from collections.abc import Callable
from dataclasses import dataclass, field
from itertools import chain
from typing import ClassVar, Self, final, override


def format_src(src: str) -> str:
    return f"${{_{src.upper()}}}"


@final
@dataclass(frozen=True, slots=True)
class ReplaceUnique:
    src: str
    dest: str  # | Callable[[], str]

    def __call__(self, string: str) -> str:
        return string.replace(self.src, self.dest)

    @classmethod
    def auto_format(cls, src: str, dest: str):
        return cls(format_src(src), dest)

    # @override
    # def __str__(self) -> str:
    #     if not self.dest:
    #         return ""
    #     if isinstance(self.dest, str):
    #         return self.dest
    #     return self.dest()


@final
@dataclass(frozen=True, slots=True)
class ReplaceDynamic:
    val: str
    fmt: str = field(init=False)

    def __post_init__(self):
        setter = super(ReplaceDynamic, self).__setattr__
        setter("fmt", format_src(self.val))

    def __call__(self, string: str) -> str:
        return string.replace(self.fmt, self.val)

    # def __str__(self) -> str:
    #     return self.val if isinstance(self.val, str) else self.val.fmt
    def build_placeholder(self, *args: "ReplaceDynamic"):
        data = ((rep.val.upper(), rep.fmt) for rep in chain((self,), args))
        src: tuple[str, ...]
        dest: tuple[str, ...]
        src, dest = zip(*data)
        return ReplaceUnique("_".join(src), "_".join(dest))


@dataclass(frozen=True, slots=True)
class ReplaceStatic:
    src: ClassVar[ReplaceDynamic]
    dest: None | str | Callable[[], str]

    def __call__(self, string: str) -> str:
        return string.replace(self.src.fmt, str(self))

    @override
    def __str__(self) -> str:
        if not self.dest:
            return ""
        if isinstance(self.dest, str):
            return self.dest
        return self.dest()

    @classmethod
    def two_stage(cls, dest: str) -> tuple[Self, ReplaceDynamic]:
        dest_var = ReplaceDynamic(dest)
        return cls(dest_var.fmt), dest_var