# app/main.py — Sparrow FastAPI application factory
from __future__ import annotations

import logging
import os
from contextlib import asynccontextmanager
from pathlib import Path

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

from app.api.routes import router
from app.db.store import get_connection, run_migrations

logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Read env at startup — not at import time — so tests can inject values
    db_path = os.environ.get("SPARROW_DB_PATH", "data/sparrow.db")
    data_dir = os.environ.get("SPARROW_DATA_DIR", "data")
    env = os.environ.get("SPARROW_ENV", "development")

    Path(db_path).parent.mkdir(parents=True, exist_ok=True)
    Path(data_dir).mkdir(parents=True, exist_ok=True)

    conn = get_connection(db_path)
    run_migrations(conn)
    app.state.conn = conn
    app.state.data_dir = data_dir

    logger.info("Sparrow started (env=%s, db=%s, data=%s)", env, db_path, data_dir)
    yield

    conn.close()
    logger.info("Sparrow shut down.")


def create_app() -> FastAPI:
    env = os.environ.get("SPARROW_ENV", "development")
    app = FastAPI(
        title="Sparrow",
        description="AI music continuation — branching chain editor",
        version="0.1.0",
        lifespan=lifespan,
    )

    # CORS: open in dev, tighten in production via env
    origins = (
        ["*"] if env == "development"
        else os.environ.get("SPARROW_CORS_ORIGINS", "").split(",")
    )
    app.add_middleware(
        CORSMiddleware,
        allow_origins=origins,
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    app.include_router(router)
    return app


app = create_app()