import gc
import logging
import os
import shutil
import tempfile
import time

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware

from chartmetric_summary_generator3 import final_score_calculation

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

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
SESSIONS_ROOT = os.path.join(BASE_DIR, "sessions")   # all per-request dirs live here
os.makedirs(SESSIONS_ROOT, exist_ok=True)

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(levelname)s - %(message)s",
)
logger = logging.getLogger(__name__)


def _cleanup_session(session_dir: str) -> None:
    """Remove the entire per-request temp directory, tolerating locked files."""
    if not os.path.exists(session_dir):
        return
    try:
        gc.collect()
        time.sleep(0.1)
        shutil.rmtree(session_dir, ignore_errors=True)
        logger.info(f"Cleaned up session dir: {session_dir}")
    except Exception as e:
        logger.warning(f"Could not fully clean up {session_dir}: {e}")


@app.get("/")
def read_root():
    return {"Hello": "200 ok"}


@app.post("/fanbase_score")
async def fanbase_score(request: Request):
    session_dir = tempfile.mkdtemp(dir=SESSIONS_ROOT)
    logger.info(f"Created session dir: {session_dir}")

    try:
        data     = await request.json()
        task_id  = data["track_id"].strip()
        logger.info(f"Processing start – task_id={task_id}  session={session_dir}")

        fanbase_score_count = final_score_calculation(task_id, session_dir)
        logger.info(f"Fan Base Count: {fanbase_score_count}")

        return {"fanbase_count": fanbase_score_count}

    except Exception as e:
        logger.error(f"Request failed: {e}")
        return {"error": str(e)}

    finally:
        _cleanup_session(session_dir)