import json
import os
import logging
from modules.core.state import state

# Configure logging
logger = logging.getLogger(__name__)

# Global state
PLAYLISTS_FILE = os.path.join(os.getcwd(), "playlists.json")

# Ensure the file exists and contains at least an empty JSON object
if not os.path.isfile(PLAYLISTS_FILE):
    logger.info(f"Creating new playlists file at {PLAYLISTS_FILE}")
    with open(PLAYLISTS_FILE, "w") as f:
        json.dump({}, f, indent=2)

def load_playlists():
    """Load the entire playlists dictionary from the JSON file."""
    try:
        with open(PLAYLISTS_FILE, "r") as f:
            content = f.read().strip()
            if not content:
                logger.warning("Playlists file is empty, returning empty dict")
                return {}
            playlists = json.loads(content)
            logger.debug(f"Loaded {len(playlists)} playlists")
            return playlists
    except (json.JSONDecodeError, ValueError) as e:
        logger.error(f"Playlists file is corrupted, resetting to empty: {e}")
        save_playlists({})
        return {}

def save_playlists(playlists_dict):
    """Save the entire playlists dictionary back to the JSON file."""
    logger.debug(f"Saving {len(playlists_dict)} playlists to file")
    with open(PLAYLISTS_FILE, "w") as f:
        json.dump(playlists_dict, f, indent=2)

def list_all_playlists():
    """Returns a list of all playlist names."""
    playlists_dict = load_playlists()
    playlist_names = list(playlists_dict.keys())
    logger.debug(f"Found {len(playlist_names)} playlists")
    return playlist_names

def get_playlist(playlist_name):
    """Get a specific playlist by name."""
    playlists_dict = load_playlists()
    if playlist_name not in playlists_dict:
        logger.warning(f"Playlist not found: {playlist_name}")
        return None
    logger.debug(f"Retrieved playlist: {playlist_name}")
    return {
        "name": playlist_name,
        "files": playlists_dict[playlist_name]
    }

def create_playlist(playlist_name, files):
    """Create or update a playlist."""
    playlists_dict = load_playlists()
    playlists_dict[playlist_name] = files
    save_playlists(playlists_dict)
    logger.info(f"Created/updated playlist '{playlist_name}' with {len(files)} files")
    # Keep the board's /playlists/<name>.txt mirror in sync (autostart runs it).
    from modules.core import board_settings
    board_settings.mirror_playlist_async(playlist_name, files)
    return True

def modify_playlist(playlist_name, files):
    """Modify an existing playlist."""
    logger.info(f"Modifying playlist '{playlist_name}' with {len(files)} files")
    return create_playlist(playlist_name, files)

def delete_playlist(playlist_name):
    """Delete a playlist."""
    playlists_dict = load_playlists()
    if playlist_name not in playlists_dict:
        logger.warning(f"Cannot delete non-existent playlist: {playlist_name}")
        return False
    del playlists_dict[playlist_name]
    save_playlists(playlists_dict)
    logger.info(f"Deleted playlist: {playlist_name}")
    from modules.core import board_settings
    board_settings.unmirror_playlist_async(playlist_name)
    return True

def add_to_playlist(playlist_name, pattern):
    """Add a pattern to an existing playlist."""
    playlists_dict = load_playlists()
    if playlist_name not in playlists_dict:
        logger.warning(f"Cannot add to non-existent playlist: {playlist_name}")
        return False
    playlists_dict[playlist_name].append(pattern)
    save_playlists(playlists_dict)
    logger.info(f"Added pattern '{pattern}' to playlist '{playlist_name}'")
    from modules.core import board_settings
    board_settings.mirror_playlist_async(playlist_name, playlists_dict[playlist_name])
    return True

def rename_playlist(old_name, new_name):
    """Rename an existing playlist."""
    if not new_name or not new_name.strip():
        logger.warning("Cannot rename playlist: new name is empty")
        return False, "New name cannot be empty"

    new_name = new_name.strip()

    playlists_dict = load_playlists()
    if old_name not in playlists_dict:
        logger.warning(f"Cannot rename non-existent playlist: {old_name}")
        return False, "Playlist not found"

    if old_name == new_name:
        return True, "Name unchanged"

    if new_name in playlists_dict:
        logger.warning(f"Cannot rename playlist: '{new_name}' already exists")
        return False, "A playlist with that name already exists"

    # Copy files to new key and delete old key
    playlists_dict[new_name] = playlists_dict[old_name]
    del playlists_dict[old_name]
    save_playlists(playlists_dict)
    logger.info(f"Renamed playlist '{old_name}' to '{new_name}'")
    from modules.core import board_settings
    board_settings.unmirror_playlist_async(old_name)
    board_settings.mirror_playlist_async(new_name, playlists_dict[new_name])
    return True, f"Playlist renamed to '{new_name}'"