"""
HF Hub Storage Client - Optional cloud storage for videos
Uploads videos to Hugging Face Hub Dataset repository
"""
import logging
from pathlib import Path
from typing import Optional

logger = logging.getLogger(__name__)

# Will be imported if available
try:
    from huggingface_hub import HfApi, create_repo
    HF_HUB_AVAILABLE = True
except ImportError:
    HF_HUB_AVAILABLE = False
    logger.warning("huggingface_hub not installed. Cloud storage disabled.")


class HFStorageClient:
    """
    Optional HF Hub storage for videos.
    
    If HF_REPO and HF_TOKEN are set, uploads videos to HF Dataset repo.
    Otherwise, does nothing (graceful degradation).
    
    Structure:
    - your-repo/
      - short_video/
        - video_id.mp4
      - story_reels/
        - video_id.mp4
      - [future_module]/
        - video_id.mp4
    """
    
    def __init__(self, repo_id: str = None, token: str = None):
        """
        Initialize HF storage client.
        
        Args:
            repo_id: HF repo ID (e.g., "username/ncakit-videos")
            token: HF token with write access
        """
        self.enabled = bool(repo_id and token and HF_HUB_AVAILABLE)
        self.repo_id = repo_id
        self.token = token
        self.api = None
        
        if self.enabled:
            self._initialize()
        else:
            if repo_id and token and not HF_HUB_AVAILABLE:
                logger.warning("HF credentials provided but huggingface_hub not installed")
            elif not repo_id or not token:
                logger.info("HF cloud storage disabled (HF_REPO or HF_TOKEN not set)")
    
    def _initialize(self):
        """Initialize HF API and create repo if needed"""
        try:
            self.api = HfApi(token=self.token)
            
            # Create repo if not exists (private for security)
            try:
                create_repo(
                    repo_id=self.repo_id,
                    repo_type="dataset",
                    token=self.token,
                    exist_ok=True,
                    private=True  # Private repo - uses HF_TOKEN for access
                )
                logger.info(f"HF storage enabled: {self.repo_id}")
            except Exception as e:
                logger.warning(f"Could not create/verify repo: {e}")
                
        except Exception as e:
            logger.error(f"Failed to initialize HF storage: {e}")
            self.enabled = False
    
    def upload_video(
        self, 
        local_path: Path, 
        video_id: str, 
        folder: str = "videos"
    ) -> Optional[str]:
        """
        Upload video to HF Hub.
        
        Args:
            local_path: Path to local video file
            video_id: Unique video ID
            folder: Folder name (e.g., "short_video", "story_reels")
            
        Returns:
            Public URL if successful, None otherwise
        """
        if not self.enabled:
            return None
        
        if not local_path.exists():
            logger.error(f"Video file not found: {local_path}")
            return None
        
        try:
            # Upload file
            path_in_repo = f"{folder}/{video_id}.mp4"
            
            self.api.upload_file(
                path_or_fileobj=str(local_path),
                path_in_repo=path_in_repo,
                repo_id=self.repo_id,
                repo_type="dataset"
            )
            
            # Generate download URL (with ?download=true for direct download)
            public_url = f"https://huggingface.co/datasets/{self.repo_id}/resolve/main/{path_in_repo}?download=true"
            
            logger.info(f"Uploaded to HF: {public_url}")
            return public_url
            
        except Exception as e:
            logger.error(f"Failed to upload to HF Hub: {e}")
            return None
    
    def delete_video(self, video_id: str, folder: str = "videos") -> bool:
        """
        Delete video from HF Hub.
        
        Args:
            video_id: Video ID to delete
            folder: Folder name
            
        Returns:
            True if successful
        """
        if not self.enabled:
            return False
        
        try:
            path_in_repo = f"{folder}/{video_id}.mp4"
            
            self.api.delete_file(
                path_in_repo=path_in_repo,
                repo_id=self.repo_id,
                repo_type="dataset"
            )
            
            logger.info(f"Deleted from HF: {path_in_repo}")
            return True
            
        except Exception as e:
            logger.error(f"Failed to delete from HF Hub: {e}")
            return False


# Singleton instance (initialized in modules/__init__.py or app startup)
_hf_storage: Optional[HFStorageClient] = None


def get_hf_storage() -> Optional[HFStorageClient]:
    """Get the global HF storage client"""
    return _hf_storage


def init_hf_storage(repo_id: str = None, token: str = None) -> HFStorageClient:
    """Initialize the global HF storage client"""
    global _hf_storage
    _hf_storage = HFStorageClient(repo_id=repo_id, token=token)
    return _hf_storage