from collections.abc import AsyncIterator
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.exceptions import HTTPException
from fastapi.middleware.cors import CORSMiddleware

# from fastapi.requests import Request
from fastapi.responses import JSONResponse
from fastapi_cache import FastAPICache
from fastapi_cache.backends.redis import RedisBackend
from fastapi_cache.decorator import cache
from logging_config import logger
from redis import asyncio as aioredis
from request_response_models import BasicError, ConvertRequest, MolFileModel


@asynccontextmanager
async def lifespan(_: FastAPI) -> AsyncIterator[None]:
    redis = aioredis.from_url("redis://redis:6379")
    FastAPICache.init(RedisBackend(redis), prefix="fastapi-cache")
    yield


app = FastAPI(lifespan=lifespan)


origins = [
    "http://localhost",
    "http://localhost:8001",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


@app.post(
    "/convert",
    responses={
        200: {"description": "Coversion Successful", "model": MolFileModel},
        400: {"description": "Item created", "model": BasicError},
    },
)
def convert_molecule(req: ConvertRequest):
    try:
        # Rad the string and format from request
        mol = pybel.readstring(req.format, req.text)

        if req.add_hydrogen:
            mol.addh()
        if req.convert_3d:
            mol.make3D()
        if req.optimize_geometry:
            mol.localopt()

        logger.info(f"Converting from format {req.format}")

        # To compute the Number of electrons and orbitals
        atoms = [(atom.atomicnum, atom.coords) for atom in mol.atoms]

        mol_pyscf = gto.Mole()
        mol_pyscf.atom = atoms
        mol_pyscf.basis = "sto-3g"  # simple basis
        mol_pyscf.charge = mol.charge  # default net charge
        mol_pyscf.spin = mol.spin - 1  # multiplicity - 1
        mol_pyscf.build()

        # Export the resulting molecule
        mol.OBMol.SetTitle(
            f"Charge={mol.charge} Multiplicity={mol.spin} Electrons={mol_pyscf.nelectron} Orbitals={mol_pyscf.nao_nr()}"
        )

        mol2string = mol.write("xyz")
        return JSONResponse({"molfile": mol2string}, 200)
    except Exception as e:
        raise HTTPException(status_code=400, detail={"error": str(e)})


@app.get("/informats")
@cache()
async def get_informats():
    return pybel.informats


@app.get(
    "/health",
    responses={
        200: {
            "description": "Is the service running?",
            "content": {"application/json": {"example": {"status": "healthy"}}},
        },
    },
)
@cache()
async def health_check():
    return {"status": "healthy"}