# NotificationService class
#
# Used for notifing users with emails about different events
#
# Ex.
#   NotificationService.new.new_issue(issue, current_user)
#
class NotificationService
  # Always notify user about ssh key added
  # only if ssh key is not deploy key
  #
  # This is security email so it will be sent
  # even if user disabled notifications
  def new_key(key)
    if key.user
      Notify.delay.new_ssh_key_email(key.id)
    end
  end

  # TODO: When we close an issue we should send next emails:
  #
  #  * issue author if his notification level is not Disabled
  #  * issue assignee if his notification level is not Disabled
  #  * project team members with notification level higher then Participating
  #
  def close_issue(issue, current_user)
    recipients = reject_muted_users([issue.author, issue.assignee])

    # Dont send email to me when I close an issue
    recipients.delete(current_user)

    recipients.each do |recipient|
      Notify.delay.issue_status_changed_email(recipient.id, issue.id, issue.state, current_user.id)
    end
  end

  # When we reassign an issue we should send next emails:
  #
  #  * issue old assignee if his notification level is not Disabled
  #  * issue new assignee if his notification level is not Disabled
  #
  def reassigned_issue(issue, current_user)
    reassign_email(issue, current_user, 'reassigned_issue_email')
  end

  # When create an issue we should send next emails:
  #
  #  * issue assignee if his notification level is not Disabled
  #
  def new_issue(issue, current_user)

    if issue.assignee && issue.assignee != current_user
      # skip if assignee notification disabled
      return true if issue.assignee.notification.disabled?

      Notify.delay.new_issue_email(issue.id)
    end
  end

  # When create a merge request we should send next emails:
  #
  #  * mr assignee if his notification level is not Disabled
  #
  def new_merge_request(merge_request, current_user)
    if merge_request.assignee && merge_request.assignee != current_user
      # skip if assignee notification disabled
      return true if merge_request.assignee.notification.disabled?

      Notify.delay.new_merge_request_email(merge_request.id)
    end
  end

  # When we reassign a merge_request we should send next emails:
  #
  #  * merge_request old assignee if his notification level is not Disabled
  #  * merge_request assignee if his notification level is not Disabled
  #
  def reassigned_merge_request(merge_request, current_user)
    reassign_email(merge_request, current_user, 'reassigned_merge_request_email')
  end

  # Notify new user with email after creation
  def new_user(user)
    # Dont email omniauth created users
    Notify.delay.new_user_email(user.id, user.password) unless user.extern_uid?
  end

  # Notify users on new note in system
  #
  # TODO: split on methods and refactor
  #
  def new_note(note)
    if note.notify
      users = note.project.users
      users = reject_muted_users(users)
      users.delete(note.author)

      # Note: wall posts are not "attached" to anything, so fall back to "Wall"
      noteable_type = note.noteable_type.presence || "Wall"
      notify_method = "note_#{noteable_type.underscore}_email".to_sym

      if Notify.respond_to? notify_method
        users.each do |user|
          Notify.delay.send(notify_method, user.id, note.id)
        end
      end
    elsif note.notify_author && note.commit_author
      Notify.delay.note_commit_email(note.commit_author.id, note.id)
    end
  end

  def new_team_member(users_project)
    Notify.delay.project_access_granted_email(users_project.id)
  end

  def update_team_member(users_project)
    Notify.delay.project_access_granted_email(users_project.id)
  end

  protected

  # Remove users with disabled notifications from array
  # Also remove duplications and nil recipients
  def reject_muted_users(users)
    users.compact.uniq.reject do |user|
      user.notification.disabled?
    end
  end

  def reassign_email(target, current_user, method)
    recipients = User.where(id: [target.assignee_id, target.assignee_id_was])

    # reject users with disabled notifications
    recipients = reject_muted_users(recipients)

    # Reject me from recipients if I reassign an item
    recipients.delete(current_user)

    recipients.each do |recipient|
      Notify.delay.send(method, recipient.id, target.id, target.assignee_id_was)
    end
  end
end