# edit this configuration file to define what should be installed on
# your system. Help is available in the configuration.nix(5) man page, on
# https://search.nixos.org/options and in the NixOS manual (`nixos-help`).

{ config, lib, pkgs, paths, self, keys, ... }:

{
  # NAS Mounting
  hoardingcow-mount.enable = true;

  # Flakesss
  nix.settings.experimental-features = [ "nix-command" "flakes" "flake-self-attrs" ];
  nix.settings.trusted-users = [ "root" "gortium" ];

  # Garbage collection
  nix.gc = {
    automatic = true;
    dates = "daily";  # You can also use "daily" or a cron-like spec
    options = "--delete-older-than 30d";
  };

  nix.settings = {
    keep-derivations = true;
    keep-outputs = true;
    auto-optimise-store = true;
  };

  # Use the systemd-boot EFI boot loader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = false;

  # 1. Force the kernel to ignore BIOS resource locks
  boot.kernelParams = [ 
    "acpi_enforce_resources=lax" 
    "nct6775.force_id=0xd120" # This forces the driver to ignore BIOS locks for NCT6116
    "transparent_hugepage=always" # because mucho ram
  ];
  # 2. Load the specific drivers found by sensors-detect
  boot.kernelModules = [ "nct6775" "lm96163" "iptable_nat" "iptable_filter" ];
  # 3. Force the nct6775 driver to recognize the chip if it's stubborn
  boot.extraModprobeConfig = ''
    options nct6775 force_id=0xd280
  '';

  boot.blacklistedKernelModules = [ "eeepc_wmi" ];
  networking.hostName = "lazyworkhorse"; # Define your hostname.
  # Pick only one of the below networking options.
  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.
  networking.networkmanager.enable = true;  # Easiest to use and most distros use this by default.
  networking.hostId = "deadbeef";

  # WireGuard VPN client -- always up, connects to wg-easy server
  # Create age-encrypted secrets before deploying (run on the host):
  #   echo -n "<private_key>" | agenix -e secrets/wireguard_private_key.age
  #   echo -n "<preshared_key>" | agenix -e secrets/wireguard_preshared_key.age
  networking.wireguard.interfaces = {
    wg0 = {
      ips = [ "10.8.0.3/24" ];
      privateKeyFile = config.age.secrets.wireguard_private_key.path;
      peers = [
        {
          publicKey = "rY9zII3AOm8rog2rv02PyA3Bq7zdvTOGkZapfCV1DkE=";
          presharedKeyFile = config.age.secrets.wireguard_preshared_key.path;
          allowedIPs = [ "10.8.0.0/24" ];
          endpoint = "vpn.lazyworkhorse.net:51820";
          persistentKeepalive = 25;
        }
      ];
    };
  };

  # Set your time zone.
  time.timeZone = "America/Montreal";

  # Locales
  i18n.defaultLocale = "en_CA.UTF-8";
  i18n.supportedLocales = [
    "en_CA.UTF-8/UTF-8"
  ];
  i18n.extraLocaleSettings = {
    LC_ADDRESS = "en_CA.UTF-8";
    LC_IDENTIFICATION = "en_CA.UTF-8";
    LC_MEASUREMENT = "en_CA.UTF-8";
    LC_MONETARY = "en_CA.UTF-8";
    LC_NAME = "en_CA.UTF-8";
    LC_NUMERIC = "en_CA.UTF-8";
    LC_PAPER = "en_CA.UTF-8";
    LC_TELEPHONE = "en_CA.UTF-8";
    LC_TIME = "en_CA.UTF-8";
    LC_CTYPE = "en_CA.UTF-8";
  };

  programs.zsh = {
    enable = true;
    autosuggestions.enable = true;
    syntaxHighlighting.enable = true;
    enableCompletion = true;
  
    setOptions = [ "HIST_IGNORE_ALL_DUPS" "SHARE_HISTORY" ]; 
  };
  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # Select internationalisation properties.
  # i18n.defaultLocale = "en_US.UTF-8";
  # console = {
  #   font = "Lat2-Terminus16";
  #   keyMap = "us";
  #   useXkbConfig = true; # use xkb.options in tty.
  # };

  # Configure keymap in X11
  # services.xserver.xkb.layout = "us";
  # services.xserver.xkb.options = "eurosign:e,caps:escape";

  # Enable CUPS to print documents.
  services.printing.enable = true;

  # Enable sound.
  # services.pulseaudio.enable = true;
  # OR
  services.pipewire = {
    enable = true;
    pulse.enable = true;
  };

