class Card < ApplicationRecord
  include Assignable, Attachments, Broadcastable, Closeable, Colored, Entropic, Eventable,
    Exportable, Golden, Mentions, Multistep, Pinnable, Postponable, Promptable,
    Readable, Searchable, Stallable, Statuses, Storage::Tracked, Taggable, Triageable, Watchable

  belongs_to :account, default: -> { board.account }
  belongs_to :board
  belongs_to :creator, class_name: "User", default: -> { Current.user }

  has_many :comments, dependent: :destroy
  has_one_attached :image, dependent: :purge_later

  has_rich_text :description

  before_save :set_default_title, if: :published?
  before_create :assign_number

  after_save   -> { board.touch }, if: :published?
  after_touch  -> { board.touch }, if: :published?
  after_update :handle_board_change, if: :saved_change_to_board_id?

  scope :reverse_chronologically, -> { order created_at:     :desc, id: :desc }
  scope :chronologically,         -> { order created_at:     :asc,  id: :asc  }
  scope :latest,                  -> { order last_active_at: :desc, id: :desc }
  scope :with_users,              -> { preload(creator: [ :avatar_attachment, :account ], assignees: [ :avatar_attachment, :account ]) }
  scope :preloaded,               -> { with_users.preload(:column, :tags, :steps, :closure, :goldness, :activity_spike, :image_attachment, board: [ :entropy, :columns ], not_now: [ :user ]).with_rich_text_description_and_embeds }

  scope :indexed_by, ->(index) do
    case index
    when "stalled" then stalled
    when "postponing_soon" then postponing_soon
    when "closed" then closed
    when "not_now" then postponed.latest
    when "golden" then golden
    when "draft" then drafted
    else all
    end
  end

  scope :sorted_by, ->(sort) do
    case sort
    when "newest" then reverse_chronologically
    when "oldest" then chronologically
    when "latest" then latest
    else latest
    end
  end

  delegate :accessible_to?, to: :board

  def publicly_accessible?
    published? && board.publicly_accessible?
  end

  def card
    self
  end

  def to_param
    number.to_s
  end

  def move_to(new_board)
    transaction do
      card.update!(board: new_board)
      card.events.update_all(board_id: new_board.id)
    end
  end

  def filled?
    title.present? || description.present?
  end

  private
    STORAGE_BATCH_SIZE = 1000

    # Override to include comments, but only load comments that have attachments.
    # Cards can have thousands of comments; most won't have attachments.
    # Streams in batches to avoid loading all IDs into memory at once.
    def storage_transfer_records
      comment_ids_with_attachments = storage_comment_ids_with_attachments

      if comment_ids_with_attachments.any?
        [ self, *comments.where(id: comment_ids_with_attachments).to_a ]
      else
        [ self ]
      end
    end

    def storage_comment_ids_with_attachments
      direct = []
      rich_text_map = {}

      # Stream comment IDs in batches to avoid loading all into memory
      comments.in_batches(of: STORAGE_BATCH_SIZE) do |batch|
        batch_ids = batch.pluck(:id)

        direct.concat \
          ActiveStorage::Attachment
            .where(record_type: "Comment", record_id: batch_ids)
            .distinct
            .pluck(:record_id)

        ActionText::RichText
          .where(record_type: "Comment", record_id: batch_ids)
          .pluck(:id, :record_id)
          .each { |rt_id, comment_id| rich_text_map[rt_id] = comment_id }
      end

      embed_comment_ids = if rich_text_map.any?
        rich_text_map.keys.each_slice(STORAGE_BATCH_SIZE).flat_map do |batch_ids|
          ActiveStorage::Attachment
            .where(record_type: "ActionText::RichText", record_id: batch_ids)
            .distinct
            .pluck(:record_id)
        end.filter_map { |rt_id| rich_text_map[rt_id] }
      else
        []
      end

      (direct + embed_comment_ids).uniq
    end

    def set_default_title
      self.title = "Untitled" if title.blank?
    end

    def handle_board_change
      old_board = account.boards.find_by(id: board_id_before_last_save)

      transaction do
        update! column: nil
        track_board_change_event(old_board.name)
        grant_access_to_assignees unless board.all_access?
      end

      remove_inaccessible_notifications_later
    end

    def track_board_change_event(old_board_name)
      track_event "board_changed", particulars: { old_board: old_board_name, new_board: board.name }
    end

    def grant_access_to_assignees
      board.accesses.grant_to(assignees)
    end

    def assign_number
      self.number ||= account.increment!(:cards_count).cards_count
    end
end