"""
Utilities for interacting with the Hugging Face Hub.
"""
import os
from huggingface_hub import HfApi, login, hf_hub_download


def upload_to_hub(to_parse_file, results_file, repo_id=None):
    """
    Uploads files to the Hugging Face Hub.
    
    Args:
        to_parse_file: Path to the categories file
        results_file: Path to the results file
        repo_id: Hub repository ID
        
    Returns:
        True if upload succeeded, False otherwise
    """
    try:
        # Use environment variable HUGGING_FACE_STORAGE_REPO if available
        # Otherwise, use default value
        if repo_id is None:
            repo_id = os.getenv("HUGGING_FACE_STORAGE_REPO", "leaderboard-explorer/leaderboard_explorer")
            if os.getenv("HUGGING_FACE_STORAGE_REPO"):
                print(f"Using target dataset specified in HUGGING_FACE_STORAGE_REPO: {repo_id}")
            else:
                print(f"No target dataset specified, using default value: {repo_id}")
        
        # Check if token is available
        token = os.getenv("HUGGING_FACE_HUB_TOKEN")
        if not token:
            print("ERROR: Environment variable HUGGING_FACE_HUB_TOKEN is not defined.")
            return False
        
        # Connect to Hub
        print("Connecting to Hugging Face Hub...")
        login(token=token)
        api = HfApi()
        
        # Upload JSON files
        print(f"\n--- UPLOADING CATEGORIES FILE ---")
        print(f"Local file: {to_parse_file}")
        print(f"Destination: {repo_id}/best_model_for_category_list.json")
        print(f"Uploading...")
        
        try:
            api.upload_file(
                path_or_fileobj=to_parse_file,
                path_in_repo="best_model_for_category_list.json",
                repo_id=repo_id,
                repo_type="dataset",
                commit_message="Update leaderboard categories"
            )
            print(f"Upload of {to_parse_file} successful!")
        except Exception as e:
            print(f"Note when uploading {to_parse_file}: {e}")
            if "No files have been modified since last commit" in str(e):
                print("→ The categories file is identical to the one already on the Hub. No changes needed.")
            else:
                print(f"→ ERROR: Upload failed for another reason.")
                raise e
        
        print(f"\n--- UPLOADING RESULTS FILE ---")
        print(f"Local file: {results_file}")
        print(f"Destination: {repo_id}/best_model_for_results.json")
        print(f"Uploading...")
        
        try:
            api.upload_file(
                path_or_fileobj=results_file,
                path_in_repo="best_model_for_results.json",
                repo_id=repo_id,
                repo_type="dataset",
                commit_message="Update leaderboard results"
            )
            print(f"Upload of {results_file} successful!")
        except Exception as e:
            print(f"Note when uploading {results_file}: {e}")
            if "No files have been modified since last commit" in str(e):
                print("→ The results file is identical to the one already on the Hub. No changes needed.")
            else:
                print(f"→ ERROR: Upload failed for another reason.")
                raise e
        
        print(f"\nUpload operation completed: files have been processed!")
        return True
    except Exception as e:
        print(f"GENERAL ERROR during file upload to Hub: {e}")
        return False


def download_from_hub(repo_id=None):
    """
    Downloads files from the Hugging Face Hub.
    
    Args:
        repo_id: Hub repository ID
        
    Returns:
        True if download succeeded, False otherwise
    """
    try:
        # Use environment variable HUGGING_FACE_STORAGE_REPO if available
        # Otherwise, use default value
        if repo_id is None:
            repo_id = os.getenv("HUGGING_FACE_STORAGE_REPO", "leaderboard-explorer/leaderboard_explorer")
            if os.getenv("HUGGING_FACE_STORAGE_REPO"):
                print(f"Using source dataset specified in HUGGING_FACE_STORAGE_REPO: {repo_id}")
            else:
                print(f"No source dataset specified, using default value: {repo_id}")
        
        # Check if token is available
        token = os.getenv("HUGGING_FACE_HUB_TOKEN")
        if not token:
            print("ERROR: Environment variable HUGGING_FACE_HUB_TOKEN is not defined.")
            return False
        
        # Connect to Hub
        login(token=token)
        
        # Create data directory if it doesn't exist
        script_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
        data_dir = os.path.join(script_dir, "data")
        os.makedirs(data_dir, exist_ok=True)
        
        # List of required and optional files
        required_files = [
            "final_leaderboards.json",
            "best_model_for_category_list.json"
        ]
        
        optional_files = [
            "best_model_for_results.json"
        ]
        
        # Download required files first
        for filename in required_files:
            local_path = os.path.join(data_dir, filename)
            try:
                # Download file
                print(f"Downloading {filename} from {repo_id}...")
                hf_hub_download(
                    repo_id=repo_id,
                    filename=filename,
                    repo_type="dataset",
                    local_dir=data_dir,
                    local_dir_use_symlinks=False
                )
                print(f"File {filename} successfully downloaded to {local_path}")
            except Exception as e:
                print(f"ERROR: Unable to download required file {filename}: {e}")
                return False
        
        # Download optional files next
        for filename in optional_files:
            local_path = os.path.join(data_dir, filename)
            try:
                print(f"Downloading {filename} from {repo_id}...")
                hf_hub_download(
                    repo_id=repo_id,
                    filename=filename,
                    repo_type="dataset",
                    local_dir=data_dir,
                    local_dir_use_symlinks=False
                )
                print(f"File {filename} successfully downloaded to {local_path}")
            except Exception as e:
                print(f"WARNING: Unable to download optional file {filename}: {e}")
                print(f"This is not a problem, a new file will be created if necessary.")
        
        return True
    except Exception as e:
        print(f"ERROR during file download from Hub: {e}")
        return False