import json
import numpy as np
from typing import Dict, Any, Optional, Union
import threading
import time
import hashlib
import logging
import os
import shutil
import uuid
from pathlib import Path

class LocalStorage:
    """
    Local storage implementation for GPU memory management.
    Maintains backward compatibility with previous storage interfaces.
    """
    
    # Singleton instance
    _instance = None
    _lock = threading.Lock()

    def __new__(cls, storage_path: str = "storage"):
        with cls._lock:
            if cls._instance is None:
                cls._instance = super().__new__(cls)
                # Convert to absolute path if relative
                if not os.path.isabs(storage_path):
                    storage_path = os.path.abspath(storage_path)
                cls._instance._init_singleton(storage_path)
            return cls._instance

    def _init_singleton(self, storage_path: str):
        """Initialize the singleton instance with local storage"""
        if hasattr(self, 'initialized'):
            return
        
        # Setup storage paths
        self.base_path = Path(storage_path)
        self.vram_path = self.base_path / "vram_blocks"
        self.models_path = self.base_path / "models"
        self.cache_path = self.base_path / "cache"
        self.state_path = self.base_path / "states"
        
        # Create directories
        for path in [self.vram_path, self.models_path, self.cache_path, self.state_path]:
            path.mkdir(parents=True, exist_ok=True)
            
        # Basic state management
        self.lock = threading.Lock()
        self._closing = False
        self._connected = True
        
        # Resource monitoring
        self.resource_monitor = {
            'vram_used': 0,
            'active_tensors': 0,
            'loaded_models': set(),
            'last_updated': time.time()
        }
        
        # Storage statistics
        self.stats = {
            'total_size': 0,
            'available_size': float('inf'),
            'model_count': 0,
            'tensor_count': 0
        }
        
        # Initialize registries
        self.model_registry = {}
        self.tensor_registry = {}
        
        self.initialized = True
        self._connected = True
        
        # Initialize monitoring
        self.resource_monitor = {
            'vram_used': 0,
            'active_tensors': 0,
            'loaded_models': set(),
            'last_updated': time.time()
        }
        
        # Initialize registries
        self.model_registry = {}
        
        self.initialized = True
        
    def is_connected(self) -> bool:
        """Check if storage is connected (always True for local storage)"""
        return self._connected and not self._closing and self.ping()
        
    def close(self):
        """Close storage connection"""
        self._closing = True
        self._connected = False
        
        # Initialize resource monitoring
        self.resource_monitor = {
            'vram_used': 0,
            'active_tensors': 0,
            'loaded_models': set(),
            'last_updated': time.time()
        }
        
        # Initialize model registry and connection state
        self.model_registry = {}
        self._connected = True
        self.model_registry = {}
        self._connected = True
        
    def is_model_loaded(self, model_id: str) -> bool:
        """Check if a model is loaded in local storage"""
        if not model_id:
            return False
        
        # Check if model directory exists
        model_dir = self.models_path / model_id.replace('/', '_')
        if not model_dir.exists():
            return False
            
        # Check for model files
        model_file = model_dir / "model.bin"
        config_file = model_dir / "config.json"
        
        return model_file.exists() and config_file.exists()
        self._connected = True  # Local storage is always "connected"
        
    def wait_for_connection(self, timeout: float = 30.0) -> bool:
        """
        Simulates connection wait for compatibility with previous interfaces.
        Always returns True for local storage since no connection is needed.
        """
        return self.ping()
        
    def __init__(self, storage_path: str = "storage"):
        """This will actually just return the singleton instance. 
        The actual initialization happens in __new__ and _init_singleton"""
        pass

    def _check_storage_ready(self) -> bool:
        """Check if local storage is ready for use"""
        try:
            # Verify all required directories exist and are accessible
            for path in [self.vram_path, self.models_path, self.cache_path, self.state_path]:
                if not path.exists() or not os.access(str(path), os.R_OK | os.W_OK):
                    return False
                    
            # Update storage statistics
            self.stats.update({
                'total_size': sum(f.stat().st_size for f in self.base_path.rglob('*') if f.is_file()),
                'model_count': len(list(self.models_path.glob('*'))),
                'tensor_count': len(list(self.vram_path.glob('*.npy')))
            })
            
            return True
            
        except Exception as e:
            logging.error(f"Storage check failed: {e}")
            return False

    def _check_storage(self) -> Dict[str, Any]:
        """Check local storage status and usage"""
        try:
            # Update storage monitoring
            self.storage_monitor.update({
                'total_size': sum(f.stat().st_size for f in self.base_path.rglob('*') if f.is_file()),
                'last_access': time.time(),
                'disk_usage': os.path.getsize(str(self.base_path)) if os.path.exists(str(self.base_path)) else 0
            })
            return {"status": "ok", "monitor": self.storage_monitor}
        except Exception as e:
            logging.error(f"Error checking storage: {e}")
            return {"status": "error", "message": str(e)}

    def store_tensor(self, tensor_id: str, data: np.ndarray, model_size: Optional[int] = None) -> bool:
        """Store tensor data in local storage"""
        try:
            if data is None:
                raise ValueError("Cannot store None tensor")
                
            # Calculate tensor metadata
            tensor_shape = data.shape
            tensor_dtype = str(data.dtype)
            tensor_size = data.nbytes
            
            # Save tensor data
            tensor_path = self.vram_path / f"{tensor_id}.npy"
            np.save(str(tensor_path), data)
            
            # Save metadata
            metadata = {
                'shape': tensor_shape,
                'dtype': tensor_dtype,
                'size': tensor_size,
                'timestamp': time.time(),
                'model_size': model_size if model_size is not None else -1
            }
            
            metadata_path = self.vram_path / f"{tensor_id}_meta.json"
            with open(metadata_path, 'w') as f:
                json.dump(metadata, f)
            
