require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/class/attribute_accessors'

module Rails
  module DataMapper

    mattr_accessor :configuration

    class Configuration

      def self.for(root, database_yml_hash)
        Rails::DataMapper.configuration ||= new(root, database_yml_hash)
      end

      attr_reader :root, :raw

      def environments
        raw.keys
      end

      def repositories
        @repositories ||= @raw.reject { |k,v| k =~ /defaults/ }.inject({}) do |repositories, pair|
          environment, config = pair.first, pair.last
          repositories[environment] = begin
            c = config['repositories'] || {}
            c['default'] = config.except('repositories') if config.except('repositories')
            normalize_repository_config(c)
          end
          repositories
        end
      end

      def resource_naming_convention
        @resource_naming_convention ||= {}
      end

    private

      def initialize(root, database_yml_hash)
        @root, @raw = root, database_yml_hash
      end

      def normalize_repository_config(hash)
        config = {}
        hash.each do |key, value|
          config[key] = if value.kind_of?(Hash)
            normalize_repository_config(value)
          elsif key == 'port'
            value.to_i
          elsif key == 'adapter' && value == 'postgresql'
            'postgres'
          elsif key == 'database' && hash['adapter'] == 'sqlite3'
            value == ':memory:' ? value : File.expand_path(hash['database'], root)
          else
            value
          end
        end
        config
      end

    end

  end
end