share_token.token = token
      self.share_token.shareable_type = "session"
    end

    def creator_is_musician
      unless creator && creator.musician?
        errors.add(:creator, ValidationMessages::MUST_BE_A_MUSICIAN)
      end
    end

  end
end