mastodon/app/policies/status_policy.rb

# frozen_string_literal: true

class StatusPolicy < ApplicationPolicy
  def initialize(current_account, record, preloaded_relations = {})
    super(current_account, record)

    @preloaded_relations = preloaded_relations
  end

  def show?
    return false if author.unavailable?

    if requires_mention?
      owned? || mention_exists?
    elsif private?
      owned? || following_author? || mention_exists?
    else
      current_account.nil? || (!author_blocking? && !author_blocking_domain?)
    end
  end

  # This is about requesting a quote post, not validating it
  def quote?
    owned? || active_mention_exists? || quote_approved_by_policy?
  end

  def reblog?
    !requires_mention? && (!private? || owned?) && show? && !blocking_author?
  end

  def favourite?
    show? && !blocking_author?
  end

  def destroy?
    owned?
  end

  alias unreblog? destroy?

  def update?
    owned?
  end

  private

  def quote_approved_by_policy?
    flattened_policy = record.quote_approval_policy | (record.quote_approval_policy >> 16)
    return true if flattened_policy & (Status::QUOTE_APPROVAL_POLICY_FLAGS[:unknown] | Status::QUOTE_APPROVAL_POLICY_FLAGS[:public]) != 0

    # TODO: support `:followed`
    (flattened_policy & Status::QUOTE_APPROVAL_POLICY_FLAGS[:followers] != 0) && following_author?
  end

  def requires_mention?
    record.direct_visibility? || record.limited_visibility?
  end

  def owned?
    author.id == current_account&.id
  end

  def private?
    record.private_visibility?
  end

  def mention_exists?
    return false if current_account.nil?

    if record.mentions.loaded?
      record.mentions.any? { |mention| mention.account_id == current_account.id }
    else
      record.mentions.exists?(account: current_account)
    end
  end

  def active_mention_exists?
    return false if current_account.nil?

    if record.active_mentions.loaded?
      record.active_mentions.any? { |mention| mention.account_id == current_account.id }
    else
      record.active_mentions.exists?(account: current_account)
    end
  end

  def author_blocking_domain?
    return false if current_account.nil? || current_account.domain.nil?

    author.domain_blocking?(current_account.domain)
  end

  def blocking_author?
    return false if current_account.nil?

    @preloaded_relations[:blocking] ? @preloaded_relations[:blocking][author.id] : current_account.blocking?(author)
  end

  def author_blocking?
    return false if current_account.nil?

    @preloaded_relations[:blocked_by] ? @preloaded_relations[:blocked_by][author.id] : author.blocking?(current_account)
  end

  def following_author?
    return false if current_account.nil?

    @preloaded_relations[:following] ? @preloaded_relations[:following][author.id] : current_account.following?(author)
  end

  def author
    record.account
  end
end