"""
Logging configuration for Telegram Archiver.
Supports both console and file output with OpenTelemetry integration.
"""

import logging
import sys
from pathlib import Path
from typing import Optional

# OpenTelemetry is optional - skip if not installed
try:
    from opentelemetry import trace
    from opentelemetry.sdk.trace import TracerProvider
    from opentelemetry.sdk.trace.export import ConsoleSpanExporter, SimpleSpanProcessor
    from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
    OTEL_AVAILABLE = True
except ImportError:
    OTEL_AVAILABLE = False


def setup_logging(
    log_level: str = "INFO",
    log_file: Optional[Path] = None,
    enable_otel: bool = False,
) -> None:
    """
    Configure logging for the application.

    Args:
        log_level: Logging level (DEBUG, INFO, WARNING, ERROR)
        log_file: Optional file path for log output
        enable_otel: Enable OpenTelemetry tracing
    """
    # Create root logger
    root_logger = logging.getLogger()
    root_logger.setLevel(getattr(logging, log_level.upper()))

    # Clear existing handlers
    root_logger.handlers.clear()

    # Console handler
    console_handler = logging.StreamHandler(sys.stdout)
    console_handler.setLevel(getattr(logging, log_level.upper()))
    console_formatter = logging.Formatter(
        "%(asctime)s - %(name)s - %(levelname)s - %(message)s",
        datefmt="%Y-%m-%d %H:%M:%S",
    )
    console_handler.setFormatter(console_formatter)
    root_logger.addHandler(console_handler)

    # File handler (if specified)
    if log_file:
        file_handler = logging.FileHandler(log_file, encoding="utf-8")
        file_handler.setLevel(getattr(logging, log_level.upper()))
        file_formatter = logging.Formatter(
            "%(asctime)s - %(name)s - %(levelname)s - %(message)s",
            datefmt="%Y-%m-%d %H:%M:%S",
        )
        file_handler.setFormatter(file_formatter)
        root_logger.addHandler(file_handler)

    # OpenTelemetry configuration
    if enable_otel:
        setup_opentelemetry()


def setup_opentelemetry() -> None:
    """Configure OpenTelemetry tracing."""
    if not OTEL_AVAILABLE:
        logger = logging.getLogger(__name__)
        logger.warning("OpenTelemetry not available - tracing disabled")
        return
    
    # Set up tracer provider
    trace.set_tracer_provider(TracerProvider())

    # Add console exporter (for debugging)
    trace.get_tracer_provider().add_span_processor(
        SimpleSpanProcessor(ConsoleSpanExporter())
    )

    logger = logging.getLogger(__name__)
    logger.info("OpenTelemetry tracing enabled")


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

    Args:
        name: Logger name (usually __name__)

    Returns:
        Configured logger instance
    """
    return logging.getLogger(name)