nix-cfg/hosts/vps1/akkoma/akkoma-static.nix

{ pkgs, config, lib, ... }:
let
  imperativeStaticPath = "/data/akkoma/static_i";
  declarativeStaticPath = "/data/akkoma/static_d";
  mergedStaticPath = "/data/akkoma/static";
  declarativeStaticFiles = let cfg = config.services.akkoma; in with lib; pkgs.runCommandLocal "declarative-akkoma-static" { } ''
    ${concatStringsSep "\n" (mapAttrsToList (key: val: ''
      mkdir -p $out/frontends/${escapeShellArg val.name}/
      ln -s ${escapeShellArg val.package} $out/frontends/${escapeShellArg val.name}/${escapeShellArg val.ref}
    '') cfg.frontends)}

    ${optionalString (cfg.extraStatic != null)
      (concatStringsSep "\n" (mapAttrsToList (key: val: ''
        mkdir -p "$out/$(dirname ${escapeShellArg key})"
        ln -s ${escapeShellArg val} $out/${escapeShellArg key}
      '') cfg.extraStatic))}
  '';
in
{
  environment.systemPackages = with pkgs; [ mergerfs ];
  systemd.tmpfiles.rules = [
    "d ${imperativeStaticPath} 700 akkoma akkoma -"
    "L+ ${declarativeStaticPath} - - - - ${toString declarativeStaticFiles}"
  ];
  fileSystems."${mergedStaticPath}" = {
    fsType = "fuse.mergerfs";
    device = "${imperativeStaticPath}:${declarativeStaticPath}";
    options = [ "cache.files=off" "dropcacheonclose=true" "category.create=epff" ];
  };
}