# NixOS configuration for Vultr development VPS
# Optimized for Matrix + Forgejo deployment without federation
{ config, pkgs, lib, ... }:

{
  imports = [
    ../modules/dev-services.nix
    ./vultr-hardware.nix
  ];

  # sops-nix secrets management
  sops = {
    defaultSopsFile = ../secrets/secrets.yaml;
    age.sshKeyPaths = [ "/etc/ssh/ssh_host_ed25519_key" ];

    # Secret declarations
    secrets."matrix-registration-token" = {
      mode = "0400";
    };

    secrets."acme-email" = {
      mode = "0400";
      # Using direct email value, no secret needed
    };
  };

  # Boot configuration for Vultr VPS (Legacy BIOS mode)
  boot = {
    loader = {
      grub = {
        enable = true;
        device = "/dev/vda";  # Legacy BIOS - install to MBR
        efiSupport = false;
        useOSProber = false;
      };
    };
    # Vultr uses virtio drivers
    initrd.availableKernelModules = [
      "virtio_pci"
      "virtio_blk"
      "virtio_net"
      "virtio_scsi"
    ];
  };

  # Filesystem configuration managed by vultr-hardware.nix
  # Boot partition, root partition, and swap declared via generated hardware config

  # Network configuration for Vultr
  networking = {
    hostName = "matrix";

    # Vultr-specific network interface
    useDHCP = false;
    interfaces.ens3 = {  # Vultr uses ens3
      useDHCP = true;
    };

    enableIPv6 = true;

    # Firewall - only expose reverse proxy ports
    firewall = {
      enable = true;
      allowedTCPPorts = [
        22    # SSH
        80    # HTTP (ACME challenges, redirects)
        443   # HTTPS
      ];
      allowPing = true;
      logRefusedConnections = false;  # Reduce log noise on public VPS
    };
  };

  # SSH configuration - secure but accessible for development
  services.openssh = {
    enable = true;
    settings = {
      PermitRootLogin = "prohibit-password";  # More secure than "yes"
      PasswordAuthentication = false;
      KbdInteractiveAuthentication = false;
      X11Forwarding = false;
    };
    # Basic security settings
    extraConfig = ''
      MaxAuthTries 3
      MaxSessions 10
      ClientAliveInterval 300
      ClientAliveCountMax 2
    '';
  };

  # SSH key for root and admin users
  users.users.root.openssh.authorizedKeys.keys = [
    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOqHsgAuD/8LL6HN3fo7X1ywryQG393pyQ19a154bO+h delpad-2025"
  ];

  users.users.admin = {
    isNormalUser = true;
    extraGroups = [ "wheel" ];
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOqHsgAuD/8LL6HN3fo7X1ywryQG393pyQ19a154bO+h delpad-2025"
    ];
  };

  # Enable sudo without password for development convenience
  security.sudo.wheelNeedsPassword = false;

  # Enable fail2ban for brute force protection
  security.fail2ban-enhanced = {
    enable = true;
    bantime = "1h";
    maxretry = 3;
  };

  # Enable ACME for TLS certificates
  security.acme = {
    acceptTerms = true;
    defaults.email = "admin@example.com";  # Using direct email as ACME doesn't support emailFile
  };

  # Dev services stack - simplified without federation
  services.dev-platform = {
    enable = true;
    domain = "example.com";

    matrix = {
      enable = true;
      port = 8008;
    };

    forgejo = {
      enable = true;
      subdomain = "git";
      port = 3000;
    };

    slackBridge = {
      enable = true;
    };
  };

  # Basic monitoring for development
  services.netdata = {
    enable = true;
    config = {
      global = {
        "bind to" = "127.0.0.1";  # Localhost only for security
      };
    };
  };

  # Automatic garbage collection to manage disk space
  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 7d";
  };

  # Allow insecure packages needed for Matrix bridges
  nixpkgs.config.permittedInsecurePackages = [
    "olm-3.2.16"
  ];

  # NixOS configuration optimized for VPS
  nix.settings = {
    experimental-features = [ "nix-command" "flakes" ];

    # Optimize for VPS builds and downloads
    max-jobs = "auto";
    cores = 0;  # Use all available cores
    substituters = [
      "https://cache.nixos.org"
    ];
    trusted-public-keys = [
      "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
    ];
  };

  # Timezone and locale for VPS
  time.timeZone = "UTC";
  i18n.defaultLocale = "en_US.UTF-8";

  system.stateVersion = "24.11";
}