# SPDX-FileCopyrightText: © 2026 Jeffrey C. Ollie <jeff@ocjtech.us>
# SPDX-License-Identifier: MIT

# NixOS VM test exercising zsmtp against third-party implementations:
#   - zsmtp client -> Postfix: plaintext, STARTTLS (port 25), implicit TLS
#     (port 465), verified by checking local delivery to alice's spool
#   - swaks -> zsmtp server: plaintext and STARTTLS, verified by checking
#     the received message in the server's journal

{
  testers,
  callPackage,
  runCommand,
  openssl,
}:
let
  zsmtp = callPackage ./package.nix { };

  snakeoil =
    runCommand "zsmtp-test-cert"
      {
        nativeBuildInputs = [ openssl ];
      }
      ''
        mkdir -p $out
        openssl req -x509 -newkey ec -pkeyopt ec_paramgen_curve:P-256 \
          -keyout $out/key.pem -out $out/cert.pem -days 36500 -nodes \
          -subj "/CN=localhost" \
          -addext "subjectAltName=DNS:localhost,IP:127.0.0.1"
      '';
in
testers.runNixOSTest {
  name = "zsmtp-interop";

  nodes.machine =
    { pkgs, ... }:
    {
      environment.systemPackages = [
        zsmtp
        pkgs.swaks
      ];

      users.users.alice.isNormalUser = true;

      services.postfix = {
        enable = true;
        # Implicit-TLS smtpd on port 465; allow loopback without SASL.
        enableSubmissions = true;
        submissionsOptions = {
          smtpd_client_restrictions = "permit_mynetworks,reject";
        };
        settings.main = {
          mydestination = [
            "localhost"
            "$myhostname"
          ];
          smtpd_tls_security_level = "may";
          smtpd_tls_chain_files = [
            "${snakeoil}/key.pem"
            "${snakeoil}/cert.pem"
          ];
        };
      };

      systemd.services.zsmtp-server = {
        description = "zsmtp debug server (plaintext)";
        wantedBy = [ "multi-user.target" ];
        serviceConfig = {
          ExecStart = "${zsmtp}/bin/zsmtp serve 2525";
          DynamicUser = true;
        };
      };

      systemd.services.zsmtp-server-tls = {
        description = "zsmtp debug server (STARTTLS)";
        wantedBy = [ "multi-user.target" ];
        serviceConfig = {
          ExecStart = "${zsmtp}/bin/zsmtp serve --tls-cert ${snakeoil}/cert.pem --tls-key ${snakeoil}/key.pem 2526";
          DynamicUser = true;
        };
      };
    };

  testScript = ''
    machine.wait_for_unit("postfix.service")
    machine.wait_for_open_port(25)
    machine.wait_for_open_port(465)
    machine.wait_for_unit("zsmtp-server.service")
    machine.wait_for_unit("zsmtp-server-tls.service")
    machine.wait_for_open_port(2525)
    machine.wait_for_open_port(2526)

    with subtest("zsmtp client to postfix, plaintext"):
        machine.succeed(
            "printf 'Subject: interop\\r\\n\\r\\nzsmtp to postfix plain\\r\\n'"
            " | zsmtp send 127.0.0.1 25 bob@example.com alice@localhost"
        )
        machine.wait_until_succeeds(
            "grep -r 'zsmtp to postfix plain' /var/spool/mail/alice/", timeout=60
        )

    with subtest("zsmtp client to postfix, STARTTLS"):
        machine.succeed(
            "printf 'Subject: interop\\r\\n\\r\\nzsmtp to postfix starttls\\r\\n'"
            " | zsmtp send --starttls --insecure 127.0.0.1 25"
            " bob@example.com alice@localhost"
        )
        machine.wait_until_succeeds(
            "grep -r 'zsmtp to postfix starttls' /var/spool/mail/alice/", timeout=60
        )

    with subtest("zsmtp client to postfix, implicit TLS"):
        machine.succeed(
            "printf 'Subject: interop\\r\\n\\r\\nzsmtp to postfix smtps\\r\\n'"
            " | zsmtp send --tls --insecure 127.0.0.1 465"
            " bob@example.com alice@localhost"
        )
        machine.wait_until_succeeds(
            "grep -r 'zsmtp to postfix smtps' /var/spool/mail/alice/", timeout=60
        )

    with subtest("swaks to zsmtp server, plaintext"):
        machine.succeed(
            "swaks --server 127.0.0.1:2525 --from bob@example.com"
            " --to alice@example.net --header 'Subject: swaks plain'"
            " --body 'swaks to zsmtp plain'"
        )
        machine.wait_until_succeeds(
            "journalctl -u zsmtp-server | grep 'swaks to zsmtp plain'", timeout=60
        )

    with subtest("swaks to zsmtp server, STARTTLS"):
        machine.succeed(
            "swaks --tls --server 127.0.0.1:2526 --from bob@example.com"
            " --to alice@example.net --header 'Subject: swaks starttls'"
            " --body 'swaks to zsmtp starttls'"
        )
        machine.wait_until_succeeds(
            "journalctl -u zsmtp-server-tls | grep 'swaks to zsmtp starttls'", timeout=60
        )
  '';
}