# Copyright (c) 2008-2013 Michael Dvorkin and contributors.
#
# Fat Free CRM is freely distributable under the terms of MIT license.
# See MIT-LICENSE file or http://www.opensource.org/licenses/mit-license.php
#------------------------------------------------------------------------------
require 'paper_trail'

Version.const_set :ASSETS, %w(all tasks campaigns leads accounts contacts opportunities comments emails)
Version.const_set :EVENTS, %w(all_events create view update destroy)
Version.const_set :DURATION, %w(one_hour one_day two_days one_week two_weeks one_month)

Version.class_eval do

  attr_accessible :related
  belongs_to :related, :polymorphic => true
  belongs_to :user, :foreign_key => :whodunnit

  scope :default_order,  order('created_at DESC')
  scope :include_events, lambda { |*events| where(:event => events) }
  scope :exclude_events, lambda { |*events| where('event NOT IN (?)', events) }
  scope :for,            lambda { |user| where(:whodunnit => user.id.to_s) }

  class << self

    def recent_for_user(user, limit = 10)
      # Hybrid SQL/Ruby to build a unique list of the most recent entities that the
      # user has interacted with
      versions = []
      offset = 0
      while versions.size < limit
        query = includes(:item).
                where(:whodunnit => user.id.to_s).
                where(:item_type => ENTITIES).
                limit(limit * 2).
                offset(offset).
                default_order

        break if query.size == 0
        versions += query.select {|v| v.item.present? }
        versions.uniq! {|v| [v.item_id, v.item_type]}
        offset += limit * 2
      end
      versions[0...10]
    end

    def latest(options = {})
      includes(:item, :related, :user).
      where(({:item_type => options[:asset]} if options[:asset])).
      where(({:event     => options[:event]} if options[:event])).
      where(({:whodunnit => options[:user].to_s}  if options[:user])).
      where('versions.created_at >= ?', Time.zone.now - (options[:duration] || 2.days)).
      limit(options[:max]).
      default_order
    end

    def related_to(object)
      where('(item_id = :id AND item_type = :type) OR (related_id = :id AND related_type = :type)',
        :id => object.id, :type => object.class.name)
    end

    def history(object)
      related_to(object).exclude_events(:view).default_order
    end

    def visible_to(user)
      scoped.delete_if do |version|
        if item = version.item || version.reify
          if item.respond_to?(:access) # NOTE: Tasks don't have :access as of yet.
            # Delete from scope if it shouldn't be visible
            next item.user_id != user.id &&
              item.assigned_to != user.id &&
              (item.access == "Private" ||
                (item.access == "Shared" &&
                 !item.permissions.map(&:user_id).include?(user.id)))
          end
          # Don't delete any objects that don't have :access method (e.g. tasks)
          next false
        end
        # Delete from scope if no object can be found or reified (e.g. from 'show' events)
        true
      end

    end

  end
end