{ stdenv, fetchFromGitHub, postgresql }:

stdenv.mkDerivation rec {
  name = "pg_topn-${version}";
  version = "2.2.2";

  buildInputs = [ postgresql ];

  src = fetchFromGitHub {
    owner  = "citusdata";
    repo   = "postgresql-topn";
    rev    = "refs/tags/v${version}";
    sha256 = "1bh28nrxj06vc2cvlsxlwrwad5ff3lfj3kr5cnnggwjk2dhwbbjm";
  };

  installPhase = ''
    mkdir -p $out/{lib,share/extension}

    cp *.so      $out/lib
    cp *.sql     $out/share/extension
    cp *.control $out/share/extension
  '';

  meta = with stdenv.lib; {
    description = "Efficient querying of 'top values' for PostgreSQL";
    homepage    = https://github.com/citusdata/postgresql-topn;
    maintainers = with maintainers; [ thoughtpolice ];
    platforms   = platforms.linux;
    license     = licenses.agpl3;
  };
}