feat: auto-email sending via SMTP (--send flag)

Closes #45

- New redmine_reporter/mailer.py: SMTP email sending with
  {author}/{period} template substitution, MIME attachment
  with correct content-type per file extension
- Config.get_email_config(): returns EmailConfig from YAML
  or None when not configured
- CLI --send flag: sends report after generation, works with
  --output, --commit, or standalone (saves to template path)
- 31 new tests (22 mailer + 6 CLI + 3 config)
- 249/249 tests passing, ruff clean, mypy clean

tests/test_mailer.py

@@ -0,0 +1,198 @@
+import smtplib
+from unittest import mock
+
+import pytest
+
+from redmine_reporter.client import RedmineAPIError
+from redmine_reporter.config import EmailConfig, SmtpConfig
+from redmine_reporter.mailer import build_message, send_report
+
+
+def _make_email_config(**overrides) -> EmailConfig:
+    """Создаёт EmailConfig с минимальными валидными настройками."""
+    smtp = SmtpConfig(
+        host=overrides.pop("smtp_host", "smtp.example.com"),
+        port=overrides.pop("smtp_port", 587),
+        user=overrides.pop("smtp_user", "bot@example.com"),
+        password=overrides.pop("smtp_password", "secret"),
+        tls=overrides.pop("smtp_tls", True),
+    )
+    return EmailConfig(
+        smtp=smtp,
+        from_=overrides.pop("from_", "bot@example.com"),
+        to=overrides.pop("to", ["boss@example.com"]),
+        cc=overrides.pop("cc", []),
+        bcc=overrides.pop("bcc", []),
+        subject=overrides.pop("subject", "Отчёт {author} за {period}"),
+        body_text=overrides.pop("body_text", "Во вложении отчёт."),
+        attach=overrides.pop("attach", True),
+        **overrides,
+    )
+
+
+class TestBuildMessage:
+    """Тесты формирования MIME-письма."""
+
+    def test_subject_substitution(self):
+        """{author} и {period} подставляются в тему."""
+        cfg = _make_email_config(subject="Отчёт {author} за {period}", attach=False)
+        msg = build_message(cfg, "/tmp/report.xlsx", "Кокос А.Н.", "2026-06-01--2026-06-30")
+        assert msg["Subject"] == "Отчёт Кокос А.Н. за 2026-06-01--2026-06-30"
+
+    def test_body_substitution(self):
+        """{author} и {period} подставляются в тело."""
+        cfg = _make_email_config(body_text="Автор: {author}, период: {period}", attach=False)
+        msg = build_message(cfg, "/tmp/report.xlsx", "Иванов", "Q1")
+        plain_part = msg.get_payload()[0]
+        assert "Автор: Иванов, период: Q1" in plain_part.as_string()
+
+    def test_from_header(self):
+        cfg = _make_email_config(from_="sender@example.com", attach=False)
+        msg = build_message(cfg, "/tmp/r.xlsx", "A", "P")
+        assert msg["From"] == "sender@example.com"
+
+    def test_to_header(self):
+        cfg = _make_email_config(to=["a@x.com", "b@x.com"], attach=False)
+        msg = build_message(cfg, "/tmp/r.xlsx", "A", "P")
+        assert msg["To"] == "a@x.com, b@x.com"
+
+    def test_cc_header(self):
+        cfg = _make_email_config(cc=["cc@x.com"], attach=False)
+        msg = build_message(cfg, "/tmp/r.xlsx", "A", "P")
+        assert msg["Cc"] == "cc@x.com"
+
+    def test_bcc_not_in_headers(self):
+        """BCC не должен появляться в заголовках письма."""
+        cfg = _make_email_config(bcc=["hidden@x.com"], attach=False)
+        msg = build_message(cfg, "/tmp/r.xlsx", "A", "P")
+        assert "Bcc" not in msg
+
+    def test_attachment_present_when_attach_true(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake xlsx content")
+        cfg = _make_email_config(attach=True)
+        msg = build_message(cfg, str(report), "A", "P")
+        assert len(msg.get_payload()) == 2
+
+    def test_no_attachment_when_attach_false(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake xlsx content")
+        cfg = _make_email_config(attach=False)
+        msg = build_message(cfg, str(report), "A", "P")
+        assert len(msg.get_payload()) == 1
+
+    @pytest.mark.parametrize("ext,expected_mime", [
+        (".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"),
+        (".odt", "application/vnd.oasis.opendocument.text"),
+        (".csv", "text/csv"),
+        (".html", "text/html"),
+        (".json", "application/json"),
