from __future__ import annotations

from rapidfuzz import utils_cpp, utils_py
from tests.distance.common import Levenshtein


class CustomHashable:
    def __init__(self, string):
        self._string = string

    def __eq__(self, other):
        raise NotImplementedError

    def __ne__(self, other):
        return not self.__eq__(other)

    def __hash__(self):
        return hash(self._string)


def test_empty_string():
    """
    when both strings are empty this is a perfect match
    """
    assert Levenshtein.distance("", "") == 0
    assert Levenshtein.distance("", "", weights=(1, 1, 0)) == 0
    assert Levenshtein.distance("", "", weights=(1, 1, 2)) == 0
    assert Levenshtein.distance("", "", weights=(1, 1, 5)) == 0
    assert Levenshtein.distance("", "", weights=(3, 7, 5)) == 0


def test_score_cutoff_overflow():
    """
    when score_cutoff was out of bounds for size_t we had an overflow error
    """
    assert Levenshtein.distance("", "") == 0
    assert Levenshtein.distance("", "", score_cutoff=2**63) == 0


def test_cross_type_matching():
    """
    strings should always be interpreted in the same way
    """
    assert Levenshtein.distance("aaaa", "aaaa") == 0
    assert Levenshtein.distance("aaaa", ["a", "a", "a", "a"]) == 0
    assert Levenshtein.distance(b"aaaa", b"aaaa") == 0
    assert Levenshtein.distance("aaaa", b"aaaa") == 0
    # todo add support in pure python
    assert Levenshtein.distance("aaaa", [ord("a"), ord("a"), "a", "a"]) == 0
    assert Levenshtein.distance([0, -1], [0, -2]) == 1
    assert (
        Levenshtein.distance(
            [CustomHashable("aa"), CustomHashable("aa")],
            [CustomHashable("aa"), CustomHashable("bb")],
        )
        == 1
    )


def test_word_error_rate():
    """
    it should be possible to use levenshtein to implement a word error rate
    """
    assert Levenshtein.distance(["aaaaa", "bbbb"], ["aaaaa", "bbbb"]) == 0
    assert Levenshtein.distance(["aaaaa", "bbbb"], ["aaaaa", "cccc"]) == 1


def test_simple_unicode_tests():
    """
    some very simple tests using unicode with scorers
    to catch relatively obvious implementation errors
    """
    s1 = "ÁÄ"
    s2 = "ABCD"
    assert Levenshtein.distance(s1, s2) == 4  # 2 sub + 2 ins
    assert Levenshtein.distance(s1, s2, weights=(1, 1, 0)) == 2  # 2 sub + 2 ins
    assert Levenshtein.distance(s1, s2, weights=(1, 1, 2)) == 6  # 2 del + 4 ins / 2 sub + 2 ins
    assert Levenshtein.distance(s1, s2, weights=(1, 1, 5)) == 6  # 2 del + 4 ins
    assert Levenshtein.distance(s1, s2, weights=(1, 7, 5)) == 12  # 2 sub + 2 ins
    assert Levenshtein.distance(s2, s1, weights=(1, 7, 5)) == 24  # 2 sub + 2 del

    assert Levenshtein.distance(s1, s1) == 0
    assert Levenshtein.distance(s1, s1, weights=(1, 1, 0)) == 0
    assert Levenshtein.distance(s1, s1, weights=(1, 1, 2)) == 0
    assert Levenshtein.distance(s1, s1, weights=(1, 1, 5)) == 0
    assert Levenshtein.distance(s1, s1, weights=(3, 7, 5)) == 0


def test_Editops():
    """
    basic test for Levenshtein.editops
    """
    assert Levenshtein.editops("0", "").as_list() == [("delete", 0, 0)]
    assert Levenshtein.editops("", "0").as_list() == [("insert", 0, 0)]

    assert Levenshtein.editops("00", "0").as_list() == [("delete", 1, 1)]
    assert Levenshtein.editops("0", "00").as_list() == [("insert", 1, 1)]

    assert Levenshtein.editops("qabxcd", "abycdf").as_list() == [
        ("delete", 0, 0),
        ("replace", 3, 2),
        ("insert", 6, 5),
    ]
    assert Levenshtein.editops("Lorem ipsum.", "XYZLorem ABC iPsum").as_list() == [
        ("insert", 0, 0),
        ("insert", 0, 1),
        ("insert", 0, 2),
        ("insert", 6, 9),
        ("insert", 6, 10),
        ("insert", 6, 11),
        ("insert", 6, 12),
        ("replace", 7, 14),
        ("delete", 11, 18),
    ]

    ops = Levenshtein.editops("aaabaaa", "abbaaabba")
    assert ops.src_len == 7
    assert ops.dest_len == 9


def test_Opcodes():
    """
    basic test for Levenshtein.opcodes
    """
    assert Levenshtein.opcodes("", "abc").as_list() == [("insert", 0, 0, 0, 3)]


def test_mbleven():
    """
    test for regressions to previous bugs in the cached Levenshtein implementation
    """
    assert Levenshtein.distance("0", "101", score_cutoff=1) == 2
    assert Levenshtein.distance("0", "101", score_cutoff=2) == 2
    assert Levenshtein.distance("0", "101", score_cutoff=3) == 2


def testCaseInsensitive():
    assert Levenshtein.distance("new york mets", "new YORK mets", processor=utils_cpp.default_process) == 0
    assert Levenshtein.distance("new york mets", "new YORK mets", processor=utils_py.default_process) == 0