"""Unit tests for application configuration and validation."""

import os
import tempfile

import pytest
from pydantic import ValidationError

from app.config import Settings

# Module-level temp dir for tests that need real existing directories.
_test_tmpdir = tempfile.mkdtemp()


def _minimal_settings(**overrides: object) -> Settings:
    """Create a Settings with valid defaults for unit tests.

    Uses _test_tmpdir (module-level) for paths that require existing directories.
    """
    defaults = {
        "database_path": os.path.join(_test_tmpdir, "test.db"),
        "fail2ban_socket": "/tmp/fake_fail2ban.sock",
        "fail2ban_config_dir": _test_tmpdir,
        "session_secret": "test-secret-key-do-not-use-in-production",
    }
    defaults.update(overrides)  # type: ignore[arg-type]
    return Settings(**defaults)  # type: ignore[arg-type]


# ---------------------------------------------------------------------------
# fail2ban_start_command validation tests
# ---------------------------------------------------------------------------


def test_fail2ban_start_command_validates_simple_command() -> None:
    """Simple fail2ban commands without special characters are accepted."""
    settings = _minimal_settings(fail2ban_start_command="fail2ban-client start")
    assert settings.fail2ban_start_command == "fail2ban-client start"


def test_fail2ban_start_command_validates_systemctl_command() -> None:
    """systemctl commands are accepted."""
    settings = _minimal_settings(fail2ban_start_command="systemctl start fail2ban")
    assert settings.fail2ban_start_command == "systemctl start fail2ban"


def test_fail2ban_start_command_accepts_quoted_paths() -> None:
    """Commands with quoted paths containing spaces are accepted."""
    settings = _minimal_settings(fail2ban_start_command='"/opt/my tools/fail2ban-client" start')
    assert settings.fail2ban_start_command == '"/opt/my tools/fail2ban-client" start'


def test_fail2ban_start_command_rejects_mismatched_quotes() -> None:
    """Commands with mismatched quotes raise ValidationError."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(fail2ban_start_command='"/opt/my tools/fail2ban-client start')
    error_msg = str(exc_info.value)
    assert "fail2ban_start_command" in error_msg
    assert "mismatched quotes" in error_msg or "No closing quotation" in error_msg


def test_fail2ban_start_command_error_includes_problematic_value() -> None:
    """Validation errors include the problematic command value."""
    problematic_command = '"/opt/broken start'
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(fail2ban_start_command=problematic_command)
    error_msg = str(exc_info.value)
    assert problematic_command in error_msg


def test_fail2ban_start_command_default_value_is_valid() -> None:
    """The default fail2ban_start_command value is valid and parseable."""
    settings = _minimal_settings()
    assert settings.fail2ban_start_command == "fail2ban-client start"


def test_fail2ban_start_command_single_quoted() -> None:
    """Commands with single quotes are accepted."""
    settings = _minimal_settings(fail2ban_start_command="'/usr/bin/fail2ban-client' start")
    assert settings.fail2ban_start_command == "'/usr/bin/fail2ban-client' start"


def test_fail2ban_start_command_multiple_arguments() -> None:
    """Commands with multiple arguments are accepted."""
    settings = _minimal_settings(fail2ban_start_command="fail2ban-client -c /etc/fail2ban start")
    assert settings.fail2ban_start_command == "fail2ban-client -c /etc/fail2ban start"


# ---------------------------------------------------------------------------
# session_secret validation tests
# ---------------------------------------------------------------------------


def test_session_secret_enforces_minimum_length() -> None:
    """session_secret must be at least 32 characters."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(session_secret="short-secret")
    error_msg = str(exc_info.value)
    assert "session_secret" in error_msg
    assert "32" in error_msg or "at least" in error_msg


def test_session_secret_accepts_32_characters() -> None:
    """session_secret with exactly 32 characters is accepted."""
    secret_32 = "a" * 32
    settings = _minimal_settings(session_secret=secret_32)
    assert settings.session_secret == secret_32


def test_session_secret_accepts_longer_than_32() -> None:
    """session_secret with more than 32 characters is accepted."""
    secret_64 = "b" * 64
    settings = _minimal_settings(session_secret=secret_64)
    assert settings.session_secret == secret_64


def test_session_secret_error_message_includes_guidance() -> None:
    """Validation error for short session_secret includes secret generation guidance."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(session_secret="too-short")
    error_msg = str(exc_info.value)
    assert "session_secret" in error_msg


def test_session_secret_rejects_weak_secrets() -> None:
    """Common weak words in session_secret are rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(session_secret="password1234567890123456789012345")
    error_msg = str(exc_info.value)
    assert "too weak" in error_msg or "weak" in error_msg


