module Commontator
  class Comment < ActiveRecord::Base
    belongs_to :creator, :polymorphic => true
    belongs_to :editor, :polymorphic => true
    belongs_to :thread

    has_one :commontable, :through => :thread

    validates_presence_of :creator, :on => :create
    validates_presence_of :editor, :on => :update
    validates_presence_of :thread
    validates_presence_of :body

    validates_uniqueness_of :body, :scope => [:creator_type, :creator_id, :thread_id],
                                   :message => 'has already been posted'

    protected

    cattr_accessor :acts_as_votable_initialized

    public

    def is_votable?
      return true if acts_as_votable_initialized
      return false unless self.class.respond_to?(:acts_as_votable)
      self.class.acts_as_votable
      self.class.acts_as_votable_initialized = true
    end

    def get_vote_by(user)
      return nil unless is_votable? && user && user.is_commontator
      votes.where(:voter_type => user.class.name, :voter_id => user.id).first
    end

    def is_modified?
      !editor.nil?
    end

    def is_deleted?
      !deleted_at.blank?
    end

    def delete_by(user)
      return false if is_deleted?
      self.deleted_at = Time.now
      self.editor = user
      self.save
    end

    def undelete_by(user)
      return false unless is_deleted?
      self.deleted_at = nil
      self.editor = user
      self.save
    end

    def created_timestamp
      config = thread.config
      "#{config.comment_create_verb_past.capitalize} on " + \
        created_at.strftime(config.timestamp_format)
    end

    def updated_timestamp
      config = thread.config
      is_modified? ? ("Last #{config.comment_edit_verb_past} on " + \
        updated_at.strftime(config.timestamp_format)) : ''
    end

    ##################
    # Access Control #
    ##################

    def can_be_read_by?(user)
      ((!is_deleted? || thread.config.deleted_comments_are_visible) &&\
        thread.can_be_read_by?(user)) ||\
      thread.can_be_edited_by?(user)
    end

    def can_be_created_by?(user)
      !thread.is_closed? && user == creator && thread.can_be_read_by?(user)
    end

    def can_be_edited_by?(user)
      (!thread.is_closed? && !is_deleted? &&\
        (thread.comments.last == self || thread.config.can_edit_old_comments) &&\
        user == creator && thread.config.can_edit_own_comments && thread.can_be_read_by?(user)) ||\
      (thread.config.admin_can_edit_comments && thread.can_be_edited_by?(user))
    end

    def can_be_deleted_by?(user)
      (!thread.is_closed? && (!is_deleted? || editor == user) &&\
        (thread.comments.last == self || thread.config.can_delete_old_comments) &&\
        user == creator && thread.config.can_delete_own_comments &&\
        thread.can_be_read_by?(user)) ||\
      thread.can_be_edited_by?(user)
    end

    def can_be_voted_on?
      !thread.is_closed? && is_votable? && !is_deleted? && thread.config.can_vote_on_comments
    end

    def can_be_voted_on_by?(user)
      can_be_voted_on? && user && user.is_commontator && user != creator && thread.can_be_read_by?(user)
    end
  end
end