import pytest

from server.utils import (
    ensure_parent_dir,
    get_client_ip,
    get_mac_from_arp,
    load_config,
    normalize_mac,
    validate_imsi,
    validate_mac,
    validate_op_key,
)


class _FakeRequest:
    def __init__(self, headers=None, remote_addr=None):
        self.headers = headers or {}
        self.remote_addr = remote_addr


class TestClientResolution:
    def test_client_ip_prefers_forwarded(self):
        req = _FakeRequest(headers={"X-Forwarded-For": "203.0.113.7, 10.0.0.1"},
                           remote_addr="10.0.0.1")
        assert get_client_ip(req) == "203.0.113.7"

    def test_client_ip_falls_back_to_remote_addr(self):
        assert get_client_ip(_FakeRequest(remote_addr="192.168.4.10")) == "192.168.4.10"

    def test_client_ip_empty_when_unknown(self):
        assert get_client_ip(_FakeRequest()) == ""

    def test_mac_from_arp_match(self, tmp_path):
        arp = tmp_path / "arp"
        arp.write_text(
            "IP address       HW type     Flags       HW address            Mask     Device\n"
            "192.168.4.10     0x1         0x2         AA:BB:CC:DD:EE:FF     *        wlan0\n"
        )
        assert get_mac_from_arp("192.168.4.10", str(arp)) == "aa:bb:cc:dd:ee:ff"

    def test_mac_from_arp_no_match(self, tmp_path):
        arp = tmp_path / "arp"
        arp.write_text("IP address ...\n192.168.4.99 0x1 0x2 11:22:33:44:55:66 * wlan0\n")
        assert get_mac_from_arp("192.168.4.10", str(arp)) is None

    def test_mac_from_arp_missing_file(self):
        assert get_mac_from_arp("192.168.4.10", "/no/such/arp") is None


class TestEnsureParentDir:
    def test_bare_filename_does_not_crash(self):
        # No directory component -> must be a no-op, not FileNotFoundError.
        ensure_parent_dir("subscribers.db")

    def test_creates_nested_dirs(self, tmp_path):
        target = tmp_path / "a" / "b" / "x.db"
        ensure_parent_dir(str(target))
        assert (tmp_path / "a" / "b").is_dir()


class TestMac:
    def test_valid(self):
        assert validate_mac("aa:bb:cc:dd:ee:ff")

    def test_invalid(self):
        assert not validate_mac("nope")
        assert not validate_mac("")

    def test_normalize_dashes_and_case(self):
        assert normalize_mac("AA-BB-CC-DD-EE-FF") == "aa:bb:cc:dd:ee:ff"

    def test_normalize_no_separator(self):
        assert normalize_mac("aabbccddeeff") == "aa:bb:cc:dd:ee:ff"


class TestImsi:
    def test_valid(self):
        assert validate_imsi("302720000000001")

    def test_wrong_length(self):
        assert not validate_imsi("30272000000000")

    def test_non_digit(self):
        assert not validate_imsi("30272000000000x")


class TestOpKey:
    def test_valid(self):
        assert validate_op_key("63bfa50ee6523365ff14c1f45f88737d")

    def test_wrong_length(self):
        assert not validate_op_key("abcd")

    def test_non_hex(self):
        assert not validate_op_key("zz" * 16)


class TestLoadConfig:
    def _base(self):
        return (
            "network: {mcc: '302', mnc: '720', op_key: '63bfa50ee6523365ff14c1f45f88737d'}\n"
            "server: {host: '0.0.0.0', port: 5000}\n"
            "database: {path: '/tmp/x.db'}\n"
            "rate_limiting: {window_hours: 1}\n"
            "profile: {profile_name: 'P', carrier_name: 'C'}\n"
        )

    def test_valid(self, tmp_path):
        p = tmp_path / "c.yaml"
        p.write_text(self._base())
        cfg = load_config(str(p))
        assert cfg["network"]["mcc"] == "302"

    def test_missing_file(self):
        with pytest.raises(FileNotFoundError):
            load_config("/no/such/config.yaml")

    def test_empty_file(self, tmp_path):
        p = tmp_path / "empty.yaml"
        p.write_text("")
        with pytest.raises(ValueError, match="empty or not a mapping"):
            load_config(str(p))

    def test_missing_section(self, tmp_path):
        p = tmp_path / "c.yaml"
        p.write_text("network: {op_key: '63bfa50ee6523365ff14c1f45f88737d'}\n")
        with pytest.raises(ValueError, match="Missing required config section"):
            load_config(str(p))

    def test_bad_op_key(self, tmp_path):
        p = tmp_path / "c.yaml"
        p.write_text(self._base().replace("63bfa50ee6523365ff14c1f45f88737d", "abcd"))
        with pytest.raises(ValueError, match="op_key"):
            load_config(str(p))