# ---------------------------------------------------------------------------
# database_path validation tests
# ---------------------------------------------------------------------------


def test_database_path_parent_must_exist() -> None:
    """database_path parent directory must exist."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(database_path="/nonexistent/parent/test.db")
    error_msg = str(exc_info.value)
    assert "parent directory does not exist" in error_msg


def test_database_path_parent_must_be_writable() -> None:
    """database_path parent directory must be writable."""
    with tempfile.TemporaryDirectory() as tmpdir:
        # Create a read-only directory
        readonly_dir = os.path.join(tmpdir, "readonly")
        os.makedirs(readonly_dir, exist_ok=True)
        os.chmod(readonly_dir, 0o555)

        try:
            with pytest.raises(ValidationError) as exc_info:
                _minimal_settings(database_path=os.path.join(readonly_dir, "test.db"))
            error_msg = str(exc_info.value)
            assert "not writable" in error_msg
        finally:
            os.chmod(readonly_dir, 0o755)


def test_database_path_with_existing_writable_parent_is_accepted() -> None:
    """database_path with existing writable parent is accepted."""
    with tempfile.TemporaryDirectory() as tmpdir:
        settings = _minimal_settings(database_path=os.path.join(tmpdir, "test.db"))
        assert settings.database_path == os.path.join(tmpdir, "test.db")


# ---------------------------------------------------------------------------
# fail2ban_socket validation tests
# ---------------------------------------------------------------------------


def test_fail2ban_socket_nonexistent_is_accepted() -> None:
    """fail2ban_socket path that doesn't exist yet is accepted (deferred creation)."""
    settings = _minimal_settings(fail2ban_socket="/nonexistent/socket.sock")
    assert settings.fail2ban_socket == "/nonexistent/socket.sock"


def test_fail2ban_socket_existing_must_be_readable() -> None:
    """fail2ban_socket that exists must be readable."""
    with tempfile.NamedTemporaryFile() as f:
        # Make it unreadable
        os.chmod(f.name, 0o000)
        try:
            with pytest.raises(ValidationError) as exc_info:
                _minimal_settings(fail2ban_socket=f.name)
            error_msg = str(exc_info.value)
            assert "not readable" in error_msg
        finally:
            os.chmod(f.name, 0o644)


def test_fail2ban_socket_existing_readable_is_accepted() -> None:
    """fail2ban_socket that exists and is readable is accepted."""
    with tempfile.NamedTemporaryFile() as f:
        settings = _minimal_settings(fail2ban_socket=f.name)
        assert settings.fail2ban_socket == f.name


# ---------------------------------------------------------------------------
# geoip_db_path validation tests
# ---------------------------------------------------------------------------


def test_geoip_db_path_none_is_accepted() -> None:
    """geoip_db_path set to None is accepted."""
    settings = _minimal_settings(geoip_db_path=None)
    assert settings.geoip_db_path is None


def test_geoip_db_path_nonexistent_is_rejected() -> None:
    """geoip_db_path that doesn't exist is rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(geoip_db_path="/nonexistent/GeoLite2-Country.mmdb")
    error_msg = str(exc_info.value)
    assert "does not exist" in error_msg


def test_geoip_db_path_existing_is_accepted() -> None:
    """geoip_db_path that exists is accepted."""
    with tempfile.NamedTemporaryFile() as f:
        settings = _minimal_settings(geoip_db_path=f.name)
        assert settings.geoip_db_path == f.name


