"""
Logging Configuration

Provides structured logging setup for the application.
Based on Python Quick Start Guide best practices.
"""

import logging
import sys
from typing import Optional
from datetime import datetime


def setup_logging(
    log_level: str = "INFO",
    environment: str = "development"
) -> None:
    """
    Configure application logging.

    Args:
        log_level: Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL)
        environment: Environment name (development, production)

    Usage:
        setup_logging(log_level="INFO", environment="production")
    """
    level = getattr(logging, log_level.upper(), logging.INFO)

    # Clear existing handlers
    root_logger = logging.getLogger()
    for handler in root_logger.handlers[:]:
        root_logger.removeHandler(handler)

    # Console handler
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setLevel(level)

    # Format based on environment
    if environment == "development":
        # Human-readable format for development
        formatter = logging.Formatter(
            fmt='%(asctime)s | %(levelname)-8s | %(name)s:%(funcName)s:%(lineno)d | %(message)s',
            datefmt='%H:%M:%S'
        )
    else:
        # Structured format for production (easier to parse)
        formatter = logging.Formatter(
            fmt='%(asctime)s | %(levelname)s | %(name)s | %(message)s',
            datefmt='%Y-%m-%d %H:%M:%S'
        )

    console_handler.setFormatter(formatter)
    root_logger.addHandler(console_handler)
    root_logger.setLevel(level)

    # Suppress noisy loggers
    logging.getLogger('werkzeug').setLevel(logging.WARNING)
    logging.getLogger('urllib3').setLevel(logging.WARNING)


def get_logger(name: str) -> logging.Logger:
    """
    Get a logger instance.

    Args:
        name: Logger name (typically __name__)

    Returns:
        Logger instance

    Example:
        logger = get_logger(__name__)
        logger.info("User logged in", extra={"user_id": 123})
    """
    return logging.getLogger(name)


# ==========================================
# Structured Logging Helpers
# ==========================================

def log_audit_event(
    logger: logging.Logger,
    action: str,
    user_id: Optional[int] = None,
    ip_address: Optional[str] = None,
    **kwargs
) -> None:
    """
    Log an audit event with structured data.

    Args:
        logger: Logger instance
        action: Action performed (e.g., "login_success", "user_created")
        user_id: User ID performing action
        ip_address: IP address of request
        **kwargs: Additional context data

    Example:
        log_audit_event(
            logger,
            action="login_success",
            user_id=123,
            ip_address="192.168.1.1",
            username="admin"
        )
    """
    extra_data = {
        'action': action,
        'user_id': user_id,
        'ip_address': ip_address,
        'timestamp': datetime.utcnow().isoformat(),
        **kwargs
    }

    # Filter out None values
    extra_data = {k: v for k, v in extra_data.items() if v is not None}

    logger.info(f"AUDIT: {action}", extra=extra_data)


def log_security_event(
    logger: logging.Logger,
    event_type: str,
    severity: str = "warning",
    **kwargs
) -> None:
    """
    Log a security-related event.

    Args:
        logger: Logger instance
        event_type: Type of security event (e.g., "failed_login", "rate_limit_exceeded")
        severity: Severity level (debug, info, warning, error, critical)
        **kwargs: Additional context data

    Example:
        log_security_event(
            logger,
            event_type="failed_login",
            severity="warning",
            username="admin",
            ip_address="192.168.1.1",
            attempts=3
        )
    """
    extra_data = {
        'event_type': event_type,
        'timestamp': datetime.utcnow().isoformat(),
        **kwargs
    }

    log_method = getattr(logger, severity.lower(), logger.warning)
    log_method(f"SECURITY: {event_type}", extra=extra_data)


# ==========================================
# Request Logging Helpers
# ==========================================

def log_request(
    logger: logging.Logger,
    method: str,
    path: str,
    status_code: int,
    duration_ms: float,
    user_id: Optional[int] = None
) -> None:
    """
    Log an HTTP request.

    Args:
        logger: Logger instance
        method: HTTP method (GET, POST, etc.)
        path: Request path
        status_code: HTTP status code
        duration_ms: Request duration in milliseconds
        user_id: Authenticated user ID (if any)

    Example:
        log_request(
            logger,
            method="POST",
            path="/api/users",
            status_code=201,
            duration_ms=45.2,
            user_id=123
        )
    """
    extra_data = {
        'method': method,
        'path': path,
        'status_code': status_code,
        'duration_ms': round(duration_ms, 2),
        'user_id': user_id
    }

    # Filter out None values
    extra_data = {k: v for k, v in extra_data.items() if v is not None}

    # Use different log levels based on status code
    if status_code >= 500:
        logger.error(f"{method} {path} {status_code}", extra=extra_data)
    elif status_code >= 400:
        logger.warning(f"{method} {path} {status_code}", extra=extra_data)
    else:
        logger.info(f"{method} {path} {status_code}", extra=extra_data)


# ==========================================
# Error Logging Helpers
# ==========================================

def log_exception(
    logger: logging.Logger,
    error: Exception,
    context: Optional[str] = None,
    **kwargs
) -> None:
    """
    Log an exception with context.

    Args:
        logger: Logger instance
        error: Exception instance
        context: Additional context about where error occurred
        **kwargs: Additional context data

    Example:
        try:
            # Some operation
        except Exception as e:
            log_exception(
                logger,
                error=e,
                context="Failed to create user",
                user_id=123
            )
    """
    extra_data = {
        'error_type': type(error).__name__,
        'error_message': str(error),
        'context': context,
        **kwargs
    }

    # Filter out None values
    extra_data = {k: v for k, v in extra_data.items() if v is not None}

    logger.error(
        f"Exception: {type(error).__name__}: {str(error)}",
        extra=extra_data,
        exc_info=True
    )