"""
Data Manager Service

Manages the active data file path for model training.
Persists configuration to a JSON file so it survives restarts.
"""

import json
import logging
from datetime import datetime
from pathlib import Path

from app.core.config import get_settings

logger = logging.getLogger(__name__)

CONFIG_FILENAME = "data_config.json"


def _config_path() -> Path:
    """Get path to the data config file."""
    settings = get_settings()
    return settings.artifacts_dir / CONFIG_FILENAME


def get_active_data_path() -> Path:
    """
    Get the currently active data file path.
    Returns custom path if set, otherwise returns default.
    """
    settings = get_settings()
    config_file = _config_path()

    if config_file.exists():
        try:
            config = json.loads(config_file.read_text(encoding="utf-8"))
            custom_path = config.get("active_data_path")
            if custom_path:
                custom_path = Path(custom_path)
                if custom_path.exists():
                    return custom_path
                else:
                    logger.warning("Custom data path no longer exists: %s", custom_path)
        except (json.JSONDecodeError, KeyError) as e:
            logger.warning("Failed to read data config: %s", e)

    return settings.data_path


def set_active_data_path(path: Path) -> None:
    """Set the active data file path."""
    config_file = _config_path()
    config_file.parent.mkdir(parents=True, exist_ok=True)

    config = {
        "active_data_path": str(path),
        "updated_at": datetime.now().isoformat(),
    }

    config_file.write_text(json.dumps(config, indent=2), encoding="utf-8")
    logger.info("Updated active data path to: %s", path)


def reset_to_default() -> None:
    """Reset to use the default data file."""
    config_file = _config_path()
    if config_file.exists():
        config_file.unlink()
        logger.info("Reset to default data path")


def save_uploaded_file(content: bytes, original_filename: str) -> Path:
    """
    Save uploaded file content to the data/raw directory.
    Returns the path to the saved file.
    """
    settings = get_settings()
    upload_dir = settings.root_dir / "data" / "raw"
    upload_dir.mkdir(parents=True, exist_ok=True)

    # Generate timestamped filename
    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    # Keep original extension
    suffix = Path(original_filename).suffix or ".csv"
    filename = f"uploaded_data_{timestamp}{suffix}"

    file_path = upload_dir / filename
    file_path.write_bytes(content)

    logger.info("Saved uploaded file to: %s", file_path)
    return file_path


def get_data_info() -> dict:
    """Get information about the current data configuration."""
    settings = get_settings()
    active_path = get_active_data_path()
    default_path = settings.data_path

    return {
        "active_path": str(active_path),
        "active_filename": active_path.name,
        "active_exists": active_path.exists(),
        "is_custom": active_path != default_path,
        "default_path": str(default_path),
        "default_filename": default_path.name,
        "default_exists": default_path.exists(),
    }