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

# mercury — Raspberry Pi 3B+ (aarch64). Network DNS + DHCP (+ adblock).
# Boots from an SD image (see flake: nixosConfigurations.mercury), so there is
# no disko / hardware-configuration here — the sd-image module provides them.
{
  imports = [
    ../../common.nix           # shared base: user / ssh / nix / firewall
    ./secrets.nix              # sops-nix: darman password (age key on boot part.)
    ../../services/unbound.nix      # local recursive resolver (127.0.0.1:5335)
    ../../services/pihole.nix        # DNS adblock + DHCP (declarative static leases)
  ];

  networking.hostName = "mercury";

  # ---- Static networking ----
  # A DNS/DHCP server must have a fixed address. Fill in the Pi's real values
  # (from `ip -brief a` / `ip route` on the running Pi). eth0 = the Pi's NIC.
  networking.useDHCP = false;
  networking.usePredictableInterfaceNames = false;   # keep it named eth0
  networking.interfaces.eth0.ipv4.addresses = [
    { address = "10.0.0.10"; prefixLength = 24; }     # the Pi's current IP
  ];
  # VERIFY with `ip route` on the Pi — assuming the router is .1.
  networking.defaultGateway = { address = "10.0.0.1"; interface = "eth0"; };
  # Resolvers for the Pi's OWN lookups (not the LAN service). Kept public so the
  # host resolves during boot without depending on its own pihole/unbound.
  networking.nameservers = [ "1.1.1.1" "9.9.9.9" ];

  # DNS adblock + DHCP (pihole) and the recursive resolver (unbound) come from
  # the imported service modules. pihole forwards to unbound at 127.0.0.1:5335.

  # ---- pihole web admin password (from sops) ----
  # pihole.toml is nix-managed read-only, so `pihole setpassword` can't write it.
  # Instead pihole-FTL reads FTLCONF_* env vars (they override the toml). Render
  # an env file from the sops secret and feed it to the service — password stays
  # out of the repo and the nix store.
  sops.secrets.pihole_webpassword = { };
  sops.templates."pihole-ftl.env".content =
    "FTLCONF_webserver_api_password=${config.sops.placeholder.pihole_webpassword}";
  systemd.services.pihole-ftl.serviceConfig.EnvironmentFile =
    config.sops.templates."pihole-ftl.env".path;

  # Do not modify after first flash.
  system.stateVersion = "26.05";
}