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

let
  cfg = config.syncthing-custom;
  
  # Device groupings
  pcDevices = [ "macbook" "imac" "thinkpad" "nfss" ];
  touchDevices = [ "iphone" "ipad" ];
  allDevices = pcDevices ++ touchDevices;

  # Common versioning configuration
  commonVersioning = {
    type = "staggered";
    params = {
      maxAge = "15552000"; # 180 days in seconds
      cleanInterval = "3600"; # Clean every hour
    };
  };

  liteVersioning = {
    type = "staggered";
    params = {
      maxAge = "2592000"; # 30 days in seconds
      cleanInterval = "3600"; # Clean every hour
    };
  };

in
{
  options.syncthing-custom = {
    enabledFolders = lib.mkOption {
      type = lib.types.listOf lib.types.str;
      default = [ "Credentials" "Documents" "Archive" "Media" ];
      description = "List of Syncthing folders to enable for this host.";
    };
    enableGui = lib.mkOption {
      type = lib.types.bool;
      default = true;
      description = "Whether to enable the Syncthing web GUI.";
    };
  };

  config = {
  # Enable Syncthing service
  services.syncthing = {
    enable = true;
    # Don't enable tray on server (Linux) or macOS
    tray.enable = false;
    
    # Listen on all interfaces for the GUI
    guiAddress = lib.mkIf cfg.enableGui "127.0.0.1:8384";
    
    # Declarative configuration - will override any GUI changes
    overrideDevices = true;
    overrideFolders = true;
    
    settings = {
      # Define all devices
      devices = {
        "iphone" = {
          id = "NMWI5MP-J4FC4A6-SDDXZPD-G66TJCO-2W7KGFD-RJWQ53U-I7GUVWP-WHF4QQO";
        };
        "thinkpad" = {
          id = "OMZKASU-QPZDCQ2-7QRHRD4-3TPAXLM-AYRMWXB-A6E5OIZ-MGR422V-JYARQA6";
        };
        "ipad" = {
          id = "ZN3W6K7-VTRRRMT-Y35PSVU-EARJ6FP-6JBFIOF-YAFUAUZ-2TSFW3T-5YGDZAO";
        };
        "macbook" = {
          id = "XPAMYJX-D7UZKPI-JBLTAWG-EBPSFYV-NEFV42V-NIUZKQN-KTVTGGP-OOXL5AT";
        };
        "imac" = {
          id = "2ST6EEF-KN3R2E6-PN64WAS-XGJ22NV-BAWAQX6-OCZLYE3-V5IM2SE-S22REAA";
        };
        "nfss" = {
          id = "S4QZW76-BOLIOW7-DVP326F-JIGW5DW-3PAD47L-OA456LB-2L6JZW7-YUGJRA6";
        };
      };
      
      # Define shared folders (only enabled ones)
      folders =
        (lib.optionalAttrs (lib.elem "Credentials" cfg.enabledFolders) {
          "Credentials" = {
            path = "~/Credentials";
            devices = allDevices;
            ignorePerms = true;
            versioning = commonVersioning;
          };
        })
        // (lib.optionalAttrs (lib.elem "Documents" cfg.enabledFolders) {
          "Documents" = {
            path = "~/Documents";
            devices = pcDevices;
            ignorePerms = true;
            versioning = commonVersioning;
          };
        })
        // (lib.optionalAttrs (lib.elem "Media" cfg.enabledFolders) {
          "Media" = {
            path = "~/Media";
            devices = lib.filter (d: d != "iphone") allDevices;
            ignorePerms = true;
            versioning = liteVersioning;
          };
        })
        // (lib.optionalAttrs (lib.elem "Archive" cfg.enabledFolders) {
          "Archive" = {
            path = "~/Archive";
            devices = allDevices;
            ignorePerms = true;
            versioning = commonVersioning;
          };
        });
      
      # GUI settings with authentication
      gui = {
        enabled = cfg.enableGui;
        user = "yanlin";
        password = "";
        useTLS = false;
        insecureSkipHostcheck = true;
      };
      
      # Additional settings
      options = {
        urAccepted = -1;  # Disable usage reporting
        relaysEnabled = true;
        localAnnounceEnabled = true;
        globalAnnounceEnabled = true;
      };
    };
  };

  # Override the launchd agent to add RunAtLoad on macOS
  launchd.agents.syncthing = lib.mkIf (pkgs.stdenv.isDarwin && config.services.syncthing.enable) {
    config.RunAtLoad = true;
  };

  # For NixOS systems, we need to add Syncthing as a manual service in Traefik
  # Since Syncthing runs as a systemd service (not container), we'll handle routing via static config
  # or create a container wrapper for it to use with service discovery
  };
}