{ config, pkgs, inputs, ... }:

{
  # =========================================================================
  # IMPORTS & NIX CONFIGURATION
  # =========================================================================
  imports = [
    ./hardware-configuration.nix
    inputs.noctalia-greeter.nixosModules.default
  ];

  nix.settings.experimental-features = [ "nix-command" "flakes" ];
  nixpkgs.config.allowUnfree = true;

  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 7d";
  };

  # Dynamic binary execution & FHS compatibility
  programs.nix-ld.enable = true;
  services.envfs.enable = true;
  security.polkit.enable = true;
  # =========================================================================
  # BOOT & KERNEL CONFIGURATION
  # =========================================================================
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  boot.kernelParams = [
    "drm.edid_firmware=DP-1:edid/mi_edid.bin"
    "video=DP-1:2560x1440@180"
  ];

  # Custom EDID firmware loading for monitor
  hardware.firmware = [
    (pkgs.runCommand "custom-edid" {} ''
      mkdir -p $out/lib/firmware/edid
      cp ${./mi_edid.bin} $out/lib/firmware/edid/mi_edid.bin
    '')
  ];

  # =========================================================================
  # HARDWARE, FILESYSTEMS & GRAPHICS
  # =========================================================================
  fileSystems."/mnt/giga" = {
    device = "/dev/disk/by-uuid/bfed3a37-05e1-465b-a4b7-d74cd31bf937";
    fsType = "ext4";
    options = [ "defaults" "user" "rw" ];
  };

  hardware.graphics = {
    enable = true;
    enable32Bit = true;
  };

  services.xserver.videoDrivers = [ "nvidia" ];
  hardware.nvidia = {
    modesetting.enable = true;
    powerManagement.enable = false;
    open = false;
    nvidiaSettings = true;
    package = config.boot.kernelPackages.nvidiaPackages.latest;
  };

  # =========================================================================
  # NETWORKING, DNS & VPN
  # =========================================================================
  networking.hostName = "opus";
  networking.networkmanager.enable = true;

  # Systemd-Resolved (Encrypted DNS)
  services.resolved = {
    enable = true;
    settings = {
      Resolve = {
        DNSOverTLS = "true";
        DNSSEC = "true";
        Domains = [ "~." ];
        DNS = "76.76.2.2#p2.freedns.controld.com";
        FallbackDNS = "1.1.1.1";
      };
    };
  };

  # Mullvad VPN Daemon
  services.mullvad-vpn = {
    enable = true;
    package = pkgs.mullvad-vpn;
  };

  # Avahi (Printer / Network Discovery)
  services.avahi = {
    enable = true;
    nssmdns4 = true;
    openFirewall = true;
  };

  # =========================================================================
  # LOCALIZATION & TIMEZONE
  # =========================================================================
  time.timeZone = "Etc/GMT-7";
  i18n.defaultLocale = "en_US.UTF-8";
  i18n.extraLocaleSettings = {
    LC_ADDRESS = "en_US.UTF-8";
    LC_IDENTIFICATION = "en_US.UTF-8";
    LC_MEASUREMENT = "en_US.UTF-8";
    LC_MONETARY = "en_US.UTF-8";
    LC_NAME = "en_US.UTF-8";
    LC_NUMERIC = "en_US.UTF-8";
    LC_PAPER = "en_US.UTF-8";
    LC_TELEPHONE = "en_US.UTF-8";
    LC_TIME = "en_US.UTF-8";
  };

  # =========================================================================
  # USER ACCOUNTS & PRIVILEGES
  # =========================================================================
  users.users."seraphim" = {
    isNormalUser = true;
    description = "seraphim";
    shell = pkgs.fish; # Sets Fish as your default user shell
    extraGroups = [ "networkmanager" "wheel" ];
    packages = with pkgs; [];
  };

  security.doas = {
    enable = true;
    extraRules = [
      {
        users = [ "seraphim" ];
        keepEnv = true;
        persist = true;
      }
    ];
  };

  # =========================================================================
  # SHELLS & ENHANCEMENTS
  # =========================================================================
programs.fish = {
    enable = true;
    interactiveShellInit = ''
      set -g fish_greeting "" # Disables the welcome message
      fzf --fish | source
    '';
    shellAliases = {
      ls = "eza -al --icons=auto";
      ll = "eza -al --icons=auto";
    };
  };

  programs.starship.enable = true;

  # =========================================================================
  # DISPLAY, WAYLAND & DESKTOP ENVIRONMENT
  # =========================================================================
  programs.niri.enable = true;
  programs.noctalia-greeter = {
    enable = true;
    settings = {
      cursor = {
        theme = "Bibata-Modern-Ice";
        size = 24;
        path = "${pkgs.bibata-cursors}/share/icons";
      };
    };
  };

  qt = {
    enable = true;
    platformTheme = "qt5ct";
    style = "breeze";
  };

  xdg.portal = {
    enable = true;
    extraPortals = [
      pkgs.xdg-desktop-portal-gnome
      pkgs.xdg-desktop-portal-gtk
    ];
  };

  # Environment Variables
  environment.variables = {
    SSL_CERT_FILE = "/etc/ssl/certs/ca-certificates.crt";
    NIX_SSL_CERT_FILE = "/etc/ssl/certs/ca-certificates.crt";
  };

  environment.sessionVariables = {
    SHELL = "${pkgs.fish}/bin/fish";
    LIBVA_DRIVER_NAME = "nvidia";
    XCURSOR_THEME = "Bibata-Modern-Ice";
    XCURSOR_SIZE = "20";
    __GLX_VENDOR_LIBRARY_NAME = "nvidia";
    NIXOS_OZONE_WL = "1";
    CC = "clang";
    ELECTRON_OZONE_PLATFORM_HINT = "auto";
    GSK_RENDERER = "ngl";
    QT_QPA_PLATFORM = "wayland;xcb";
    QT_ENABLE_HIGHDPI_SCALING = "1";
    QT_AUTO_SCREEN_SCALE_FACTOR = "1";
    QT_SCREEN_SCALE_FACTORS = "1.5";
  };

