# SPDX-License-Identifier: AGPL-3.0-only
# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0

"""Structured logging handlers and middleware.

LoggingMiddleware (request/response logging with timing),
filter_sensitive_data (structlog processor for sanitization), and
get_logger (factory for structured loggers).
"""

import re
import time

import structlog
from starlette.types import ASGIApp, Message, Receive, Scope, Send

from utils.native_path_leases import redact_native_paths

logger = structlog.get_logger(__name__)
_NATIVE_PATH_LEASE_RE = re.compile(
    r"(?i)(\b(?:native_path_lease|nativePathLease)[\"']?\s*[:=]\s*[\"']?)[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+"
)
_EXCLUDED_PATHS = {
    "/api/train/status",
    "/api/train/metrics",
    "/api/train/hardware",
    "/api/system",
}
_EXCLUDED_SUFFIXES = (
    ".png",
    ".jpg",
    ".jpeg",
    ".svg",
    ".ico",
    ".woff",
    ".woff2",
    ".ttf",
)


class LoggingMiddleware:
    """ASGI request logger that avoids BaseHTTPMiddleware streaming wrappers."""

    def __init__(self, app: ASGIApp) -> None:
        self.app = app

    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
        if scope["type"] != "http":
            await self.app(scope, receive, send)
            return

        path = scope["path"]
        excluded = (
            path in _EXCLUDED_PATHS
            or path.startswith("/assets/")
            or path.endswith(_EXCLUDED_SUFFIXES)
        )
        start_time = time.perf_counter()
        status_code = 500

        async def send_wrapper(message: Message) -> None:
            nonlocal status_code
            if message["type"] == "http.response.start":
                status_code = message["status"]
            await send(message)

        try:
            await self.app(scope, receive, send_wrapper)
        except Exception as exc:
            logger.error(
                "request_failed",
                path = path,
                method = scope["method"],
                status_code = status_code,
                error = str(exc),
                process_time_ms = round((time.perf_counter() - start_time) * 1000, 2),
                exc_info = True,
            )
            raise
        else:
            if not excluded:
                logger.info(
                    "request_completed",
                    method = scope["method"],
                    path = path,
                    status_code = status_code,
                    process_time_ms = round((time.perf_counter() - start_time) * 1000, 2),
                )


def filter_sensitive_data(logger, method_name, event_dict):
    """Structlog processor to redact native path leases from logs."""

    def filter_value(value):
        if isinstance(value, str):
            try:
                value = redact_native_paths(value)
            except Exception:
                pass
            value = _NATIVE_PATH_LEASE_RE.sub(r"\1<redacted native path lease>", value)
            return value
        elif isinstance(value, dict):
            return {
                k: "<redacted native path lease>"
                if str(k).replace("_", "").lower() == "nativepathlease"
                else filter_value(v)
                for k, v in value.items()
            }
        elif isinstance(value, list):
            return [filter_value(item) for item in value]
        return value

    return {
        k: "<redacted native path lease>"
        if str(k).replace("_", "").lower() == "nativepathlease"
        else filter_value(v)
        for k, v in event_dict.items()
    }


def get_logger(name: str) -> structlog.BoundLogger:
    """Get a bound structured logger for a module (name is usually __name__)."""
    return structlog.get_logger(name)