class DatabaseCleaner::Spec::DatabaseHelper

def self.with_all_dbs &block
  %w[mysql2 sqlite3 postgres].map(&:to_sym).each do |db|
    yield new(db)
  end
end

def create_db
  if db == :sqlite3
    # NO-OP
  elsif db == :postgres
    establish_connection default_config.merge('database' => 'postgres')
    connection.execute "CREATE DATABASE #{default_config['database']}" rescue nil
  else
    establish_connection default_config.merge("database" => nil)
    connection.execute "CREATE DATABASE IF NOT EXISTS #{default_config['database']}"
  end
end

def db_config
  config_path = 'spec/support/config.yml'
  @db_config ||= YAML.load(IO.read(config_path))
end

def default_config
  db_config[db.to_s]
end

def drop_db
  if db == :sqlite3
    begin
      File.unlink(db_config['sqlite3']['database'])
    rescue Errno::ENOENT
    end
  elsif db == :postgres
    # FIXME
    connection.execute "DROP TABLE IF EXISTS users"
    connection.execute "DROP TABLE IF EXISTS agents"
  else
    connection.execute "DROP DATABASE IF EXISTS #{default_config['database']}"
  end
end

def establish_connection(config = default_config)
  raise NotImplementedError
end

def load_schema
  connection.execute <<-SQL
    CREATE TABLE IF NOT EXISTS users (
      id SERIAL PRIMARY KEY,
      name INTEGER
    );
  SQL
  connection.execute <<-SQL
    CREATE TABLE IF NOT EXISTS agents (
      name INTEGER
    );
  SQL
end

def setup
  create_db
  establish_connection
  load_schema
end

def teardown
  drop_db
end