from __future__ import annotations

import logging
import os
import re
import sys

# pythonjsonlogger rinominato in .json; keep fallback per compat
try:
    from pythonjsonlogger.json import JsonFormatter as _JsonFormatter  # noqa: N813
except ImportError:
    from pythonjsonlogger.jsonlogger import JsonFormatter as _JsonFormatter  # noqa: N813

SECRET_PATTERNS = [
    (re.compile(r"Bearer\s+[\w\-\._]+", re.IGNORECASE), "Bearer ***"),
    (re.compile(r'("api_key"\s*:\s*")[^"]+(")'), r'\1***\2'),
    (re.compile(r'("password"\s*:\s*")[^"]+(")'), r'\1***\2'),
    (re.compile(r'("private_key"\s*:\s*")[^"]+(")'), r'\1***\2'),
    (re.compile(r'("client_secret"\s*:\s*")[^"]+(")'), r'\1***\2'),
    (re.compile(r"sk-[\w]{20,}"), "sk-***"),
]


class SecretsFilter(logging.Filter):
    def filter(self, record: logging.LogRecord) -> bool:
        msg = record.getMessage()
        for pattern, replacement in SECRET_PATTERNS:
            msg = pattern.sub(replacement, msg)
        record.msg = msg
        record.args = ()  # already formatted into msg
        return True


def get_json_logger(name: str, level: int = logging.INFO) -> logging.Logger:
    logger = logging.getLogger(name)
    if logger.handlers:
        return logger  # already configured
    logger.setLevel(level)
    handler = logging.StreamHandler(sys.stderr)
    formatter = _JsonFormatter("%(asctime)s %(name)s %(levelname)s %(message)s")
    handler.setFormatter(formatter)
    handler.addFilter(SecretsFilter())
    logger.addHandler(handler)
    logger.propagate = False
    return logger


def configure_root_logging(
    *,
    level: str | int | None = None,
    format_type: str | None = None,
) -> None:
    """CER-P5-009: configura il root logger con JSON o text formatter.

    Env overrides:
    - LOG_LEVEL (default INFO)
    - LOG_FORMAT=json|text (default json — production-ready structured log)

    Applica SecretsFilter su entrambi i format.
    """
    lvl_raw = level if level is not None else os.environ.get("LOG_LEVEL", "INFO")
    lvl = logging.getLevelName(lvl_raw.upper()) if isinstance(lvl_raw, str) else lvl_raw
    fmt = (format_type or os.environ.get("LOG_FORMAT") or "json").lower()

    root = logging.getLogger()
    # Rimuovi handler esistenti (basicConfig li avrebbe lasciati duplicati)
    for h in list(root.handlers):
        root.removeHandler(h)

    handler = logging.StreamHandler(sys.stderr)
    if fmt == "json":
        handler.setFormatter(
            _JsonFormatter("%(asctime)s %(name)s %(levelname)s %(message)s")
        )
    else:
        handler.setFormatter(
            logging.Formatter("%(asctime)s %(levelname)s %(name)s %(message)s")
        )
    handler.addFilter(SecretsFilter())
    root.addHandler(handler)
    root.setLevel(lvl)