  # Fonts Configuration
  fonts.fontconfig.enable = true;
  fonts.packages = with pkgs; [
    font-awesome
    nerd-fonts.jetbrains-mono
    nerd-fonts.symbols-only
    jetbrains-mono
    noto-fonts-color-emoji
  ];

  # =========================================================================
  # AUDIO & SERVICES
  # =========================================================================
  security.rtkit.enable = true;
  services.pipewire = {
    enable = true;
    alsa.enable = true;
    alsa.support32Bit = true;
    pulse.enable = true;
  };

  # Printing (CUPS)
  services.printing = {
    enable = true;
    drivers = with pkgs; [
      brlaser
      gutenprint
      cups-filters
    ];
  };

  # MPD Music Server
  services.mpd = {
    enable = true;
    user = "seraphim";
    openFirewall = false;
    settings = {
      music_directory = "/mnt/giga/music";
      bind_to_address = "any";
      port = 6600;
      auto_update = "yes";
      audio_output = [
        {
          type = "pulse";
          name = "PipeWire Output";
          mixer_type = "hardware";
        }
      ];
    };
  };

  systemd.services.mpd.environment = {
    XDG_RUNTIME_DIR = "/run/user/1000";
  };

  # System Utilities & Gaming
  services.gvfs.enable = true;
  services.tumbler.enable = true;
  services.gnome.gnome-keyring.enable = true;
  programs.dconf.enable = true;

  services.journald.extraConfig = ''
    SystemMaxUse=50M
    MaxRetentionSec=1month
  '';

  programs.steam = {
    enable = true;
    remotePlay.openFirewall = true;
    dedicatedServer.openFirewall = true;
  };

  programs.throne = {
    enable = true;
    tunMode.enable = true;
  };

  # =========================================================================
  # USER SERVICES
  # =========================================================================
  systemd.user.services.swingmusic = {
    description = "Swing Music Local Server";
    wantedBy = [ "graphical-session.target" ];
    after = [ "graphical-session.target" ];
    serviceConfig = {
      ExecStart = "/home/seraphim/.swingmusic/swingmusic";
      Restart = "on-failure";
      WorkingDirectory = "/home/seraphim";
      NoNewPrivileges = true;
      PrivateTmp = true;
      ProtectSystem = "strict";
      ProtectHome = "false";
      RestrictAddressFamilies = [ "AF_INET" "AF_INET6" ];
    };
  };

  systemd.user.services.mpd-mpris = {
    description = "MPD MPRIS Service for Waybar";
    wantedBy = [ "default.target" ];
    after = [ "graphical-session.target" ];
    serviceConfig = {
      ExecStart = "${pkgs.mpd-mpris}/bin/mpd-mpris -network tcp -host 127.0.0.1 -port 6600";
      Restart = "on-failure";
    };
  };

  systemd.user.services.niri.enableDefaultPath = false;

  # =========================================================================
  # SYSTEM PACKAGES
  # =========================================================================
  environment.systemPackages = with pkgs; [
    # Flake Inputs & Hardware Overrides
    inputs.noctalia.packages.${pkgs.stdenv.hostPlatform.system}.default
    (btop.override { cudaSupport = true; })

    # Terminals & CLI Utilities
    cacert
    tree
    pkgs.rsync
    duf
    eza
    fastfetch
    fd
    foot
    fzf
    ghfetch
    ghostty
    hyfetch
    stow
    util-linux
    pkgs.vimPlugins.im-select-nvim

    # Audio & Music Controls
    brightnessctl
    mpc
    mpd
    mpd-mpris
    mpv
    pamixer
    pavucontrol
    playerctl
    rmpc

    # Text Editors
    micro
    neovim
    (emacs-pgtk.override {
      withNativeCompilation = true;
    })

    # File Managers & Archiving
    file-roller
    kdePackages.ark
    kdePackages.qt6ct
    loupe
    nautilus
    sushi
    yazi

    # Utilities & Disk Tools
    caligula
    cryptsetup
    yt-dlp

    # GStreamer Codecs
    gst_all_1.gst-plugins-bad
    gst_all_1.gst-plugins-base
    gst_all_1.gst-plugins-good
    gst_all_1.gst-plugins-ugly

    # Wayland, Desktop UI & Utilities
    adwaita-icon-theme
    bibata-cursors
    cliphist
    fuzzel
    grim
    hicolor-icon-theme
    hyprpolkitagent
    noctalia-shell
    slurp
    wl-clipboard
    wtype
    xwayland-satellite

    # Desktop Applications & Office
    claude-code
    keepassxc
    libreoffice
    hunspellDicts.ru_RU
    nvidia-vaapi-driver
    opencode
    telegram-desktop
    vesktop
    obsidian
    pkgs.lutris
    pkgs.qbittorrent
    pkgs.prismlauncher

    # Software Development & Toolchains
    black
    cargo
    clang
    clippy
    gcc
    git
    gnumake
    nodejs
    pyright
    python3
    rust-analyzer
    rustc
    tree-sitter
  ];

  system.stateVersion = "26.05";
}