module ActiveRecord
  class Base
    def self.load_cpk_adapter(adapter)
      if adapter.to_s == 'postgresql'
        require "composite_primary_keys/connection_adapters/#{adapter}_adapter.rb"
      end
    end
    
    def self.establish_connection(spec = ENV["DATABASE_URL"])
      resolver = ConnectionSpecification::Resolver.new spec, configurations
      spec = resolver.spec
      
      # CPK
      load_cpk_adapter(spec.config[:adapter])
      
      unless respond_to?(spec.adapter_method)
        raise AdapterNotFound, "database configuration specifies nonexistent #{spec.config[:adapter]} adapter"
      end

      remove_connection
      connection_handler.establish_connection name, spec
    end

    class << self
      # Returns the connection currently associated with the class. This can
      # also be used to "borrow" the connection to do database work unrelated
      # to any of the specific Active Records.
      def connection
        retrieve_connection
      end

      # Returns the configuration of the associated connection as a hash:
      #
      #  ActiveRecord::Base.connection_config
      #  # => {:pool=>5, :timeout=>5000, :database=>"db/development.sqlite3", :adapter=>"sqlite3"}
      #
      # Please use only for reading.
      def connection_config
        connection_pool.spec.config
      end

      def connection_pool
        connection_handler.retrieve_connection_pool(self)
      end

      def retrieve_connection
        connection_handler.retrieve_connection(self)
      end

      # Returns true if Active Record is connected.
      def connected?
        connection_handler.connected?(self)
      end

      def remove_connection(klass = self)
        connection_handler.remove_connection(klass)
      end

      def clear_active_connections!
        connection_handler.clear_active_connections!
      end

      delegate :clear_reloadable_connections!,
        :clear_all_connections!,:verify_active_connections!, :to => :connection_handler
    end
  end
end