import json
import os
import threading
import time
from typing import Dict, Optional
import logging

logger = logging.getLogger(__name__)

class AccessTracker:
    """Tracks when video URLs are accessed, storing data in JSON file and keeping it in memory"""
    
    def __init__(self, json_file_path: str = "access_times.json"):
        self.json_file_path = json_file_path
        self.access_times: Dict[str, float] = {}
        self.lock = threading.Lock()
        self._load_from_file()
    
    def _load_from_file(self) -> None:
        """Load access times from JSON file into memory"""
        try:
            if os.path.exists(self.json_file_path):
                with open(self.json_file_path, 'r') as f:
                    self.access_times = json.load(f)
                logger.info(f"Loaded {len(self.access_times)} access times from {self.json_file_path}")
            else:
                logger.info(f"Access times file {self.json_file_path} does not exist, starting fresh")
        except Exception as e:
            logger.error(f"Error loading access times from {self.json_file_path}: {e}")
            self.access_times = {}
    
    def _save_to_file(self) -> None:
        """Save current access times from memory to JSON file"""
        try:
            with open(self.json_file_path, 'w') as f:
                json.dump(self.access_times, f, indent=2)
            logger.debug(f"Saved {len(self.access_times)} access times to {self.json_file_path}")
        except Exception as e:
            logger.error(f"Error saving access times to {self.json_file_path}: {e}")
    
    def record_access(self, video_id: str) -> None:
        """Record that a video was accessed at the current time"""
        current_time = time.time()
        with self.lock:
            self.access_times[video_id] = current_time
            self._save_to_file()
        logger.debug(f"Recorded access for {video_id} at {current_time}")
    
    def get_last_access(self, video_id: str) -> Optional[float]:
        """Get the last access time for a video (returns None if never accessed)"""
        with self.lock:
            return self.access_times.get(video_id)
    
    def get_all_access_times(self) -> Dict[str, float]:
        """Get a copy of all access times"""
        with self.lock:
            return self.access_times.copy()
    
    def remove_access_record(self, video_id: str) -> None:
        """Remove access record for a video (e.g., when video is deleted)"""
        with self.lock:
            if video_id in self.access_times:
                del self.access_times[video_id]
                self._save_to_file()
                logger.debug(f"Removed access record for {video_id}")