{ config, lib, pkgs, ... }:

let
  inherit (lib) types;

  cfg = config.mine.zrepl;

  # helpers
  zreplFilesystems = lib.listToAttrs (
    lib.forEach cfg.datasets (dataset: lib.nameValuePair dataset true)
  );
    
in {
  options = {
    mine.zrepl = {
      enable = lib.mkEnableOption "zrepl snapshot";

      datasets = lib.mkOption {
        type = types.listOf types.str;
        default = [
          "rpool/safe<"
        ];
      };
    };
  };

  config = lib.mkIf cfg.enable {
    services.zrepl = {
      enable = true;
      settings.jobs = [
        # push
        {
          name = "snapjob";
          type = "snap";

          filesystems = zreplFilesystems;

          snapshotting = {
            type = "periodic";
            interval = "5m";
            prefix = "zrepl_";
          };

          pruning = {
            keep = [
              {
                type = "grid";
                regex = "^zrepl_.*";

                # 1. keep all snapshots for 30 minutes
                # 2. keep one every 15 minutes for 2 hours
                # 3. keep one every hour for 1 day
                grid = "1x30m(keep=all) | 8x15m | 24x1h";
              }
            ];
          };
        }
      ];
    };
  };
}

# {
#   services.zrepl = {
#     enable = true;
#     settings.jobs = [
#       {
#         type = "push";
#         name = "safesnapshots";

#         filesystems = [
#           "rpool/safe<"
#         ];

#         snapshotting = {
#           type = "periodic";
#           interval = "5m";
#           prefix = "zrepl_";
#         };

#         pruning = {
#           keep_sender = [
#             {
#               type = "grid";
#               regex = "^zrepl_.*";

#               # 1. keep all snapshots for 30 minutes
#               # 2. keep one every 15 minutes for 2 hours
#               # 3. keep one every hour for 1 day
#               grid = "1x30m(keep=all) | 8x15m | 14x1d";
#             }
#           ];
#         };
#       }
#     ];
#   };
# }