{ stdenv
, pkgs
, lib
, buildBowerComponents
, fetchbower
, fetchurl
, nodejs
}:

let
  nodePackages = import ./node-packages.nix {
    inherit pkgs nodejs;
    inherit (stdenv.hostPlatform) system;
  };

  bowerPackages = (buildBowerComponents {
    name = "${cryptpad.name}-bower-packages";
    generated = ./bower-packages.nix;
    src = cryptpad.src;
  }).overrideAttrs (old: {
    bowerPackages = old.bowerPackages.override (old_: {
      # add missing dependencies:
      # Those dependencies are EOL and they are not installed by buildBowerComponents,
      # but they are required, otherwise the resolver crashes.
      # * add the second jquery ~2.1.0 entry
      # * add the second bootstrap ~3.1.1 entry
      paths = old_.paths ++ [
        (fetchbower "jquery" "2.1.0" "~2.1.0" "02kwvz93vzpv10qnp7s0dz3al0jh77awwrizb6wadsvgifxssnlr")
        (fetchbower "bootstrap" "3.1.1" "~3.1.1" "06bhjwa8p7mzbpr3jkgydd804z1nwrkdql66h7jkfml99psv9811")
      ];
    });
  });

  # find an element in an attribute set
  findValue = pred: default: set:
    let
      list =
        lib.concatMap
          (name:
            let v = set.${name}; in
            if pred name v then [ v ] else [ ]
          )
          (lib.attrNames set)
      ;
    in
    if list == [ ] then default
    else lib.head list
  ;

  # The cryptpad package attribute key changes for each release. Get it out
  # programatically instead.
  cryptpad = findValue
    (k: v: v.packageName == "cryptpad")
    (throw "cryptpad not found")
    nodePackages
  ;

  combined = cryptpad.override {
    postInstall = ''
      out_cryptpad=$out/lib/node_modules/cryptpad

      substituteInPlace $out_cryptpad/lib/workers/index.js --replace "lib/workers/db-worker" "$out_cryptpad/lib/workers/db-worker"

      # add the bower components
      ln -sv \
        ${bowerPackages}/bower_components \
        $out_cryptpad/www/bower_components

      # add executable
      mkdir $out/bin
      cat <<EOF > $out/bin/cryptpad
      #!${stdenv.shell}
      exec ${nodejs}/bin/node $out_cryptpad/server.js
      EOF
      chmod +x $out/bin/cryptpad
    '';

    meta.maintainers = with lib.maintainers; [ davhau ];

  };
in
combined