{ config, lib, pkgs, ... }:
{
  krebs.go = {
    enable = true;
  };
  services.nginx = {
    enable = true;
    virtualHosts.go = {
      locations."/".extraConfig = ''
        proxy_set_header Host go.lassul.us;
        proxy_pass http://localhost:1337;
      '';
      serverAliases = [
        "go.lassul.us"
      ];
    };
  };
  krebs.htgen.go = {
    port = 3333;
    script = ''. ${pkgs.writeDash "go" ''
      find_item() {
        if test ''${#1} -ge 7; then
          set -- "$(find "$STATEDIR/items" -mindepth 1 -maxdepth 1 \
              -regex "$STATEDIR/items/$1[0-9A-Za-z]*$")"
          if test -n "$1" && test $(echo "$1" | wc -l) = 1; then
            echo "$1"
            return 0
          fi
        fi
        return 1
      }

      STATEDIR=$HOME
      mkdir -p "$STATEDIR/items"

      case "$Method $Request_URI" in
        "GET /"*)
          if item=$(find_item "''${Request_URI#/}"); then
            uri=$(cat "$item")
            printf 'HTTP/1.1 302 Found\r\n'
            printf 'Content-Type: text/plain\r\n'
            printf 'Connection: closed\r\n'
            printf 'Location: %s\r\n' "$uri"
            printf '\r\n'
            exit
          fi
        ;;
        "POST /")
          uri=$(mktemp -t htgen.$$.content.XXXXXXXX)
          trap 'rm $uri >&2' EXIT

          head -c "$req_content_length" \
            | grep -Eo 'https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)' \
            | head -1 \
            > $uri
          sha256=$(sha256sum -b "$uri" | cut -d\  -f1)
          base32=$(${pkgs.nixStable}/bin/nix-hash --to-base32 --type sha256 "$sha256")
          item="$STATEDIR/items/$base32"
          ref="http://$req_host/$base32"

          if ! test -e "$item"; then
            mkdir -v -p "$STATEDIR/items" >&2
            cp -v $uri "$item" >&2
          fi

          base32short=$(echo "$base32" | cut -b-7)
          if item=$(find_item "$base32short"); then
            ref="http://$req_host/$base32short"
          fi

          printf 'HTTP/1.1 200 OK\r\n'
          printf 'Content-Type: text/plain; charset=UTF-8\r\n'
          printf 'Connection: close\r\n'
          printf '\r\n'
          printf '%s\n' "$ref"
          exit
        ;;
      esac
    ''}'';
  };
}