{ config, lib, pkgs, ... }:
let
  nextcloud = "nextcloud";
  proton = "proton";
  syncType = lib.types.submodule (
    { name, ... }: {
      options = {
        type = lib.mkOption {
          type = lib.types.enum [
            nextcloud
            proton
          ];
        };

        autoStart = lib.mkOption {
          type = lib.types.bool;
          description = "Whether to start this sync automatically.";
          default = true;
        };

        systemdDependencies = lib.mkOption {
          type = lib.types.attrsOf lib.types.str;
          description = "The systemd services this sync depends on.";
          example = {
            secrets = "sops-nix.service";
          };
        };

        environment = lib.mkOption {
          type = lib.types.attrsOf lib.types.envVar;
          description = "The environment variables to pass to the service.";
          default = {};
        };

        preLaunch = lib.mkOption {
          type = lib.types.lines;
          description = "A set of statements to run before launching the sync.";
          default = [];
        };
      };
    });
in {
  options = {
    programs.rclone = {
      enable = lib.mkEnableOption "rclone";

      configs = lib.mkOption {
        type = lib.types.attrsOf syncType;
        description = "The synchronizations to set up.";
        default = {};
      };
    };
  };

  config =
    let
      cfg = config.programs.rclone;
    in {
      home.packages = lib.optional cfg.enable pkgs.rclone;

      systemd.user = lib.optionalAttrs cfg.enable {
        enable = true;

        services = {
          rclone = {
            Unit = {
              Description = "rclone Starter";
              Documentation = "man:rclone(1)";
            };

            Service = {
              Type = "simple";

              ExecStartPre =
                let
                  script = pkgs.writeShellScriptBin "rclone-pre" ''
                    sleep 10
                  '';
                in
                  (lib.getExe script);

              ExecStart =
                let
                  script = pkgs.writeShellScriptBin "rclone" ''
                    systemctl --user start rclone.target
                  '';
                in
                  (lib.getExe script);
            };
          };
        };

        targets.rclone = {
          Unit = {
            Description = "rclone Mounts";
            Documentation = "man:rclone(1)";
          };
        };
      };
    };
}