import time

import pytest

from mdgrep import QuerySyntaxError, QueryTimeout, compile_query


def m(query, text):
    return compile_query(query).matches(text)


# ── Terms ────────────────────────────────────────────────────────────────

def test_substring_case_insensitive():
    assert m("rust", "The Rustacean book")
    assert m("RUST", "trusted")
    assert not m("rust", "golang")


def test_umlauts_case_insensitive():
    assert m("übersetzung", "Die ÜBERSETZUNG ist fertig")
    assert m("ÄRGER", "kein ärger")


def test_phrase_matches_any_whitespace():
    assert m('"open source"', "Open\n   Source software")
    assert not m('"open source"', "open the source")


def test_phrase_escaped_quote():
    assert m(r'"say \"hi\""', 'they say "hi" loudly')


def test_regex():
    assert m(r"/llms?\b/", "Large LLMs today")
    assert m(r"/gpt-\d+/", "GPT-5 release")
    assert not m(r"/^foo$/", "foobar")


def test_regex_escaped_slash():
    assert m(r"/tcp\/ip/", "TCP/IP stack")


def test_words_with_special_characters():
    assert m("AT&T", "at&t merger")
    assert m("TCP/IP", "the tcp/ip suite")
    assert m("e-mail", "send an E-Mail")


def test_lowercase_keywords_are_terms():
    assert m("and", "this AND that")
    assert not m("and", "nothing here")


# ── Boolean logic ────────────────────────────────────────────────────────

@pytest.mark.parametrize("query", ["a b", "a AND b", "a UND b", "a & b", "a && b"])
def test_and_variants(query):
    assert compile_query(query).matches("a b")
    assert not compile_query(query).matches("a only")


@pytest.mark.parametrize("query", ["a OR b", "a ODER b", "a | b", "a || b"])
def test_or_variants(query):
    assert compile_query(query).matches("b only")
    assert not compile_query(query).matches("nothing")


@pytest.mark.parametrize("query", ["NOT x", "NICHT x", "-x", "!x"])
def test_not_variants(query):
    assert compile_query(query).matches("abc")
    assert not compile_query(query).matches("xyz")


def test_precedence_and_binds_tighter_than_or():
    q = compile_query("alpha OR beta AND gamma")   # alpha OR (beta AND gamma)
    assert q.matches("alpha")
    assert not q.matches("beta")
    assert q.matches("beta gamma")


def test_parentheses_override_precedence():
    q = compile_query("(alpha OR beta) AND gamma")
    assert not q.matches("alpha")
    assert q.matches("alpha gamma")
    assert q.matches("beta gamma")


def test_not_binds_tighter_than_and():
    q = compile_query("NOT alpha beta")            # (NOT alpha) AND beta
    assert q.matches("beta")
    assert not q.matches("alpha beta")


def test_nested_groups_and_negation():
    q = compile_query("(rust OR go) AND NOT (crypto OR /blockchain/)")
    assert q.matches("Rust compiler")
    assert not q.matches("Go crypto wallet")
    assert not q.matches("rust blockchain")


def test_double_negation():
    assert m("NOT NOT foo", "foo")


# ── Spans (highlighting) ─────────────────────────────────────────────────

def test_spans_merged_and_sorted():
    q = compile_query("open OR source")
    assert q.spans("open source open") == [(0, 4), (5, 11), (12, 16)]


def test_spans_exclude_negated_terms():
    q = compile_query("rust -crypto")
    assert q.spans("rust and crypto") == [(0, 4)]


def test_spans_double_negation_counts_as_positive():
    q = compile_query("NOT NOT foo")
    assert q.spans("a foo") == [(2, 5)]


def test_spans_ignore_empty_regex_matches():
    q = compile_query("/x*/")
    assert q.spans("abc") == []
    assert q.spans("axxb") == [(1, 3)]


def test_spans_overlapping_merged():
    q = compile_query("abc OR bcd")
    assert q.spans("abcd") == [(0, 4)]


# ── Errors ───────────────────────────────────────────────────────────────

@pytest.mark.parametrize("query,code,position", [
    ("", "empty_query", 0),
    ("   ", "empty_query", 0),
    ("(a OR b", "unclosed_paren", 0),
    ("a OR b)", "unexpected_paren", 6),
    ("a OR", "missing_operand", 4),
    ("OR a", "missing_operand", 0),
    ("a AND OR b", "missing_operand", 6),
    ("()", "empty_group", 0),
    ('"open', "unterminated_phrase", 0),
    ("x /abc", "unterminated_regex", 2),
    ("x /a(b/", "invalid_regex", 2),
    ("NOT", "missing_operand", 3),
])
def test_syntax_errors(query, code, position):
    with pytest.raises(QuerySyntaxError) as exc:
        compile_query(query)
    assert exc.value.code == code
    assert exc.value.position == position
    assert exc.value.to_dict()["code"] == code


def test_limits():
    with pytest.raises(QuerySyntaxError) as exc:
        compile_query("a" * 20, max_length=10)
    assert exc.value.code == "too_long"
    with pytest.raises(QuerySyntaxError) as exc:
        compile_query("a b c d", max_terms=3)
    assert exc.value.code == "too_many_terms"


# ── Timeouts (ReDoS protection) ──────────────────────────────────────────

def test_catastrophic_regex_times_out():
    q = compile_query("/(a|aa)+$/")
    text = "a" * 36 + "!"
    start = time.monotonic()
    with pytest.raises(QueryTimeout):
        q.matches(text, timeout=0.2)
    assert time.monotonic() - start < 2


def test_spans_timeout():
    q = compile_query("/(a|aa)+$/")
    with pytest.raises(QueryTimeout):
        q.spans("a" * 36 + "!", timeout=0.2)


def test_expired_deadline_raises():
    q = compile_query("foo")
    with pytest.raises(QueryTimeout):
        q.matches("foo", deadline=time.monotonic() - 1)