"""
f(a, b) 计算 a -> b 的编辑距离，使用的方法是之前asr榜单的方法
g(a, b) 计算 a -> b 的编辑距离，使用的是原始的编辑距离计算方法
test() 是对拍程序
"""

import random
import string
from copy import deepcopy
from typing import List, Tuple

import Levenshtein


def mapping(gt: str, dt: str):
    return [i for i in gt], [i for i in dt]


def token_mapping(
    tokens_gt: List[str], tokens_dt: List[str]
) -> Tuple[List[str], List[str]]:
    arr1 = deepcopy(tokens_gt)
    arr2 = deepcopy(tokens_dt)
    operations = Levenshtein.editops(arr1, arr2)
    for op in operations[::-1]:
        if op[0] == "insert":
            arr1.insert(op[1], None)
        elif op[0] == "delete":
            arr2.insert(op[2], None)
    return arr1, arr2


def cer(tokens_gt_mapping: List[str], tokens_dt_mapping: List[str]):
    """输入的是经过编辑距离映射后的两个 token 序列，返回 1-cer, token-cnt"""
    insert = sum(1 for item in tokens_gt_mapping if item is None)
    delete = sum(1 for item in tokens_dt_mapping if item is None)
    equal = sum(
        1
        for token_gt, token_dt in zip(tokens_gt_mapping, tokens_dt_mapping)
        if token_gt == token_dt
    )
    replace = len(tokens_gt_mapping) - insert - equal  # - delete
    return replace, delete, insert


def f(a, b):
    return cer(*token_mapping(*mapping(a, b)))


def raw(tokens_gt, tokens_dt):
    arr1 = deepcopy(tokens_gt)
    arr2 = deepcopy(tokens_dt)
    operations = Levenshtein.editops(arr1, arr2)
    insert = 0
    delete = 0
    replace = 0
    for op in operations:
        if op[0] == "insert":
            insert += 1
        if op[0] == "delete":
            delete += 1
        if op[0] == "replace":
            replace += 1
    return replace, delete, insert


def g(a, b):
    return raw(*mapping(a, b))


def check(a, b):
    ff = f(a, b)
    gg = g(a, b)
    if ff != gg:
        print(ff, gg)
    return ff == gg


def random_string(length):
    letters = string.ascii_lowercase
    return "".join(random.choice(letters) for i in range(length))


def test():
    for _ in range(10000):
        a = random_string(30)
        b = random_string(30)
        if not check(a, b):
            print(a, b)
            break


test()