            # Update tensor registry
            with self.lock:
                self.tensor_registry[tensor_id] = metadata
                self.resource_monitor['vram_used'] += tensor_size
                self.resource_monitor['active_tensors'] += 1
            return True
                
        except Exception as e:
            logging.error(f"Error storing tensor {tensor_id}: {str(e)}")
            return False

    def load_tensor(self, tensor_id: str) -> Optional[np.ndarray]:
        """Load tensor data from local storage"""
        try:
            tensor_path = self.vram_path / f"{tensor_id}.npy"
            metadata_path = self.vram_path / f"{tensor_id}_meta.json"
            
            # Check if tensor files exist
            if not tensor_path.exists() or not metadata_path.exists():
                logging.warning(f"Tensor {tensor_id} not found in local storage")
                return None
            
            # Load metadata
            with open(metadata_path, 'r') as f:
                metadata = json.load(f)
            
            # Load tensor data
            arr = np.load(str(tensor_path))
            
            # Update registry if not present
            if tensor_id not in self.tensor_registry:
                with self.lock:
                    self.tensor_registry[tensor_id] = metadata
            
            return arr
                
        except Exception as e:
            logging.error(f"Error loading tensor {tensor_id}: {str(e)}")
            return None

    def store_state(self, component: str, state_id: str, state_data: Dict[str, Any]) -> bool:
        """Store component state in local storage"""
        try:
            # Create component directory if needed
            component_dir = self.state_path / component
            component_dir.mkdir(parents=True, exist_ok=True)
            
            # Save state data with timestamp
            state_file = component_dir / f"{state_id}.json"
            data_to_save = {
                "data": state_data,
                "timestamp": time.time()
            }
            
            with open(state_file, 'w') as f:
                json.dump(data_to_save, f, indent=2)
            
            return True
                
        except Exception as e:
            logging.error(f"Error storing state for {component}/{state_id}: {str(e)}")
            return False

    def load_state(self, component: str, state_id: str) -> Optional[Dict[str, Any]]:
        """Load component state from local storage"""
        try:
            state_file = self.state_path / component / f"{state_id}.json"
            
            if not state_file.exists():
                logging.warning(f"State file not found for {component}/{state_id}")
                return None
                
            with open(state_file, 'r') as f:
                saved_data = json.load(f)
                
            return saved_data.get('data')
                
        except Exception as e:
            logging.error(f"Error loading state for {component}/{state_id}: {str(e)}")
            return None

    def cache_data(self, key: str, data: Any) -> bool:
        """Cache data via HTTP API"""
        try:
            request_data = {"data": data}
            
            response = self._make_request(
                'POST',
                f'/cache/{key}',
                json=request_data
            )
            
            return response and response.get('status') == 'success'
            
        except Exception as e:
            logging.error(f"Error caching data for key {key}: {str(e)}")
            return False

    def get_cached_data(self, key: str) -> Optional[Any]:
        """Get cached data via HTTP API"""
        try:
            response = self._make_request("GET", f"/cache/{key}")
            
            if response and response.get('status') == 'success':
                return response.get('data')
            return None
            
        except Exception as e:
            logging.error(f"Error getting cached data for key {key}: {str(e)}")
            return None

    def load_model(self, model_name: str, model_path: Optional[str] = None, model_data: Optional[Dict] = None) -> bool:
        """Load a model from local storage"""
        try:
            # Check if model is already loaded
            if self.is_model_loaded(model_name):
                logging.info(f"Model {model_name} already loaded")
                return True

            # Generate model directory path
            model_dir = self.models_path / model_name.replace('/', '_')
            model_dir.mkdir(parents=True, exist_ok=True)
            
            # Clean up any existing files
            for existing_file in model_dir.glob('*'):
                try:
                    if existing_file.is_file():
                        existing_file.unlink()
                except Exception as e:
                    logging.warning(f"Could not remove existing file {existing_file}: {e}")
            
            # Save model data if provided
            if model_data:
                model_config_path = model_dir / "config.json"
                with open(model_config_path, 'w') as f:
                    json.dump(model_data, f, indent=2)
                
                # Update model registry
                with self.lock:
                    self.model_registry[model_name] = {
                        'path': str(model_dir),
                        'config': model_data,
                        'loaded_at': time.time(),
                        'hash': self._calculate_model_hash(model_path) if model_path else None
                    }
                    self.resource_monitor['loaded_models'].add(model_name)
            
            # Copy model files if path provided
            if model_path and os.path.exists(model_path):
                model_file_path = model_dir / "model.bin"
                shutil.copy2(model_path, model_file_path)
            
            logging.info(f"Successfully loaded model {model_name} to local storage")
            return True
            
        except Exception as e:
            logging.error(f"Error loading model {model_name}: {str(e)}")
            return False


    def _calculate_model_hash(self, model_path: str) -> str:
        """Calculate SHA256 hash of model file"""
        try:
            sha256_hash = hashlib.sha256()
            with open(model_path, "rb") as f:
                for byte_block in iter(lambda: f.read(4096), b""):
                    sha256_hash.update(byte_block)
            return sha256_hash.hexdigest()
        except Exception as e:
            logging.error(f"Error calculating model hash: {str(e)}")
            return ""


    def ping(self) -> bool:
        """Check if local storage is accessible"""
        if self._closing:
            return False
        return self._check_storage_ready()
# Compatibility aliases for existing code
HTTPGPUStorage = LocalStorage
WebSocketGPUStorage = LocalStorage