eprothro/cassie

require_relative 'table_definition'

module Cassie::Schema::Migration::DSL
    # Module grouping methods used in migrations to make table operations like:
    # - adding/removing columns
    # - changing column types
    # - renaming columns
  module ColumnOperations
    # Adds a column to a table.
    #
    # options: same options you would pass to create a table with that column
    # (i.e. :limit might be applicable)

    def add_column(table_name, column_name, type, options = {})
      table_definition = TableDefinition.new

      if !table_definition.respond_to?(type)
        raise Errors::MigrationDefinitionError("Type '#{type}' is not valid for cassandra migration.")
      end

      table_definition.send(type, column_name, options)

      announce_operation "add_column(#{column_name}, #{type})"

      cql =  "ALTER TABLE #{table_name} ADD "
      cql << table_definition.to_add_column_cql
      announce_suboperation cql

      execute cql
    end

    # Removes a column from the table
    def remove_column(table_name, column_name)
      announce_operation "drop_table(#{table_name})"

      cql =  "ALTER TABLE #{table_name} DROP #{column_name}"
      announce_suboperation cql

      execute cql
    end
  end
end