class PgTester

# File lib/pg_tester.rb, line 10
def initialize(opts={})
  @user            = opts.fetch(:user) { 'pgtester' }
  @database        = opts.fetch(:database) { 'pgtester' }
  @port            = opts.fetch(:port) { 6433 }
  @host            = opts.fetch(:host) { 'localhost' }
  @data_dir        = opts.fetch(:data_dir) { '/tmp/pg_tester' }
  @initdb_path     = opts.fetch(:initdb_path) { shell_out('which initdb') }
  @pgctl_path      = opts.fetch(:pgctl_path) { shell_out('which pg_ctl') }
  @createuser_path = opts.fetch(:createuser_path) { shell_out('which createuser') }
  @createdb_path   = opts.fetch(:createdb_path) { shell_out('which createdb') }
  @connection      = nil

  raise 'please install postgresql' unless @initdb_path && !@initdb_path.empty?
end

# File lib/pg_tester.rb, line 25
def create_data_dir()
  Dir.mkdir(@data_dir) unless File.exists? @data_dir
end

# File lib/pg_tester.rb, line 71
def exec(query)
  if block_given?
    setup
    yield(@connection.exec(query))
    teardown
  else
    raise 'please run setup' unless @connection
    return @connection.exec(query)
  end
end

# File lib/pg_tester.rb, line 82
def exec_params(query, params)
  if block_given?
    setup
    yield(@connection.exec_params(query, params))
    teardown
  else
    raise 'please run setup' unless @connection
    return @connection.exec_params(query, params)
  end 
end

# File lib/pg_tester.rb, line 33
def initdb()
  shell_out "#{@initdb_path} #{@data_dir} -A trust -E utf-8"
end

# File lib/pg_tester.rb, line 29
def remove_data_dir()
  FileUtils.remove_dir(@data_dir)
end

# File lib/pg_tester.rb, line 37
def rundb()
  pid = Process.fork { shell_out "#{@pgctl_path} start -o '-p #{@port}' -D #{@data_dir}" }
  # give a second for postgresql to startup
  sleep(1)
  Process.detach(pid)
end

# File lib/pg_tester.rb, line 56
def setup()
  create_data_dir
  initdb
  rundb
  setup_test_user
  setup_test_database
  setup_pg_connection
end

# File lib/pg_tester.rb, line 52
def setup_pg_connection()
  @connection = PG::Connection.open(:user => @user, :dbname => @database, :port => @port)
end

# File lib/pg_tester.rb, line 48
def setup_test_database()
  shell_out "#{@createdb_path} -p #{@port} #{database} -O #{user}"
end

# File lib/pg_tester.rb, line 44
def setup_test_user()
  shell_out "#{@createuser_path} -s -p #{@port} -l #{user} -w"
end

# File lib/pg_tester.rb, line 65
def teardown()
  @connection.close() if @connection
  shell_out "#{@pgctl_path} stop -m fast -o '-p #{@port}' -D #{data_dir}"
  remove_data_dir
end

# File lib/pg_tester.rb, line 95
def shell_out(cmd)
  result = `#{cmd}`
  result.strip
end