# Updating an installed router to a newer nixos-router.
#
# "Versions" are copies of this repository evaluated as flakes of their own
# (a different source path, VERSION, commit time, and for version 2 a settings
# migration), so the whole path runs for real: a builder signs releases as
# binary caches (router-release), and the router takes them, with these rules:
#
#   - signed with another key, or not signed at all: refused,
#   - not newer than the installed version: refused,
#   - upload in the web UI: imported, the configuration flake points at the new
#     source, settings.json is migrated, the router is rebuilt offline and the
#     update waits for confirmation; unconfirmed, everything goes back,
#   - the same update pulled from a server and confirmed in the web UI: the
#     router runs the new version and rebuilds to exactly itself.
{ self, pkgs }:
let
  inherit (pkgs) lib;
  common = import ./common.nix;
  keys = ./update-keys;

  # A version of the repository: its source (with the test key as update key)
  # evaluated as a flake that has been told its commit time.
  mkVersion =
    {
      name,
      version,
      serial,
      extra ? "",
    }:
    let
      src = pkgs.runCommand "nixos-router-${name}" { } ''
        cp -r ${self.outPath} $out
        chmod -R u+w $out
        cp ${keys}/good.pub $out/keys/update.pub
        printf '%s\n' ${version} > $out/VERSION
        ${extra}
      '';
      flake = (import "${src}/flake.nix").outputs {
        self = flake // {
          outPath = src;
          lastModified = serial;
          rev = name;
        };
        inherit (self.inputs) nixpkgs;
      };
    in
    flake // { inherit src; };

  v1 = mkVersion {
    name = "v1";
    version = "1.0.0";
    serial = 1000;
    # Settings version 0: the real migrations are not part of this test.
    extra = "rm $out/migrations/*.jq";
  };
  v2 = mkVersion {
    name = "v2";
    version = "2.0.0";
    serial = 2000;
    # Settings version 1: the time zone becomes explicit.
    extra = ''
      echo '.system.timeZone = "Europe/Berlin"' > $out/migrations/1.jq
    '';
  };

  release = v: v.lib.mkRelease {
    inherit pkgs;
    # The router has all it needs to rebuild; keep the bundles small.
    includeReference = false;
  };
  release1 = release v1;
  release2 = release v2;
  tool = v: r: "${v.lib.mkReleaseTool { inherit pkgs; release = r; }}/bin/router-release";

  settings = pkgs.writeText "settings.json" (
    builtins.toJSON {
      system = {
        hostName = "router";
        stateVersion = "26.11";
      };
      router = {
        wan.interface = "eth1";
        lans.main = {
          interface = "eth2";
          internet = true;
          ipv4.address = "192.168.10.1";
          dhcp.pool = {
            start = "192.168.10.100";
            end = "192.168.10.199";
          };
        };
      };
    }
  );

  # Only so the test driver can talk to the installed system; and a short
  # rollback timeout, so that an unconfirmed update comes back soon.
  local = pkgs.writeText "local.nix" ''
    { modulesPath, pkgs, ... }:
    {
      imports = [ (modulesPath + "/testing/test-instrumentation.nix") ];
      router.rollback.timeout = "90s";
      environment.systemPackages = [ pkgs.jq ];
    }
  '';

  configDir = v1.lib.mkConfigDir { inherit pkgs settings local; };
  toplevel =
    (v1.lib.mkRouterSystem {
      settings = "${configDir}/settings.json";
      modules = [ "${configDir}/local.nix" ];
    }).config.system.build.toplevel;

  sharedDisk = {
    virtualisation.diskImage = "./target.qcow2";
    virtualisation.diskSize = 8192;
  };
  builderIp = "192.168.10.60";
in
pkgs.testers.runNixOSTest {
  name = "router-update";

  nodes = {
    installer =
      { lib, ... }:
      {
        imports = [
          sharedDisk
          self.nixosModules.installer
          common.tools
        ];
        router.installer.system = toplevel;
        virtualisation.memorySize = 2048;
        virtualisation.fileSystems."/".autoFormat = true;
        virtualisation.emptyDiskImages = [ 1024 ];
        virtualisation.rootDevice = "/dev/vdb";
        nix.settings.substituters = lib.mkForce [ ];
      };

    target = {
      imports = [ sharedDisk ];
      virtualisation.memorySize = 4096;
      virtualisation.vlans = [
        1
        2
      ];
      virtualisation.useBootLoader = true;
      virtualisation.useEFIBoot = true;
      virtualisation.useDefaultFilesystems = false;
      virtualisation.efi.keepVariables = false;
      virtualisation.fileSystems."/" = {
        device = "/dev/disk/by-label/this-is-not-real-and-will-never-be-used";
        fsType = "ext4";
      };
    };

