from __future__ import annotations

import logging
import time
import sys
from pathlib import Path

# Ensure top-level `training`, `chemistry`, etc. packages are importable
ROOT = Path(__file__).resolve().parents[2]
sys.path.insert(0, str(ROOT / 'src'))

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel

from .predictor import HybridDDIPredictor


logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)s %(name)s %(message)s')
logger = logging.getLogger('medcare_ddi.api')

predictor = HybridDDIPredictor.from_default_paths()

app = FastAPI(title='MEDCARE-DDI Hybrid Predictor', version='2.0.0')

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


class PredictionRequest(BaseModel):
    # Accept both frontend keys (`drug_a`, `drug_b`) and legacy keys (`drug_a_id`, `drug_b_id`).
    drug_a_id: str | None = None
    drug_b_id: str | None = None
    drug_a: str | None = None
    drug_b: str | None = None


@app.get('/health')
def health() -> dict[str, object]:
    return predictor.health()


@app.post('/predict')
def predict(request: PredictionRequest) -> dict[str, object]:
    started_at = time.perf_counter()
    # Prefer explicit `drug_a`/`drug_b` from frontend; fall back to legacy `drug_a_id` fields.
    drug_a = (request.drug_a or request.drug_a_id or '')
    drug_b = (request.drug_b or request.drug_b_id or '')
    result = predictor.predict(drug_a, drug_b)
    latency_ms = round((time.perf_counter() - started_at) * 1000, 2)

    logger.info(
        'prediction_completed source=%s severity=%s confidence=%.3f latency_ms=%.2f drug_a=%s drug_b=%s',
        result['source'],
        result['severity'],
        result['confidence'],
        latency_ms,
        result['drug_a_name'],
        result['drug_b_name'],
    )

    return {
        **result,
        'latency_ms': latency_ms,
    }