from contextlib import asynccontextmanager
import os

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

from .routers import admin, annotations, auth, backup, pdfs, ws
from .database import SessionLocal
from .models import User, UserRole, UserStatus
from .security import hash_password


def _seed_admin() -> None:
    """Create the default admin account if it does not exist yet."""
    username = os.getenv("ADMIN_USERNAME", "admin")
    password = os.getenv("ADMIN_PASSWORD", "Admin@12345")
    email    = os.getenv("ADMIN_EMAIL",    "admin@lms.local")

    db = SessionLocal()
    try:
        exists = db.query(User).filter(User.username == username).first()
        if not exists:
            db.add(User(
                username      = username,
                email         = email,
                password_hash = hash_password(password),
                role          = UserRole.admin,
                status        = UserStatus.approved,
            ))
            db.commit()
            print(f"[seed] Admin account '{username}' created.")
        else:
            print(f"[seed] Admin account '{username}' already exists — skipped.")
    finally:
        db.close()


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Tables are managed by Alembic migrations.
    # Run: alembic upgrade head  (done by docker-compose entrypoint)
    _seed_admin()
    yield


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

app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:3000", "http://localhost:3001"],
    allow_credentials=True,                   # required for cookies
    allow_methods=["*"],
    allow_headers=["*"],
)

app.include_router(auth.router, prefix="/api")
app.include_router(admin.router, prefix="/api")
app.include_router(backup.router, prefix="/api")
app.include_router(pdfs.router, prefix="/api")
app.include_router(annotations.router, prefix="/api")
app.include_router(ws.router)  # WebSocket — no /api prefix (ws:// path)