    # Where releases are made and signed, served, and uploaded from.
    builder =
      { lib, pkgs, ... }:
      {
        imports = [ common.tools ];
        virtualisation.vlans = [ 2 ];
        virtualisation.memorySize = 2048;
        virtualisation.diskSize = 6144;
        networking.interfaces.eth1.ipv4.addresses = lib.mkForce [
          {
            address = builderIp;
            prefixLength = 24;
          }
        ];
        networking.firewall.enable = false;
        environment.systemPackages = [ pkgs.python3 ];
        virtualisation.additionalPaths = [
          release1
          release2
        ];
        environment.etc."keys/good.sec".source = "${keys}/good.sec";
        environment.etc."keys/evil.sec".source = "${keys}/evil.sec";
      };
  };

  testScript = ''
    installer.start()
    installer.wait_for_unit("multi-user.target")
    installer.succeed("mkdir -p /root/secrets && cp -r ${configDir} /root/secrets/config")
    installer.succeed("router-install --yes --secrets /root/secrets /dev/vda >&2")
    installer.shutdown()

    target.state_dir = installer.state_dir
    target.start()
    builder.start()
    target.wait_for_unit("multi-user.target")
    builder.wait_for_unit("multi-user.target")
    target.succeed("echo hunter2hunter2 | router-webui passwd /var/lib/router/webui-password")
    target.wait_for_unit("router-webui.service")

    ui = "https://192.168.10.1"

    def release_json(): return target.succeed("cat /etc/router-release")
    def version(): return target.succeed("jq -r .version /etc/router-release").strip()
    def current(): return target.succeed("readlink -f /run/current-system").strip()
    def flake_source(): return target.succeed("grep -o 'path:[^\"]*' /var/lib/router/config/flake.nix").strip()
    def serve(directory, port):
        builder.succeed(f"systemd-run --unit=serve-{port} -p WorkingDirectory={directory} ${pkgs.python3}/bin/python3 -m http.server {port} --bind ${builderIp}")
        builder.wait_for_open_port(port, "${builderIp}")
    def sign(tool, key, out):
        builder.succeed(f"{tool} --key /etc/keys/{key}.sec --out {out} --compression none >&2")
    def update_from(port, flags=""):
        return target.execute(f"router-update {flags} --url http://${builderIp}:{port} 2>&1")
    def login():
        builder.succeed(f"curl -sk -c /tmp/jar -o /dev/null -d password=hunter2hunter2 {ui}/login")
    def csrf(path):
        return builder.succeed(f"curl -sk -b /tmp/jar {ui}{path} | grep -o 'name=\"csrf\" value=\"[^\"]*' | head -1 | cut -d'\"' -f4").strip()
    def csrf_from_query(path):
        return builder.succeed(f"curl -sk -b /tmp/jar {ui}{path} | grep -o 'upload?csrf=[^\"]*' | head -1 | cut -d= -f2").strip()
    def update_finished():
        target.wait_until_succeeds(
            "test $(systemctl show -p ActiveState --value router-update.service) = inactive"
            " && test $(systemctl show -p Result --value router-update.service) = success", timeout=900)

    v1_flake = flake_source()

    with subtest("the installed router is version 1 and trusts the update key"):
        assert version() == "1.0.0", release_json()
        assert v1_flake == "path:${v1.src}", v1_flake
        target.succeed("test -s /etc/router-update-keys")

    sign("${tool v2 release2}", "evil", "/root/evil")
    serve("/root/evil", 8001)
    sign("${tool v2 release2}", "good", "/root/good")
    serve("/root/good", 8004)
    # The good release without its signatures.
    builder.succeed("cp -r /root/good /root/unsigned && sed -i '/^Sig:/d' /root/unsigned/cache/*.narinfo")
    serve("/root/unsigned", 8002)
    sign("${tool v1 release1}", "good", "/root/old")
    serve("/root/old", 8003)

