import os
import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from sqlalchemy import select, update, text

from database import Base, engine, SessionLocal
from models import User, EggCollection, FlockHistory, FeedPurchase, OtherPurchase
from auth import hash_password
from routers import eggs, flock, feed, stats, other
from routers import auth_router, admin

logger = logging.getLogger("yolkbook")


def _seed_admin():
    """Create or update the admin user from environment variables.
    Also assigns any records with NULL user_id to the admin (post-migration).
    """
    admin_username = os.environ["ADMIN_USERNAME"]
    admin_password = os.environ["ADMIN_PASSWORD"]

    with SessionLocal() as db:
        admin_user = db.scalars(
            select(User).where(User.username == admin_username)
        ).first()

        if admin_user is None:
            admin_user = User(
                username=admin_username,
                hashed_password=hash_password(admin_password),
                is_admin=True,
            )
            db.add(admin_user)
            db.commit()
            db.refresh(admin_user)
            logger.info("Admin user '%s' created.", admin_username)
        else:
            # Always sync password + admin flag from env vars
            admin_user.hashed_password = hash_password(admin_password)
            admin_user.is_admin = True
            db.commit()

        # Assign orphaned records (from pre-migration data) to admin
        for model in [EggCollection, FlockHistory, FeedPurchase, OtherPurchase]:
            db.execute(
                update(model)
                .where(model.user_id == None)  # noqa: E711
                .values(user_id=admin_user.id)
            )
        db.commit()


def _run_migrations():
    """Apply incremental schema changes that create_all won't handle on existing tables."""
    with SessionLocal() as db:
        # v2.1 — timezone column on users
        try:
            db.execute(text(
                "ALTER TABLE users ADD COLUMN timezone VARCHAR(64) NOT NULL DEFAULT 'UTC'"
            ))
            db.commit()
        except Exception:
            db.rollback()  # column already exists — safe to ignore


@asynccontextmanager
async def lifespan(app: FastAPI):
    Base.metadata.create_all(bind=engine)
    _run_migrations()
    _seed_admin()
    yield


app = FastAPI(title="Yolkbook API", lifespan=lifespan)

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

app.include_router(auth_router.router)
app.include_router(admin.router)
app.include_router(eggs.router)
app.include_router(flock.router)
app.include_router(feed.router)
app.include_router(other.router)
app.include_router(stats.router)


@app.get("/api/health")
def health():
    return {"status": "ok"}