src/api.py

import os
import sys
from typing import Dict, Any

# Workaround for Python 3.10: Add NotRequired to typing module
if sys.version_info < (3, 11):
    try:
        from typing_extensions import NotRequired
        import typing
        if not hasattr(typing, 'NotRequired'):
            typing.NotRequired = NotRequired
    except ImportError:
        pass

# Try to import MPRester, handle case where key is missing/invalid gracefully
try:
    from mp_api.client import MPRester
except ImportError:
    MPRester = None

class MaterialsProjectAdapter:
    def __init__(self, api_key: str = None):
        self.api_key = api_key
        self.has_key = api_key is not None and len(api_key) > 10 and MPRester is not None

    def get_material_properties(self, formula: str) -> Dict[str, Any]:
        print(f"CONTACTING MATERIALS PROJECT: {formula}...")

        if self.has_key:
            try:
                with MPRester(self.api_key) as mpr:
                    docs = mpr.materials.summary.search(
                        formula=[formula],
                        fields=["band_gap", "volume", "formation_energy_per_atom"]
                    )
                    if docs:
                        best_match = min(docs, key=lambda x: x.formation_energy_per_atom)
                        return {
                            "source": "Materials Project (Real Data)",
                            "band_gap": float(best_match.band_gap),
                            "volume": float(best_match.volume),
                            "is_estimated": False
                        }
            except Exception as e:
                print(f"❌ API ERROR: {str(e)}. Switching to fallback.")
        # Fallback if no key or API fails
        return self._generate_fallback(formula)

    def _generate_fallback(self, formula: str) -> Dict[str, Any]:
        return {
            "source": "Theoretical Estimation (Fallback)",
            "band_gap": 2.0,
            "volume": 200.0,
            "is_estimated": True
        }