  # Nix Helper cli tool
  environment.sessionVariables = {
    NH_FLAKE = paths.flake;
  };

  # Enable touchpad support (enabled default in most desktopManager).
  # services.libinput.enable = true;

  # nvim please
  environment.variables.EDITOR = "nvim";

  # List packages installed in system profile.
  # You can use https://Search.nixos.org/ to find more packages (and options).
  environment.systemPackages = with pkgs; [
    neovim
    docker-compose
    wget
    age
    agenix
    git
    nh
    lm_sensors
    rocmPackages.rocminfo
    rocmPackages.rocm-smi
    nvtopPackages.amd
    clinfo
    ncurses
    kitty.terminfo
    nodejs_22
    uv
    openclaw
    (python3.withPackages (ps: with ps; [
      openai-whisper
    ]))
  ];

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = {
  #   enable = true;
  #   enableSSHSupport = true;
  # };

  # List services that you want to enable:

  # Enable the OpenSSH daemon
  services.openssh = {
    enable = true;
    ports = [ 2424 ];
    settings = {
      PasswordAuthentication = false;
      KbdInteractiveAuthentication = false;
      # Additional hardening settings below in SERVER HARDENING section
    };
    hostKeys = [
      {
        path = "/etc/ssh/ssh_host_ed25519_key";
        type = "ed25519";
      }
    ];
  };

  services.dockerStacks = {
    versioncontrol = {
      path = self + "/assets/compose/versioncontrol";
      ports = [ 2222 ];
    };
    
    network = {
      path = self + "/assets/compose/network";
      envFile = config.age.secrets.containers_env.path;
      ports = [ 80 443 ];
    };

    passwordmanager = {
      path = self + "/assets/compose/passwordmanager";
    };

    ai = {
      path = self + "/assets/compose/ai";
      envFile = config.age.secrets.containers_env.path;
      ports = [ 22000 ];  # Syncthing TCP sync
    };

    cloudstorage = {
      path = self + "/assets/compose/cloudstorage";
      envFile = config.age.secrets.containers_env.path;
    };

    homeautomation = {
      path = self + "/assets/compose/homeautomation";
      envFile = config.age.secrets.containers_env.path;
    };

    authentification = {
      path = self + "/assets/compose/authentification";
    };

    backup = {
      path = self + "/assets/compose/backup";
      envFile = config.age.secrets.containers_env.path;
    };

    coms = {
      path = self + "/assets/compose/coms";
      envFile = config.age.secrets.containers_env.path;
    };

    finance = {
      path = self + "/assets/compose/finance";
    };

    homepage = {
      path = self + "/assets/compose/homepage";
    };

    vpn = {
      path = self + "/assets/compose/vpn";
      envFile = config.age.secrets.containers_env.path;
    };

    # tak = {
    #   path = self + "/assets/compose/tak";
    # };
  };

  services.opencode = {
    enable = true;
    port = 4099;
    ollamaUrl = "http://127.0.0.1:11434/v1"; 
  };
  
  # Private host ssh key managed by agenix
  age = {
    identityPaths = paths.identities;
    secrets = {
      containers_env = {
        file = ../../secrets/containers.env.age;
        path = "/run/secrets/containers.env";
        owner = "root";
        group = "root";
        mode = "0400";
      };
      lazyworkhorse_host_ssh_key = {
        file = ../../secrets/lazyworkhorse_host_ssh_key.age;
        owner = "root";
        group = "root";
        mode = "0600";
        path = "/etc/ssh/ssh_host_ed25519_key";
      };
      ai_ssh_key = {
        file = ../../secrets/ai_ssh_key.age;
        owner = "root";
        group = "root";
        mode = "0600";
        path = "/home/ai-worker/.ssh/ai_ssh_key";
      };
      openclaw_gateway_token = {
        file = ../../secrets/openclaw_gateway_token.age;
        owner = "root";
        group = "ai-worker";
        mode = "0440";
        path = "/run/secrets/openclaw_gateway_token";
      };
      wireguard_private_key = {
        file = ../../secrets/wireguard_private_key.age;
        owner = "root";
        group = "root";
        mode = "0400";
        path = "/run/secrets/wireguard_private_key";
      };
      wireguard_preshared_key = {
        file = ../../secrets/wireguard_preshared_key.age;
        owner = "root";
        group = "root";
        mode = "0400";
        path = "/run/secrets/wireguard_preshared_key";
      };
    };
  };

  # OpenClaw Node service (host-side execution for Docker gateway)
  services.openclaw-node = {
    enable = true;
    user = "ai-worker";
    gatewayHost = "127.0.0.1";
    gatewayPort = 18789;
    gatewayTokenFile = "/run/secrets/openclaw_gateway_token";
    displayName = "lazyworkhorse-host";
  };

