module SimpleAutocomplete
  VERSION = File.read( File.join(File.dirname(__FILE__),'..','VERSION') ).strip
end

#Example:
#
#  # Controller
#  class BlogController < ApplicationController
#    autocomplete_for :post, :title
#  end
#
#  # View
#  <%= text_field :post, title, :class => 'autocomplete', 'autocomplete_url'=>autocomplete_for_post_title_posts_path %>
#
#  #routes.rb
#  map.resources :users, :collection => { :autocomplete_for_user_name => :get}
#
#  # Options
#  By default, autocomplete_for limits the results to 10 entries,
#  and sorts by the given field.
#
#  autocomplete_for takes a third parameter, an options hash to
#  the find method used to search for the records:
#
#    autocomplete_for :post, :title, :limit => 15, :order => 'created_at DESC'
#
#  # Block
#  with a block you can generate any output you need(passed into render :inline):
#    autocomplete_for :post, :title do |items|
#      items.map{|item| "#{item.title} -- #{item.id}"}.join("\n")
#    end
class ActionController::Base
  def self.autocomplete_for(object, method, options = {}, &block)
    define_method("autocomplete_for_#{object}_#{method}") do
      model = object.to_s.camelize.constantize
      find_options = {
        :conditions => [ "LOWER(#{method}) LIKE ?", '%'+params[:q].to_s.downcase + '%' ],
        :order => "#{method} ASC",
        :limit => 10
        }.merge!(options)

      @items = model.scoped(find_options)

      out = if block_given?
        instance_exec @items, &block
      else
        %Q[<%= @items.map {|item| h(item.#{method})}.uniq.join("\n")%>]
      end
      render :inline => out
    end
  end
end

# Store the value of the autocomplete field as association
# autocomplete_for('user','name')
# -> the auto_user_name field will be resolved to a User, using User.find_by_autocomplete_name(value)
# -> Post has autocomplete_for('user','name')
# -> User has find_by_autocomplete('name')
class ActiveRecord::Base
  def self.autocomplete_for(model, attribute, options={})
    name = options[:name] || model.to_s.underscore
    name = name.to_s
    model = model.to_s.camelize.constantize

    # is the correct finder defined <-> warn users
    finder = "find_by_autocomplete_#{attribute}"
    unless model.respond_to? finder
      raise "#{model} does not respond to #{finder}, maybe you forgot to add auto_complete_for(:#{attribute}) to #{model}?"
    end

    #auto_user_name= "Hans"
    define_method "auto_#{name}_#{attribute}=" do |value|
      send "#{name}=", model.send(finder, value)
    end

    #auto_user_name
    define_method "auto_#{name}_#{attribute}" do
      send(name).try(:send, attribute).to_s
    end
  end

  def self.find_by_autocomplete(attr)
    metaclass = (class << self; self; end)
    metaclass.send(:define_method, "find_by_autocomplete_#{attr}") do |value|
      return if value.blank?
      self.first(:conditions => [ "LOWER(#{attr}) = ?", value.to_s.downcase ])
    end
  end
end