{ system ? builtins.currentSystem
, config ? { }
, pkgs ? import ../../.. { inherit system config; }
}:

with pkgs.lib;

let
  baseModule = { config, ... }: {
    imports = [
      {
        options.test-helpers = {
          rclone = mkOption { type = types.str; };
          upload-sample = mkOption { type = types.str; };
          check-sample = mkOption { type = types.str; };
          init = mkOption { type = types.str; default = ""; };
          extraTests = mkOption { type = types.either types.str (types.functionTo types.str); default = ""; };
        };
        options.adminuser = mkOption { type = types.str; };
        options.adminpass = mkOption { type = types.str; };
      }
    ];

    adminuser = "root";
    adminpass = "hunter2";

    test-helpers.rclone = "${pkgs.writeShellScript "rclone" ''
      set -euo pipefail
      export PATH="${pkgs.rclone}/bin:$PATH"
      export RCLONE_CONFIG_NEXTCLOUD_TYPE=webdav
      export RCLONE_CONFIG_NEXTCLOUD_URL="http://nextcloud/remote.php/dav/files/${config.adminuser}"
      export RCLONE_CONFIG_NEXTCLOUD_VENDOR="nextcloud"
      export RCLONE_CONFIG_NEXTCLOUD_USER="${config.adminuser}"
      export RCLONE_CONFIG_NEXTCLOUD_PASS="$(rclone obscure ${config.adminpass})"
      exec "$@"
    ''}";
    test-helpers.upload-sample = "${pkgs.writeShellScript "rclone-upload" ''
      <<<'hi' rclone rcat nextcloud:test-shared-file
    ''}";
    test-helpers.check-sample = "${pkgs.writeShellScript "check-sample" ''
      set -e
      diff <(echo 'hi') <(rclone cat nextcloud:test-shared-file)
    ''}";

    nodes = {
      client = { ... }: {};
      nextcloud = {
        networking.firewall.allowedTCPPorts = [ 80 ];
        services.nextcloud = {
          enable = true;
          hostName = "nextcloud";
          https = false;
          database.createLocally = true;
          config = {
            adminpassFile = "${pkgs.writeText "adminpass" config.adminpass}"; # Don't try this at home!
          };
        };
      };
    };

    testScript = args@{ nodes, ... }: let
      inherit (config) test-helpers;
    in mkBefore ''
      nextcloud.start()
      client.start()
      nextcloud.wait_for_unit("multi-user.target")

      ${test-helpers.init}

      with subtest("Ensure nextcloud-occ is working"):
          nextcloud.succeed("nextcloud-occ status")
          nextcloud.succeed("curl -sSf http://nextcloud/login")

      with subtest("Upload/Download test"):
          nextcloud.succeed(
              "${test-helpers.rclone} ${test-helpers.upload-sample}"
          )
          client.wait_for_unit("multi-user.target")
          client.succeed(
              "${test-helpers.rclone} ${test-helpers.check-sample}"
          )

      ${if builtins.isFunction test-helpers.extraTests then test-helpers.extraTests args else test-helpers.extraTests}
    '';
  };

  genTests = version:
    let
      testBase.imports = [
        baseModule
        {
          nodes.nextcloud = { pkgs, ... }: {
            services.nextcloud.package = pkgs.${"nextcloud${toString version}"};
          };
        }
      ];

      callNextcloudTest = path:
        let
          name = "${removeSuffix ".nix" (baseNameOf path)}${toString version}";
        in nameValuePair name (import path {
          inherit system pkgs testBase;
          name = "nextcloud-${name}";
        });
    in map callNextcloudTest [
      ./basic.nix
      ./with-mysql-and-memcached.nix
      ./with-postgresql-and-redis.nix
      ./with-objectstore.nix
    ];
in
listToAttrs (concatMap genTests [ 27 28 29 ])