import textwrap
import pytest
from datetime import datetime, timezone, timedelta
from openvpncertupdate import load_all_certs, load_expiring_certs, CertInfo, _parse_index_line, get_email


def _fmt(dt: datetime) -> str:
    return dt.strftime("%y%m%d%H%M%S") + "Z"


def make_pki(tmp_path, now):
    pki = tmp_path / "pki"
    pki.mkdir()
    content = textwrap.dedent(f"""\
        V\t{_fmt(now + timedelta(days=10))}\t\t02\tunknown\t/CN=soon
        V\t{_fmt(now + timedelta(days=90))}\t\t03\tunknown\t/CN=later
        V\t{_fmt(now - timedelta(days=15))}\t\t04\tunknown\t/CN=past15
        V\t{_fmt(now - timedelta(days=40))}\t\t05\tunknown\t/CN=past40
        R\t{_fmt(now + timedelta(days=10))}\t230101Z,keyCompromise\t06\tunknown\t/CN=revoked
    """)
    (pki / "index.txt").write_text(content)
    return str(pki)


def test_filters_within_window(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    certs = load_expiring_certs(pki, days_past=30, days_ahead=14)
    cns = {c.cn for c in certs}
    assert "soon" in cns        # 10d ahead < 14d threshold
    assert "later" not in cns   # 90d > 14d
    assert "past15" in cns      # 15d past < 30d threshold
    assert "past40" not in cns  # 40d past > 30d threshold
    assert "revoked" not in cns # R status skipped


def test_sorted_ascending(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    certs = load_expiring_certs(pki, days_past=30, days_ahead=14)
    dates = [c.expires for c in certs]
    assert dates == sorted(dates)


def test_days_left_negative_for_expired(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    certs = load_expiring_certs(pki, days_past=30, days_ahead=14)
    expired = next(c for c in certs if c.cn == "past15")
    assert expired.days_left < 0


def test_parse_4digit_year():
    line = "V\t20251231120000Z\t\t07\tunknown\t/CN=future"
    result = _parse_index_line(line)
    assert result is not None
    cn, dt, email = result
    assert cn == "future"
    assert dt.year == 2025
    assert email == ""


def test_parse_email_from_dn():
    line = "V\t20251231120000Z\t\t07\tunknown\t/CN=alice/emailAddress=alice@example.com"
    result = _parse_index_line(line)
    assert result is not None
    cn, dt, email = result
    assert cn == "alice"
    assert email == "alice@example.com"


def test_parse_email_absent_returns_empty():
    line = "V\t20251231120000Z\t\t07\tunknown\t/CN=bob"
    result = _parse_index_line(line)
    assert result is not None
    cn, dt, email = result
    assert cn == "bob"
    assert email == ""


def test_load_expiring_certs_populates_email(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = tmp_path / "pki"
    pki.mkdir()
    expiry = now + timedelta(days=5)
    line = f"V\t{expiry.strftime('%y%m%d%H%M%S')}Z\t\t01\tunknown\t/CN=carol/emailAddress=carol@example.com\n"
    (pki / "index.txt").write_text(line)
    certs = load_expiring_certs(str(pki), days_past=0, days_ahead=14)
    assert len(certs) == 1
    assert certs[0].email == "carol@example.com"


def test_load_all_certs_includes_all_valid(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    certs = load_all_certs(pki)
    cns = {c.cn for c in certs}
    # All V-status entries included regardless of expiry window
    assert cns == {"soon", "later", "past15", "past40"}
    # Revoked entry excluded
    assert "revoked" not in cns


def test_load_all_certs_sorted_ascending(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    certs = load_all_certs(pki)
    dates = [c.expires for c in certs]
    assert dates == sorted(dates)


def _make_duplicate_cn_pki(tmp_path, now):
    """index.txt with an old (still V-status, never revoked) entry for
    "dave" plus a newer reissued V-status entry for the same CN."""
    pki = tmp_path / "pki"
    pki.mkdir()
    e_old = (now - timedelta(days=5)).strftime("%y%m%d%H%M%S") + "Z"   # expired, left unrevoked
    e_new = (now + timedelta(days=365)).strftime("%y%m%d%H%M%S") + "Z"  # reissued, far future
    content = (
        f"V\t{e_old}\t\t01\tunknown\t/CN=dave/emailAddress=old@example.com\n"
        f"V\t{e_new}\t\t02\tunknown\t/CN=dave/emailAddress=newest@example.com\n"
    )
    (pki / "index.txt").write_text(content)
    return str(pki), e_old, e_new


def test_load_all_certs_dedups_to_last_valid_entry(tmp_path):
    # A CN left unrevoked after expiring, then reissued, must appear once
    # — as its most recent entry — not as two rows.
    now = datetime.now(tz=timezone.utc)
    pki, _e_old, _e_new = _make_duplicate_cn_pki(tmp_path, now)
    certs = load_all_certs(pki)
    dave_rows = [c for c in certs if c.cn == "dave"]
    assert len(dave_rows) == 1
    assert dave_rows[0].email == "newest@example.com"
    assert dave_rows[0].days_left > 300


def test_load_expiring_certs_filters_by_current_entry_not_stale_duplicate(tmp_path):
    # The stale (unrevoked) old entry for "dave" falls inside the
    # recently-expired window, but the *current* entry (reissued, far in
    # the future) doesn't — so "dave" must NOT show up as "expiring soon".
    now = datetime.now(tz=timezone.utc)
    pki, _e_old, _e_new = _make_duplicate_cn_pki(tmp_path, now)
    certs = load_expiring_certs(pki, days_past=30, days_ahead=14)
    assert "dave" not in {c.cn for c in certs}


def test_get_email_reads_from_index_txt(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = tmp_path / "pki"
    pki.mkdir()
    expiry = now + timedelta(days=5)
    line = f"V\t{expiry.strftime('%y%m%d%H%M%S')}Z\t\t01\tunknown\t/CN=carol/emailAddress=carol@example.com\n"
    (pki / "index.txt").write_text(line)
    assert get_email(str(pki), "carol") == "carol@example.com"


def test_get_email_missing_cn_returns_empty(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    assert get_email(pki, "nobody") == ""


def test_get_email_ignores_revoked_entry(tmp_path):
    now = datetime.now(tz=timezone.utc)
    pki = make_pki(tmp_path, now)
    # "revoked" CN in make_pki() has status R, not V
    assert get_email(pki, "revoked") == ""


def test_get_email_picks_last_valid_entry_among_duplicates(tmp_path):
    # index.txt is append-only: a CN can have several lines (old ones R,
    # or multiple V if a cert was reissued without going through this
    # tool's revoke-first flow). The most recently appended V line wins.
    now = datetime.now(tz=timezone.utc)
    pki = tmp_path / "pki"
    pki.mkdir()
    e1 = (now + timedelta(days=5)).strftime("%y%m%d%H%M%S") + "Z"
    e2 = (now + timedelta(days=365)).strftime("%y%m%d%H%M%S") + "Z"
    content = (
        f"R\t{e1}\t230101Z,superseded\t01\tunknown\t/CN=dave/emailAddress=old@example.com\n"
        f"V\t{e1}\t\t02\tunknown\t/CN=dave/emailAddress=older-valid@example.com\n"
        f"V\t{e2}\t\t03\tunknown\t/CN=dave/emailAddress=newest@example.com\n"
    )
    (pki / "index.txt").write_text(content)
    assert get_email(str(pki), "dave") == "newest@example.com"