  # Public host ssh key (kept in sync with the private one)
  environment.etc."ssh/ssh_host_ed25519_key.pub".text =
    "${keys.hosts.lazyworkhorse.main}";

  services.fstrim.enable = true;

  services.zfs.autoSnapshot.enable = true;
  services.zfs.autoScrub.enable = true;
  
  # Mi50 config
  hardware.graphics = {
    enable = true;
    enable32Bit = true; # Useful for some compatibility layers
    extraPackages = with pkgs; [
      rocmPackages.clr.icd # OpenCL/HIP runtime
    ];
  };
  nixpkgs.config.rocmTargets = [ "gfx906" ];
  environment.variables = {
    # This "tricks" ROCm into supporting the MI50 if using newer versions
    HSA_OVERRIDE_GFX_VERSION = "9.0.6";
    # Ensures the system sees both GPUs
    HIP_VISIBLE_DEVICES = "0,1";
  };

 # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # =============================================================================
  # SERVER HARDENING - Firewall, Fail2ban, SSH, Kernel
  # =============================================================================
  
  # Firewall - default deny, explicit allow
  networking.firewall = {
    # Enable firewall with default deny policy (NixOS firewall denies all by default)
    enable = true;
    allowPing = true;
    
    # Only essential ports exposed to internet
    allowedTCPPorts = [
      2424  # SSH (non-standard port)
      2222  # Gitea (version control)
      80    # HTTP (Traefik redirect)
      443   # HTTPS (Traefik)
      # 8000  # Portainer - REVIEW: internal only?
      # 4242  # Coms - REVIEW: internal only?
      # 5000  # TAK API - REVIEW: internal only?
      # 8087  # TAK Connect - REVIEW: internal only?
      # 8089  # TAK Management - REVIEW: internal only?
    ];
    
    allowedUDPPorts = [
      51820 # WireGuard VPN
    ];
    
    # Rate limiting and attack prevention
    extraCommands = ''
      # 1. Wipe the INPUT chain clean at the start of every activation
      iptables -F INPUT
      
      # Rate limit SSH connections (max 20 new connections per 60 seconds)
      iptables -A INPUT -p tcp --dport 2424 -m state --state NEW -m recent --set
      iptables -A INPUT -p tcp --dport 2424 -m state --state NEW -m recent --update --seconds 60 --hitcount 20 -j DROP
      
      # Rate limit HTTP/HTTPS (protects Traefik)
      iptables -A INPUT -p tcp --dport 80 -m state --state NEW -m limit --limit 25/minute --limit-burst 100 -j ACCEPT
      iptables -A INPUT -p tcp --dport 443 -m state --state NEW -m limit --limit 25/minute --limit-burst 100 -j ACCEPT
      
      # Drop invalid packets
      iptables -A INPUT -m state --state INVALID -j DROP
      
      # Log dropped packets (rate limited)
      iptables -A INPUT -m limit --limit 5/min -j LOG --log-prefix "IPTables-Dropped: " --log-level 4

      # 3. CRITICAL: Re-link the NixOS default firewall chain
      # Without this line, the 'allowedTCPPorts' in your Nix config will be ignored!
      iptables -A INPUT -j nixos-fw
    '';
  };

  # Fail2ban - automatic IP banning
  services.fail2ban = {
    enable = true;
    maxretry = 3;
    bantime = "1h";
    banaction = "iptables-multiport";
    
    jails = {
      # SSH brute force protection (uses systemd journal backend)
      sshd = {
        enabled = true;
        settings = {
          filter = "sshd";
          port = "2424";
          maxretry = 3;
          bantime = "1h";
        };
      };
      
      # Recidive - ban repeat offenders for 1 week
      recidive = {
        enabled = true;
        settings = {
          filter = "recidive";
          logpath = "/var/log/fail2ban.log";
          bantime = "1w";
          findtime = "1d";
          maxretry = 3;
        };
      };
      
      # HTTP authentication failures (Traefik)
      http-auth = {
        enabled = true;
        settings = {
          filter = "traefik-auth";
          port = "80,443";
          logpath = "/var/log/traefik/access.log";
          maxretry = 5;
          bantime = "1h";
        };
      };
      
      # HTTP scanning/attacks (Traefik)
      http-botsearch = {
        enabled = true;
        settings = {
          filter = "traefik-botsearch";
          port = "80,443";
          logpath = "/var/log/traefik/access.log";
          maxretry = 2;
          bantime = "2h";
        };
      };
    };
  };
  
