module PluginAWeek #:nodoc:
  module PluginMigrations
    module Extensions #:nodoc:
      # Adds support for the plugin schema info table
      module SchemaStatements
        def self.included(base) #:nodoc:
          base.class_eval do
            alias_method_chain :initialize_schema_information, :plugins
            alias_method_chain :dump_schema_information, :plugins
          end
        end
        
        # Creates the plugin schema info table
        def initialize_schema_information_with_plugins
          initialize_schema_information_without_plugins
          
          begin
            execute "CREATE TABLE #{PluginAWeek::PluginMigrations::Migrator.schema_info_table_name} (plugin_name #{type_to_sql(:string)}, version #{type_to_sql(:integer)})"
          rescue ActiveRecord::StatementInvalid
            # Schema has been initialized
          end
        end
        
        # Dumps the plugin schema info table as well as information about the
        # current plugin migrations
        def dump_schema_information_with_plugins
          schema_information = []
          
          dump = dump_schema_information_without_plugins
          schema_information << dump if dump
          
          begin
            plugins = ActiveRecord::Base.connection.select_all("SELECT * FROM #{PluginAWeek::PluginMigrations::Migrator.schema_info_table_name}")
            plugins.each do |plugin|
              if (version = plugin['version'].to_i) > 0
                plugin_name = ActiveRecord::Base.quote_value(plugin['plugin_name'])
                schema_information << "INSERT INTO #{PluginAWeek::PluginMigrations::Migrator.schema_info_table_name} (plugin_name, version) VALUES (#{plugin_name}, #{version})"
              end
            end
          rescue ActiveRecord::StatementInvalid 
            # No Schema Info
          end
          
          schema_information.join(";\n")
        end
      end
    end
  end
end

ActiveRecord::ConnectionAdapters::SchemaStatements.class_eval do
  include PluginAWeek::PluginMigrations::Extensions::SchemaStatements
end