# ---------------------------------------------------------------------------
# fail2ban_config_dir validation tests
# ---------------------------------------------------------------------------


def test_fail2ban_config_dir_nonexistent_is_rejected() -> None:
    """fail2ban_config_dir that doesn't exist is rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(fail2ban_config_dir="/nonexistent/fail2ban/config")
    error_msg = str(exc_info.value)
    assert "does not exist" in error_msg


def test_fail2ban_config_dir_existing_is_accepted() -> None:
    """fail2ban_config_dir that exists is accepted."""
    with tempfile.TemporaryDirectory() as tmpdir:
        settings = _minimal_settings(fail2ban_config_dir=tmpdir)
        assert settings.fail2ban_config_dir == tmpdir


# ---------------------------------------------------------------------------
# trusted_proxies configuration tests
# ---------------------------------------------------------------------------


def test_trusted_proxies_default_is_empty_list() -> None:
    """By default, trusted_proxies is an empty list (no trusted proxies)."""
    settings = _minimal_settings()
    assert settings.trusted_proxies == []


def test_trusted_proxies_accepts_single_ip() -> None:
    """Single IP address is accepted."""
    settings = _minimal_settings(trusted_proxies="192.168.1.1")
    assert settings.trusted_proxies == ["192.168.1.1"]


def test_trusted_proxies_accepts_single_cidr() -> None:
    """Single CIDR range is accepted."""
    settings = _minimal_settings(trusted_proxies="10.0.0.0/8")
    assert settings.trusted_proxies == ["10.0.0.0/8"]


def test_trusted_proxies_accepts_comma_separated_list() -> None:
    """Comma-separated list of IPs and CIDRs is accepted."""
    settings = _minimal_settings(trusted_proxies="192.168.1.1,10.0.0.0/8,172.16.0.0/12")
    assert settings.trusted_proxies == ["192.168.1.1", "10.0.0.0/8", "172.16.0.0/12"]


def test_trusted_proxies_accepts_list() -> None:
    """List of IPs and CIDRs is accepted."""
    settings = _minimal_settings(trusted_proxies=["192.168.1.1", "10.0.0.0/8"])
    assert settings.trusted_proxies == ["192.168.1.1", "10.0.0.0/8"]


def test_trusted_proxies_strips_whitespace() -> None:
    """Whitespace around IPs is stripped."""
    settings = _minimal_settings(trusted_proxies="  192.168.1.1  ,  10.0.0.0/8  ")
    assert settings.trusted_proxies == ["192.168.1.1", "10.0.0.0/8"]


def test_trusted_proxies_rejects_invalid_ip() -> None:
    """Invalid IP address is rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(trusted_proxies="not-an-ip")
    error_msg = str(exc_info.value)
    assert "trusted_proxies" in error_msg or "Invalid IP" in error_msg


def test_trusted_proxies_rejects_invalid_cidr() -> None:
    """Invalid CIDR range is rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(trusted_proxies="10.0.0.0/33")
    error_msg = str(exc_info.value)
    assert "trusted_proxies" in error_msg or "Invalid IP" in error_msg


def test_trusted_proxies_rejects_one_invalid_in_list() -> None:
    """One invalid IP in a list causes entire list to be rejected."""
    with pytest.raises(ValidationError) as exc_info:
        _minimal_settings(trusted_proxies="192.168.1.1,invalid-ip,10.0.0.0/8")
    error_msg = str(exc_info.value)
    assert "trusted_proxies" in error_msg or "Invalid IP" in error_msg


def test_trusted_proxies_accepts_ipv6_address() -> None:
    """IPv6 address is accepted."""
    settings = _minimal_settings(trusted_proxies="2001:db8::1")
    assert settings.trusted_proxies == ["2001:db8::1"]


def test_trusted_proxies_accepts_ipv6_cidr() -> None:
    """IPv6 CIDR range is accepted."""
    settings = _minimal_settings(trusted_proxies="2001:db8::/32")
    assert settings.trusted_proxies == ["2001:db8::/32"]


def test_trusted_proxies_accepts_mixed_ipv4_and_ipv6() -> None:
    """Mixed IPv4 and IPv6 addresses and ranges are accepted."""
    settings = _minimal_settings(trusted_proxies="192.168.1.0/24,2001:db8::/32,10.0.0.1")
    assert settings.trusted_proxies == ["192.168.1.0/24", "2001:db8::/32", "10.0.0.1"]