from __future__ import annotations

from contextvars import ContextVar, Token
from typing import Any
from uuid import uuid4


CORRELATION_HEADER = "X-Correlation-ID"
_correlation_id: ContextVar[str | None] = ContextVar(
    "cloud_correlation_id",
    default=None,
)
_SENSITIVE_KEYS = {
    "authorization",
    "token",
    "bearer_token",
    "password",
    "screenshot",
    "ui_tree",
    "typed_text",
    "text_input",
}


def new_correlation_id() -> str:
    return uuid4().hex


def normalize_correlation_id(value: str | None) -> str:
    if value is None:
        return new_correlation_id()
    normalized = value.strip()
    if not normalized or len(normalized) > 128:
        return new_correlation_id()
    return normalized


def bind_correlation_id(correlation_id: str) -> Token[str | None]:
    return _correlation_id.set(correlation_id)


def reset_correlation_id(token: Token[str | None]) -> None:
    _correlation_id.reset(token)


def current_correlation_id() -> str:
    correlation_id = _correlation_id.get()
    return correlation_id or new_correlation_id()


def redact_sensitive_fields(value: Any) -> Any:
    if isinstance(value, dict):
        return {
            key: "[REDACTED]"
            if key.lower() in _SENSITIVE_KEYS
            else redact_sensitive_fields(item)
            for key, item in value.items()
        }
    if isinstance(value, list):
        return [redact_sensitive_fields(item) for item in value]
    if isinstance(value, tuple):
        return tuple(redact_sensitive_fields(item) for item in value)
    return value