{ env, ruby_2_5, bundlerEnv, defaultGemConfig, fetchedGithub, stdenv, writeText, pkgs }:
let
  varDir = "/var/lib/mastodon_immae";
  socketsDir = "/run/mastodon";
  gems = bundlerEnv {
    name = "mastodon-env";
    ruby = ruby_2_5;
    gemset = ./gemset.nix;
    gemdir = (fetchedGithub ./mastodon.json).src;
    groups = [ "default" "production" "test" "development" ];
    gemConfig = defaultGemConfig // {
      cld3 = attrs: {
        buildInputs = with pkgs; [ protobuf protobufc pkgconfig ];
      };
      idn-ruby = attrs: {
        buildInputs = with pkgs; [ libidn ];
      };
      rpam2 = attrs: {
        buildInputs = with pkgs; [ pam ];
      };
    };
  };
  yarnModules = let
      info = fetchedGithub ./mastodon.json;
    in
      pkgs.yarn2nix.mkYarnModules {
        name = "mastodon-yarn-modules";
        packageJSON = "${info.src}/package.json";
        yarnLock = "${info.src}/yarn.lock";
        yarnNix = ./yarn-packages.nix;
        pkgConfig = {
          uws = {
            postInstall = ''
              node-gyp rebuild > build_log.txt 2>&1 || true
              '';
            buildInputs = with pkgs; [ nodePackages.node-gyp ];
          };
          node-zopfli = {
            postInstall = ''
              node-pre-gyp install --fallback-to-build
              '';
            buildInputs = with pkgs; [ nodePackages.node-pre-gyp ];
          };
          node-sass = {
            buildInputs = with pkgs; [ binutils libsass python ];
            postInstall = let
              nodeHeaders = pkgs.fetchurl {
                url = "https://nodejs.org/download/release/v${pkgs.nodejs.version}/node-v${pkgs.nodejs.version}-headers.tar.gz";
                sha256 = "12zzsf8my43b8qnlacp871ih5vqafl2vlpqp51xp6h3gckn2frwy";
              };
            in
              ''
                export AR=${pkgs.binutils.bintools}/bin/ar
                node scripts/build.js --tarball=${nodeHeaders}
              '';
          };
        };
      };
  mastodon = stdenv.mkDerivation (fetchedGithub ./mastodon.json // rec {
    installPhase = ''
      cp -a . $out
      cp -a ${yarnModules}/node_modules $out
    '';
    buildInputs = [ yarnModules gems ];
  });
  config = writeText "mastodon_environment" ''
    REDIS_HOST=${env.redis.host}
    REDIS_PORT=${env.redis.port}
    REDIS_DB=${env.redis.db}
    DB_HOST=${env.postgresql.socket}
    DB_USER=${env.postgresql.user}
    DB_NAME=${env.postgresql.database}
    DB_PASS=${env.postgresql.password}
    DB_PORT=${env.postgresql.port}

    LOCAL_DOMAIN=mastodon.immae.eu
    LOCAL_HTTPS=true
    ALTERNATE_DOMAINS=immae.eu

    PAPERCLIP_SECRET=${env.paperclip_secret}
    SECRET_KEY_BASE=${env.secret_key_base}
    OTP_SECRET=${env.otp_secret}

    VAPID_PRIVATE_KEY=${env.vapid.private}
    VAPID_PUBLIC_KEY=${env.vapid.public}

    SMTP_DELIVERY_METHOD=sendmail
    SMTP_FROM_ADDRESS=notifications@mastodon.immae.eu
    SENDMAIL_LOCATION="/run/wrappers/bin/sendmail"
    PAPERCLIP_ROOT_PATH=${varDir}

    STREAMING_CLUSTER_NUM=1

    # LDAP authentication (optional)
    LDAP_ENABLED=true
    LDAP_HOST=ldap.immae.eu
    LDAP_PORT=636
    LDAP_METHOD=simple_tls
    LDAP_BASE="dc=immae,dc=eu"
    LDAP_BIND_DN="cn=mastodon,ou=services,dc=immae,dc=eu"
    LDAP_PASSWORD="${env.ldap.password}"
    LDAP_UID="uid"
    LDAP_SEARCH_FILTER="(&(%{uid}=%{email})(memberOf=cn=users,cn=mastodon,ou=services,dc=immae,dc=eu))"
    '';

    railsRoot = stdenv.mkDerivation {
      name = "mastodon_immae";
      inherit config mastodon;
      builder = writeText "build_mastodon_immae" ''
        source $stdenv/setup
        set -a
        source $config
        set +a
        cp -a $mastodon $out
        cd $out
        chmod u+rwX . public
        chmod -R u+rwX config/
        sed -i -e 's@^end$@  config.action_mailer.sendmail_settings = { location: ENV.fetch("SENDMAIL_LOCATION", "/usr/sbin/sendmail") }\nend@' config/environments/production.rb
        RAILS_ENV=production ${gems}/bin/rails assets:precompile
        rm -rf tmp/cache
        ln -sf ../../../../../../../${varDir}/tmp/cache tmp
        '';
      buildInputs = [ gems gems.ruby pkgs.nodejs pkgs.yarn ];
    };
in
  {
    inherit railsRoot config varDir socketsDir gems;
    nodeSocket = "${socketsDir}/live_immae_node.sock";
    railsSocket = "${socketsDir}/live_immae_puma.sock";
  }