module BetterAr
  module ClassMethods

    # Breaks down the hash to do a {ActiveRecord::Relation} query
    #
    # example:
    #  User.all(:age => 10, :limit! => 2, :offset! => 3, :order! => :name)
    #
    # is the same as:
    #  User.where(:age => 10).limit(2).offset(3).order(:name)
    #
    # if the key :conditions is present it will fall back to legacy
    #
    # any key with the '!' at the end will be assumed to be a sql operator. The key should match either an {ActiveRecord::Relation} instance method or an ARel predicate.
    #
    # Implicit joins are supported.
    # example:
    #  User.all(:records => {:name => 'test'})
    #
    # is the same as:
    #  User.joins(:records).where(:records => {:name => 'test'})
    #
    # @param [Hash]
    #   Optional
    # @return [ActiveRecord::Relation]
    def all(opts = {})
      relation = scoped.clone

      unless opts.key?(:conditions)
        unless opts.empty?
          opts.keys.select { |key| key.to_s =~ /!$/ }.each do |predicate|
            if value = opts.delete(predicate)
              relation = relation.send(predicate.to_s.sub('!',''), value)
            end
          end

          reflect_on_all_associations.map(&:name).each do |name|
            if opts.key?(name)
              relation = relation.joins(name)
            end
          end

          relation.where(opts)
        end

        if opts.empty?
          relation
        else
          relation.where(opts)
        end
      else
        relation.all(opts)
      end
    end

    # Forces a limit of 1 on the collection
    #
    # example:
    #  User.first(:age => 10, :name => 'Brian')
    #
    # is the same as:
    #  User.where(:age => 10, :name => 'Brian').limit(1).first
    #
    # if the key :conditions is present it will fall back to legacy
    #
    # @param [Hash]
    #   Optional follows same convention as {#all}
    # @return [ActiveRecord::Base]
    def first(opts = {})
      unless opts.key?(:conditions)
        all(opts.merge(:limit! => 1)).first
      else
        scoped.first(opts)
      end
    end

    # Does a count on the query
    #
    # example:
    #  User.count(:age => 20)
    #
    # is the same as:
    #  User.where(:age => 20).count
    #
    # if the key :conditions is present it will fall back to legacy
    #
    # @param [Hash]
    #   Optional follows same convention as {#all}
    # @return [Integer]
    def count(opts = {})
      unless opts.key?(:conditions)
        all(opts).count
      else
        scoped.count(opts)
      end
    end
  end

end

ActiveRecord::Base.class_eval do
  class << self
    remove_method :all
    remove_method :first
    remove_method :count
  end
end

ActiveRecord::Base.send(:extend, BetterAr::ClassMethods)