  # Custom fail2ban filters for Traefik
  environment.etc."fail2ban/filter.d/traefik-auth.conf".text = ''
    [Definition]
    failregex = ^<HOST> -.*"(GET|POST|HEAD|PUT|DELETE).*" (401|403) \d+.*$
    ignoreregex =
  '';
  
  environment.etc."fail2ban/filter.d/traefik-botsearch.conf".text = ''
    [Definition]
    failregex = ^<HOST> -.*"(GET|POST|HEAD|PUT|DELETE).*" 404 \d+.*$
                ^<HOST> -.*"(GET|POST|HEAD|PUT|DELETE).*/(\.|wp-|php|admin|login|xmlrpc|\.env|\.git|\.aws|\.azure).*" \d+.*$
    ignoreregex =
  '';

  # SSH hardening
  services.openssh.settings = {
    PermitRootLogin = "no";
    MaxAuthTries = 3;
    MaxSessions = 20;
    LoginGraceTime = 30;
    ClientAliveInterval = 300;
    ClientAliveCountMax = 2;
    PermitEmptyPasswords = "no";
    ChallengeResponseAuthentication = "no";
    UsePAM = true;
    LogLevel = "VERBOSE";
    X11Forwarding = false;
    AllowTcpForwarding = "no";
    AllowAgentForwarding = "no";
    PermitTunnel = "no";
  };

  # Kernel network hardening
  boot.kernel.sysctl = {
    # IP Spoofing protection
    "net.ipv4.conf.all.rp_filter" = 1;
    "net.ipv4.conf.default.rp_filter" = 1;
    
    # Ignore ICMP broadcasts
    "net.ipv4.icmp_echo_ignore_broadcasts" = 1;
    
    # Disable source routing
    "net.ipv4.conf.all.accept_source_route" = 0;
    "net.ipv4.conf.default.accept_source_route" = 0;
    "net.ipv6.conf.all.accept_source_route" = 0;
    "net.ipv6.conf.default.accept_source_route" = 0;
    
    # Disable redirects
    "net.ipv4.conf.all.send_redirects" = 0;
    "net.ipv4.conf.default.send_redirects" = 0;
    
    # SYN flood protection
    "net.ipv4.tcp_syncookies" = 1;
    "net.ipv4.tcp_max_syn_backlog" = 2048;
    "net.ipv4.tcp_synack_retries" = 2;
    "net.ipv4.tcp_syn_retries" = 5;
    
    # Log martian packets
    "net.ipv4.conf.all.log_martians" = 1;
    "net.ipv4.conf.default.log_martians" = 1;
    
    # Ignore redirects
    "net.ipv4.conf.all.accept_redirects" = 0;
    "net.ipv4.conf.default.accept_redirects" = 0;
    "net.ipv4.conf.all.secure_redirects" = 0;
    "net.ipv4.conf.default.secure_redirects" = 0;
    "net.ipv6.conf.all.accept_redirects" = 0;
    "net.ipv6.conf.default.accept_redirects" = 0;
    
    # Connection tuning
    "net.core.somaxconn" = 4096;
    "net.core.netdev_max_backlog" = 65536;
    "net.ipv4.tcp_max_orphans" = 65536;
    "net.ipv4.tcp_fin_timeout" = 15;
    "net.ipv4.tcp_keepalive_time" = 300;
    "net.ipv4.tcp_keepalive_probes" = 5;
    "net.ipv4.tcp_keepalive_intvl" = 15;
  };

  # Audit logging
  security.auditd.enable = true;
  
  # Fail2ban log directory
  systemd.tmpfiles.rules = [
    "d /var/log/fail2ban 0755 root root -"
    "d /var/log/traefik 0755 root root -"
  ];

  # Copy the NixOS configuration file and link it from the resulting system
  # (/run/current-system/configuration.nix). This is useful in case you
  # accidentally delete configuration.nix.
  # system.copySystemConfiguration = true;

  # This option defines the first version of NixOS you have installed on this particular machine,
  # and is used to maintain compatibility with application data (e.g. databases) created on older NixOS versions.
  #
  # Most users should NEVER change this value after the initial install, for any reason,
  # even if you've upgraded your system to a new NixOS release.
  #
  # This value does NOT affect the Nixpkgs version your packages and OS are pulled from,
  # so changing it will NOT upgrade your system - see https://nixos.org/manual/nixos/stable/#sec-upgrading for how
  # to actually do that.
  #
  # This value being lower than the current NixOS release does NOT mean your system is
  # out of date, out of support, or vulnerable.
  #
  # Do NOT change this value unless you have manually inspected all the changes it would make to your configuration,
  # and migrated your data accordingly.
  #
  # For more information, see `man configuration.nix` or https://nixos.org/manual/nixos/stable/options#opt-system.stateVersion .
  system.stateVersion = "25.05"; # Did you read the comment?

}