"""
Configuration management for DynamisLab.

Handles loading of CelerisLab configurations and project settings.
"""

import os
import sys
from pathlib import Path
from typing import Optional, Tuple

# Determine project root directory
_current_file = Path(__file__).resolve()
_project_root = _current_file.parent.parent.parent  # Go up to DynamisLabNew/

# Configuration directory (relative to project root)
CONFIG_DIR = _project_root / 'configs'

# Output directories
MODELS_DIR = _project_root / 'models'
OUTPUT_DIR = _project_root / 'output'
TENSORBOARD_DIR = _project_root / 'tensorboard'

# Create output directories if they don't exist
MODELS_DIR.mkdir(exist_ok=True)
OUTPUT_DIR.mkdir(exist_ok=True)
TENSORBOARD_DIR.mkdir(exist_ok=True)


def setup_celeris_import() -> None:
    """
    Setup CelerisLab import path.
    
    Assumes CelerisLab is either:
    1. Installed as a package (pip install CelerisLab)
    2. Available as a git submodule in project root
    3. Available via PYTHONPATH environment variable
    """
    try:
        # Try to import CelerisLab (it might be installed)
        import CelerisLab
        return
    except ImportError:
        pass
    
    # Check for CelerisLab as submodule
    celeris_submodule = _project_root / 'CelerisLab' / 'src'
    if celeris_submodule.exists():
        sys.path.insert(0, str(celeris_submodule))
        return
    
    # If still not found, raise error with helpful message
    raise ImportError(
        "CelerisLab not found. Please either:\n"
        "  1. Install it: pip install -e ../CelerisLab\n"
        "  2. Add as git submodule: git submodule add <url> CelerisLab\n"
        "  3. Set PYTHONPATH to include CelerisLab src directory"
    )


def load_celeris_configs(
    cuda_config_path: Optional[str] = None,
    field_config_path: Optional[str] = None
) -> Tuple:
    """
    Load CelerisLab configurations.
    
    Args:
        cuda_config_path: Optional path to CUDA config. If None, uses CONFIG_DIR.
        field_config_path: Optional path to field config. If None, uses CONFIG_DIR.
    
    Returns:
        Tuple of (config_cuda, config_field)
    """
    # Setup CelerisLab import
    setup_celeris_import()
    
    from CelerisLab import utils
    
    # Set environment variable to point to our configs
    os.environ['CELERISLAB_CONFIG_DIR'] = str(CONFIG_DIR)
    
    # Load configurations - CelerisLab will find them automatically
    if cuda_config_path is None:
        config_cuda = utils.load_cuda_config()
    else:
        config_cuda = utils.load_cuda_config(cuda_config_path)
    
    if field_config_path is None:
        config_field = utils.load_flow_field_config()
    else:
        config_field = utils.load_flow_field_config(field_config_path)
    
    return config_cuda, config_field


def get_model_path(model_name: str) -> Path:
    """Get full path for a model file."""
    return MODELS_DIR / f"{model_name}.zip"


def get_tensorboard_logdir(run_name: str) -> Path:
    """Get TensorBoard log directory for a run."""
    logdir = TENSORBOARD_DIR / run_name
    logdir.mkdir(exist_ok=True)
    return logdir


def get_output_path(filename: str) -> Path:
    """Get full path for an output file."""
    return OUTPUT_DIR / filename


# Expose project paths for convenience
__all__ = [
    'CONFIG_DIR',
    'MODELS_DIR',
    'OUTPUT_DIR',
    'TENSORBOARD_DIR',
    'setup_celeris_import',
    'load_celeris_configs',
    'get_model_path',
    'get_tensorboard_logdir',
    'get_output_path',
]