# This file configures camden.tazj.in, my homeserver.

{ pkgs, lib, ... }:

config: let
  nixpkgs = import pkgs.third_party.nixpkgsSrc {
    config.allowUnfree = true;
  };
in pkgs.lib.fix(self: {
  imports = [ ../modules/tailscale.nix ];

  # camden is intended to boot unattended, despite having an encrypted
  # root partition.
  #
  # The below configuration uses an externally connected USB drive
  # that contains a LUKS key file to unlock the disk automatically at
  # boot.
  #
  # TODO(tazjin): Configure LUKS unlocking via SSH instead.
  boot = {
    initrd = {
      availableKernelModules = [
        "ahci" "xhci_pci" "usbhid" "usb_storage" "sd_mod" "sdhci_pci"
        "rtsx_usb_sdmmc" "r8169"
      ];

      kernelModules = [ "dm-snapshot" ];

      luks.devices.camden-crypt = {
        fallbackToPassword = true;
        device = "/dev/disk/by-label/camden-crypt";
        keyFile = "/dev/sdb";
        keyFileSize = 4096;
      };
    };

    loader = {
      systemd-boot.enable = true;
      efi.canTouchEfiVariables = true;
    };

    cleanTmpDir = true;
  };

  fileSystems = {
    "/" = {
      device = "/dev/disk/by-label/camden-root";
      fsType = "ext4";
    };

    "/home" = {
      device = "/dev/disk/by-label/camden-home";
      fsType = "ext4";
    };

    "/boot" = {
      device = "/dev/disk/by-label/BOOT";
      fsType = "vfat";
    };
  };

  nix = {
    maxJobs = lib.mkDefault 4;

    nixPath = [
      "depot=/home/tazjin/depot"
      "nixpkgs=${pkgs.third_party.nixpkgsSrc}"
    ];
  };
  nixpkgs.pkgs = nixpkgs;

  powerManagement.cpuFreqGovernor = lib.mkDefault "powersave";

  networking = {
    hostName = "camden";
    interfaces.enp1s0.useDHCP = true;
    firewall.allowedTCPPorts = [ 22 8080 80 443 ];
  };

  time.timeZone = "UTC";

  # System-wide application setup
  programs.fish.enable = true;
  programs.mosh.enable = true;

  environment.systemPackages =
    # programs from the depot
    (with pkgs; [
      third_party.git
      third_party.tailscale
    ]) ++

    # programs from nixpkgs
    (with nixpkgs; [
      curl emacs26-nox gnupg pass pciutils direnv
    ]);

  users = {
    # Set up my own user for logging in and doing things ...
    users.tazjin = {
      isNormalUser = true;
      uid = 1000;
      extraGroups = [ "git" "wheel" ];
      shell = nixpkgs.fish;
    };

    # Set up a user & group for general git shenanigans
    groups.git = {};
    users.git = {
      group = "git";
      isNormalUser = false;
    };
  };

  # Services setup
  services.openssh.enable = true;
  services.haveged.enable = true;

  # Join Tailscale into home network
  services.tailscale = {
    enable = true;
    relayConf = "/etc/tailscale.conf";
    package = pkgs.third_party.tailscale;
    aclFile = pkgs.nix.tailscale {
      ACLs = [
        # Allow any traffic from myself
        {
          Action = "accept";
          Users = [ "mail@tazj.in" ];
          Ports = [ "*:*" ];
        }
      ];
    } ;
  };

  # Run cgit for the depot. The onion here is nginx(thttpd(cgit)).
  systemd.services.cgit = {
    wantedBy = [ "multi-user.target" ];
    script = "${pkgs.web.cgit-taz}/bin/cgit-launch";

    serviceConfig = {
      Restart = "on-failure";
      User = "git";
      Group = "git";
    };
  };

  # Provision a TLS certificate outside of nginx to avoid
  # nixpkgs#38144
  security.acme.certs."tazj.in" = {
    user = "nginx";
    group = "nginx";
    webroot = "/var/lib/acme/acme-challenge";
    extraDomains = {
      "git.tazj.in" = null;
      "www.tazj.in" = null;

      # Local domains (for this machine only)
      "camden.tazj.in" = null;
      "git.camden.tazj.in" = null;
    };
    postRun = "systemctl reload nginx";
  };

  # serve my website
  services.nginx = {
    enable = true;
    enableReload = true;

    recommendedTlsSettings = true;
    recommendedGzipSettings = true;
    recommendedProxySettings = true;

    commonHttpConfig = ''
      log_format json_combined escape=json
      '{'
          '"time_local":"$time_local",'
          '"remote_addr":"$remote_addr",'
          '"remote_user":"$remote_user",'
          '"request":"$request",'
          '"status": "$status",'
          '"body_bytes_sent":"$body_bytes_sent",'
          '"request_time":"$request_time",'
          '"http_referrer":"$http_referer",'
          '"http_user_agent":"$http_user_agent"'
      '}';

      access_log syslog:server=unix:/dev/log json_combined;
    '';

    virtualHosts.homepage = {
      serverName = "tazj.in";
      serverAliases = [ "camden.tazj.in" ];
      default = true;
      useACMEHost = "tazj.in";
      root = pkgs.web.homepage;
      addSSL = true;

      extraConfig = ''
        ${pkgs.web.blog.oldRedirects}

        location ~* \.(webp|woff2)$ {
          add_header Cache-Control "public, max-age=31536000";
        }

        location /blog/ {
          alias ${pkgs.web.blog.rendered}/;

          if ($request_uri ~ ^/(.*)\.html$) {
            return 302 /$1;
          }

          try_files $uri $uri.html $uri/ =404;
        }

        location /blobs/ {
          alias /var/www/blobs/;
        }
      '';
    };

    virtualHosts.cgit = {
      serverName = "git.tazj.in";
      serverAliases = [ "git.camden.tazj.in" ];
      useACMEHost = "tazj.in";
      addSSL = true;

      extraConfig = ''
        # Static assets must always hit the root.
        location ~ ^/(favicon\.ico|cgit\.(css|png))$ {
           proxy_pass http://localhost:2448;
        }

        # Everything else hits the depot directly.
        location / {
            proxy_pass http://localhost:2448/cgit.cgi/depot/;
        }
      '';
    };
  };

  system.stateVersion = "19.09";
})