    def unchanged():
        assert version() == "1.0.0"
        assert flake_source() == v1_flake
        target.succeed("test ! -e /var/lib/router/config.pre-update")
        target.fail("grep -q '\"version\"' /var/lib/router/config/settings.json")

    with subtest("an update signed with another key is refused"):
        rc, out = update_from(8001)
        assert rc != 0 and "not signed with this router's update key" in out, out
        unchanged()

    with subtest("an update without signatures is refused"):
        rc, out = update_from(8002)
        assert rc != 0 and "not signed with this router's update key" in out, out
        unchanged()

    with subtest("a release that is not newer is refused"):
        rc, out = update_from(8003)
        assert rc != 0 and "not newer" in out, out
        unchanged()

    with subtest("a bundle uploaded in the web UI is verified, installed and migrated"):
        login()
        token = csrf_from_query("/update")
        assert token
        assert "Install a bundle" in builder.succeed(f"curl -sk -b /tmp/jar {ui}/update")
        # (-F puts the file after the other fields, as the page's form does.)
        assert builder.succeed(
            f"curl -sk -b /tmp/jar -o /dev/null -w '%{{http_code}}' -F bundle=@/root/good/router-update-2.0.0.bundle '{ui}/update/upload?csrf=wrong'").strip() == "403"
        builder.succeed(f"curl -sk -b /tmp/jar -o /dev/null -F bundle=@/root/good/router-update-2.0.0.bundle '{ui}/update/upload?csrf={token}'")
        update_finished()
        assert version() == "2.0.0", release_json()
        assert flake_source() == "path:${v2.src}", flake_source()
        settings = target.succeed("cat /var/lib/router/config/settings.json")
        assert '"version": 1' in settings and "Europe/Berlin" in settings, settings
        assert target.succeed("readlink /etc/localtime").strip().endswith("Europe/Berlin")
        target.succeed("systemctl is-active router-rollback.timer")
        target.succeed("test -d /var/lib/router/config.pre-update")

    with subtest("an update that is not confirmed is rolled back, configuration included"):
        target.wait_until_succeeds("test $(jq -r .version /etc/router-release) = 1.0.0", timeout=300)
        unchanged()
        assert "Berlin" not in target.succeed("cat /var/lib/router/config/settings.json")
        assert target.succeed("readlink /etc/localtime").strip().endswith("/UTC")
        target.wait_for_unit("router-webui.service")

    with subtest("the same update, pulled from a server in the web UI, can be confirmed"):
        login()
        token = csrf("/update")
        form = lambda path, data: builder.succeed(
            f"curl -sk -b /tmp/jar -o /tmp/out -w '%{{http_code}}' --data-urlencode csrf={token} {data} {ui}{path}").strip()
        assert form("/update/url", "--data-urlencode url=http://${builderIp}:8004/") == "303"
        assert "Available: <strong>2.0.0</strong>" in (form("/update/check", "") and builder.succeed("cat /tmp/out"))
        assert form("/update/install", "") == "303"
        update_finished()
        assert version() == "2.0.0"
        target.succeed("systemctl is-active router-rollback.timer")
        login()
        token = csrf("/")
        builder.succeed(f"curl -sk -b /tmp/jar -o /dev/null --data-urlencode csrf={token} {ui}/confirm")
        target.wait_until_fails("systemctl is-active router-rollback.timer", timeout=60)
        target.wait_until_succeeds("test $(systemctl show -p ActiveState --value router-confirm.service) = inactive")
        target.succeed("test ! -e /var/lib/router/config.pre-update")
        assert target.succeed("readlink -f /nix/var/nix/profiles/system").strip() == current()
        assert target.succeed("readlink /etc/localtime").strip().endswith("Europe/Berlin")

    with subtest("the updated router rebuilds to exactly itself, offline"):
        out = target.succeed("router-apply 2>&1")
        assert "no changes" in out, out

    with subtest("the old release is not accepted any more"):
        rc, out = update_from(8003)
        assert rc != 0 and "not newer" in out, out
        assert version() == "2.0.0"
  '';
}