"""
Timing utilities for the COBY system.
"""

import time
from datetime import datetime, timezone
from typing import Optional


def get_current_timestamp() -> datetime:
    """
    Get current UTC timestamp.
    
    Returns:
        datetime: Current UTC timestamp
    """
    return datetime.now(timezone.utc)


def format_timestamp(timestamp: datetime, format_str: str = "%Y-%m-%d %H:%M:%S.%f") -> str:
    """
    Format timestamp to string.
    
    Args:
        timestamp: Timestamp to format
        format_str: Format string
        
    Returns:
        str: Formatted timestamp string
    """
    return timestamp.strftime(format_str)


def parse_timestamp(timestamp_str: str, format_str: str = "%Y-%m-%d %H:%M:%S.%f") -> datetime:
    """
    Parse timestamp string to datetime.
    
    Args:
        timestamp_str: Timestamp string to parse
        format_str: Format string
        
    Returns:
        datetime: Parsed timestamp
    """
    dt = datetime.strptime(timestamp_str, format_str)
    # Ensure timezone awareness
    if dt.tzinfo is None:
        dt = dt.replace(tzinfo=timezone.utc)
    return dt


def timestamp_to_unix(timestamp: datetime) -> float:
    """
    Convert datetime to Unix timestamp.
    
    Args:
        timestamp: Datetime to convert
        
    Returns:
        float: Unix timestamp
    """
    return timestamp.timestamp()


def unix_to_timestamp(unix_time: float) -> datetime:
    """
    Convert Unix timestamp to datetime.
    
    Args:
        unix_time: Unix timestamp
        
    Returns:
        datetime: Converted datetime (UTC)
    """
    return datetime.fromtimestamp(unix_time, tz=timezone.utc)


def calculate_time_diff(start: datetime, end: datetime) -> float:
    """
    Calculate time difference in seconds.
    
    Args:
        start: Start timestamp
        end: End timestamp
        
    Returns:
        float: Time difference in seconds
    """
    return (end - start).total_seconds()


def is_timestamp_recent(timestamp: datetime, max_age_seconds: int = 60) -> bool:
    """
    Check if timestamp is recent (within max_age_seconds).
    
    Args:
        timestamp: Timestamp to check
        max_age_seconds: Maximum age in seconds
        
    Returns:
        bool: True if recent, False otherwise
    """
    now = get_current_timestamp()
    age = calculate_time_diff(timestamp, now)
    return age <= max_age_seconds


def sleep_until(target_time: datetime) -> None:
    """
    Sleep until target time.
    
    Args:
        target_time: Target timestamp to sleep until
    """
    now = get_current_timestamp()
    sleep_seconds = calculate_time_diff(now, target_time)
    
    if sleep_seconds > 0:
        time.sleep(sleep_seconds)


def get_milliseconds() -> int:
    """
    Get current timestamp in milliseconds.
    
    Returns:
        int: Current timestamp in milliseconds
    """
    return int(time.time() * 1000)


def milliseconds_to_timestamp(ms: int) -> datetime:
    """
    Convert milliseconds to datetime.
    
    Args:
        ms: Milliseconds timestamp
        
    Returns:
        datetime: Converted datetime (UTC)
    """
    return datetime.fromtimestamp(ms / 1000.0, tz=timezone.utc)


def round_timestamp(timestamp: datetime, seconds: int) -> datetime:
    """
    Round timestamp to nearest interval.
    
    Args:
        timestamp: Timestamp to round
        seconds: Interval in seconds
        
    Returns:
        datetime: Rounded timestamp
    """
    unix_time = timestamp_to_unix(timestamp)
    rounded_unix = round(unix_time / seconds) * seconds
    return unix_to_timestamp(rounded_unix)


class Timer:
    """Simple timer for measuring execution time"""
    
    def __init__(self):
        self.start_time: Optional[float] = None
        self.end_time: Optional[float] = None
    
    def start(self) -> None:
        """Start the timer"""
        self.start_time = time.perf_counter()
        self.end_time = None
    
    def stop(self) -> float:
        """
        Stop the timer and return elapsed time.
        
        Returns:
            float: Elapsed time in seconds
        """
        if self.start_time is None:
            raise ValueError("Timer not started")
        
        self.end_time = time.perf_counter()
        return self.elapsed()
    
    def elapsed(self) -> float:
        """
        Get elapsed time.
        
        Returns:
            float: Elapsed time in seconds
        """
        if self.start_time is None:
            return 0.0
        
        end = self.end_time or time.perf_counter()
        return end - self.start_time
    
    def __enter__(self):
        """Context manager entry"""
        self.start()
        return self
    
    def __exit__(self, exc_type, exc_val, exc_tb):
        """Context manager exit"""
        self.stop()