+        (".md", "text/markdown"),
+    ])
+    def test_mime_type_by_extension(self, ext, expected_mime, tmp_path):
+        report = tmp_path / f"report{ext}"
+        report.write_text("content")
+        cfg = _make_email_config()
+        msg = build_message(cfg, str(report), "A", "P")
+        attachment_part = msg.get_payload()[1]
+        assert attachment_part.get_content_type() == expected_mime
+
+    def test_missing_attachment_file_raises_error(self, tmp_path):
+        """Если файл вложения не существует — RedmineAPIError."""
+        cfg = _make_email_config()
+        missing = str(tmp_path / "nonexistent.xlsx")
+        with pytest.raises(RedmineAPIError, match="Не удалось прочитать файл"):
+            build_message(cfg, missing, "A", "P")
+
+
+class TestSendReport:
+    """Тесты отправки письма."""
+
+    def test_send_success(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config()
+
+        with mock.patch("smtplib.SMTP") as mock_smtp_class:
+            mock_smtp = mock.MagicMock()
+            mock_smtp_class.return_value.__enter__.return_value = mock_smtp
+
+            send_report(cfg, str(report), "Кокос А.Н.", "2026-06-01--2026-06-30")
+
+            mock_smtp_class.assert_called_once_with("smtp.example.com", 587, timeout=30)
+            mock_smtp.starttls.assert_called_once()
+            mock_smtp.login.assert_called_once_with("bot@example.com", "secret")
+            mock_smtp.send_message.assert_called_once()
+
+    def test_send_no_tls(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config(smtp_tls=False)
+
+        with mock.patch("smtplib.SMTP") as mock_smtp_class:
+            mock_smtp = mock.MagicMock()
+            mock_smtp_class.return_value.__enter__.return_value = mock_smtp
+
+            send_report(cfg, str(report), "A", "P")
+
+            mock_smtp.starttls.assert_not_called()
+
+    def test_send_connection_error(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config()
+
+        with mock.patch("smtplib.SMTP", side_effect=OSError("Connection refused")):
+            with pytest.raises(RedmineAPIError, match="Не удалось подключиться к SMTP"):
+                send_report(cfg, str(report), "A", "P")
+
+    def test_send_auth_error(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config()
+
+        with mock.patch("smtplib.SMTP") as mock_smtp_class:
+            mock_smtp = mock.MagicMock()
+            mock_smtp_class.return_value.__enter__.return_value = mock_smtp
+            mock_smtp.login.side_effect = smtplib.SMTPAuthenticationError(535, b"Bad auth")
+
+            with pytest.raises(RedmineAPIError, match="Ошибка аутентификации SMTP"):
+                send_report(cfg, str(report), "A", "P")
+
+    def test_send_timeout_error(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config()
+
+        with mock.patch("smtplib.SMTP", side_effect=TimeoutError()):
+            with pytest.raises(RedmineAPIError, match="Таймаут соединения с SMTP"):
+                send_report(cfg, str(report), "A", "P")
+
+    def test_send_generic_smtp_error(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config()
+
+        with mock.patch("smtplib.SMTP") as mock_smtp_class:
+            mock_smtp = mock.MagicMock()
+            mock_smtp_class.return_value.__enter__.return_value = mock_smtp
+            mock_smtp.send_message.side_effect = smtplib.SMTPException("Something went wrong")
+
+            with pytest.raises(RedmineAPIError, match="Ошибка отправки письма"):
+                send_report(cfg, str(report), "A", "P")
+
+    def test_send_includes_cc_and_bcc(self, tmp_path):
+        report = tmp_path / "report.xlsx"
+        report.write_text("fake content")
+        cfg = _make_email_config(to=["a@x.com"], cc=["cc@x.com"], bcc=["bcc@x.com"])
+
+        with mock.patch("smtplib.SMTP") as mock_smtp_class:
+            mock_smtp = mock.MagicMock()
+            mock_smtp_class.return_value.__enter__.return_value = mock_smtp
+
+            send_report(cfg, str(report), "A", "P")
+
+            call_args = mock_smtp.send_message.call_args
+            msg = call_args.args[0]
+            assert msg["To"] == "a@x.com"
+            assert msg["Cc"] == "cc@x.com"